Väitöskirjat

Recent Submissions

  • Angove, Charlotte (Helsingin yliopisto, 2020)
    Aquatic plant meadows provide a variety of global ecosystem services. Their populations are declining globally. To conserve and restore aquatic plant meadows and the services which they provide, it is necessary to understand their ecology. A key approach which allows us to explore plant ecology is to investigate the relationships between plant functional traits and ecosystem processes. By investigating plant functional traits, it is possible to develop insights about functional diversity and plant growth strategies. In this thesis, plant functional traits, functional diversity and plant growth strategies are used to investigate aquatic plant biomass production responses to the environment. A series of manipulative experiments were conducted in situ in submerged aquatic plant meadows of the northern Baltic Sea using SCUBA. Firstly, the role of plant traits, species identity and sediment porewater NH₄⁺ availability for plant nitrogen uptake rates were investigated using a short-term (3.5 h) nitrogen enrichment experiment (Chapter I). Secondly, a 15-week transplant experiment was conducted to explore plant functional trait and functional diversity relationships to productivity (Chapter II). Finally, a similar experiment with additions of the bivalve Limecola balthica (12 weeks) was conducted to investigate infauna effects to plant functional trait–productivity relationships (Chapter III). Chapter I showed that short-term nitrogen uptake rates from the sediment were driven by plant-biomass related demands. Similarly, results suggested that plants likely drained ammonium availability from their adjacent sediment porewater. Overall, Chapter I parameterised the possible unfulfilled potential for larger temperate aquatic plants to cycle nutrients. Chapter II results showed strong relationships between productivity and traits which enhanced light capture (height and leaf area). Leaf tissue δ¹³C and functional richness were also related to community productivity. The relationship between height and productivity was likely exacerbated by a competitive height interaction between the tallest and second tallest species. Overall, functional richness was related to community biomass production, likely by selecting for traits which enhanced light capture (selection effect) with potential consequences to carbon supply. Findings support inferences from previous studies of aquatic plant communities which showed that height is strongly related to aquatic plant productivity and trait identity may be more descriptive for primary production compared to functional diversity indices. Chapter III results showed Specific Root Length (SRL) exhibited the strongest relationship to productivity. Leaf area was also related to community production and Median Maximum Root Length (MMRL) exhibited a marginally non-significant relationship to productivity. SRL exhibited collinearity to species identity, therefore it was not possible to interpret SRL effects separately to other traits which may coincide with species identity. Community SRL was related to community shoot frequency, not aboveground biomass production. SRL and shoot proliferation both represent strategies to enhance nutrient absorption from the sediment. Relationships between plant leaf tissue nutrient concentrations (N (% DW), δ¹⁵N, δ¹³C) and L. balthica condition index suggested that L. balthica affected the sediment nutrient supply and enriched the plants with nutrients. Overall, Chapter III showed that infauna, common in aquatic plant meadows, can change aquatic plant trait-productivity relationships and thus arguably the drivers for submerged aquatic plant community growth. Findings of this thesis can be applied to a variety of other temperate submerged aquatic plant communities. Targeted research questions could contribute to further understanding of submerged aquatic plant ecosystem ecology, including the ecology of monocultures. This thesis summary suggests updating the current description of context-dependent seagrass biomass responses to sediment nutrient enrichment. It proposes a model which, once tested, would help to improve predictive modelling for submerged aquatic plant biomass responses to future change. Also, results of this thesis contribute towards increasing effectiveness of future management by providing insights to infauna effects on plant functioning. This is beneficial to current restoration development because infauna additions to submerged aquatic plant meadows are an option for increasing seagrass restoration success and seagrass resilience to future change. This thesis identifies that there is requirement for further research in seagrass meadows which form dense root-rhizome mattes, and it describes potential options for future research. It also recommends isotope-tracing experiments and compound-specific isotope tracing experiments to better understand mechanisms of nutrient exchange between infauna and temperate submerged aquatic plants. It has empirically shown current limitations of global plant trait syntheses and it identifies constructive steps forward to improve the global perspective of plant trait ecology. Finally, this thesis advocates the value of insights gained from data-rich functional diversity experiments and plant functional trait experiments. To conclude, this thesis has improved the collective understanding of temperate aquatic plant ecosystem functioning.
