Dissertations and theses


Digital dissertations and theses from the University of Helsinki. Contains both open access theses as well as metadata records.

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  • Mäenpää, Kalle (Alma Talent Oy, 2022)
    This study investigates the legal effects of contract negotiations under Finnish law. As a rule, contract negotiations are not binding. There is always a risk that negotiations are terminated before a binding contract has been concluded. Negotiating parties can incur considerable costs and losses during the negotiations. For example, it may be necessary to start preparing the contractual relationship even before the conclusion of the contract. However, if the negotiations are terminated before the conclusion of the contract, these efforts go to waste. Negotiations may also be terminated due to the reprehensible conduct of one of the negotiating parties. A party can also enter the negotiations with no real intention of reaching an agreement with the other party. In these situations, the party who has broken off the negotiations may be liable for the losses caused to the other party. The liability for broken negotiations has traditionally been referred to as culpa in contrahendo. Traditionally a contract has been seen to come into existence when the contracting parties have exchanged their expressions of will. However, it is generally accepted in legal praxis and in jurisprudence that the conclusion of contract based on expressions of will is not the only possible way to conclude contracts. In contract negotiations, the parties can also show their agreement merely by conduct. A contract is concluded in contract negotiations when the parties intend to be legally bound, and they reach a sufficient agreement. However, these criteria must be interpreted in a way that contractual obligations do not arise accidentally. In this study culpa in contrahendo is understood as an independent form of non-contractual liability. Liability is based on non-statutory norms that derive from established business practices. Compensation for so called pure property damage based on culpa in contrahendo does not require compliance with the special conditions of the Finnish Tort Liability Act. Culpa in contrahendo is a failure to exercise sufficient care in contract negotiations. In contract negotiations, the parties are required to negotiate in good faith with an intention to reach an agreement. Parties must provide each others with sufficient and correct information about their intentions of concluding the contract and the content of their contractual obligations. The other party should not be unduly pressured into concluding the agreement. Violation of these obligations during contract negotiations may give rise to an obligation on the party in breach to compensate the injured party. Compensation for culpa in contrahendo is measured by reliance interest, which is a form of standard compensation for participating in negotiations. Reliance interest covers the costs of contract negotiations and in some cases the loss caused by the lost opportunities to conclude contracts with third parties. Reliance interest is usually greater than the damage determined by causal relationship of the culpa and its effects, but less than expectation interest. However, the amount of compensation cannot be determined according to reliance interest in all situations. The method of determining damages according to the causal relationship between actions of the party in breach and the result may also be used in a situation where these two are in conflict. However, the legal effects of culpa in contrahendo are not, in principle, determined by expectation interest.
  • Piilo, Sanna (Helsingin yliopisto, 2022)
    The high-latitudes are warming at more than twice the rate of the global average. Warming and the consequent changes in hydrology affect peatland functioning, especially through changes in vegetation and carbon dynamics. The majority of the world’s peatlands are found in the Northern Hemisphere, forming a globally significant carbon storage and they are in constant interaction with the atmosphere through carbon uptake and release. The global importance of peatlands is widely recognised; however, the role played by high-latitude peatlands in changing climates is still unclear. It is not thoroughly understood how warmer future climates and hydrological changes will affect peatland vegetation and carbon processes. These uncertainties result from the complexity of peatlands and from the manifold future trajectories that are affected by different forcing factors from climate to local conditions. In this dissertation, I aim to increase our knowledge of high-latitude peatland vegetation and carbon dynamics under changing climatic conditions. My approach is palaeoecological, because I use peat records as an archive to reconstruct the response of high-latitude peatlands to known changes in climate. Peatlands function as important archives, since under anoxic and acidic conditions, peat-forming plant remains are well preserved. By identifying these plant remains, we can reconstruct past vegetation compositions. The various peat-forming plants have their own ecological niche, since they prefer and require specific hydrological or nutritional conditions and thus are good indicators for past hydrological changes and conditions. For this dissertation, I collected, in total, 47 peat records from eastern Canada, northern Sweden and Finland, the Kola Peninsula and the northeast of European Russia. I investigated how peatland habitats, carbon accumulation and cycling of our study sites have changed in response to changes in climate. For this, I used plant macrofossils, peat geochemical measurements and dating methods. In addition, I statistically inspected the change in vegetation compositions over time and used a model of carbon accumulation that considered peat decay aspects to determine whether carbon accumulation has been higher or lower than what we would otherwise predict, based on carbon accumulation models. My results show that during recent centuries, the vegetation compositions of the microhabitats examined have mostly changed from typical wet sedge fen vegetation to Sphagnum moss-dominated intermediate surfaces and dry moss- and dwarf shrub-dominated surfaces. During recent decades, these vegetation compositions have remained rather stable, with no major changes in vegetation. However, the spatiotemporal variation within and between the study sites was prominent, and thus to detect any large-scale signals from the data it was essential to use multiple samples and sampling points. Based on my data, it was plausible to consider that if high-latitude peatland vegetation changes from sedge fen vegetation to more hummocky vegetation types, high-latitude peatland carbon accumulation and sink capacity may remain significant or even increase. To better predict the role of peatlands under changing climates, it is crucial that peatland vegetation responses, carbon dynamics and their linkages with climate are more thoroughly understood. My data also support the prevailing understanding that peatlands are important carbon sinks and storages and thus preserving ecosystems that form a nature-based solution to the problem of mitigating the effects of climate warming is highly important.
  • Su, Peifeng (Helsingin yliopisto, 2022)
    Air pollution and climate change pose threats to human health and the environment. Gathering climatic and environmental data, such as visibility, temperature, relative humidity, and mass concentration of aerosol particles with diameter of 2.5 or 10 micrometers or less (PM2.5, PM10, respectively), is the first step in understanding the processes that contribute to air pollution and climate change. Ground-based in situ stations are sparsely and unevenly distributed, meaning that these stations cannot offer spatially seamless coverage for parameters. Satellite observations provide global coverage. Clouds, however, lead to missing values in some satellite products, like the land surface temperature (LST) datasets derived from thermal infrared bands. Finding a method that can automatically produce consistent identification results is essential since new particle formation (NPF), a significant source of atmospheric aerosols, is also tied to the environment and climate. By developing deep learning techniques and utilizing images that contain climatic and environmental information, this thesis seeks to answer three research questions about climate and the environment. The first study focuses on retrieving parameters from Red-Green-Blue (RGB) and hyperspectral images captured near the ground. The second study seeks to retrieve spatially seamless air temperature from satellite-derived LST products that contain missing values. The last research aims to automatically identify the new particle formation (NPF) events and obtain the related parameters such as growth rate, start time, and end time of each event. In summary, the main findings of this thesis are as follows. (1) A model was proposed to simultaneously retrieve a suite of parameters, including visibility, temperature, relative humidity, PM2.5, and PM10, from images captured near the ground. The proposed model achieves generally better retrieval results compared with three classic deep learning models. RGB images are more cost-efficient than hyperspectral images for retrieving parameters. Images with relatively lower spatial resolution can also be used for retrieval. Retrieving multiple parameters is not only possible for images captured at a fixed location but for images captured on a continental scale. (2) By leveraging a UNet model and an image-to-image training approach, it is possible to extract spatially seamless air temperature by filling the gaps in satellite-derived LST with a specified constant value. The retrieval results are with a higher spatial resolution and generally better retrieval accuracy compared with the fifth generation reanalysis for the global climate and weather (ERA5) of the European Center for Medium-Range Weather Forecasts (ECMWF). (3) Leveraging the typical features of image objects, instance segmentation methods such as Mask R-CNN can be applied to detect NPF events from aerosol number size distribution datasets. Other derivatives, such as growth rates, start times, and end times, can also be determined automatically. The proposed method improves the automatic level for analyzing the NPF events and obtains consistent results for NPF datasets collected in different sites.
