Browsing by Title

Sort by: Order: Results:

Now showing items 12293-12312 of 24327
  • Thum, Tea (Helsingin yliopisto, 2009)
    Man-induced climate change has raised the need to predict the future climate and its feedback to vegetation. These are studied with global climate models; to ensure the reliability of these predictions, it is important to have a biosphere description that is based upon the latest scientific knowledge. This work concentrates on the modelling of the CO2 exchange of the boreal coniferous forest, studying also the factors controlling its growing season and how these can be used in modelling. In addition, the modelling of CO2 gas exchange at several scales was studied. A canopy-level CO2 gas exchange model was developed based on the biochemical photosynthesis model. This model was first parameterized using CO2 exchange data obtained by eddy covariance (EC) measurements from a Scots pine forest at Sodankylä. The results were compared with a semi-empirical model that was also parameterized using EC measurements. Both of the models gave satisfactory results. The biochemical canopy-level model was further parameterized at three other coniferous forest sites located in Finland and Sweden. At all the sites, the two most important biochemical model parameters showed seasonal behaviour, i.e., their temperature responses changed according to the season. Modelling results were improved when these changeover dates were related to temperature indices. During summer-time the values of the biochemical model parameters were similar at all the four sites. Different control factors for CO2 gas exchange were studied at the four coniferous forests, including how well these factors can be used to predict the initiation and cessation of the CO2 uptake. Temperature indices, atmospheric CO2 concentration, surface albedo and chlorophyll fluorescence (CF) were all found to be useful and have predictive power. In addition, a detailed simulation study of leaf stomata in order to separate physical and biochemical processes was performed. The simulation study brought to light the relative contribution and importance of the physical transport processes. The results of this work can be used in improving CO2 gas exchange models in boreal coniferous forests. The meteorological and biological variables that represent the seasonal cycle were studied, and a method for incorporating this cycle into a biochemical canopy-level model was introduced.
  • Haapala, Jari (Helsingin yliopisto, 2000)
  • Heinävaara, Sirpa (2003)
    MONISYÖPÄPOTILAIDEN ELINAIKAENNUSTEET TAUSTA Yhä useammalla syöpäpotilaalla on diagnosoitu kaksi tai useampia primaarisyöpiä. Näiden monisyöpäpotilaiden joukko kasvaa, koska useimpien syöpäpotilaiden elinaikaennusteet ovat parantuneet ja odotettavissa oleva elinikä on pidentynyt. Tämän potilasjoukon kasvaessa on yhä kiinnostavampaa tietää, kuinka monisyöpäpotilaat selviytyvät uudesta primaarisyövästään verrattuna niihin potilaihin, jotka sairastavat samaa syöpää ensimmäisenä syöpänään. Aiheesta tehtyjen aikaisempien tutkimusten tulokset ovat olleet ristiriitaisia. Ristiriitaisten tulosten taustalla saattaa olla käytettyjen analyysimenetelmien heikkous: Seuraajasyöpään liittyvää elinaikaennustetta arvioitaessa ei ole huomioitu taustalla olevan ensimmäisen syövän vaikutusta kuolleisuuteen. TAVOITE: MONISYÖPÄPOTILAIDEN ELINAIKAENNUSTEET MAHDOLLIKSI Väitöskirjassa esitellään neljä vaihtoehtoista tilastollista mallia, joilla monisyöpäpotilaiden eloonjäämistä voidaan arvioida ensimmäisen ja seuraajasyövän osalta. Uudet vaihtoehdot ovat laajennuksia ja mukaelmia malleista, joita käytetään arvioitaessa syöpäpotilaiden suhteellista (relative) ja syykohtaista (cause-specific) eloonjäämistä. Eloonjäämistä vertaillaan mallien välillä sekä saman syövän suhteen ensimmäisenä ja seuraajasyöpänä. Toiseen syöpään liittyvän eloonjäämisen arvioiminen loi tarpeen luoda uusia käsitteitä, erityisesti kun kyse oli kahdesti samaan primaarisyöpään sairastuneista monisyöpäpotilaista: On pystyttävä arvioimaan eloon-jäämistä esim. rintasyövän suhteen sekä ensimmäisenä että seuraajasyöpänä. TULOKSET JA JOHTOPÄÄTÖKSET Eloonjäämistä ensimmäisen ja seuraajasyövän suhteen voidaan arvioida uusilla suhteelliseen ja syykohtaiseen eloonjäämiseen perustuvilla malleilla. Seuraajasyöpään liittyvää eloonjäämistä ei tulisi arvioida, jollei taustalla olevaan ensimmäiseen syöpään liittyvää kuolleisuutta ole otettu huomioon. Eloonjäämisennusteisiin ensimmäisen ja seuraajasyövän suhteen vaikuttavat mm. syövän sijainti ja se, onko monisyöpäpotilaalla kaksi samaa primaarisyöpää vai ei. Useimmiten eloonjäämisennusteet eivät eroa ensimmäisen ja seuraajasyövän välillä. Voimakkaiden päätelmien teko on edelleen vaikeaa, sillä käytettävissä olevat väestöpohjaisetkin aineistot ovat toistaiseksi varsin suppeita.
