Väitöskirjat

Recent Submissions

  • Winkler, Alexander (Helsingin yliopisto, 2017)
    The next evolutionary step in medical imaging and radiation therapy is to employ novel detector technologies capable of photon counting operations. These detectors allow to acquire the spectrum of the radiation for each pixel. Currently used energy integrating detectors do not allow this. Two types of detector materials capable of photon counting operation are discussed in this work. With the result that the detector technology based on CdTe and CdZnTe is more matured than GaAs. The spectral information of photon counting detectors can be used for numerous applications and diagnostic improvements. A distinct example is presented for boron neutron capture therapy (BNCT). This therapy lacks an accurate real time method to determine the 10B concentration within the patient. Previous approaches failed because of the low signal to noise ratio of the used signal. A method has been proposed to improve this therapy by employing CdTe based photon counting detectors. These detectors allow detection of a secondary signal with a higher signal to noise ratio. Additionally, efforts to produce CdTe based photon counting detector arrays, for medical applications, are described.
  • Railas, Lauri (The Faculty of Law of the University of Helsinki and the author, 2004)
  • Vaura, Tuomas (Helsingin yliopisto, 2017)
    The overall theme of my study concerns the thirteenth- and early fourteenth-century academic discussions about the incarnation from the point of view medieval philosophical psychology. This study will especially explore the following questions: what themes were included in the discussions about knowledge, will, and passions in Christ’s human nature, what the main psychological ideas employed in the psychology of the incarnation were, and whether the teachings about Christ’s human soul were derived from psychology as a discipline of natural philosophy. The method of this study is a systematic analysis of the psychological conceptions. This includes the historical and philosophical construction of psychological ideas in these discussions about Christ’s human soul. The most important sources of this study are commentaries on Peter Lombard’s Sentences. The sources of this study are composed, for example, by Alexander of Hales and other early Franciscan theologians, Bonaventure, Albert the Great, Thomas Aquinas, Giles of Rome, Peter of Tarentaise, Richard Middleton, John Duns Scotus, William Ockham, Peter Auriol, Walter Chatton, Durand of St. Pourçain and Peter of Palude. As theologians studied the knowledge, will and passions of Christ separately, this study is also divided into a corresponding set of three chapters. In the first chapter, I examine the discussion about the knowledge of Christ. The main questions are what kind of dknowledge the human Christ had and whether his soul knew everything that God knows. In the second chapter, I study the discussion about Christ’s will and ask what kind of human wills Christ had and how these wills were related to each other. In the third chapter, I turn to a study of the passions of Christ. I ask how Christ’s human soul was passible, what passions he had and how he was simultaneously able to have pain, sadness and joy. My study proves that some emphases in the discussions about the psychology of the incarnation indicate that the early Franciscan theologians and Aquinas established two traditions about the application of psychology to Christology; while the Franciscan theologians usually followed the Franciscan tradition, the Dominican theologians usually followed the Thomistic tradition. However, the study also shows that the traditions were not unequivocal in terms of their flexibility on all questions, since not all Franciscan theologians followed the Franciscan tradition and not all Dominicans followed the Thomistic tradition. In addition, this study shows that in the discussions about the knowledge, will and passion of Christ, theologians applied various ideas from psychology as a branch of natural philosophy in developing their views about theological matters, but Christological views also influenced the philosophical thought of some theologians.