  • Miettinen, Teemu (Helsingin yliopisto, 2022)
    The validity of pain intensity as the primary measure in chronic pain treatment has been questioned. It may be important to look at other pain-related factors as well, such as how widespread the pain is or how it interferes with different life activities. These pain-related factors may combine into different pain phenotypes. Understanding how these pain phenotypes associate with, for example, lifestyle and psychological factors may help in targeting treatment better. The aim of this dissertation was to examine pain phenotypes of patients entering tertiary pain care and the features or problems that are associated with them. More specifically, the aims were: · to investigate pain phenotypes with respect to different levels of pain interference and factors associated with them; · to use a data-driven approach to elucidate patient subgroups with different pain phenotypes and investigate factors associated with these, using machine learning methods from a multifactorial set of data; · to elucidate metabolomic markers associated with more severe pain phenotypes by investigating metabolomic markers and pathways with respect to the pain phenotypes found in the previous study, and to two common comorbidities of severe pain, obesity and recurring sleep problems; and · to examine how patients with recurring sleep problems differ from those who sleep normally in the areas of pain and pain-related anxiety, childhood adversities experienced, use of sleep and pain medications, self-reported diseases, and sleep disorders. This was a cross-sectional study. The study data were collected at six pain clinics (three multidisciplinary and three facial pain clinics) in Finland. The whole cohort comprised 473 patients from whom broad data were collected, including sociodemographic factors, previous treatments, comorbidities, lifestyle variables, psychological factors, and others. At multidisciplinary pain clinics with 320 participants, nurses also measured patients’ weight, height, waist circumference, and blood pressure; blood samples were taken for the analysis of metabolomics data. Pain phenotypes combined with levels of pain interference showed adverse changes in different sets of factors when pain interfered highly with either the “activity” or the “affective” dimension. High activity pain interference was associated with reduced exercising, higher body mass index, and higher avoidance of pain, than where both interference dimensions remained low. High affective pain interference was associated with more depression, greater cognitive anxiety, and lower activity engagement when pain was present. When both interference dimensions were high, the previous adverse changes accumulated, smoking was more prevalent, and pain-related anxiety was more pronounced, with fear of pain and physiological anxiety reactions higher than with other pain phenotypes. Data-driven subgrouping of patients resulted in three groups. The groups at the extremes showed pain phenotypes with low pain intensity and pain interference at one end, and combination of high pain intensity, high pain interference and the greatest number of pain sites at the other. In the machine learning analysis, the most informative variables among pain-related factors predicting group membership were affective pain interference and number of pain sites. Of the other factors, sleep problems was the most informative, followed by fear of pain, poorer self-rated health, and lower systolic blood pressure. When metabolomic factors were investigated in relation to pain phenotypes elucidated in the previous data-driven study (least severe pain phenotype in contrast to the two more severe phenotypes combined), obesity, and sleep problems, three metabolomic markers (NAD, AMP, and cysteine) emerged across analyses. Obesity showed association with alterations in amino acid metabolism. Sleep problems were associated with several markers relating to methionine metabolism, which results suggested was downregulated in recurring sleep problems. Patients with recurring sleep problems showed more pain-related anxiety than those sleeping normally, and results suggested physiological anxiety reactions as significant factors for greater difficulties with sleep. Multiple health conditions (for example, asthma and depression) were more prevalent among those with recurring sleep problems. Those with sleep problems reported significantly more restless legs symptoms than those sleeping normally. Having five or more childhood adversities was associated with recurring sleep problems. Finally, the reported use of pain and sleep medications was higher in those with recurring sleep problems than in those who slept normally. To conclude, patient subgroups with varying pain phenotypes were discovered in the studies. Previous studies have highlighted the role of psychosocial factors in those with the most severe pain phenotypes. The results of these studies suggest the importance of sleep and lifestyle-related factors as well. Research into metabolomics may give new insights to why pain becomes more severe for some. Sleep is affected by multiple factors, not only pain, in patients with chronic pain.
  • Uusitalo, Laura (Helsingin yliopisto, 2022)
    This thesis discusses how Bayesian networks can be used to improve data analytics in the field of environmental assessment and management. The data-analytic challenge is that ecosystems are complex and potentially changing, while the available data are relatively sparse both in terms of the number of observations and in which ecosystem components they cover. This thesis takes steps towards better analysis of these sparse data through combining pre-existing, uncertain information such as modelling results and expert knowledge with modern, probabilistic data analysis. The first theme of the thesis is how variable discretization in Bayesian network classifiers, particularly tree-augmented Naïve Bayes, can help understand the relationships between environmental factors at different levels. This work explores different discretizations of the class variable and discusses the implications of the differences between the resulting models, and contributes to the still relatively quiet discussion about discretization schemes in Bayesian networks. The second theme is detecting change in the ecological processes based on the sparse, often noisy data. This thesis builds dynamic Bayesian network models to detect change in the Central Baltic Sea ecosystem interactions, and explores the effect of different model structures in detecting the ecosystem change. It is shown that the hidden variables of the models can identify ecosystem change, and that this result does not depend on the exact model structure or hidden variable set-up. The third theme is decision support models that aim to integrate information regarding all interlinked aspects of the decision problem such as different parts of the ecosystems as well as economic and societal considerations. To be useful, decision support models need to be able to provide estimates of uncertainty of the different assessments and projections. This thesis reviews and evaluates various uncertainty assessment methods. Further, this thesis builds a large probabilistic meta-model to demonstrate how a Bayesian network based decision support model can be used to summarise a large body of research and model projections about potential management alternatives and climate scenarios Bayesian networks are showing their strength for different tasks of environmental data analytics. Elegant handling of missing data, explicit and rigorous handling of uncertainty, and the possibility to use prior scientific knowledge and data together in analyses in a transparent way are strong advantages for Bayesian analysis for environmental data that often contain missing values and are scarce. In addition to being flexible and, thus, able to integrate different types of information and data, they are transparent, allowing critical assessment and discussion of the models. This is important as environmental data analytics are often used to support decision making on the use of ecosystems, affecting the lives of current and future generations.