  • Heinävaara, Sirpa (2003)
    With increasing number of subsequent primary cancers there is a growing concern to know how cancer patients survive with their subsequent cancer compared to those with their respective first cancer. Results of earlier studies have been conflicting and have not lead to firm conclusions. One reason for conflicting results might be a lack appropriate methodology as survival from subsequent cancer has usually not been adjusted for an extra hazard due to an underlying first cancer. This study presents four alternative models for estimating survival of patients with multiple cancers. Models are extensions and modifications to those proposed earlier for estimating relative and cause-specific survival of patients with a single cancer. The assessment of survival from subsequent cancer raised a need for introducing new concepts, especially when survival of patients with their multiple cancers of the same site is concerned. Survival estimates from cancer are compared between the models, and between a first and subsequent tumour of the same site. The importance of adjusting survival from subsequent cancer to that from a underlying first cancer is also highlighted. The results show that survival from cancer as a first and subsequent tumour can be reliably assessed with the newly introduced models based either on the relative and cause-specific survival. The results also show that survival from cancer as a first and subsequent tumour may be dependent on the site of cancer and whether patients' cancers are of the same site or not. Nevertheless, survival from a subsequent cancer is not usually different from that from a respective first cancer. However, even with large population-based data, a lack of power often prevents the detection of modest differences in survival.
  • Heinävaara, Sirpa (Helsingin yliopisto, 2003)
  • Lindström, Riitta (Helsingin yliopisto, 2014)
    Mesencephalic astrocyte-derived neurotrophic factor (MANF) and cerebral dopamine neurotrophic factor (CDNF) proteins form a family of neurotrophic factors. Neurotrophic factors have been intensively studied as a putative therapeutic approach to treat neuronal injuries and neurodegenerative diseases. Mammalian MANF and CDNF have been shown to have protective and restorative effects on the nigrostriatal dopaminergic system. In addition, several studies have reported a role for MANF in the endoplasmic reticulum (ER) stress response. A recently established MANF knockout mouse model revealed that MANF functions in the pancreatic insulin-producing beta cells and might be involved in the pathogenesis of diabetes mellitus. Beyond their neurotrophic properties, MANF and CDNF appear to play a more general role in the maintenance of cellular homeostasis. In this study, Drosophila melanogaster was used as a model organism to explore the function and interaction of the MANF/CDNF protein family in vivo. The sole member of the MANF/CDNF family in Drosophila, DmManf, was discovered to be crucial for fly development. The human orthologues, HsMANF and HsCDNF, were found to be able to substitute the endogenous DmManf. Likewise, DmManf had the cytoprotective properties of mammalian MANF in cultured murine neurons. These results support that the findings from the Drosophila model can be adapted for research in mammalian systems. MANF/CDNF proteins consist of amino (N) - and carboxy (C) -terminal domains. In this work, several functional features identified in mammalian MANF structure were explored in the Drosophila model. Separate N- or C-terminal domain constructs, even when co-expressed together, failed to complement for the loss of endogenous DmManf. The ER retention of DmManf, mediated by the C-terminal signal sequence, and the positive charge of the N-terminal surface amino acid residues were found to be important for appropriate DmManf function. Furthermore, entering the secretory pathway via ER was essential for the stability of DmManf protein. A CXXC motif characteristic for oxidoreductases is located in the C-terminal domain of MANF. In this study, effects of a point mutation (C129S) in CXXC motif of DmManf were analysed in vivo. Intact CXXC motif was discovered to be vital for DmManf function. Furthermore, the expression of DmManf-C129S in wild type background was harmful for fly viability suggesting that this specific mutation represents either a dominant negative or a gain-of-function allele of DmManf. Utilising the unique potential of Drosophila model for in vivo screening, interactions of DmManf were studied in this work. Consistent with a previous in vitro study, a genetic interaction was found between DmManf and the fly homologue of the major ER chaperone GRP78. Moreover, DmManf interacted with other genes that encode components of ER function and the unfolded protein response. Finally, novel interactions with DmManf and genes involved in the ubiquinone synthesis pathway and mitochondria were discovered. Taken together, this study demonstrates the functional conservation of mammalian and fly proteins and provides meaningful information on structural and functional features of the MANF/CDNF protein family in vivo. The genetic interaction studies confirmed and expanded the previous knowledge on the ER-associated functions of MANF. Furthermore, novel interactions with mitochondria-related genes and DmManf were discovered.