  • Manderoos, Sirpa (Helsingin yliopisto, 2020)
    The capacity of agility has been extensively studied in sport-specific contexts. Thus, there is a great need for understanding possible explanatory factors determining the capacity of agility and the meaning of agility in physical functioning in middle-aged and older people. The Agility Test for Adults (ATA) has been developed to assess the capacity of agility more comprehensively than previously used agility tests do. The main aims of this study were to evaluate 1) the test-retest reliability of the ATA and to quantify a clinically meaningful change (MDC95), 2) the determinants of agility, 3) the feasibility of the ATA, and 4) the effects of participation in competitive sports in young adulthood or life-long LTPA on the present level of physical functioning. The International Classification of Functioning, Disability and Health (ICF) was used as a framework to define the measures of physical functioning. The study includes three study cohorts. The first includes healthy untrained adults (n = 52, 25 women and 27 men) who participated in the reliability study. The second study cohort consists of 233 healthy participants (149 women and 84 men). The third includes 100 male former elite athletes (endurance n = 50; power n = 50) and 50 matched controls aged 66 to 91 years. Both objective measures and questionnaires-based data were used. The high reliability scores of the ATA showed that it is stable and reliable in untrained adults. The magnitudes of the values identifying clinically meaningful changes in the ATA were small in both women and men. Jumping length was the main determinant of agility in women and men, whereas jumping height and age were the main determinants of the results of the ATA in a cohort of men aged 66-91 years. Data including elderly men allowed the evaluation of the feasibility of the ATA for people over sixty years old and with a large age distribution. A former elite athletic career interrelated with greater explosive force production of the lower extremities at old age among former elite power athletes, which may partly be explained by participation in competitive power type sports from young age, and not by life-long LTPA. The thesis provides recommendations for a reliable, responsive, and clinically useful measurement method of the ATA suitable for evaluating the capacity of agility in middle-aged and older adults. The ATA seems to be a more sensitive test to reveal physical disorders of a participant than the other commonly used mobility tests. By using responsive measures, it is possible to identify early decline in agility. Our data set also showed that lower limb muscle function measured by a test demanding explosive power plays an important role in maintaining or enhancing the capacity of agility.
  • Kalenius, Aleksi (Helsingin yliopisto, 2020)
    One of the fundamental questions of all societies is the possible trade-off between quality of outcomes and equality of opportunity. The question of a possible trade-off between equality of opportunity and level of outcomes has a long history in the sociology of education, and it has been seen as a fundamental question of the field. Economics literature recognises that equality of opportunity is not, unlike equality of outcomes, in a trade-off with quality of outcomes. Rather, inequalities of opportunity generate inefficiency and are thus in a trade-off with the level of outcomes. Here, building on this difference, we make a distinction between outcome trade-off and opportunity trade-off. Equality of opportunity is standardly measured indirectly, taking outcomes associated with circumstances to be due to circumstances and thus an indication of inequality of opportunity. This approach assumes that the circumstances of the individual are independent of the responsibility characteristics. The assumption flows from taking responsibility to be inseparable from individual freedom, whereby an individual should not be held responsible for the direct or indirect consequences of unchosen circumstances. When responsibility is directly linked to individual choice, we may also take any between-types differences in outcomes between groups facing different environments as evidence of the differential effects of those environments. Equality of opportunity is a causal concept, decomposing the outcomes as due to just and unjust causes. Due to the complexity of social phenomena such as intergenerational mobility, well-defined causality is out of reach, yet the concept of opportunity requires counterfactuals and causality. We propose that, rather than abandoning the causal core of the concept of equality of opportunity, or high standards in identifying well-defined causality, complex circumstances should be understood as ill-defined treatments. The area of education reveals interesting tensions because cognitive outcomes cannot be redistributed. It is usually taken to follow that differences in cognitive outcomes that are due to innate ability are not unjust, even though this means making individuals effectively responsible for something beyond their choice or control – their innate ability. This is what makes the opportunity trade-off possible. It arises because individuals in different circumstances may differ by innate ability. To bridge the gap between responsibility linked to freedom and learning outcomes linked to innate ability, we propose a typology of responsibility characteristics to allow for a more explicit recognition of the reasons for holding individuals responsible for causes beyond their control. The core concept introduced is natural responsibility characteristic, referring to a cause that individuals are held responsible for, but beyond the influence of persons individually or collectively. This makes natural responsibility characteristics historically contingent rules of regulation that depend on the level of technology, broadly construed. The two hypotheses on the causes of the association between background circumstances and cognitive outcomes emphasise ability and opportunity. The opportunity hypothesis takes outcome differences associated with circumstances as being due to the opportunities that different groups face, while the ability hypothesis takes differences to arise from between-group differences in innate ability. Both innate ability and opportunity can be observed only indirectly, but the opportunity hypothesis predicts that the between-type difference is minimised with high outcomes, while the ability hypothesis leads us to expect that equality of opportunity and the level of outcomes form a trade-off. The two perspectives can be combined in an ability-opportunity curve, the peak of which depends on the contribution