  • Seppänen, Sirke (Helsingin yliopisto, 2022)
    Improvisation is commonly understood as a performance or creating something without preparation. As an art form, improvised theatrical plays are created spontaneously on stage without a script. As an applied form of theatre, improvisation has been utilised in fields requiring collaboration and a tolerance for uncertainty, such as in the business and education sectors. This dissertation contributes to the literature in educational research by investigating applied improvisation as a tool to promote student teachers’ interpersonal competence. Applied improvisation enables individuals to explore and practise teaching-related encounters in a fictional and psychologically safe context. Psychological safety is particularly important when practising challenging interactions. Despite the fictionality of the context, bodily experiences during improvisations may promote experiential learning. The research summarised in this dissertation was guided by two primary research questions. First, I asked whether improvisation training influenced student teachers’ interpersonal competence and social stress. Student teachers (n = 19) participated in a 7-week (17.5-h) improvisation intervention, comprising the fundamentals of theatre improvisation and status expression (verbal and nonverbal behaviours indicating the social dominance of a person). The impact of the intervention was measured using subjective self-reports (interpersonal confidence, i.e., belief regarding one’s capability related to effective social interactions, self-esteem and experienced stress) and a large array of physiological measurements (heart rate, heart rate variability, skin conductance, facial muscle activity, frontal electroencephalogram (EEG) alpha asymmetry and stress hormone cortisol). Self-reports, physiological measurements and Trier Social Stress Tests (TSST; including public speaking) were performed before and after the improvisation intervention. An improvisation course was arranged for the control group (n = 20) following the intervention study. One year later, the long-term effects of improvisation training on self-reported interpersonal confidence were measured in a follow-up study. Second, I asked how real versus fictional social rejections impact experienced stress and psychophysiological responses. Student teachers (n = 39) participated in an experiment including both real (interview) and fictional (improvisation exercises) dyadic interactions. In the real condition, student teachers were unaware that the interviewer was an actor trained to include subtle social rejections during the interview by using three types of social rejections: devaluing, interrupting and nonverbal rejections. In the fictional condition, student teachers were informed in advance which social rejection type would be used during a later improvisation exercise. Experienced stress and psychophysiological reactivity during social rejections were measured under both experimental conditions. Following an improvisation intervention, interpersonal confidence and its components of performance confidence and a tolerance for failure increased relative to controls, whilst one year later the improved performance confidence persisted. Furthermore, a heterogeneous treatment effect was found. Those with the lowest pretest interpersonal confidence score benefited most from the improvisation intervention. No between-group differences in self-esteem were observed. Psychological and physiological indications of relief from performance-related stress were also observed following improvisation training. In addition, interpersonal confidence moderated self-reported and cardiovascular stress responses. Thus, interpersonal confidence may be worth controlling for in future research which examines the effects of interventions aimed at relieving social stress. The results also support the notion that repetition may also diminish performance-related stress, since the control group exhibited decreases in cardiovascular stress during some of the test conditions. The primary finding regarding the second research question emerged through the absence of any systematic attenuation of the psychophysiological reactivity to fictional versus real-world social rejections. In other words, although student teachers knew that improvised social rejections were fictional, their psychophysiological responses during improvisation remained relatively similar and associated with those of real-world rejections. It appears as though personal relevance and engagement during improvisation explain the relatively similar bodily responses. This result suggests that interpersonal encounters can be realistically modelled through applied improvisation. In this dissertation research, I also produced a validated self-report measure, the Interpersonal Confidence Questionnaire (ICQ), to evaluate the impact of social interaction training relying on applied improvisation. Using an additional dataset (n = 208), I validated the questionnaire and examined the impact of improvisation training on a larger sample. A confirmatory factor analysis identified six factors—performance confidence, flexibility, listening skills, a tolerance for failure, collaboration motivation and presence—that contribute to interpersonal confidence. Thus, the ICQ appeared valid and reliable as a self-report measure of interpersonal confidence. In summary, the findings from this research indicate that a relatively brief improvisation intervention promotes interpersonal confidence, specifically amongst those with low interpersonal confidence. Furthermore, improvisation training serves as an intervention against performance anxiety and generates long-term improvements to performance confidence. This dissertation provides a theoretical framework and empirical support for the application of improvisation as a tool to develop interpersonal competence skills, particularly within professions requiring face-to-face interactions. Regardless of the fictionality of the improvisational context, genuine emotions and experiences may emerge, serving as experiential learning experiences. The significance of these findings may extend to theatre-based practices and drama education in general, which rely on holistic action and personal engagement in fictional contexts. The findings agree with previous research, suggesting that including the improvisation method in teacher education curricula can enhance student teachers’ interpersonal competence as well as their skills related to sensitive and responsive teaching. Finally, this dissertation contributes to social neuroscience by recommending an ecologically valid experimental design wherein naturally unfolding social interactions can be achieved using improvisation techniques. Keywords: experiential learning, fictionality, improvisation, interpersonal confidence, intervention, psychophysiology, social interaction, social rejection, social stress, teacher education, theatre-based practices
  • Mönkäre, Saana (Helsingin yliopisto, 2022)
    Dementia disorders are a major health challenge as the life expectancy of the population increases. Vascular cognitive impairment (VCI) is the second most common cause of dementia after Alzheimer's disease, based on clinical studies. Several different vascular changes can cause VCI, and genetic factors underlying the pathogenesis of VCI are largely unknown. The aim of this study was to examine the genetic background of VCI in Finnish patients and to investigate the genetic and clinical spectrum of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in Finland. The study subjects of the first and second studies included a total of 80 patients with VCI. Whole-exome sequencing (WES) was performed in both studies, and copy-number variant (CNV) analysis using SNP-array was performed on all samples in the second study. The studies revealed that in addition to NOTCH3 variants, variants in COL4A1, COL4A2, HTRA1 and TREX1 are also found in Finnish patients with VCI. Interestingly, the studies also identified several variants in genes linked to neurodegenerative disorders indicating that cerebrovascular pathology may be associated with neurodegeneration in the pathogenesis of VCI. The study showed WES to be useful in diagnosing patients with suspected inherited VCI. The third study showed a duplication in chromosome 13 including COL4A1 and COL4A2 genes in a Finnish family with an autosomal dominantly inherited small vessel disease. The study described the clinical features of the disease, and droplet digital PCR (ddPCR) showed that the duplication caused an upregulation of COL4A1 and COL4A2. The fourth study retrospectively examined the spectrum of NOTCH3 variants and clinical features in Finnish CADASIL patients (n=294). The study showed that in addition to the most common NOTCH3 variants (p.Arg133Cys and p.Tyr1069Cys) several other less common NOTCH3 variants were detected in Finnish CADASIL patients and were often associated with severe clinical features. In conclusion, this is the first study revealing the genetic and clinical spectrum of VCI and CADASIL in the Finnish population. In addition, this study revealed novel insights into the molecular basis of VCI. This thesis highlights the power of advanced sequencing technologies in identifying causal genetic variants, and provides tools for diagnostics and genetic counseling of patients with VCI.
  • Wasiljeff, Joonas (Helsingin yliopisto, 2022)
    This thesis investigates the aridification of Asian continental interiors and the underlying mechanisms affecting aridity during the Eocene-Oligocene Transition and during the Oligocene. The Eocene-Oligocene Transition, at circa 34 Ma, is widely considered to have been the most dramatic climatic shift of the past 50 million years. In the context of Asian continental environments, the Eocene-Oligocene Transition was associated with increased seasonality, dramatic cooling, turnovers in biota, and drying of the environment. The causal mechanism for environmental cooling is likely linked to geographical reorganization of continents and oceanic currents, decline in atmospheric CO2 and permanent glaciation in Antarctica. On the other hand, Oligocene climate was possibly regulated by recurring glacial-interglacial episodes in response to astronomical forcing and changing summer insolation, inducing variations in sea level, atmospheric and oceanic circulation, concentration of CO2, and temperature. However, responses of Asian terrestrial environments to Oligocene climate dynamics have remained poorly constrained. In this dissertation, lithostratigraphical and sedimentological characteristics, depositional environments as well as paleoprecipitation and weathering regimes were determined in the region of Ulantatal, situated in Inner Mongolia of China. In addition, a high-resolution temporal framework was established for the Ulantatal sediments using magnetostratigraphy in conjunction with biostratigraphical correlation. Ulantatal also hosts profuse micromammalian faunas which had previously lacked a proper temporal framework. It has now proven possible to calibrate these faunas with contemporaneous Mongolian Valley of Lakes mammal paleocommunities, where the ages are constrained by a combination of radiometric dating and magnetostratigraphy. Using the calibrated mammalian faunas in Ulantatal to anchor the magnetostratigraphy, it was possible to infer an age of around 35 to 27 Ma for the Ulantatal deposits. Sedimentological investigations revealed that the sediments have a massive structure with a bimodal grain size distribution which, together with their geochemical and mineralogical compositions, suggests that bulk of the sediments in Ulantatal are eolian in origin. In contrast, the oldest, latest Eocene beds display hydraulic structures typical of floodplain deposits. Modelling of past rainfall based on bulk sediment geochemistry, mineral magnetic properties and the mammal fossil triple oxygen isotope compositions suggested that the region around Ulantatal was in a stable semi-arid state from the latest Eocene until around 31 Ma in late Oligocene time. In contrast to some other contemporaneous records in the vicinity of the Tibetan Plateau, no dramatic shifts in the proxy records were observed across the Eocene-Oligocene Transition. Instead, the proxy records remained unchanged. However, it is typical for the terrestrial realm to respond in a heterogeneous way to global climatic forcings and may be overprinted by local or regional factors. The Late Oligocene after 31 Ma, on the other hand, is marked by increased shifts in precipitation and weathering intensity. This increased instability may reflect an intensified Asian monsoon system. Uplift of the Tibetan Plateau, changes in atmospheric CO2, retreat of the Paratethys Sea and subsequent influences on land-sea thermal contrasts, and/or changes in the Intertropical Convergence Zone have likely affected the onset and intensification of the monsoon system.