  • Patronen, Outi (Helsingin yliopisto, 2017)
    The purpose of this thesis is to examine how the Orthodox population in Border Karelia, who did not previously have surnames, adopted or were given surnames primarily over the decades from the 1890s to the 1920s. Border Karelia refers to the six municipalities located northeast of Lake Ladoga that were ceded to the Soviet Union after World War II: Suojärvi, Korpiselkä, Soanlahti, Suistamo, Impilahti, and Salmi. Border Karelia was a stronghold of the Finnish Orthodox church, and it had a population of 50 000 inhabitants in 1939. The adoption of surnames is studied as a part of the Fennification of the culture in Border Karelia, and the Fennification of the Orthodox Karelian population is contrasted with the history of other language minorities in Finland and in neighboring areas. The research material, consisting of 2 357 surnames of the Orthodox population in Border Karelia, was collected from the 1818 and 1820–1925 tax registers of the Salmi region in the Vyborg province. The population of Border Karelia became a target of Fennification due to the rise of Karelianism. The aim was to tie the Karelian-speaking Orthodox population of the borderlands into the central areas of Finland as much as possible. The Fennification began with the founding of the Sortavala seminar (1880) and the newspaper Laatokka (1882). The inhabitants of Border Karelia had always faced East, to Olonets Karelia, but the Western influence increased due to the independence of Finland and the closing of the eastern border. The changes in the Karelian language and culture were observed already in the 1920s. The theoretic part of the thesis examines the status of the Karelian language of Border Karelia by investigating the domains of spoken language and the writers of Karelian articles published in the newspaper Laatokka. The main hindrance to the development of Karelian as a written standard language was the fact that it was not recognized as a distinct language due to political reasons: the languages spoken in Border Karelia and in East Karelia were both considered dialects of the Finnish language due to the aim of the Fennification of East Karelia. Karelian was also not accepted as a suitable language for education. The status and issues of the Karelian-speaking population of Border Karelia, a linguistic and religious minority, can be easily compared to Skolt Sámi: both populations have been targets of Fennification and have not received support, for example, for the development of written standard languages from the mainland. Before 1880 most of the population in Border Karelia were registered in Swedish tax registers and in Russian Orthodox parish registers with only their Russian given names and patronymics; only a few had inherited surnames. The surnames in Border Karelia are divided into ten groups. The largest group is surnames based on hypocorisms of given names that were originally estate names (Reittu) and surnames based on bynames (Löllö). Other name groups include surnames evolved from Russian patronymics (Kononoff), surnames from Orthodox clergymen (Solntsev), various Russian surnames (Komaroff) and randomly assigned or adopted surnames that are similar to surnames in Savonia or Finnish North Karelia. The Finnish elementary school has been recognized as the main factor for the Fennification of the Karelian Orthodox minority in several studies in various research fields. Additional reasons for assigning surnames to the population in Border Karelia were the enclosure carried out in Border Karelia and the independence of peasants in Border Karelia.
  • Muurinen, Johanna (Helsingin yliopisto, 2017)
    Agricultural antibiotic use is considered to foster the development and spread of resistant pathogens threatening human health and thus it is suggested that the use of antibiotics in production animals should be limited. Unlike in many big countries in the world, Finnish animal production uses antibiotics predominantly for treating bacterial infections. Nonetheless, the circulation of antibiotic resistance genes through intersecting ecosystems, such as production animal farms, might have a considerable role in transferring resistance genes from environmental bacteria to human or animal associated bacteria. Agroecosystems are unique settings where bacteria originating from animals and the environment are constantly mixed due to land application of manure and ingestion of harvested forage by production animals. In this work it was clarified if genes related to antibiotic resistance and transfer disseminate from farms to the environment due to manure fertilization, if the abundance of these genes is affected by winter storage of manure and if resistance gene abundances are elevated in soils at crop harvesting time, and thus potentially cycled into the animal gut via forage. A field-compatible protocol for detecting antibiotic concentrations sensed by bacteria in different samples was also established. Manure had the highest abundance of genes related to antibiotic resistance and transfer, and the abundance increased during storage. The genes abundant in manure disseminated to soil when manure was applied; however, at the harvesting time the soil resistome resembled the resistome of unfertilized soil. Antibiotic resistance genes were also detected in ditch water but most of them were undetected in manure, suggesting that genes in manure were not spreading to receiving waters. The results propose that manure fertilization does not inevitably generate a risk of disseminating antibiotic resistance and that agricultural practices largely determine whether or not the use of antibiotics in production animals contaminates the agricultural environment with resistance determinants. The presented field-use suitable assay can be used for samples with minor matrix-effects, e.g. surface waters. With further method development, the protocol could help in progressing from detection of antibiotics to the evaluation of their ecological effects in the studied environment.