  • Ruusuvuori, Kai (Helsingin yliopisto, 2015)
    New particle formation is an important process in the atmosphere. As ions are constantly produced in the atmosphere, the behaviour and role of charged particles in atmospheric processes needs to be understood. In order to gain insight on the role of charge in atmospheric new particle formation, the electron structure of the molecules taking part in this process needs to be taken into account using quantum chemical methods. Quantum chemical density functional theory was employed in an effort to reproduce an experimentally observed sign preference. While computational results on molecular structures agreed well with results obtained by other groups, the computationally obtained sign preference was opposite to the experimentally observed. Possible reasons for this discrepancy were found in both computational results and experiments. Simulations of clusters containing water, pyridine, ammonia and a proton were performed using density functional theory. The clusters were found to form a core consisting of ammonium ion and water with the pyridine molecule bonding to the ammonium ion. However, the solvation of the ammonium ion was observed to affect the possibility of proton transfer. Calculations of proton affinities and gas phase basicities of several compounds, which can be considered as candidates to form atmospheric ions in the boreal forest, were performed. The generally small differences between the calculated gas phase basicites and proton affinities implied only small entropy changes in the protonation reaction. Comparison with experiments resulted in the conclusion that the largest experimentally observed peaks of atmospheric ions most likely corresponded to pyridine and substituted pyridines. Furthermore, a combination of low proton affinity and high observed cation concentration was concluded to imply a high concentration of neutral parent molecules in the atmosphere. A combination of quantum chemistry and a code for modelling cluster dynamics was employed to study the use of protonated acetone monomers and dimers as the ionization reagent in a chemical ionization atmospheric pressure interface time-of-flight mass spectrometer (CI-APi-TOF). The results showed that the ionization reagents successfully charged dimethylamine monomers. However, there were discrepancies between the simulated and measured cluster distributions. Possible reasons for this discrepancy were found in both measurements and the modelling parameters.
  • Hiippala, Tuomo (Helsingin yliopisto, 2013)
    This dissertation studied the structure of multimodal artefacts, or how language, image and other semiotic modes combine and interact in documents. This places the study within the emerging field of multimodal research, which uses linguistic methods to study the interaction of multiple semiotic modes. Despite the growing amount of multimodal research, the structure of multimodal artefacts has not received the attention it warrants. Previous studies have been either very detailed or exceedingly abstract, leaving a significant gap between data and theory, which this dissertation attempted to bridge. To do so, the dissertation adopted a data-driven approach to multimodal analysis, addressing the structure of multimodal artefacts, the factors that shape the artefact structure, and the role of structure in the recognition and interpretation of the artefacts. The data consisted of tourist brochures produced by the city of Helsinki between 1967 and 2008, which allowed a longitudinal perspective to their multimodal structure. A total of 58 double-pages were annotated for their content, visual appearance, layout and rhetorical organisation, and compiled into an XML-based multimodal corpus. To study the corpus, the dissertation developed visualisation methods that combined information from multiple analytical layers of the corpus to represent the multimodal structures in the data. The study revealed the functional motivation behind the structure of the tourist brochures, identifying patterns in their hierarchical and rhetorical organisation, which were used to fulfil specific communicative tasks. The configuration of these patterns, in turn, signalled how the brochure was to be interpreted. The results also showed that after the year 1985, which marked the introduction of desktop publishing software, the organising principles of the tourist brochures have shifted towards a more fragmented and non-linear structure.
  • Repola, Jaakko (2013)
    Biomass equations for above- and below-ground tree components of Scots pine (Pinus sylvestris L), Norway spruce (Picea abies [L.] Karst) and birch (Betula pendula Roth and Betula pubescens Ehrh.) were compiled using empirical material from a total of 102 stands (908 pine, 613 spruce and 127 birch trees). These stands located mainly on mineral soil sites representing a large part of Finland. Biomass equations were derived for the total aboveground biomass and for the individual tree components (stem wood, stem bark, living and dead branches, needles, stump, and roots). Three multivariate models with different number of independent variables for above-ground biomass and one for below-ground biomass were constructed. The simplest model formulations, multivariate models (1) were based mainly on tree diameter and height as independent variables. In more elaborated multivariate models (2) and (3) additional commonly measured tree variables such age, crown length, bark thickness and radial growth rate were added. In the modelling approach, the basic assumption was that the biomasses of the tree components on the same site and in the same tree are dependent. This statistical dependency was taken into account by applying a multivariate procedure. Based on the verified statistical dependence among the biomass components, the multivariate procedure had a number of advantages compared to the traditionally independently estimated equations by enabling more flexible application of the equations, ensuring better biomass additivity, and giving the more reliable parameter estimates. The generalization and applicability of the models may be restricted by the fact that the study material was not an objective, representative sample, and some tree components were poorly represented. Despite these shortcomings, the models provided logical biomass predictions for individual tree components in Finland.