  • Kalalahti, Inari (Helsingin yliopisto, 2022)
    Background: Prostate cancer (PC) is the leading cause of cancer incidence among men in Western countries. Following the introduction of the prostate-specific antigen (PSA) laboratory test in the 1990s, the incidence of PC increased sharply. PC is primarily diagnosed through a prostate biopsy (PB), a generally safe procedure. However, PB can be associated with complications, such as infection, bleeding and pain. Infection, the most feared complication, can vary from a lower urinary tract infection (UTI) to febrile sepsis and even death. Known risk factors for postbiopsy infections are rectal fluoroquinolone-resistant bacteria, travelling to areas with high antimicrobial resistance (AMR) and the recent use of antibiotics. A concerning fact is that biopsy-related infections and hospitalisation are increasing at the global level. This is due to increasing levels of AMR to fluoroquinolones, the most commonly used antibiotic prophylaxis in transrectal PB. Increasing levels of AMR have been associated with ciprofloxacin (CIP), an antibiotic agent in the fluoroquinolones class. Today, most PCs are detected at an early stage when active treatment is not yet indicated. The recommended treatment in such cases is active surveillance (AS). In AS, patients are monitored regularly through PSA tests and repeat PBs. Most AS protocols rely heavily on repeat biopsies to detect cancer progression and patients undergo several biopsies during AS. PB is an extremely frequent procedure, whereby more than 1 million biopsies are performed annually in Europe and the United States. With each biopsy, however, the man is at risk of complications. In this thesis, I examine the risk factors for postbiopsy complications and how complications can be reduced. I also investigate how to safely reduce the number of biopsies needed and, thereby, reduce biopsy-related complications in men undergoing AS for PC. Study I: In AS for PC, men undergo repeat PBs to detect possible disease progression. A previous complication can lead to a reluctance to adhere to the recommended biopsy schedule. It has also been suggested that serial biopsies in AS serve as an independent risk factor for infection. In this study, we investigated the risk factors for biopsy-related complications and examine how a previous complication affected subsequent surveillance. Study II: The major risk factor for a postbiopsy infection is the presence of rectal fluoroquinolone-resistant E. coli. However, an infection can be caused by fluoroquinolone-sensitive bacteria. In study II, we investigated how postbiopsy infections are associated with AMR E. coli, specifically resistance to CIP, in the rectal flora of men undergoing PB. Bacterial isolates in rectal swabs were analysed and compared with infections occurring after a biopsy. Study III: Many different AS protocols exist, although little evidence supports one over another. Frequent follow-up predisposes men to biopsy complications. By contrast, infrequent follow-up risks missing cancer progression in some men. In study III, we compared the outcomes of two different surveillance cohorts: 1) the European Randomised Study of Screening for Prostate Cancer (ERSPC) cohort and 2) the Prostate Cancer Research International: Active Surveillance (PRIAS) cohort. The outcomes of these cohorts were compared based on overall survival (OS), prostate cancer-specific survival (CSS), metastasis-free survival (MFS) and treatment-free survival (TFS). Study IV: Magnetic resonance imaging–targeted biopsy (MRI-TB) has improved the detection of clinically significant PC. In MRI-TB, fewer biopsy cores are taken compared with a systematic biopsy (SB). Although some studies have examined infectious complications associated with MRI-TB, no larger studies have been published to date. In study IV, we investigated the rate of infections following MRI-TB compared with SB in a retrospective analysis. Main results and conclusions: Study I: We found no evidence that repeat biopsies in AS served as an independent risk factor for postbiopsy infections. However, complications following biopsy were common, whereby one in five men reported a complication. Men experiencing a complication were less likely to participate in further biopsies as indicated by the AS protocol. Thus, unnecessary biopsies should be avoided during AS to increase compliance with the surveillance protocol and in order to minimise biopsy-related complications. Study II: Rectal E. coli with a moderately lower sensitivity to CIP (e.g., non-wild-type isolates) were associated with postbiopsy infections. The presence of these bacteria increased the risk of a postbiopsy infection. The non-wild-type isolates possess resistance mechanisms rendering them less susceptible to antibiotics, although they are not yet classified as resistant according to the commonly used susceptibility breakpoints. To prevent infection with these isolates, a longer course of prophylaxis or a different antibiotic agent may be needed. The findings in this study explain why many seemingly sensitive E. coli can cause an infection despite administering an appropriate prophylaxis. Study III: The surveillance protocol with frequent biopsies did not improve outcomes in patients with low-risk PC during follow-up. Here, we observed no difference between cohorts for any of the survival endpoints. Recurrent PB predisposes men to biopsy-related complications. To minimise the risk of infection and increase adherence to AS protocols in the long term, follow-up relying on less frequent biopsies should be promoted particularly during the early follow-up period. Study IV: Infectious complications were more common after SB compared with MRI-TB. We found no difference in severe infections, which was expected, since the study lacked the statistical power to show a difference given the low rate of septic infections occurring at our centre. The risk of UTIs, however, increased when additional biopsy cores were taken. All steps need to be taken to reduce the risk of a postbiopsy infection and MRI-TB serves as an additional tool to achieve this.