  • Scheinin, Ilari (Helsingin yliopisto, 2017)
    Chromosomal copy number aberrations are one of the main mechanisms that give rise to the proliferative capabilities of cancer cells. These aberrations can be quantified with technologies that generate measurements genome-wide and with high resolution. Hence, they produce vast amounts of data, which requires tailored bioinformatic solutions for analysis and management. Two such high-resolution and genome-wide technologies are DNA microarrays, which are successively replaced by next-generation sequencing approaches. This dissertation describes three novel bioinformatic solutions for copy number analysis in cancer with these technologies. CanGEM is a publicly-accessible database solution for storage of raw and processed copy number data from cancer research experiments. The contents of the database can be queried based on clinical and copy number data. Clinical data is collected using appropriate controlled vocabularies. Copy number data is collected as raw microarray data and automated analysis identifies the locations of chromosomal aberrations. In order to allow integration of data measured with different microarray platforms, a copy number status is derived for every known human gene. CGHpower is a statistical power calculator for copy number experiments that compare two groups. It estimates genome complexity of a cancer type in question from a pilot data set of the sample series, and assesses the number of samples required to satisfy statistical requirements. It can be used either in the planning stages of experiments, including as a justification in grant applications, or to verify whether sufficient samples were included in past experiments. Performance of this bioinformatic solution is evaluated with real and simulated data sets. QDNAseq is a preprocessing solution to detect copy number aberrations from shallow whole-genome next-generation sequencing data. It corrects the observed sequencing coverage for known systematic biases and allows filtering of spurious regions in the genome. A new list of such problematic regions is derived from public data generated by the 1000 Genomes Project. Performance of the solution is evaluated relative to other similar published solutions and DNA microarrays, and also compared to theoretical statistical expectations. An application of the QDNAseq method is also presented in a translational research project with the aim to identify copy number aberrations in tumors of patients with low-grade glioma. Aberrations identified by shallow whole-genome next-generation sequencing and QDNAseq are used to evaluate associations with patient survival, and also to assess intratumoral heterogeneity and temporal evolution of these tumors. A loss in chromosome 10q is identified to be associated with poor prognosis, and the finding validated in two independent data sets. From the assessment of intratumoral heterogeneity and temporal tumor evolution, the well-characterized co-deletion of 1p/19q is found to be the only chromosomal aberration that is consistently present or absent across the entire tumor and possible future recurrences. This is compatible with the present view of its role as an early event in the development of these tumors. The text concludes with a discussion of lessons learned from the development process and application of the three described bioinformatic solutions. Better awareness of and adherence to established best practices from the software development field would have been useful, and together with more careful consideration of implementation decisions could have resulted…
  • Ylä-Anttila, Tuukka (Helsingin yliopisto, 2017)
    Populism has often been understood as a description of political parties and politicians, who have been labelled either populist or not. This dissertation argues that it is more useful to conceive of populism in action: as something that is done rather than something that is. I propose that the populist toolkit is a collection of cultural practices, which politicians and citizens use to make sense of and do politics, by claiming that ‘the people’ are opposed by a corrupt elite – a powerful claim in contemporary politics, both in Finland and internationally. The concept of the populist toolkit has analytical utility, since it can separate a set of populist repertoires from others, for example that of exclusionary nationalism, and takes seriously the effect culture has on action, while avoiding cultural determinism. I study four instances in which the populist toolkit was used in Finnish politics from 2007 to 2016. As data, I use party publications, a Voting Advice Application, newspaper articles and opinion pieces, and a large set of online media data. Methodologically, I employ qualitative text analysis informed by theories of populism, cultural practices, frame analysis and Laurent Thévenot’s sociology of engagements, as well as topic modeling. Article I argues that the state of the Eurozone in 2011 gave the Finns Party an opportunity to frame the situation as a crisis for Finland and to present itself as a righteous populist challenger to established parties. Article II shows that the Finns Party uses anti-feminist arguments to present itself as a populist alternative. Article III presents a theory of how populist argumentation can use familiar emotional experiences in bonding ‘the people’ together. Article IV tackles the populist epistemology: while populism can be critical of intellectuals and experts in general, the article shows that another populist strategy is counterknowledge, incorporating alternative knowledge authorities. This strategy is particularly employed by the populist radical right. After the monumental success of right-wing populism in Western democracies, the next big question is whether left-wing or liberal actors will take up the tools of populism, or will they rather position themselves on the side of pluralism, democratic institutions and scientific expertise. This will have to be assessed by future studies.