of innate ability differences to between-group differences in outcomes. The causal chain between genetics and cognitive outcomes is insufficiently understood to provide clarity to the role of genes in explaining between-group differences in cognitive outcomes. While all researched human traits are heritable and we find an association between genetics and outcomes, unobservable associations between environment and genetics currently prevent well-defined identification of the causal contribution of genetics to between-group differences. The empirical sections of the work approach the question of equality of learning opportunity and the level of learning outcomes using IALS and PIAAC, two studies of adult skills. The ability-opportunity curve is approached, observing the association between equality of opportunity and the level of learning outcomes for different parental education types. The results indicate a positive association between equality of learning opportunity and the level of adult skills for all parental education types, matching the prediction of the opportunity hypothesis. While high proficiency can be achieved with high levels of equality of opportunity, the two usually go together. The positive association between equality of opportunity and the level of learning outcomes is stronger for lower parental education types and on longer time frames. The longer-term equality of opportunity is a strong predictor of the level of learning outcomes even in the short term. Equality of outcomes, here captured by income inequality, explains much of the same variation as equality of opportunity, supporting the opportunity-equalising effects of income equality attested to by the Great Gatsby curve. Longer-term equality indicators also predict learning outcomes of the high parental education type over time to the same degree as contemporary equality indicators, implying that equality indicators may provide advance warning of the direction of the evolution of learning outcomes. The results imply that developed countries still find themselves on the upward-sloping section of the ability-opportunity curve. In the analysis of possible traces of education reforms in between-cohort differences in equality of opportunity, IALS and PIAAC paint a largely concordant picture of the evolution of proficiency across cohorts. The pattern applies to the youngest groups of IALS, implying that cohort discontinuities in adulthood may be associated with differences in educational experiences in youth and with policy reforms. Comparing the timing of the observed discontinuities with the timing of education policy reforms, we identify 29 discontinuities that can be associated with notable changes in education policy. Reforms towards longer education and more comprehensive schooling seem mainly to be associated with improved equality of learning opportunity, while in some countries similar reforms in the 1990s seem to be associated with declining equality of opportunity. A brief, slightly more in-depth, look at Finland reveals a large increase in inequality in the 1990s, which broadly matches other data sources. The observation is of interest for several reasons. It would, if the results of our analyses are anything to go by, predict a later decline in learning outcomes, something that Finland has famously observed over the last 13-25 years. In addition, many of the internationally-known characteristics of the Finnish education system have been linked to the reforms of the 1990s and those reforms have been used to explain the rise of Finland to international fame and to the position of a global benchmark. The timing of the increase in inequality matches these reforms. The results suggest that the causes of Finnish success might have been misidentified and that we may have, both nationally and internationally, learnt the wrong lessons from Finland. Keywords: equality of opportunity, learning outcomes, large-scale survey, adult skills, education policy
  • Rodionov, Andrei (Helsingin yliopisto, 2020)
    Spinal cord injury (SCI) is a devastating condition and consequent loss of motor control remains one of the main causes of disability. Motor recovery after SCI depends on the amount of spared and restored neural connections in the spinal cord. Most SCIs are incomplete and even neurologically complete injuries possess some spared neural connections. Damaged motor pathways can be reactivated by external stimulation. However, current treatment approaches are mainly palliative, such as assisting adaptation to impairments. Thus, there is a need for novel therapies to induce neuroplasticity in the spinal cord and strengthen weak and disrupted neural connections. In this thesis, paired associative stimulation (PAS) was applied as a long-term treatment for chronic incomplete SCI of traumatic origin. PAS is a non-invasive neuromodulation paradigm where descending volleys induced by transcranial magnetic stimulation (TMS) of the motor cortex are timed to coincide with antidromic volleys elicited by peripheral nerve electrical stimulation (PNS). The stimulation protocol was designed to coincide TMS- and PNS-induced volleys at the cortico-motoneuronal synapses in the spinal cord. Continuous pairing of TMS and PNS stimuli can change synaptic efficacy and produce long-term potentiation (LTP)-like plasticity in the corticospinal tract. Augmentation of synaptic strength at the spinal level has clear therapeutic value for SCI, as it can enhance motor control over paralyzed muscles. The aim of the thesis was to investigate the possible therapeutic effects of long-term PAS on hand and leg motor function in individuals with chronic incomplete SCI of traumatic origin. Study I explored long-term PAS therapeutic potential by providing long-term PAS until full recovery of hand muscle strength or until improvements ceased. The PAS protocol was designed to coincide TMS- and PNS-induced volleys in the cervical spinal cord, which is both the location of the stimulated lower motor neuron cell bodies and the site of the injury. Improvements up to normal values of hand muscle strength (Manual Muscle Test [MMT]) and increased amplitude of motor evoked potentials (MEPs) were obtained after more than 1-year stimulation in a participant with SCI. The participant regained almost complete self-care of the upper body. This was the first demonstration of restoring normal strength and range of movement of individual hand muscles by means of long-term PAS. The effect persisted over 6 months of follow up. Study II probed the effects of long-term PAS on leg muscle strength and walking in a group of five people with SCI. The PAS protocol was designed to coincide TMS- and PNS-induced volleys in the lumbar spinal