  • De Martino, Gianluca (Helsingin yliopisto, 2022)
    The subject of this work is the cult of goddess Hera in the Greek colony of Poseidonia, in Southern Italy. The work focuses on the process through which the local Italic Lucanians preserved and continued the cult after they had taken control of the city from the Greeks sometime between 420 and 410 BCE. Archaeological material, such as votive clay figurines, and the topographical and architectural features of several cultic places were employed as the primary data sources. By combining evidence from the iconographic typologies of the clay figurines and the topography and the architecture of both Greek and Lucanian sanctuaries, this work postulates that the absorption and the reshaping of the cult of Hera was a natural process for the Lucanians, since they had long had deities who shared the same attributes as Hera in their own religion. Scholars have studied the cult of Hera in Poseidonia almost exclusively as a Greek phenomenon. The Lucanians have been considered only as adopters of the cult following a unidirectional Hellenisation process. Older research has dismissed or underestimated the influence of the Lucanians on the cult and their decisive role in preserving it until the Roman Imperial period. If one dismisses a sort of pervasive Hellenisation as the reason behind the appropriation of the cult by the Lucanians, then the causes may lay in the nature of Poseidoniate Hera herself, and in specific features of the Lucanian religion. The Hera of Poseidonia had her roots in that particular Hera worshipped in the Argolid in mainland Greece. This Argive Hera had pre-Homeric features, according to which she was the patron goddess of vegetation and fertility, with a strong chthonic character. The Achaean cities of Magna Graecia, including Poseidonia, held Hera as one of their main deities. Archaeological evidence suggests that her cult in Poseidonia continued and thrived when the Lucanians, a non-Greek population, came into control of the city. In fact, most of the votive gifts dedicated to Hera in Poseidonia are dated to the Lucanian period. The Greeks and the Lucanians created a multicultural society, which was reflected by their shared religious worship of the goddess. This process was facilitated by the fact that several Lucanian female deities, and particularly Mefitis, the main goddess of Lucanian religion, shared similar attributes with Poseidoniate Hera. Comparing the votive figurines recovered from Paestan sanctuaries dedicated to Hera and the topographical features of her sanctuaries to the main features of Lucanian cultic places, and to the iconography of votive gifts dedicated in Lucanian sanctuaries, this research suggests that widely shared religious similarities enabled the continuation of the cult of Hera in Poseidonia/Paestum. In addition, by taking into consideration Lucanian religion and the architectonic and topographic planning of its shrines, it is possible to suggest possible solutions to several problematic issues related to the cult of Hera in the Lucanian period, such as the changes in the iconography of the goddess in votive figurines, and certain architectonic features introduced in the Lucanian period that are reminiscent of Lucanian construction practices. Concerning ritual practices, the increase in common ritual dining was the result of the arrival of chthonic cults in Lucanian Paestum, or at least the addition of chthonic aspects typical of the agrarian and chthonic cults of the Lucanian inland to existing Greek cults. This was true for the cult of Hera as well. The archaeological evidence suggests the arrival of Lucanian rural chthonic religious practices connected with common ritual dining in the form of bone finds related to chthonic cults (dogs, cockerels), the development of peculiar forms of incense burners, and the presence of sacrificial pits and water channels associated with altars. The cult of Hera thrived throughout the Greek and Lucanian periods until the foundation of the Roman colony of Paestum in 273 BCE, when it was incorporated into the cult of the Capitoline Triad and gradually lost its primacy to cults favoured by the new Roman colonists.
  • Wikström, Valtteri (Helsingin yliopisto, 2022)
    Interpersonal communication depends on a variety of signals, which humans have evolved to observe and understand in face-to-face interaction. Direct social perception and primary intersubjectivity refer to the ability to process non-verbal signals about the mental states of other people quickly and automatically, as a way to sort of co-experience them. Mediated communication is often necessary and even preferred due to different reasons, such as distance, time, or the use of technological tools, but currently there is no match for physical presence when it comes to engaging the mechanisms of primary intersubjectivity for understanding emotion and intent. This thesis is about the development of digital tools for improving collaboration in synchronous computer-mediated communication. While exploring multimodal technologies for communication, a lack of quantifiable measures for assessing the effects of prototypes on cooperation was identified. To this end, collaborative performance tasks were developed for a series of studies and used in order to investigate cooperation in computer-mediated interaction. In Study I, a joint coordination task in the form of a collaborative car racing game was used to study inter-brain synchronization without physical presence. The study revealed that EEG synchonization happens in the online gaming context. EEG synchronization was connected to task performance both momentarily, with higher gamma synchrony occurring during better performance, and pairwise, with higher overall alpha synchrony among high-performing pairs. Study II details the development and testing of a collaborative block design task, which was created to assess pair performance in social virtual reality (VR). The task can also be replicated in face-to-face interaction, making it possible to compare effects in these two domains. Individual visuospatial intelligence was identified as a factor that needs to be controlled when using the collaborative block design task. In Study III, a mouse controlled visual guidance task was developed to study the application of heart rate sharing in online chat box customer service. Combining quantitative and qualitative data, the study revealed that biosignal sharing might not be an optimal strategy for supporting cooperation and presence in customer service text chat. Taken together, the results suggest that both cooperative task performance and inter-brain synchronization can be meaningful measures in the development of synchronous computer-mediated communication. A final task, SynchroMouse is presented as a possible activity for increasing inter-brain and interpersonal synchronization online.
  • Dufva, Olli (Helsingin yliopisto, 2022)
    Cancer immunotherapy, or activating immunity against malignant cells, is a promising treatment option in hematological malignancies. More effective immunotherapies could be applied with higher precision if we better understood how immune properties depend on the cancer type and genetic makeup of the cancer cells, which mechanisms determine whether a cancer cell is eliminated by immune cells, and how to pharmacologically exploit such mechanisms. Functional genomics provides tools such as gene expression profiling and genetic perturbation screens to study immunological processes in cancer. This work aimed to discover connections between the immune properties and molecular subtypes of blood cancers (study I), the genetic basis and drug sensitivity profile of aggressive natural killer (NK) cell leukemia (study II), resistance mechanisms of lymphocyte cytotoxicity (studies III and IV), and combination treatments with chimeric antigen receptor (CAR) T cell therapy (study IV) using functional genomics and high-throughput drug screening. Genomic data from over 10,000 blood cancer patients revealed genetic determinants of immune infiltration such as a myelodysplastic syndrome-like subtype in acute myeloid leukemia (AML), regulation of antigen presentation by DNA methylation, and immune features typical for certain cancer types, such as the inhibitory immune regulator VISTA in myeloid malignancies and cancer-germline antigens in multiple myeloma. By exposing blood cancer cells to NK cells, we found differences in NK cell activation responses and sensitivity to NK cells depending on the cancer type, with AML being more susceptible than B cell acute lymphoblastic leukemia. Genome-scale CRISPR screens revealed cancer cell-intrinsic regulators of sensitivity to NK cells, explaining observed differences in sensitivity and highlighting new regulators such as adhesion molecules SPN, SELPLG, and CD44 and transcriptional regulators MYB, YTHDF2, and CMIP. Out of over 500 oncology drugs, a class of drugs known as SMAC mimetics sensitized leukemia cells to killing by CAR T cells. Somatic mutations in STAT3, DDX3X, RAS-MAPK genes and several epigenetic modifiers constituted the genetic basis of aggressive NK cell leukemia. JAK and BCL2 family inhibitors emerged as potential therapies in NK cell malignancies. The findings suggest that considering molecular subtypes of cancer may be useful in the search for optimal immunotherapies, and provide leads on genetic mechanisms and drugs that could facilitate development of new precision medicine and immunotherapy approaches in hematological malignancies.