  • Heinonen, Esko (Helsingin yliopisto, 2017)
    This dissertation consists of four research articles whose unifying theme is the existence and non-existence of continuous entire non-constant solutions for nonlinear differential operators on Riemannian manifolds. The existence of such solutions depends heavily on the geometry of the manifold and, in the case of complete and simply connected Riemannian manifolds, we prove the existence under assumptions on the sectional curvature. In the first and fourth article we study the existence of minimal graphic functions by solving the asymptotic Dirichlet problem. Here the idea is to compactify the Cartan-Hadamard manifold by adding an asymptotic boundary and equipping the resulting space with the cone topology. Then one can solve the asymptotic Dirichlet problem i.e. prove the existence of entire solutions with prescribed continuous boundary values on the asymptotic boundary. In the fourth article we prove also a non-existence result by showing that asymptotically non-negative sectional curvature implies uniform gradient estimate for minimal graphic functions with at most linear growth. The second article deals with the existence of A-harmonic functions and the third article with the existence of f-minimal graphs. In the case of A-harmonic functions, we improve an earlier result of A. Vähäkangas by relaxing the assumption on the curvature upper bound. Here, again, we solve the asymptotic Dirichlet problem in order to get the existence result. We solve the asymptotic Dirichlet problem also for the f-minimal equation, but differing from the other papers, here we consider also the existence in the case of bounded domains.
  • Liu, Jinxiu (Helsingin yliopisto, 2017)
    Land cover is critical information to various land management and scientific applications, including biogeochemical and climate modeling. In addition, fire is an essential factor in shaping of vegetation structures, as well as for the functioning of savanna ecosystems. Remote sensing has long been an important and effective means of mapping and monitoring land cover and burned area over large areas in a consistent and robust way. Owing to the free and open Landsat archive and the increasing availability of high spatial resolution imagery, seasonal features from the temporal domain and the use of texture features from the spatial domain create new opportunities for land cover characterization and burned area detection. This thesis examined the application of satellite image time series and texture information in land cover characterization and burned area detection. First, the utility of seasonal features derived from Landsat time series (LTS) in improving accuracies of land cover classification and attribute prediction in a savanna area in southern Burkina Faso was studied. Then, the temporal profiles from LTS were explored for mapping burned areas over a 16 year period, and MODIS burned area product was used for comparison. Finally, the application of texture features derived from high spatial resolution data in land cover classification and attribute predictions was investigated in a savanna area of Burkina Faso and an urban fringe area in Beijing. According to the results, firstly, seasonal features from LTS based on all available imagery during one year as input led to a significant increase in land cover classification accuracy in comparison to the dry and wet season single date imagery. The harmonic model used for time series modeling provided a robust method for extracting seasonal features, and the influence of burned pixels on seasonal features could be considered simultaneously. Secondly, the annual burned area mapping based on a harmonic model and breakpoint identification with LTS was capable of detecting small and patchy burn scars with higher accuracy than MODIS burned area product. The approach demonstrated the potential of LTS for improving burned area detection in savannas, and was robust against data gaps caused by clouds and Landsat 7 missing lines. Thirdly, predictive models of tree crown cover (CC) using RapidEye and LTS imagery achieved similar accuracy, indicating the importance of texture and seasonal features from RapidEye and LTS imagery, respectively. Predictions of aboveground carbon and tree species richness, which were strongly correlated with CC, were promising using RapidEye and LTS imagery. Finally, the optimized window size texture classification improved classification accuracy in comparison to the classifications with single window size texture features and multiple window size texture features in an urban fringe area in Beijing, indicating the importance of multiscale texture information. Keywords: Landsat time series, texture, land cover classification, burned area, savanna, tree crown cover
  • Alava, Henni (Helsingin yliopisto, 2017)
    This study explores how the Catholic and Protestant (Anglican) Churches have influenced the negotiation of societal co-existence in the aftermath of over two decades of brutal war in northern Uganda. Drawing from a total of nine months of ethnographic fieldwork between 2012 and 2016 that focused on a Catholic and a Protestant parish in Kitgum town, this study provides a historically grounded ethnographic analysis of the relationship between mainline churches and politics in Acholiland. It argues that churches, as socially, politically, and materially embedded institutions, have performed as sites of, and provided individuals and communities resources for, narrative imagination. The two churches were at the forefront of the Acholi Religious Leaders’ Peace Initiative (ARLPI), which gained global acclaim and local respect for its efforts to draw the international community’s attention to the war, and to convince the warring parties to embark on peace talks. Yet the churches, which have been deeply entangled in Ugandan politics since the country's independence, were themselves hard-hit by the war and, as this study