cord but the site of the injury was in the cervical spinal cord. Long-term PAS delivered for 2 months significantly increased the total lower limb MMT score. This effect was stable over a 1-month follow up. Walking speed increased after 2 months of PAS in all participants. This study was the first demonstration that long-term PAS may significantly increase leg muscle strength and affect walking. The MMT score prior to the intervention was a good predictor of changes in walking speed. Study III developed a novel technique that enables probing neural excitability at the cervical spinal level by utilizing focal magnetic coil and anatomy-specific models for re-positioning of the coil. The technique enabled recording of highly reproducible MEPs and was suitable for accurate maintenance and retrieval of the focal coil position at the cervical level. In summary, this thesis contributes to the understanding of therapeutic efficacy of long-term PAS for restoration of motor control over hand and leg muscles after chronic SCI. This work challenges the view that chronic SCI is an irreversible pathologic condition and demonstrates the possibility of restoring neurological function many years postinjury when spontaneous recovery is extremely rare. The increased amplitude of MEPs, sustainable motor improvements, and the effects observed regardless of injury location indicate that PAS induces stable changes in the corticospinal pathways.
  • Kormacheva, Daria (Helsingin yliopisto, 2020)
    This thesis addresses the topic of collocations and their behavior based on Russian language data. In the course of four articles, I develop a better understanding of collocations that is based on a corpus-driven approach. Collocations are defined as statistically significant co-occurrences of tokens or lexemes within a syntactic phrase that are extracted by statistics-based automatic analysis tools and are restricted to various extents: from semantically not-idiomatic to full idioms. In the article “Evaluation of collocation extraction methods for the Russian language” (2017), my co-authors and I discuss of the methods used to extract statistical collocations and provide results pertaining to the comparison of five metrics for extracting statistics-based collocations as well as the raw frequency. First, this research has demonstrated that the results of the discussed metrics are often correlated and, second, that the degree of idiomaticity of the extracted units varies significantly. In “What do we get from extracting collocations? Linguistic analysis of automatically obtained Russian MWEs” (2015), I offer a comparison of the empirical and phraseological perspectives on collocations and introduce research where I attempt to position empirical collocations within the scope of a phraseological theory. This research demonstrates that empirical collocations have different tendencies to form idiomatic lexical units and I reveal the shortcomings of describing the idiomaticity of expressions in terms of strict classes. In “Choosing between lexeme vs. token in Russian collocations” (2019), I examine grammatical profiling as a method used to define the optimal level of representation for collocations. I have demonstrated that collocations have different distributional preferences across the corpus. I have also analyzed the relationship between token and lexeme collocations based on the degree to which their grammatical profiles resemble the grammatical profiles of their headwords (although the border between the two types is not clear-cut). I also offered a plausible method of differentiating between these two collocation types. Finally, in “Constructional generalization over Russian collocations” (2016) my co-authors and I present the main concepts of Construction Grammar and introduce the research where a substantial number of automatically extracted collocations were demonstrated to form clusters of words that belong to the same semantic class, even when they are not idiomatic. Such constructional generalizations have shown that there is a more abstract level on which collocations can be stable as a class rather than on the level of single collocations.
  • Myllykangas, Jukka-Pekka (Helsingin yliopisto, 2020)
    Methane is a powerful greenhouse gas that contributes significantly to global warming. In aquatic systems, microbes in anoxic sediments are the main methane producers. However, due to effective oxidative filters in the sediments and the water column, most of the methane produced does not end up in the atmosphere. This study explores methane dynamics in the Baltic Sea from the open sea, to estuaries and specific microbial processes. Major inflow cycles control methane dynamics in the open Baltic by bringing oxygen to the deep basins, where methane typically accumulates in large amounts during stagnation. The introduction of oxygen during a major inflow in 2014–2015 caused the disappearance of methane from the deep basins due to a combination of oxidation and displacement. However, the effects of the inflow were short-lived and methane started accumulating again in less than a year after the inflow. The coastal areas were more dynamic, and the primary source of methane varied with distance offshore. Near the river mouth of the studied estuarine system, methane brought in by the river was the most important source, whereas further offshore sedimentary methanogenesis fuelled by a legacy of eutrophication was the primary source. Atmospheric fluxes of methane were highest near the river mouth and decreased seawards, while bathymetry was the main control of sedimentary fluxes. Seasonality had a strong effect on methane dynamics, with methane concentrations generally increasing towards winter. However, as in the open Baltic, displacement also played a role at times, removing large amounts of methane at a time. While aerobic methane oxidation in the water column was the primary sink offshore, in the coastal areas anaerobic oxidation of methane (AOM) was by far the most important sink. Offshore, sulphate mediated AOM is expected to be the most important type of AOM. However in this study, metal mediated AOM was an equally important sink in the sediments. Both rates of AOM, and microbial community abundances, were highest below the main sulfidic zone in the sediment, pointing towards non-sulphate AOM pathways. Overall, eutrophication has had a large impact on methane dynam ics in the Baltic Sea. The legacy of past eutrophication fuels methanogenesis in the coastal areas to this day, despite reductions in nutrient and organic matter input from land, leading to enhanced atmospheric flux of methane. In the future, climate change will likely exacerbate methane emissions from the Baltic Sea.