  • Ruotsalainen, Sanni (Helsingin yliopisto, 2022)
    Coronary artery disease (CAD) is the most common of the cardiovascular diseases and the leading cause of premature death and disability worldwide, with both environmental and genetic factors impacting on individual’s risk of developing CAD. Aim of this thesis is to improve understanding of the genetic background of CAD and its risk factors as well as improve the risk estimation for CAD 1) by developing statistical methods and tools used in multivariate genetic analysis of biomarkers, 2) by expanding the traditionally used biomarker set for coronary artery disease, 3) by studying an isolated population to identify high-impact variants either very rare or absent in other populations and 4) by identifying individuals in high- risk for CAD using both traditional and genetic risk factors. We enabled further investigation of known association between CAD and KIV2-CN, a copy number repeat in LPA with known causal effect on CAD in larger sample sizes without costly sequencing. This was done by developing an imputation method to estimate KIV2-CN using information on the genetic variants in close proximity. We additionally developed multivariate methods used in genetic studies to enable essential follow-up analysis tools also for multivariate GWAS. We both improved the detection of genetic associations for the correlated inflammatory biomarkers and enabled fine-mapping of the observed associations. In addition, by extending our research outside of the traditional CAD biomarkers with Lp(a) and inflammation we gained relevant information on genetic determinants of Lp(a) and their impact on CAD risk, as well as potential novel shared genetic link between inflammation and venous thromboembolism. In a large Finnish biobank study, we identified a highly Finnish-enriched variant in MFGE8 gene to associate with CAD. Interestingly, this variant was not associated with traditional risk factors for CAD, such as blood lipids, but instead, our results are in line with previous literature on MFGE8 and inflammatory aging process of the arteries. Lastly, we estimated and communicated risk for CAD using both traditional risk factors for CAD as well as by combining information on traditional risk factors and genetic risk information. We saw that knowledge of one’s risk for CAD did have impact on health behaviour that reflected as improved risk factor profile, both genetic and traditional risk having independent effect on the behaviour change. Findings in this thesis show how we can gain important knowledge on the genetic background of coronary artery disease and its risk factors by methodological advances, by expanding biomarkers analyzed as well as by investigating isolated populations with enrichment of rare high-impact variants. This knowledge can further be applied to other common, complex diseases.
  • Heiskanen, Laura (Helsingin yliopisto, 2022)
    Nuorten rikollisuudessa on havaittu viime aikoina muutoksia, jotka ovat herättäneet keskustelua nuorten väkivallan vakavuudesta. Koska sosioekonomisesti huono-osaisten nuorten rikollisuuden on todettu olevan kasvussa, on syytä pohtia, onko näillä asioilla yhteyttä. Monet kriminologiset teoriat pyrkivät selittämään rikollisuutta ja sen riskitekijöitä keskittymättä tarkemmin väkivaltatekojen vakavuuteen. Tässä tutkielmassa tarkastellaan väkivallan vakavuutta ja siihen liittyviä lapsuuden riskitekijöitä kriminologisen teoriakehyksen ja tutkimuskirjallisuudessa käydyn keskustelun pohjalta. Tutkielmassa tarkasteltiin laajan rekisteriaineistosta poimitun otoksen (n = 733 571) avulla 15–20-vuotiaiden nuorten väkivaltarikollisuutta ja lapsuuden huono-osaisuuden yhteyttä väkivaltatekojen vakavuuteen ja toistuvuuteen. Tutkimuksessa lapsuuden huono-osaisuuden mittareina käytettiin sijoittamista kodin ulkopuolelle, vanhempien väkivaltarikollisuutta, perheen saamaa toimeentulotukea ja vanhempien matalaa koulutusta. Analyysimenetelmänä käytettiin multinomiaalista logistista regressioanalyysia ja tuloksia tarkasteltiin myös ennustettujen todennäköisyyksien avulla absoluuttisten erojen selvittämiseksi. Väkivallan vakavuuden ja tekojen toistuvuuden perusteella muodostettujen ryhmien tarkastelu osoittaa, että vakavan väkivallan sekä toistuvan lievän väkivallan ryhmät ovat keskenään hyvin samankaltaisia. Vain pieni osa nuorista on epäiltynä vakavasta väkivaltarikoksesta tai monista lievistä väkivaltateoista. Näissä ryhmissä tehdään kuitenkin henkilömäärään suhteutettuna kaikkein eniten kaikkia rikoksia, eli ryhmät kuvaavat hyvin rikosaktiivista osaa nuorista. Tutkimustulosten perusteella kaikki mitatut huono-osaisuuden muodot lisäävät riskiä tehdä vakavaa tai toistuvaa väkivaltaa. Vakavasta väkivallasta sekä useista lievistä väkivaltateoista epäillyt nuoret näyttäytyvät erityisen huono-osaisina. Vaikka lapsuuden huono-osaisuus lisääkin väkivallan riskiä suuresti verrattaessa niihin, joilla näitä kokemuksia ei ole, todellisuudessa riski syyllistyä vakavaan väkivaltarikokseen on erittäin pieni myös huono-osaisen lapsuuden kokeneiden nuorten keskuudessa. Tutkimuksen perusteella kriminologinen teoriakehys on hyödyllinen myös väkivallan vakavuuden ja vakaviin tekoihin liittyvien riskitekijöiden tarkastelussa. Rikoksentorjunnan kannalta tutkimuksen relevanssi on auttaa tunnistamaan niitä lapsia, jotka tulevat todennäköisemmin tekemään nuoruudessaan eniten väkivaltaa tai vakavimpia väkivaltatekoja. Tutkimuksen tulosten perusteella näyttää siltä, että huono-osaisuutta lapsuudessaan kokeneet ovat suuremmassa riskissä tehdä väkivaltarikoksia nuoruutensa aikana kuin ne nuoret, joilla tällaisia riskitekijöitä ei ole.
  • Valtonen, Virpi (Helsingin yliopisto, 2022)
    The decline of biodiversity, endangered animals and climate change have brought animals into studies of different scientific fields and discussions in the media in a new way. The ongoing eco-crisis also requires a critical examination of the idea of education, which is traditionally limited to interaction between humans. In many places, anthropocentric or human-centered thinking still pervades curricula at different school levels and Finnish educational practices in general. In my theoretical-methodological dissertation research, I argue that, at the latest, it is now time to start thinking critically about what kinds of ways of knowing, being and doing guide our relationships with animals in the context of education and learning, and what means could be used to achieve broader understanding and acceptance of the multispecies world relationship. In this research, I present the theoretical, methodological, and pedagogical contributions of multispecies education. Broadly speaking, the question is about the relationships between humans and other animals and their place in society, education, and learning. In this research are interwoven less traditional ways of knowing, theories of affect and perspectives of human–animal studies. The perspectives are examined through a posthumanist perception of humans and the world and are delivered through storytelling about relations and relativity with other animals. The dissertation is divided into three parts and each part answers the following research questions, respectively. Research question 1. What kind of turns and developmental phases in different fields of science and research have begun to make the necessity of multispecies education visible? In the first part of the research, I will present the twists and turns in science that serve as justification for the necessity of multispecies education. The justifications can be found in the framework of posthumanist thinking, the changes in knowledge and attitudes related to other animals, and the recognition of affects in our human–animal relationships. Research question 2. How can forms of multispecies education be studied? In the second part of the research, I position my research in a post-qualitative research orientation and present a methodological approach to support the implementation of multispecies pedagogy. I am introducing a method of storytelling that I have termed rag-rug storytelling. It can be used to critically examine multispecies relationships and find action-oriented and invisible worlds of phenomena. Research question 3. What kind of conceptual framework and pedagogy does multispecies education require? In the third part of the research, I build a conceptual and pedagogical framework for multispecies education. A conceptual change is needed as a premise for multispecies education. This study, instead of influencing the turn interaction, is seen as intra-action, where relativity, agency and situationality between humans and other animals are interwoven. Knowing is seen as diffraction rather than reflection, and embodied knowing / not-knowing is taken alongside factual knowing when examining human–animal relationships. What if-knowledge invites you to the edges of fuzzy gaps where you can never be sure of anything. I present three dimensions as pedagogical premises for multispecies education: These include the affective dimension, the ethological dimension and the ethical–political dimension. The affective dimension emphasizes the examination of the emotions of human individuals and from the perspective of action, suggesting that in multispecies education the handling of awkward and sticky emotions also play a central role. The ethological dimension emphasizes the understanding of animal feelings and consciousness and suggests that schools implement more real encounters with other animals. The ethical and political dimension emphasizes everyday activism related to animal relations, which can be implemented by participating in the activities of, for example, animal welfare associations. All three pedagogical dimensions are interwoven here and are mutually supporting elements in the pedagogical practices of multispecies education. Keywords: affect, animal turn, companion species, multispecies education, posthumanism, post-qualitative research, walking with
  • Kuitunen, Sini (Helsingin yliopisto, 2022)