shows, their political and societal role in its aftermath has been complex. First, rather than being the monolithic actors they are often perceived to be, churches are deeply woven into networks of ethnicity, kinship, party politics, government, patronage, and friendship, and the criss-crossing lines of division that cut across society also run through the churches themselves. Second, although public church events function as platforms for performances of statehood, they also provide arenas for genuine political debate and critique of Uganda’s ruling government. Third, while churches have taken part in forging a powerful and at times healing utopian vision of a peaceful future in post-war Acholiland, this utopia lends itself to entrenching boundaries of inclusion and exclusion, both within the churches, and within society. To make these claims, the study draws analytical tools from debates in the anthropology of hope and of the good, in political theology, in studies on political narratives and utopias, and in multidisciplinary research on Christianity and politics in Africa. The thread followed throughout is the Acholi concept of anyobanyoba, ‘confusion’, which emerges as both a sense of ambivalence and uncertainty, and as a state of affairs within a community. By analysing public church events at which elaborate political narratives are woven, as well as quotidian moments in which silence, fear, and hope are encountered and expressed, the study highlights how ‘confusion’ diminishes the possibilities of crafting hopeful imaginaries for a less violent future – yet also the multiple ways in which confusion and violence are addressed. The notion of confusion is also employed as an epistemological and ethical device. Acknowledging the challenges of studying violence and its aftermath; the futility of claims to absolute knowledge in situations characterised by uncertainty and silence; and the difficulty of transforming the experiences of others into text in an ethically uncompromised way; the study advocates scholarship that embraces hesitance and experimentation rather than certainty and disciplinary rigidity. In a world increasingly framed by oppositional extremes, there is a need for research that, instead of seeking clear-cut answers, asks questions that provoke recognition of complexity and confusion, and explores the ways in which communities and individuals orientate themselves towards the future in the face of them.
  • Laurent, Helene (Helsingin yliopisto, 2017)
    The Finnish laws on maternal and child health care came into force in 1944, during the last months of WWII. During the war, resources had been allocated specifically to child welfare, which resulted in record-low infant mortality rates in 1943. These seemingly controversial facts formed the starting point for my doctoral thesis on the history of preventive child health care in Finland. In my research I analyzed, how changes in the soci-ety and in medical knowledge have influenced the ideology, organization and practices of preventive child health care in the early to mid-twentieth century. I have approached the process by examining child health experts as an epistemic community, a concept coined by Peter Haas, which refers to transnational networks of knowledge-based, policy-oriented experts. In addressing my research questions, I have relied on content analysis and, where possible, also statistical data. The research material consists mainly of texts produced by health professionals. The thesis is divided into three parts. The first part ends in 1939, which marks the beginning of the Finno-Soviet Winter War, and follows the ideological and institutional development of preventive child health care in Finland. The prevailing ideology was primarily based on positive eugenics: on raising strong and healthy children for the newly independent nation. International contacts included Germany via pediatrician Arvo Ylppö, and the Anglo-Saxon world, via public health nurses. Practical work was con-ducted mainly by child welfare organizations. By the end of the 1930s, pop-ulation questions and problems in public health were activated in national politics, where special emphasis was put on the rural communities lagging in development. Public health experts joined forces to promote publicly funded preventive health care for mothers and children. The second part is set in the years of WWII, and it examines the chang-es in child health care catalyzed by the evacuations and high infant mortal-ity during the Winter War. Finland received extensive international aid, which was targeted mainly at the health care of evacuated mothers and children. The aid agency Finnish Relief and its expert-run Health Commit-tee could develop new forms of child health and welfare, e.g. ambulatory health clinics and cottage hospitals for children, in cooperation with exist-ing non-governmental organizations. Spurred on by powerful pronatalist and defense-related arguments, the laws on maternal and child health clinics were enacted in 1944. Based on the annual reports of district physi-cians, the health of children remained good from 1941 onwards, due to the focus on the welfare of children. However, 75,000 children from the most vulnerable families had been sent to Sweden. The practices and possibili-ties of public health care are discussed in a local case study of the Sortavala region in Karelia, where many health reforms were applied in advance. The last section extends to the mid-fifties and focuses on the post-war reconstruction efforts. Again, with the help of international aid agencies, a network of health centers, including maternal and child health clinics, was built to serve as basic health care units in the rural areas. By the mid-fifties, practically all pre-school children were enrolled at the clinics. The Finnish child health experts found new tasks in the World Health Organi-zation, the new center of the global epistemic community of child health.