  • Timko, Helga (Helsingin yliopisto, 2011)
    A better understanding of vacuum arcs is desirable in many of today's 'big science' projects including linear colliders, fusion devices, and satellite systems. For the Compact Linear Collider (CLIC) design, radio-frequency (RF) breakdowns occurring in accelerating cavities influence efficiency optimisation and cost reduction issues. Studying vacuum arcs both theoretically as well as experimentally under well-defined and reproducible direct-current (DC) conditions is the first step towards exploring RF breakdowns. In this thesis, we have studied Cu DC vacuum arcs with a combination of experiments, a particle-in-cell (PIC) model of the arc plasma, and molecular dynamics (MD) simulations of the subsequent surface damaging mechanism. We have also developed the 2D Arc-PIC code and the physics model incorporated in it, especially for the purpose of modelling the plasma initiation in vacuum arcs. Assuming the presence of a field emitter at the cathode initially, we have identified the conditions for plasma formation and have studied the transitions from field emission stage to a fully developed arc. The 'footing' of the plasma is the cathode spot that supplies the arc continuously with particles; the high-density core of the plasma is located above this cathode spot. Our results have shown that once an arc plasma is initiated, and as long as energy is available, the arc is self-maintaining due to the plasma sheath that ensures enhanced field emission and sputtering. The plasma model can already give an estimate on how the time-to-breakdown changes with the neutral evaporation rate, which is yet to be determined by atomistic simulations. Due to the non-linearity of the problem, we have also performed a code-to-code comparison. The reproducibility of plasma behaviour and time-to-breakdown with independent codes increased confidence in the results presented here. Our MD simulations identified high-flux, high-energy ion bombardment as a possible mechanism forming the early-stage surface damage in vacuum arcs. In this mechanism, sputtering occurs mostly in clusters, as a consequence of overlapping heat spikes. Different-sized experimental and simulated craters were found to be self-similar with a crater depth-to-width ratio of about 0.23 (sim) - 0.26 (exp). Experiments, which we carried out to investigate the energy dependence of DC breakdown properties, point at an intrinsic connection between DC and RF scaling laws and suggest the possibility of accumulative effects influencing the field enhancement factor.
  • Starrfelt, Jostein (Helsingin yliopisto, 2011)
    Ecology and evolutionary biology is the study of life on this planet. One of the many methods applied to answering the great diversity of questions regarding the lives and characteristics of individual organisms, is the utilization of mathematical models. Such models are used in a wide variety of ways. Some help us to reason, functioning as aids to, or substitutes for, our own fallible logic, thus making argumentation and thinking clearer. Models which help our reasoning can lead to conceptual clarification; by expressing ideas in algebraic terms, the relationship between different concepts become clearer. Other mathematical models are used to better understand yet more complicated models, or to develop mathematical tools for their analysis. Though helping us to reason and being used as tools in the craftmanship of science, many models do not tell us much about the real biological phenomena we are, at least initially, interested in. The main reason for this is that any mathematical model is a simplification of the real world, reducing the complexity and variety of interactions and idiosynchracies of individual organisms. What such models can tell us, however, both is and has been very valuable throughout the history of ecology and evolution. Minimally, a model simplifying the complex world can tell us that in principle, the patterns produced in a model could also be produced in the real world. We can never know how different a simplified mathematical representation is from the real world, but the similarity models do strive for, gives us confidence that their results could apply. This thesis deals with a variety of different models, used for different purposes. One model deals with how one can measure and analyse invasions; the expanding phase of invasive species. Earlier analyses claims to have shown that such invasions can be a regulated phenomena, that higher invasion speeds at a given point in time will lead to a reduction in speed. Two simple mathematical models show that analysis on this particular measure of invasion speed need not be evidence of regulation. In the context of dispersal evolution, two models acting as proof-of-principle are presented. Parent-offspring conflict emerges when there are different evolutionary optima for adaptive behavior for parents and offspring. We show that the evolution of dispersal distances can entail such a conflict, and that under parental control of dispersal (as, for example, in higher plants) wider dispersal kernels are optimal. We also show that dispersal homeostasis can be optimal; in a setting where dispersal decisions (to leave or stay in a natal patch) are made, strategies that divide their seeds or eggs into fractions that disperse or not, as opposed to randomized for each seed, can prevail. We also present a model of the evolution of bet-hedging strategies; evolutionary adaptations that occur despite their fitness, on average, being lower than a competing strategy. Such strategies can win in the long run because they have a reduced variance in fitness coupled with a reduction in mean fitness, and fitness is of a multiplicative nature across generations, and therefore sensitive to variability. This model is used for conceptual clarification; by developing a population genetical model with uncertain fitness and expressing genotypic variance in fitness as a product between individual level variance and correlations between individuals of a genotype. We arrive at expressions that intuitively reflect two of the main categorizations of bet-hedging strategies; conservative vs diversifying and within- vs between-generation bet hedging. In addition, this model shows that these divisions in fact are false dichotomies.