    Intravenous administration of drugs is associated with the highest medication error frequencies and more serious consequences to the patient than any other administration route. The bioavailability of intravenously administered medication is high, the therapeutic dose range is often narrow, and effects are hard to undo. Many intravenously administered drugs are high-alert medications, bearing a heightened risk of causing significant patient harm if used in error. Smart infusion pumps with dose error-reduction software can be used to prevent harmful medication errors in high-risk clinical settings, such as neonatal intensive care units. This study investigated intravenous medication safety in hospital settings by identifying recent research evidence related to systemic causes of medication errors (Study I) and systemic defenses to prevent these errors (Study II). The study also explored the development of dose-error reduction software in a neonatal intensive care unit (Study III). A systems approach to medication risk management based on the Theory of Human Error was applied as a theoretical framework. The study was conducted in two phases. In the first phase, a systematic review of recent research evidence on systemic causes of intravenous medication errors (Study I) and systemic defenses aiming to prevent these errors (Study II) was carried out. In Study I, 11 studies from six countries were included in the analysis. Systemic causes related to prescribing (n=6 studies), preparation (n=6), administration (n=6), dispensing and storage (n=5) and treatment monitoring (n=2) were identified. Insufficient actions to secure safe use of high-alert medications, lack of knowledge of the drug, failures in calculation tasks and in double-checking procedures, and confusion between look-alike, sound-alike medications were the leading causes of intravenous medication errors. The number of the included studies was limited, all of them being observational studies and graded as low quality. In Study II, 46 studies from 11 countries were included in the analysis. Systemic defenses related to administration (n=24 studies), prescribing (n=8), preparation (n=6), treatment monitoring (n=2), and dispensing (n=1) were identified. In addition, five studies explored defenses related to multiple stages of the medication use process. Defenses including features of closed-loop medication management systems appeared in 61% of the studies, smart pumps being the defense most widely studied (24%). The evidence quality of the included articles was limited, as 83% were graded as low quality, 13% moderate quality, and only 4% high quality. A mixed-methods study was conducted in the second phase, applying qualitative and quantitative methods (Study III). Medication error reports were used to develop simulation-type test cases to assess the suitability of dosing limits in a neonatal intensive care unit’s smart infusion pump drug library. Of all medication errors reported in the neonatal intensive care unit, 3.5% (n=21/601) involved an error or near-miss related to wrong infusion rate. Based on the identified error mechanisms, 2-, 5-, and 10-fold infusion rates and mix-ups between infusion rates of different drugs were established as test cases. When conducting the pump programming for the test cases (n=226), no alerts were triggered with infusion rates responding to the usual dosages (n=32). Of the erroneous 2-, 5-, and 10-fold infusion rates, 73% (n = 70/96) caused an alert. Mix-ups between infusion rates triggered an alert only in 24% (n=24/98) of the test cases. This study provided an overview of recent research evidence related to intravenous medication safety in hospital settings. Current intravenous medication systems remain vulnerable, which can result in patient harm. While in-hospital intravenous medication use processes are developing towards closed-loop medication management systems, combinations of different defenses and their effectiveness in error prevention should be explored. In addition to improved medication safety, implementing new systemic defenses leads to new error types, emphasizing the importance of continuous proactive risk management as an essential part of clinical practice.
  • Matikainen, Teemu (Helsingin yliopisto, 2022)
    The topic of this research is registration of an EU trade mark on the basis of distinctive character acquired through use. In EU trade mark law, and in trade mark law in general, both internationally and nationally, it has traditionally been held that a mark which is descriptive or otherwise inherently devoid of a distinctive character in relation to the goods and services for which registration is sought may be registered as a trade mark on the basis of distinctive character acquired through use. In practice, this doctrine plays an important gatekeeping role in EU trade mark law. It decides whether certain marks – irrespective of their inherent imperfections – will be registered and protected. The research examines how well this doctrine functions in its current form. In order to answer this, it is necessary to clarify the purpose of this doctrine and the conditions under which a mark can become distinctive through its use. The method of this research is doctrinal with certain comparative elements. A comparative perspective is sought from British, German, American and to some limited extent from Finnish and Swedish law. In the study, it is argued that the registration of an EU trade mark on the basis of distinctive character acquired through use is in principle justified when teleological arguments are taken into account. However, this justification ultimately depends on the formulation of the conditions for this doctrine. This doctrine conceals a number of complex conditions. In this study, the following seven conditions have been identified. The mark applied for (or incorrectly registered as an EU trade mark and sought to be invalidated), which is inherently devoid of any distinctive character, has 1) at the right time 2) by the relevant public and 3) in relation to the goods and services for which registration is sought 4) acquired a new meaning indicating commercial origin 5) through the use of the mark 6) by a significant proportion of the relevant public and 7) in a necessary part of the geographical area of the EU. Many of these conditions work reasonably well in their current form. However, it is argued that particular problems relate to conditions 6 and 7 mentioned above. In this study, they are called “core conditions” because of their practical importance. The study provides solutions for improving the current situation. Ultimately, the determination of these core conditions is complicated by fears about the extent of the de facto scope of protection and harm to competition.
  • Hätönen, Seppo (Helsingin yliopisto, 2022)
    Our devices have become accustomed to being always connected to the Internet. Our devices from handheld devices, such as smartphones and tablets, to our laptops and even desktop PCs are capable of using both wired and wireless networks, ranging from mobile networks such as 5G or 6G in the future to Wi-Fi, Bluetooth, and Ethernet. The applications running on the devices can use different transport protocols from traditional TCP and UDP to state-of-the-art protocols such as QUIC. However, most of our applications still use TCP, UDP, and other protocols in a similar way as they were originally designed in the 1980s, four decades ago. The transport connections are a single path from the source to the destination, using the end-to-end principle without taking advantage of the multiple available transports. Over the years, there have been a lot of studies on both multihoming and multipath protocols, i.e., allowing transports to use multiple paths and interfaces to the destination. Using these would allow better mobility and more efficient use of available transports. However, Internet ossification has hindered their deployment. One of the main reasons for the ossification is the IPv4 Network Address Translation (NAT) introduced in 1993, which allowed whole networks to be hosted behind a single public IP address. Unfortunately, how this many-to-one translation should be done was not standardized thoroughly, allowing vendors to implement their own versions of NAT. While breaking the end-to-end principle, the different versions of NATs also behave unpredictably when encountering other transport protocols than the traditional TCP and UDP, from forwarding packets without translating the packet headers to even discarding the packets that they do not recognize. Similarly, in the context of multiconnectivity, NATs and other middleboxes such as firewalls and load balancers likely prevent connection establishment for multipath protocols unless they are specially designed to support that particular protocol. One promising avenue for solving these issues is Software-Defined Networking (SDN). SDN allows the forwarding elements of the network to remain relatively simple by separating the data plane from the control plane. In SDN, the control plane is realized through SDN controllers, which control how traffic is forwarded by the data plane. This allows controllers to have full control over the traffic inside the network, thus granting fine-grained control of the connections and allowing faster deployment of new protocols. Unfortunately, SDN-capable network elements are still rare in Small Office / Home Office (SOHO) networks, as legacy forwarding elements that do not support SDN can support the majority of contemporary protocols. The most glaring example is the Wi-Fi networks, where the Access Points (AP) typically do not support SDN, and allow traffic to flow between clients without the control of the SDN controllers. In this thesis, we provide a background on why multiconnectivity is still hard, even though there have been decades worth of research on solving it. We also demonstrate how the same devices that made multiconnectivity hard can be used to bring SDN-based traffic control to wireless and SOHO networks. We also explore how this SDN-based traffic control can be leveraged for building a network orchestrator for controlling and managing networks consisting of heterogeneous devices and their controllers. With the insights provided by the legacy devices and programmable networks, we demonstrate two different methods for providing multiconnectivity; one using network-driven programmability, and one using a userspace library, that brings different multihoming and multipathing methods under one roof.