  • Zhang , Yurui (Helsingin yliopisto, 2017)
    As the latest epoch of the Earth’s history, the Holocene is commonly defined as the last 11.7 ka BP (hereafter referred to as ka) and represents a new phase, encompassing the time span of human civilization. The last deglaciation lasted well into the Holocene, implying that the early Holocene was characterized by a large-scale reorganization with transitions in various components of the climate system. Studying the Holocene can provide insights into how the climate system functions, apart from the theoretical contributions to climate history itself. We first conducted sets of simulations with different combinations of climate forcings for 11.5 ka and for the entire Holocene to investigate the response of the climate–ocean system to the main climate forcings. In particular, two possible freshwater flux (FWF) scenarios were further tested considering the relatively large uncertainty in reconstructed ice-sheet melting. Moreover, we compared four Holocene simulations performed with the LOVECLIM, CCSM3, FAMOUS and HadCM3 models by identifying the regions where the multi-model simulations are consistent and where they are not, and analysing the reasons at the two levels (of the models’ variables and of the model principles and physics) where mismatches were found. After this, these multi-model simulations were systematically compared with data-based reconstructions in five regions of the Northern Hemisphere (NH) extratropics, namely Fennoscandia, Greenland, North Canada, Alaska and high-latitude Siberia. Potential uncertainty sources were also analysed in both model simulations and proxy data, and the most probable climate histories were identified with the aid of additional evidence when available. Additionally, the contribution of climate change, together with forest fires and human population size, to the variation in Holocene vegetation cover in Fennoscandia was assessed by employing the variation partitioning method. With effects of climate forcings, including variations in orbital-scale insolation (ORB), melting of the ice sheets and changes in greenhouse gas (GHG) concentrations, the climate shows spatial heterogeneity both at 11.5 ka and over the course of the Holocene. At 11.5 ka, the positive summer ORB forcing overwhelms the minor negative GHG anomaly and causes a higher summer temperatures of 2–4 °C in the extratropical continents than at 0 ka. The ice-sheet forcings primarily induce climatic cooling, and the underlying mechanisms include enhanced surface albedo over ice sheets, anomalous atmospheric circulation, reduced the Atlantic Meridional Overturning Circulation (AMOC) and relevant feedbacks. In particular, the most distinct feature is a thermally contrasting pattern over North America, with simulated temperatures being around 2 °C higher than those at 0 ka for Alaska, whereas over most of Canada, temperatures are more than 3 °C lower. The geographical variability of simulated temperatures is also reflected in Holocene temperature evolution, especially during the early Holocene, as constant Holocene cooling in Alaska contrasts with strong early-Holocene warming (warming rate over 1 °C kyr-1) in northern Canada. The early-Holocene climate is sensitive to the FWF forcings and a brief comparison with proxy records suggests that our updated FWF (FWF-v2, with a larger FWF release from the Greenland ice sheet and a faster FWF from the Fennoscandian Ice sheet (FIS)) represents a more realistic Holocene temperature scenario regarding the early-Holocene warming and Holocene temperature maximum (HTM). Comparison of multiple simulations suggests that the multi-model differences are spatially heterogeneous, despite overall consistent temperatures in the NH extratropics as a whole. On the one hand, reasonably consistent temperature trends (a temporal pattern with the early-Holocene warming, following a warm period and a gradual decrease toward 0 ka) are found over the regions where the climate is strongly influenced by the ice sheets, including Greenland, N Canada, N Europe and central-West Siberia. On the other hand, large inter-model variation exists in the regions over which the ice sheet effects on the climate were relatively weak via indirect influences, such as in Alaska, the Arctic, and E Siberia. In these three regions, the signals of multi-model simulations during the early Holocene are incompatible, especially in winter, when both positive and negative early-Holocene anomalies are suggested by different models. These divergent temperatures can be attributed to inconsistent responses of model variables. Southerly winds, surface albedo and sea ice can result in divergent temperature trends across models in Alaska, Siberia and the Arctic. Further comparisons reveal that divergent responses in these climate variables across the models can be partially caused by model differences (e.g. different model physics and resolution). For instance, the newly adopted formulation of the turbulent transfer coefficient in CCSM3 causes an overestimated albedo over Siberia at 0 ka, which leads to a stronger early-Holocene warmth than in other models. Moreover, the relatively simplified sea ice representation in FAMOUS probably leads to overestimated sea ice cover in the Arctic Ocean. The coarse vertical resolution in LOVECLIM might also introduce strong responses in atmospheric circulation over Alaska. From the perspective of climate features, the transient feature of the early-Holocene climate driven by the retreating ice sheets also influences the inter-model comparisons, as this transient feature induces