  • Korhonen, Hannele (Helsingin yliopisto, 2004)
  • Zhao, Hongxia (Helsingin yliopisto, 2003)
  • Silvennoinen, Heli (2007)
    Technological development of fast multi-sectional, helical computed tomography (CT) scanners has allowed computed tomography perfusion (CTp) and angiography (CTA) in evaluating acute ischemic stroke. This study focuses on new multidetector computed tomography techniques, namely whole-brain and first-pass CT perfusion plus CTA of carotid arteries. Whole-brain CTp data is acquired during slow infusion of contrast material to achieve constant contrast concentration in the cerebral vasculature. From these data quantitative maps are constructed of perfused cerebral blood volume (pCBV). The probability curve of cerebral infarction as a function of normalized pCBV was determined in patients with acute ischemic stroke. Normalized pCBV, expressed as a percentage of contralateral normal brain pCBV, was determined in the infarction core and in regions just inside and outside the boundary between infarcted and noninfarcted brain. Corresponding probabilities of infarction were 0.99, 0.96, and 0.11, R² was 0.73, and differences in perfusion between core and inner and outer bands were highly significant. Thus a probability of infarction curve can help predict the likelihood of infarction as a function of percentage normalized pCBV. First-pass CT perfusion is based on continuous cine imaging over a selected brain area during a bolus injection of contrast. During its first passage, contrast material compartmentalizes in the intravascular space, resulting in transient tissue enhancement. Functional maps such as cerebral blood flow (CBF), and volume (CBV), and mean transit time (MTT) are then constructed. We compared the effects of three different iodine concentrations (300, 350, or 400 mg/mL) on peak enhancement of normal brain tissue and artery and vein, stratified by region-of-interest (ROI) location, in 102 patients within 3 hours of stroke onset. A monotonic increasing peak opacification was evident at all ROI locations, suggesting that CTp evaluation of patients with acute stroke is best performed with the highest available concentration of contrast agent. In another study we investigated whether lesion volumes on CBV, CBF, and MTT maps within 3 hours of stroke onset predict final infarct volume, and whether all these parameters are needed for triage to intravenous recombinant tissue plasminogen activator (IV-rtPA). The effect of IV-rtPA on the affected brain by measuring salvaged tissue volume in patients receiving IV-rtPA and in controls was investigated also. CBV lesion volume did not necessarily represent dead tissue. MTT lesion volume alone can serve to identify the upper size limit of the abnormally perfused brain, and those with IV-rtPA salvaged more brain than did controls. Carotid CTA was compared with carotid DSA in grading of stenosis in patients with stroke symptoms. In CTA, the grade of stenosis was determined by means of axial source and maximum intensity projection (MIP) images as well as a semiautomatic vessel analysis. CTA provides an adequate, less invasive alternative to conventional DSA, although tending to underestimate clinically relevant grades of stenosis.
  • Aalto, Sanna (Helsingin yliopisto, 2007)
    Infection by Epstein-Barr virus (EBV) occurs in approximately 95% of the world s population. EBV was the first human virus implicated in oncogenesis. Characteristic for EBV primary infection are detectable IgM and IgG antibodies against viral capsid antigen (VCA). During convalescence the VCA IgM disappears while the VCA IgG persists for life. Reactivations of EBV occur both among immunocompromised and immunocompetent individuals. In serological diagnosis, measurement of avidity of VCA IgG separates primary from secondary infections. However, in serodiagnosis of mononucleosis it is quite common to encounter, paradoxically, VCA IgM together with high-avidity VCA IgG, indicating past immunity. We determined the etiology of this phenomenon and found that, among patients with cytomegalovirus (CMV) primary infection a large proportion (23%) showed antibody profiles of EBV reactivation. In contrast, EBV primary infection did not appear to induce immunoreactivation of CMV. EBV-associated post-transplant lymphoproliferative disease (PTLD) is a life threatening complication of allogeneic stem cell or solid organ transplantation. PTLD may present with a diverse spectrum of clinical symptoms and signs. Due to rapidity of PTLD progression especially after stem cell transplantation, the diagnosis must be obtained quickly. Pending timely detection, the evolution of the fatal disease may be halted by reduction of immunosuppression. A