  • Hoikkala, Susanna (Helsingin yliopisto, 2020)
    In this PhD research, restrictive and disciplinary practices refer to procedures which differ from the usual regulative practices of everyday life in a children’s residential care institution in child welfare. These practices restrict child’s possibilities to act and participate or they violate the privacy of a child. In this study restrictive and disciplinary practices are interpreted as ways to govern children and young people within child welfare. The two main research questions are as follows: 1) What kind of restrictive and disciplinary practices have there been in the children’s residential care institution at different times and how have these practices been organized in the social relations of specific time? 2) How has their regulation changed? Theoretically and methodologically, the study adheres to the approach developed by Dorothy E. Smith. This approach has been used to explore the organization of restrictive and disciplinary practices as well as the distinctive forms of relations of ruling mediating their implementation. Practices under examination are interpreted as the intersection of the everyday life of residential care and the social relations governing it. The most important social relation is the generational relation. Furthermore, Michel Foucault’s idea of a history of the present is applied heuristically. In this qualitative social work research, a single case study design is applied as a research strategy. One children’s residential care institution forms the case. Data collected from the case study institution and the archive contains textual documentary data such as the journals of punishments, the decisions of restraints, the memos of meetings, daily reports and the extracts of children’s case files, produced by residential care workers. Regulative relations are examined by using the municipal guidelines and legislation as well as professional texts such as committee reports. In the analysis, three key points of transformation are first located by exploring the continuities and discontinuities of practices under examination. Secondly, these moments are analysed by applying the method of textual inquiry and close reading, which takes into account definite places and times. Thirdly, the transformation of the practices under examination and their regulation are analysed during the time period of this research. Restrictive and disciplinary practices have changed during the period under examination from the practices of punishment and disciplinary power to practices emphasizing care and caring power. For example, corporal punishments were replaced by various methods of isolation, and drug testing was implemented as a new practice. The municipal guidelines formed the regulative basis for practices under examination until 1983. Since then they have been regulated by child welfare legislation. Both practices under examination as well as the generational relations of children and residential care workers have been re-shaped by the professionalization, democratization and legalization of children’s residential care. Residential care workers have been expected to integrate the events of everyday life and the formal regulative organization of practices. They have also been expected to adjust their professional activities accordingly. Key words: Children’s residential care, restriction, discipline, history of child welfare, relation of ruling, generational relation
  • Sihvonen, Pilvi (Helsingin yliopisto, 2020)
    People expose to poor air quality both outdoors and indoors. Around 90 % of people in the world are breathing polluted air. Air pollution causes negative health effects, increases mortality and leads to harmful effects on the environment. The history of air pollution shows that the air is regarded as no one’s ‘possession’, and the responsibility of it is not recognized before its pollution has seriously damaged nature and affected people’s health. Economic growth has been considered more important than clean air and human welfare. Fast changes towards better air are possible, but they require public action and strong coordinated efforts of policymakers. People demand better air, but are influenced by confusing common opinions and contradictory public argumentation. Education provides possibilities for gaining new knowledge and shaping the cognitive schemas and behavior of people. Therefore, this study aims to contribute better air quality by investigating knowledge transfer of the holistic view of air quality in higher education. The research bridges educational and air quality knowledge in the development of Modern Educational Design Framework (MEDF). It adapted the Design Based Research methodology. The empirical part was implemented in a multidisciplinary and multicultural course at the University of Helsinki because both the students who represent future experts and researchers who work as educators need appropriate knowledge on air quality and teaching of the subject. The results show that, in addition to knowledge and awareness of air quality and its impacts, people need to feel ownership of the air and self-interest to understand their responsibility for the condition of environment to change their behavior. Understanding how our actions assist improvement of air quality, gives people a feeling of empowerment in front of the problems. Therefore, understanding the regional cultural factors behind the different social and individual manners of behavior related to air pollution is important. The research produced information on which issues and pedagogical principles should be considered in building the holistic view of air quality in aligned educational setting. Understanding the development of air quality in the internal dynamics and interplay of the social, scientific and technological process in both history and the present, and the structure and dynamics of systematic knowledge building, is important. The scientific communities need to develop interdisciplinary collaboration and skills. Active and multi-form learning environments, where the linguistic aspects and students’ pre-knowledge and backgrounds are considered, enhance learning. The organizer should consider that interdisciplinary education requires more resources than traditional one.