a large degree of uncertainty into the FWF forcing. Comparisons of multiple model results with compiled proxy data at the sub-continental scale of NH high latitudes (i.e. Fennoscandia, Greenland, north Canada, Alaska and Siberia) reveal regionally-dependent consistencies in Holocene temperatures. In Fennoscandia, simulations and pollen data suggest a summer warming of 2 °C by 8 ka, although this is less expressed in chironomid data. In Canada, an early-Holocene warming of 4 °C in summer is suggested by both the simulations and pollen results. In Greenland, the magnitude of early-Holocene warming of annual mean ranges from 6 °C in simulations to 8 °C in δ18O-based temperatures. By contrast, simulated and reconstructed summer temperatures are mismatched in Alaska. Pollen data suggest 4 °C early-Holocene warming, while the simulations indicate 2 °C Holocene cooling, and chironomid data show a stable trend. Meanwhile, a high frequency of Alaskan peatland initiation before 9 ka can either reflect a high temperature, high soil moisture content or large seasonality. In high-latitude Siberia, simulations and proxy data depict high Holocene temperatures, although these signals are noisy owing to a large spread in the simulations and to a difference between pollen and chironomid results. On the whole, these comparisons of multi-model simulations with proxy reconstructions further confirm the Holocene climate evolution patterns in Fennoscandia, Greenland and North Canada. This implies that the Holocene temperatures in these regions have been relatively well established, with a reasonable representation of Holocene climate in the multiple simulations and a plausible explanation for the underlying mechanisms. However, the Holocene climate history and underlying mechanisms in the regions of Siberia and Alaska remain inconclusive. Variation partitioning revealed that climate was the main driver of vegetation dynamics in Fennoscandia during the Holocene as a whole and before the onset of farming. Forest fires and population size had relatively small contributions to vegetation change. However, the size of the human population became a more important driver of variation in vegetation composition than climate during the agricultural period, which can be estimated to have begun at 7–6 ka in Sweden and 4–3 ka in Finland. There is a clear region-dependent pattern of change caused by the human population: the impact of human activities on vegetation dynamics was notably higher in south Sweden and southwest Finland, where land use was more intensive, in comparison with central Sweden and southeast Finland. This thesis investigates the climate responses to the main forcings during the Holocene through various approaches, which has potential implications for the interactions between ice sheets and the climate, the Holocene climate history and current global change. The atmosphere-ocean system was sensitive to the FWF forcing during the early Holocene, implying that existing uncertainties in reconstructions of ice-sheet dynamics can be constrained by applying different freshwater scenarios via a comparison with proxy data. The Holocene climate history in most of the Northern Hemisphere extratropics is relatively well established, especially in regions that were strongly influenced by ice sheets. The implications of our investigation (on the transient early-Holocene) for the current global change are twofold. First, regional heterogeneity of the climate responses implies that regional differences should be taken into account when adapting to the current global change. Second, apart from the different scenarios of GHG forcing, inter-model comparison would be a good option to reduce model-dependency in estimation of the future climate.
  • Karhu, Sanna (Helsingin yliopisto, 2017)
    In this doctoral dissertation, I provide a systematic analysis of the role of social norms in the thought of philosopher and feminist theorist, Judith Butler. More specifically, I investigate the way in which Butler theorizes the relationship between norms and violence in light of her notions of critique and resistance. The key argument of the study is that in order to understand the wide range of topics that Butler addresses in her work—such as gender normalization, the critique of violence, ethical responsiveness, and the biopolitical regulation of life—we need to pay close attention to her account of norms. Although Butler’s theorization of norms has begun to attract increasing scholarly interest, a thorough analysis of the topic has not yet been written. In order to fill this gap in previous research, my dissertation offers the first monograph-length study that explicates the problematic of norms in Butler’s thought. My study seeks to answer the following questions: What is the role of norms in Butler’s work? How does Butler conceptualize the relationship between norms, violence, and nonviolence? How should we understand critique, transformation, and resistance in the midst of norms? What are the ethical and political implications of Butler’s notion of norms? I respond to these questions by examining Butler’s theorization of norms through what I call her twofold understanding of norms. I argue that on the one hand Butler theorizes norms as mechanisms of social power that violently regulate the field of recognizable subjects, bodies, and lives, but on the other hand she conceptualizes norms in terms of the possibility of critical change and resistance. I illustrate Butler’s twofold notion of norms through four key topics, which I have organized into four main chapters. First, by examining