promising new PTLD treatment (also in Finland) is based on anti-CD-20 monoclonal antibodies. Diagnosis of PTLD has been demanding because of immunosuppression, blood transfusions and the latent nature of the virus. We set up in 1999 to our knowledge first in Finland for any microbial pathogen a real-time quantitative PCR (qPCR) for detection of EBV DNA in blood serum/plasma. In addition, we set up an in situ hybridisation assay for EBV RNA in tissue sections. In collaboration with a group of haematologists at Helsinki University Central Hospital we retrospectively determined the incidence of PTLD among 257 allogenic stem cell transplantations (SCT) performed during 1994-1999. Post-mortem analysis revealed 18 cases of PTLD. From a subset of PTLD cases (12/18) and a series of corresponding controls (36), consecutive samples of serum were studied by the new EBV-qPCR. All the PTLD patients were positive for EBV-DNA with progressively rising copy numbers. In most PTLD patients EBV DNA became detectable within 70 days of SCT. Of note, the appearance of EBV DNA preceded the PTLD symptoms (fever, lymphadenopathy, atypical lymphocytes). Among the SCT controls, EBV DNA occurred only sporadically, and the EBV-DNA levels remained relatively low. We concluded that EBV qPCR is a highly sensitive (100%) and specific (96%) new diagnostic approach. We also looked for and found risk factors for the development of PTLD. Together with a liver transplantation group at the Transplantation and Liver Surgery Clinic we wanted to clarify how often and how severely do EBV infections occur after liver transplantation. We studied by the EBV qPCR 1284 plasma samples obtained from 105 adult liver transplant recipients. EBV DNA was detected in 14 patients (13%) during the first 12 months. The peak viral loads of 13 asymptomatic patients were relatively low (<6600/ml), and EBV DNA subsided quickly from circulation. Fatal PTLD was diagnosed in one patient. Finally, we wanted to determine the number and clinical significance of EBV infections of various types occurring among a large, retrospective, nonselected cohort of allogenic SCT recipients. We analysed by EBV qPCR 5479 serum samples of 406 SCT recipients obtained during 1988-1999. EBV DNA was seen in 57 (14%) patients, of whom 22 (5%) showed progressively rising and ultimately high levels of EBV DNA (median 54 million /ml). Among the SCT survivors, EBV DNA was transiently detectable in 19 (5%) asymptomatic patients. Thereby, low-level EBV-DNA positivity in serum occurs relatively often after SCT and may subside without specific treatment. However, high molecular copy numbers (>50 000) are diagnostic for life-threatening EBV infection. We furthermore developed a mathematical algorithm for the prediction of development of life-threatening EBV infection.
  • Svinhufvud, Leena (Designmuseo, 2009)
    Modern ryijys, fabric by the yard and handicrafts. Finnish textile art and modernizing applied art during the inter-war years Textile art was in the 1920s and 1930s in the front rank of Finnish applied art and design. Modern ryijys, tapestries and fabrics by the yard by contemporary textile artists were on show in Finland and abroad. Textile art had also become interesting commercially, especially in interior textiles of modern homes. The research uses sources of the Ornamo Association of Decorative Artists, for example the Ornamo year books published from 1927, the Finnish Society of Crafts and Design and the country s only school of applied arts, the Central School of Arts and Crafts and the Museum of Applied Arts maintained by the society and also the national specialist organisation the Friends of Finnish Handicraft. It also refers to the magazines Käsiteollisuus and Kotiliesi. The art historical dissertation studies the renaissance of weaving art of the inter-war years in Finland. It problematizes the relation of the succesfull and appreciated textile art to the concept of breakthrough of Modernism (Functionalism). With the material from textile artists activities it questions the prevailing idea of slow modernization of Finnish applied art and design and challenges the polarization of craft and industry in the discourses of Modernisms of design. The public discussions about modernization of design and applied art where textile art and especially the ryijy got sometimes into difficult positions are interpreted as power struggles. After taking independence in 1917 the Finnish tradition of ryijy rugs was set as a symbol of the original culture of the young nation. The research studies the development of the so called art ryijy and the notions and meanings of hand weaving in the national context and also in relation to contemporary events in international applied art and design. It highlights the continuity of hand crafted production of textiles and the strong position of textile artists working in this field. The research opens new perspectives to Finnish textile artists by showing their activities as entrepreneurs in their own weaving studios or design studios and referring to their many relations and functions as pattern designers and educators in the growing handicraft industries.