  • Siltanen, Riikka (Helsingin yliopisto, 2020)
    In this doctoral dissertation, I examine the musical agency of composer, organist, conductor and music pedagogue Richard Faltin (1835−1918) in Finland in the second half of the 19th century. The four articles in the study cover Faltin’s active career between 1856 and 1896. During that time, Faltin worked among others as awakener of Vyborg art music life (Article I), conductor of the first opera house founded in Finland (Article II), presenter of the international music trends and Wagner pioneer in Finland (Article III) and music teacher of the University of Helsinki (Article IV). The aim of my study is to examine the effects of Faltin’s activities on the development of Finnish art music culture in the second half of the 19th century, as well as illuminating Faltin’s penchant for creating permanent structures to promote musical activity in Finland. A closer look focuses on Faltin’s role as a nurturer of the first generation of musicians born in Finland and a supporter of the musical professional identity, as well as the influence of Faltin’s extraordinarily large international contacts on creating the structure and the models of Finnish musical institutes, such as music schools, orchestras, choirs and opera houses. Methodologically, the dissertation combines the research tradition of musicology and cultural history. I approach Faltin’s musical agency as a time- and place-bound historical activity, whose boundary conditions included language dissonances in Finland in the 19th century and Finland’'s position as the Grand Duchy of Russia. These are the issues I primarily research through historical newspaper articles and overviews. On the other hand, I examine the source material of Faltin’s archival documents on personal history by means of biographical research, whereby a broader cultural picture is accompanied by a history that Faltin himself has remembered and interpreted. The National Library’s archival documents include Faltin’s correspondence, memoir manuscripts, concert programs, testimonies and other official documents, composition manuscripts, and musical and book material. The new or unpublished material presented in my research both corrects and completes the understanding of the content, breadth and significance of Faltin’s musical activities to the development of Finnish art music culture. The image of later music history as “Father of Finnish Church Music” by Faltin takes on new dimensions.
  • Jaakkonen, Anniina (Helsingin yliopisto, 2020)
    Cattle are commonly asymptomatic carriers of Shiga toxin-producing Escherichia coli (STEC) and Campylobacter jejuni, which cause gastroenteritis in humans. Especially STEC infections may lead to severe or fatal consequences. Both STEC and C. jejuni are intermittently shed in cattle feces and can contaminate bulk tank milk via fecal contamination during milking. These bacteria are effectively eliminated from milk by pasteurization, but the consumption of unpasteurized milk, or raw milk, poses a risk of infection. In recent years, the consumption of raw milk has become more popular, with public demand to relax legislation that restricts sales of raw milk. However, on-farm epidemiology of these pathogens have warranted further investigation to support the development of on-farm risk management practices and pathogen monitoring of dairy farms that sell raw milk to consumers. These studies investigated a milkborne outbreak caused by STEC (Study I) and obtained longitudinal data on the contamination of bulk tank milk by STEC and C. jejuni, and explored on-farm contamination routes of these pathogens (Study II). Furthermore, the studies revealed strain characteristics of C. jejuni that may affect survival and persistence of this pathogen in milk (Study III). The occurrence of STEC and C. jejuni, or C. jejuni alone, was determined in bulk tank milk, in-line milk filters of the milking machine, cattle feces, and the farm environment on four dairy farms (STEC and C. jejuni in Studies I and II) or one dairy farm (C. jejuni in Study III). STEC and C. jejuni isolates from the dairy farms were further subjected to phenotypic characterization and whole-genome sequencing, followed by comparative genomic analyses to explore gene contents and phylogenetic relationships between the isolates. Furthermore, questionnaire data were collected to trace back the outbreak source (Study I) and to determine on-farm risk factors associated with milk contamination using a logistic regression model (Study II). Ultimately, the results contributed to the revision of the Finnish legislation that restrict the sales of raw milk in 2017 (Study II). Study I elucidated the reservoirs and transmission routes of atypical, sorbitol-fermenting (SF) STEC O157, which have largely been unknown. The study presents microbiological and epidemiologic evidence that an outbreak of SF STEC O157 with 11 cases originated from a recreational farm housing dairy cattle and was transmitted via the consumption of raw milk. Thus, these results strongly support bovine origin of SF STEC O157. In longitudinal monitoring (Study II), one clone of STEC O157:H7, which represented a bovine-associated lineage, was simultaneously isolated on each of the three dairy farms. STEC O157:H7 persisted in two herds for up to 12 months, and a similar but distinct clone was reintroduced in one herd 2.5 years after the previous detection. These results support evidence that few STEC O157:H7 clones persist on-farm simultaneously. Unlike STEC, both persistent and numerous sporadic C. jejuni strains appeared simultaneously on dairy farms (Studies II and III). Persistence for 11 months or longer was associated with a