Butler’s often-neglected feminist theoretical background in the thought of Monique Wittig, I argue that her conception of the relationship between norms and violence critically builds on Wittig’s argument that normative heterosexuality can be understood as a form of discursive violence. Second, through explicating Butler’s conception of gender normalization vis-à-vis her generally overlooked discussions of transgender embodiment and livability, I challenge recent arguments that feminists should get rid of the concept of gender. By introducing the concept of “trans livability” I highlight Butler’s work as a contribution to trans-affirmative feminist theory. Third, by challenging the general tendency to interpret Butler as a critical humanist, I demonstrate that she puts forward a critique of anthropocentrism that offers insights into problematizing the speciesist norms that uphold not only the human-animal binary but also differentiates between livable and killable nonhuman animals. Finally, by foregrounding Butler’s psychoanalytic account of grief in terms of her critique of norms, I argue that her discussion of the normative separation between grievable and ungrievable lives does not represent a turn away from politics as many critics have argued. I contend that her account of grievability must instead be understood as a theorization of resistance. Taken together, all the four chapters of my dissertation highlight Butler’s theorization of norms as a practice of feminist critique. By elucidating the relationship between norms, violence, and social change, my study emphasizes the close relationship between feminist and queer practices of political resistance and the critique of norms.
  • Gilmore, Clifford (Helsingin yliopisto, 2017)
    Linear dynamics has been a rapidly evolving area of research since the late 1980s. Its central notion is known as hypercyclicity and many natural continuous linear operators turn out to be hypercyclic. This study is concerned with the hypercyclic and frequently hypercyclic properties of particular classes of operators. The first article of this thesis investigates the dynamics of commutator maps acting on separable Banach ideals of operators. Several necessary conditions are established which identify large classes of non-hypercyclic commutator maps. The main result proves that the commutator map induced by scalar multiples of the backward shift fails to be hypercyclic. In the second article concrete examples of hypercyclic generalised derivations acting on separable Banach ideals of operators are analysed and some necessary conditions for their hypercyclicity are identified. Conditions are also established under which the general class of elementary operators are never hypercyclic on certain Banach algebras. Notably, some curious hypercyclic behaviour is uncovered in relation to the remarkable Banach space constructed by Argyros and Haydon. The third article of this thesis solves a problem, originally posed by Blasco, Bonilla and Grosse-Erdmann (2010), on the minimal growth rates of harmonic functions that are frequently hypercyclic for the partial differentiation operators. This is done by explicitly constructing the frequently hypercyclic harmonic function.
  • Auhtola, Nea (Helsingin yliopisto, 2017)
    The aim of this doctoral thesis is to figure out how and why the caller and/or the call-taker digress from the common communicative task of an emergency call. The communicative task, which both parties engage in, is here also known as a quaestio, a text quaestion, which is to be answered through completed communicative actions. The total quaestio of an emergency call consists of two partial quaestiones: The caller provides information about the incident, whereas the call-taker asks questions to ascertain whether the appeal for help really requires resolution by the police. The materials analyzed consist of 132 German-speaking emergency calls to the national number of the German police, 110. The exact names of the emergency centres, as well as any personal names and toponyms, are anonymised in the transcribed excerpts. This study is grounded on the psycholinguistic quaestio theory. By reference to this theoretical foundation, every text, conversation and single contribution to a conversation rests on an explicit or implicit quaestio or guideline. In some cases, the participants don’t follow the socially agreed main quaestio but rather favour temporary digressive quaestiones. As a consequence, there emerge diverse subsidiary structures, which may bear a distinctive communicative relevance, since they comprise e.g. meaningful background information, personal opinions and other comments. This thesis examines the communicative functions of alternative questiones and differentiates between subsidiary structures which are initiated by the caller or the call-taker, respectively. In their subsidiary structures, callers usually provide additional information about the evidentiality of their perceptions or express their uncertainty. Call-takers in turn mainly inform the callers about the processing of the emergency call. The results of the study reveal that there do exist subsidiary structures aside from the main quaestio in the context of an emergency call. In this manner, the speakers are equipped with a simple medium to communicate essential facts about each emergency, although this further information doesn’t answer the main quaestio. The results of this thesis can be taken into consideration e.g. in the education of call-takers. Key words: quaestio, emergency call, emergency centre, police, subsidiary structure, German