  • Miettinen, Suvi (2001)
    Tämä pro gradu tarkastelee modernia identiteettiä lähtökohtanaan sen sellaisen versio, joka toteutui 1800-luvun pariisilaisen flanöörin tapauksessa. Flanööri oli väkijoukossa anonyyminä kuljeskeleva tarkkailija, jolle juuri suurkaupunki oli mielekäs ympäristö. Monet pitävät runoilija/esseisti/kriitikko Charles Baudelairea (1821-1867) osuvimpana esimerkkinä flaneerausta harjoittavasta flanööristä. Koska alun perin tahdoin tarkastella mahdollisuutta saavuttaa ja elää jotain modernia identiteettiä, joka yleisesti nähdään saavuttamattomana, jatkuvana projektina, flanööri vaikutti mielestäni tarkastelun arvoiselta. Hänen olemisentapansa mahdollistaa jonkinlaisen mielekkään elämän mahdollisuuden, vieläpä modernissa suurkaupungissa. Aloitan siis tutkielman tarkastelemalla Walter Benjaminin kirjoituksia modernista, jolloin flanöörit yleensä ja Charles Baudelaire erityisesti näyttäytyvät kulutusyhteiskunnan hyödykkeinä. Päälähteenäni tässä osiossa on Benjaminin teos "Charles Baudelaire: A Lyric Poet in the Era of High Capitalism". Näen flanöörin olennaisesti sellaisena hahmona, joka kykenee luottamaan muiden vieroksumaan hektiseen suurkaupunkiyhteisöön. Hän ikään kuin ammentaa voimaa modernista ambivalenssista, joka on muuten yleisesti nähty ahdistavana. Tältä kannalta tutkielma sivuaa luottamusta ja siitä käytyä keskustelua. Siksi tutkielman lopulla esittelen flaneeraukseen liittyviä ja sen alleviivaamia kysymyksiä luottamuksesta päälähteenäni Olli Loukolan artikkeli "Trusting Strangers? The hard case for the theory of trust". Päästäkseni luottamus-kysymyksiin ja yleensä syvemmälle flanööri-identiteettiin tarkastelen kuitenkin ensin flanöörin rinnalla Zygmunt Baumanin esittelemiä ajatuksia modernin identiteetin saavuttamattomuudesta ja modernista ambivalenssista yleensä. Tässä yhteydessä tuon esille Baumanin esittelemän parvenu-hahmon (tietynlaisen ei-toivotun tulokkaan), sillä parvenun ja flanöörin rinnakkainen tarkastelu korostaa ja uudella tavalla valaisee keskeisiä piirteitä flanöörin identiteetistä. Moderni identiteetti piirtyy yhä selkeämmin prosessina, joka on saavuttamattomuutta. Päälähteenä tässä osiossa on Baumanin artikkeli "Parvenu and pariah: heroes and victims of modernity". Tässä vaiheessa katson tarpeelliseksi tarkastella Charles Taylorin pohdintoja osviittana sille, onko modernissa mahdollista oikeastaan saavuttaa mitään. Flanöörin ja parvenun mahdollisuudet saavat taustaa Taylorin esittelemistä haasteista, joita ovat omanarvontunnon saavuttaminen, kunnia ja toisen kunnioittaminen, autenttisuuden ideaali, itselle uskollisuus ja individualismi. Päälähteinä käytän tässä Taylorin teoksia "Sources of the Self - The Making of Modern Identity" ja "Multiculturalism - Examining the Politics of Recognition". Loppuyhteenvedossa hahmottelen flanöörin identiteetin tarjoamia mahdollisuuksia. Flanööri edustaa toisaalta autenttisuuden ideaalia ja modernia individualistista vapautta, mutta hänen peruslähtökohtansa on ongelmallinen: flanööri tahtoo erottaa yksilön massasta ja massan pysyvän massana - ja pitää itse massaan etäisyyttä. Tässä näen kuitenkin yllättävän mahdollisuuden jokaisen yksilön itsensä toteuttamisen kannalta. Työ edustaa kulttuurifilosofiaa ja aatehistoriaa.
  • Teno, Petri (2006)
    Työssä tutkitaan Suomen Kuvalehden kirjallisuusjournalismia vuosina 1984-94 Michel Foucault’n Tiedon arkeologia (1969, suom. 2005) teoksessa artikuloidun diskurssianalyysin pohjalta. Sellaisia analyyttisiä käsitteitä kuin ”diskurssi”, ”diskursiivinen muodostelma” ja ”lausuma” on tutkimuksen eri vaiheissa käytetty hyväksi. Tutkimus hahmottelee kahden erilaisen lausumakokonaisuuden pohjalta kaksi erilaista diskursiivista muodostelmaa, joita työssä kutsutaan moderniksi ja postmoderniksi. Näitä muodostelmia luonnehtii niiden erilainen tapa tuottaa todellisuutta mm. ”totuus” –käsitteen toisistaan poikkeavasta mieltämistavasta johtuen. Modernit diskurssit syntyivät reaktiona valheelliseksi, tai ”vääräksi todellisuudeksi” koetun klassisen taidekulttuurin ja porvarillisen yhteiskunnan diskursseihin. Moderni tietoisuus koki korjaavansa edeltävät ajattelun puutteellisuudet ja virheet. Esimerkiksi suomalaiset modernisti orientoituneet kirjailijat ovat käyneet jatkuvaa debattia siitä, millä