few C. jejuni genotypes, especially the host generalist sequence type (ST) ST-883. C. jejuni of ST-883 outperformed other STs in environmental fitness, representing the only ST that could be isolated from bulk tank milk and milk filters and the dominant ST found from environmental samples. Therefore, ST-883 imposes a higher contamination pressure on milk than other STs among the farm isolates and represents a candidate for on-farm risk-based monitoring. In the longitudinal monitoring, STEC was rarely isolated from bulk tank milk and milk filters and only simultaneously with fecal isolation. Higher detection rates were obtained from milk filters than milk by both culture methods and real-time PCR. Therefore, milk filters are more reliable sampling targets for monitoring of STEC than milk. Isolation of C. jejuni from milk and milk filters was associated with C. jejuni clone rather than sample material, but the isolation rates of C. jejuni appeared generally poor. To enhance the isolation rates for monitoring purposes, the sampling regime also warrants further consideration. Reduced milk contamination by STEC was associated with on-farm practices: pasturing and culling of dairy cows and rigorous cleansing in the barn. Higher outdoor temperatures were associated with increased milk contamination. In Study III, C. jejuni of ST-883 persistently contaminated bulk tank milk of a dairy farm for seven months or longer after having caused a milkborne outbreak. Although ST-883 survived in refrigerated raw milk longer than other STs from the same farm, the persistence of ST-883 in bulk tank milk was likely affected by other phenotypic traits such as biofilm formation. Outbreak strain of ST-883 reversibly adapted to survival in bulk tank milk, showing biofilm formation in an on/off manner among replicate cultures and cellular heterogeneity by phase variation in genes related to capsule and oxidative stress response. Furthermore, the outbreak strain harbored a pTet-like genomic element, which may have contributed to higher biofilm quantities. This study identified candidate phenotypic and genotypic mechanisms affecting survival and persistence of C. jejuni in milk. Taken together, STEC and C. jejuni can persist on dairy farms for months or longer and contaminate bulk tank milk despite stringent on-farm hygiene measures. Although these measures cannot totally prevent milk contamination, they likely reduce the contamination pressure on milk. Therefore, cost-effective hygiene measures should be applied on all farms that sell raw drinking milk to consumers. Detection of pathogens from milk may be challenging, and milk may also be contaminated by highly virulent STEC and C. jejuni strains that show atypical phenotype, increasing their environmental endurance or hampering their detection. Therefore, only heat treatment of raw milk before consumption can adequately assure its food safety.
  • Määttä, Suvi (Helsingin yliopisto, 2020)
    The sedentary lifestyle is rooted in our lives across many settings in contemporary society. The phenomenon has raised public health concerns due to increasing knowledge of the negative health consequences of extensive sedentary behavior (SB). SB is defined as any waking behavior characterized by a low energy expenditure while in a sitting, reclining or lying posture. Already, preschool-aged children are sedentary for over half their daily waking hours. The prevalence of their SB encourages understanding of the factors associated with it. The two key settings for the development of preschool children’s SB habits are home and preschool. As postulated by the socioecological model of SB, each setting, with its social and physical environment, shapes the individual’s possibilities for SB differently. Each setting may also differ in socioeconomic status (SES). Beside settings, individual characteristics (e.g. temperament) shape behavior. These theoretical assumptions create the potential to study the interplay between individual characteristics, SES, home and preschool settings, and children’s SB. The main research focus of this dissertation was to examine examine how SES, individual factors, and home and preschool settings combine to shape preschool children’s SB. The specific questions targeted in this study were: 1) Which individual, home, and preschool factors were associated with the preschool children’s overall SB and to what extent did these factors explain variance in children’s overall SB? 2) Which factors in the preschool setting were associated with preschool children’s SB during preschool hours and did these factors in preschool setting act as moderators in the associations between parental SES and SB? 3) Did co-participation in physical activity (PA) as a parenting practice act as a mediator in the associations between parental SES and SB? and 4) Did the frequent visits to places where PA is encouraged and weekly common practices in the preschool group associate with preschool children’s SB during preschool hours? This research was based on the DAGIS (Increased Health and Wellbeing in Preschool) cross-sectional study, which was conducted in 66 preschools in Western and Southern Finland in the years 2015 and 2016. A total of 864 children, aged three to six years, participated in this study. This multimethod study included objective measurement of SB, observations, and multiple questionnaires covering the children’s characteristics, the preschool setting and the home setting. The preschool setting was defined as consisting of social, physical and organizational environments whereas the home setting comprised parenting behaviors and practices, family knowledge and social norms, and family SES. The indicators of SES were parental educational background and preschool neighborhood SES. All the main analyses in the sub-studies applied multilevel linear regression models, but additionally cross-level interactions were tested in study II and indirect effects in study III. The main results of this research were: 1) Being a boy and having higher levels of surgency temperament were associated with lower SB. Individual characteristics explained the variance in children’s SB more than the settings. 