  • Darling, Deborah Charlotte (Helsingin yliopisto, 2022)
    Languages are indexed by their cultural, economic, political and social value. In everyday life, this means that not all languages are used equally for all purposes. This is especially true for those activities associated with the more “elite” practices in society, such as (international) business, law and, in the case of this doctoral research, higher education. Communication beyond one’s language group/nation/region often requires the use of a lingua franca, and in higher education (HE) the international lingua franca has become English. Lingua francas are very important for access to, for example, wealth, social services and political domains, but they can also lead to domain-specific abandonment of other languages which has consequences for linguistic diversity, leading to impoverishment of knowledge, diversity and civil rights. This research is based on the argument that HE is a space where the indexing of languages can be challenged due to its increasing linguistic diversity from internationalisation. It also suggests that Finnish HE and, more specifically, the University of Helsinki (UH), because of its status as a bilingual institution with a trilingual language policy, is an ideal setting to investigate how the challenge of maintaining the value of linguistic diversity can be met. The presence of international students adds to local linguistic diversity and engaging with the languages they bring benefits the academic community. With this in mind, this doctoral research investigates how knowledge can be shared in a lingua franca without diminishing the potential roles that international student languages can play. To investigate this issue, data were collected from international students and local lecturers through task-based focus groups interviews and semi-structured interviews, respectively. The data were analysed using the discourse analysis to better understand language ideologies and attitudes towards and experiences of using and learning different languages from both institutional and subjective perspectives. The findings of the research show that while linguistic diversity is supported by the UH, as demonstrated by the range of language learning opportunities it offers, space for international students to use their languages is not typically provided and this appears to align with broader, global language ideologies. However, a range of mostly spontaneous and incidental approaches to linguistic inclusion surfaced in the data too. Drawing on plurilingual pedagogic theories and studies along with the findings from the analysis of the data, a linguistically-inclusive approach to courses that use English as a Medium of Instruction (EMI) is proposed. This approach seeks to encourage linguistic diversity, intercultural competence, and internationalisation at home. Importantly, it is proposed for use on EMI courses so that it does not displace Finnish as an academic or instructional language. The intention of the approach is to challenge the indexing of different languages and provide benefits for all students in HE.
  • Vuorela, Tiina (Helsingin yliopisto, 2022)
    Background. Mortality following pancreatic surgery is 1–5%. In addition, morbidity can reach 30–60% across all surgical and nonsurgical postoperative complications. The most common complications include postoperative pancreatic fistulas (POPFs), postpancreatectomy hemorrhage (PPH) and delayed gastric emptying (DGE). Several methods to reduce postpancreatectomy complications have been studied and applied in clinical practice. These include optimizing hospital volume and preoperative patient care, developing surgical techniques, administering different medications (such as somatostatin analogues or hydrocortisone), and applying scoring systems which help to recognize those patients at a higher risk for complications. In 2014, a randomized study by Allen showed that the rate of clinically relevant pancreatic fistulas (CR-POPFs) could be halved by administering somatostatin analog pasireotide. In borderline resectable pancreatic tumors, tumour is invading nearby structures such as the portal vein (PV) or the superior mesenteric vein (SMV). Venous resection and reconstruction can be performed using an autologous vein graft. Vascular resections carry a risk for thrombotic events and graft thrombosis postoperatively. Patient-related factors, such as comorbidities and additional inflammatory conditions, like periodontitis, can also impact postoperative healing. Systemic chronic inflammation due to bacterial migration from infectious tissues in the mouth can potentially increase the risk for postoperative morbidities. However, periodontal disease has not been previously studied among patients undergoing gastroenterological surgery. Aims. Our aims were to study the effect of pasireotide in preventing POPF in patients undergoing distal resection (I), and in patients at a high risk for POPF undergoing PD (II). Furthermore, we aimed to analyze the results among patients with borderline resectable pancreatic tumors undergoing PD with a venous resection and reconstruction with a spiral interposition graft (III). In study IV, we aimed to determine the prevalence of periodontal disease and its association with postoperative complications in patients undergoing elective pancreatic surgery. Materials and methods. The first three studies were retrospective cohort studies and the fourth study was a prospective cohort study. The data were collected from Helsinki University Hospital patient records. This thesis summarizes these four original studies. The patient cohort for study I consisted of patients undergoing a distal pancreatic resection between 2000 and 2016, and the patients to whom pasireotide was administered between 2014 and 2016. Study II analyzed patients undergoing a pancreaticoduodenectomy between 2014 to 2016, and who were evaluated as having an elevated risk for POPF. In study III, among 1375 patients identified as having undergone a pancreatectomy between 2005 and 2018, we analyzed those patients undergoing a venous resection and reconstruction. Short- and long-term outcomes were analyzed across different vascular surgical techniques. Study IV consisted of patients who had elective surgery due to tumours of the pancreas. Patients were screened for periodontitis using Periosafe, an MMP-8-screening rapid test. Results. In study I, pasireotide was administered to 48 out of 259 distal pancreatectomy patients. CR-POPF was diagnosed in 40 (16%) of the patients. Severe Clavien-Dindo grade 3-5 complications were in 25% of the patients. No differences in complications across the three study groups receiving pasireotide, octreotide or neither. The analysis in the study II consisted of 153 pancreticoduodenectomies, of which 58 (38%) were considered in high risk of developing a fistula. Clinically relevant fistula was diagnosed in four (2.6%) of the patients. In study III, patients undergoing a pancreatic resection with venous resection and reconstruction were 198. Spiral grafts were performed in 35%, end-to-end 39% and tangential or patch reconstruction in 26% of the venous procedures. Portal vein or superior mesenteric vein thrombosis occurred in 8 (4%) of the cases. No differences between short term postoperative complications or differences in survival in our surveillance period was seen between the different venous reconstruction techniques. The analysis of study IV consisted of 194 pancreatectomy patients, of which periodontitis was diagnosed in 68 (35%) of the patients. Postoperative thrombotic events were less (10 (42%) vs. 14 (58%), p=0.019) in patients with no periodontitis and severe postpancreatectomy haemorrhage was seen more (24 (53%) vs. 21 (47%), p=0.003) in patients with periodontitis. Conclusions. Based on our findings, we conclude the following. (I)Perioperatively administered pasireotide does not reduce complications after distal pancreatic resections. (II) In pancreaticoduodenectomy patients at high risk for POPF, the risk for POPF may be comparable to that among non-high-risk patients after perioperative pasireotide. (III) The spiral interposition graft is safe and feasible for use in reconstructions after a demanding pancreatic and venous resection. (IV) The prevalence of periodontitis is higher among patients undergoing surgery for pancreatic tumors, and seems to increase the risk for venous thromboembolic events and postoperative hemorrhage, but does not increase the risk for other postoperative complications.

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