kerrontatekniikoilla todellisuutta pystyttäisiin kaikkein todellisuudenmukaisimmin kuvamaan. Postmodernit diskurssit syntyivät skepsiksenä tätä modernin totuusprojektiota kohtaan. Postmodernissa tietoisuudessa ”totuus” olikin vain jatkuvasti muuntuva, ideologinen voimasana. Niinpä ”totuus” ei omannut näissä diskursseissa mitään ylimaallisen positiivisia konnotaatiota, vaan päinvastoin se miellettiin ennemminkin valtaan liittyvän hallinnan, joissakin tapauksissa jopa sorron ilmaisuina. ”Totuus” –käsitteen suhteellistuminen ja politisoituminen epistemologisella tasolla aiheutti levottomuutta kun postmoderni diskursiivinen muodostuma nieli itseensä uusia ”tiedon” alueita. Modernit ajattelijat tulkitsivat kehityksen omista lähtökohdistaan käsin turmiolliseksi ”johtotähdettömyyden” lisääntymiseksi, kuten esimerkiksi Veijo Meri 1990-luvun alussa. Suomen Kuvalehden kirjallisuusjournalismia voidaan luokitella varsin onnistuneesti yksittäisten juttujen koon mukaan. Tämä siksi, että juttujen tiedonintressi näyttää olleen suorassa suhteessa juttuformaattiin, jonka mukaan ne on julkaistu. Formaatti on puolestaan sanellut jutun koon. Näin voidaan jossakin määrin pitävästi seurata modernin ja postmodernin diskursiivisen muodostelman vaikutuksen kehitystä Suomen Kuvalehdessä vuosina 1984 – 94: Suomen Kuvalehden kirjallisuusjournalismi postmodernisoitui edellä määritellyssä mielessä varsin kovaa vauhtia. Merkittävin sisällöllinen ero modernisti ja postmodernisti tiedostavan juttutyypin välillä Suomen Kuvalehdessä on ollut niiden erilainen suhde valistuksellisuuteen. Moderniin tiedostavuuteen pyrkivä kirjallisuusjuttu on rakennettu humanismin aatemaailman varaan: kirjallisuus ja kirjailijat näyttäytyvät siinä poikkeuksetta pienen ihmisen ja tiedon asiamiehinä. Vastaavasti postmodernissa tietoisuudessa tätä vakavaa ohjelmaa on ollut mahdotonta löytää; kyse on ollut ennemminkin statusasemien ja saavutettujen etujen purkamisesta. Postmodernin tietoisuuden vallassa tehtyjä kirjallisuusjuttuja luonnehtiikin niiden perusrakenteista kaikuva, ehkä bahtinilaiseksikin tulkittavissa oleva karnevaalinen nauru.
  • Laamo, Jussi Petteri (2008)
    Tutkielmani liittyy moderniin kulttiteoriaan, jota täydennän kultin rakenteen kuvaamisen sekä uskonnollisten kulttien ja artistikulttien vertailtavuuden osoittamisen myötä. Primääriaineistona on Manic Street Preachers -yhtyeen internet-keskustelupalstalta nimeltä Forever Delayed tallentamani laaja keskusteluketjujen joukko vuosilta 2005–2006. Analysoin viestejä ja keskusteluja diskurssianalyysin keinoin. Internet-keskustelupalstan käyttämisessä tutkimusaineistona tukeudun Robert Arpon teokseen Internetin keskustelukulttuurit vuodelta 2005. Modernin kulttiteorian kannalta yksi tärkeimmistä vaikuttajista työssäni on Stig Söderholm ja hänen Jim Morrisonin hautapaikkaan liittyvää kulttia käsittelevä väitöskirjansa Liskokuninkaan Mytologia vuodelta 1990. Esitän modernin kultin omaavan hierarkkisen kolmiportaisen rakenteen, jossa ylimmällä tasolla on uskonnollisella kultilla ihmisen käsityskyvyn ylittävä tekijä, keskimmäisellä tasolla papisto, ja alimmalla tasolla kannattajat. Ensimmäisen ja toisen tason väliin sijoittuu kultin muodostamisvaiheessa profeetta, ja rakenne vakiintuu kolmiportaiseksi viimeistään tämän kuoltua. Artistikultin tapauksessa ylin taso ei ole yksiselitteinen, mutta siihen on luontevinta sijoittaa musiikki. Musiikki tulee tällöin ymmärtää laajasti siten, että siihen liittyy kultin seuraajien mielissä heidän käsityskykynsä ulkopuolelle sijoittuvia asioita. Toiselle portaalle sijoitan elämäkertojen kirjoittajat, jotka pohjaavat teoksensa usein erinäisissä medioissa jo esitettyihin tietoihin, kuten lehtiartikkeleihin. Alimmalla portaalla sijaitsee kultin seuraajat, yleisö. Manic Street Preachersin keskeisen olemuksen olen tiivistänyt kolmeksi teemaksi: itsetuhoisuus ja katoaminen, maskuliinisuus/rakkaus, poliittisuus ja sivistyneisyys. Esittelen näitä teemoja arvostetuimman yhtyeestä kirjoitetun elämäkerran, Simon Pricen Everything (A book about Manic Street Preachers), sekä lehtiartikkeleiden kautta. Keskustelupalstalta etsin näitä teemoja ja niihin liittyviä diskursseja, ja yhdistän tämän kokonaisuuden kultin kolmiportaiseen rakenteeseen. Lopputuloksena päädyin pitämään esimerkiksi ottamaani artistikulttia yhtenä osana maallistumiskehitystä länsimaissa. Kyse ei ole kokonaisvaltaisesta ratkaisusta sen tilan täyttämiseen, jota maallistuminen kehityskulkuna on luonut, vaan yksi osa niin kutsuttua religion a la cartea, jossa yksilöt voivat itse valita mitä osia mistäkin uskonnosta, sekä oman tulkintani mukaan myös muista uskontoon verrattavista ilmiöistä, kukin hyödyntää merkityksellistäessään omaa elämäänsä ja maailman tilaa.