2) Parental perceived barriers related to children’s outdoor PA was associated with children’s higher SB, whereas more frequent parental co-participation in PA, especially in their own yard and in nature, was associated with children’s lower SB. 3) Parental SES differences existed regarding co-participation in PA practices. Compared to parents with high SES backgrounds, parents with low SES reported visiting more frequently their own yards, and this was associated with their children’s lower SB. Parents with high SES reported more frequent visits to indoor sports facilities than parents with middle or low SES backgrounds, but this frequency did not have a statistically significant association with children’s SB. 4) Preschool practices were associated with children’s lower SB during preschool hours. Namely, more minutes spent on physical education lessons, higher numbers of PA theme weeks, more frequently conducted nature trips and early educators’ practices to break children’s SB were related to children’s lower SB. 5) Higher parental SES was associated with children’s higher SB in preschools either a higher number of organized SB theme weeks, a lower number of PA theme weeks or a lower number of PE lessons. This dissertation brings novel and practical knowledge about the important role of parental and preschool practices in relation to preschool children’s SB. The practical implications based on the results of this dissertation encourage the development of public health programs and intervention strategies related to parental and preschool practices enhancing preschool children’s healthy SB habits. More specifically, strategies inspiring families’ frequent co-participation in PA, specifically in nature and their own yards, can be beneficial. In addition, all the preschools should assure frequent nature trips, PE lessons and PA theme weeks for their children, as these practices have the potential to diminish children’s SB. However, the children’s individual characteristics also need to be reflected on better. More research is needed on the mechanisms of SES in children’s SB.
  • Ikonen, Marko (Helsingin yliopisto, 2020)
    In my doctoral thesis I emphasize Clinical supervision. The purpose of my study is to clarify the pattern on the systematic structure and the interaction between the supervisor and the supervisee. I pay attention to their interaction – how they interact together and individually. The studies carried out previously have been fragmentary. Universal Clinical Supervision is used to support professional work in many contexts,and they are even more perplexed. The components of this activity is very difficult to shape and perceive and there exists disagreement as well. There are plenty of conceptual viewpoints for this action and the theories are attributable to them. The professional guidance is internationally construed in an incoherent way. As a result of these ambiguous concepts, these aspirations have resulted in irresolvable dissolution. There is no particular theory for Clinical Supervision. Furthermore, Practices of Clinical Supervision and Työnohjaus are different around the world and the scientists ́ perception of the system of concepts are incoherent. Therefore the study is being progressed slowly. The analyses made during the last decades have maintained or even increased disparity and discrepancy. My study has three objectives.1) First I want to demonstrate that the previous approaches are incomplete to clarify these problems in professional guidance. Thus I declare why these viewpoints are confusing and have retained these problems. 2) Secondly I substantiate that all kind of guidance is constructed with a model of fixed composition and permanent elements. 3) Last but not least l will demonstrate how I will be able to formulate this broader conception. My analysis is derived from the dialogue between the structures and elements connected with philosophical literature. I explicate how the supervisor and the supervisee act individually and together. The structural study complies with the objectives mentioned above. The material for my study consists of articles written in the international nursing magazines and published in Finnish literature of Työnohjaus. In the essential literature published in the 1980’s, there is a lot of debate on its purpose and conceptions to be clarified. My study is to interconnect philosophical literature in connection with human intentional conduct and interaction. As a supervisor I take advantage of my practical experiences in my doctoral thesis. Every sort of guidance is composed of the fundamental norms and they are fixed universally applicable elements. Therefore the supervisor is able to maintain the acceptable supervision praxis. If the patient is not willing to take professional assistance, the guidance is meaningless. Furthermore, the supervisor is compelled to accept conditional premeditated aspirations. The guidance is constructive and efficient if the supervisor takes all these aspects into consideration. Especially if the supervisor attaches importance to preconditions that make individual and social behavior possible. With the help over the structure, the supervisor is to maintain the substance of guidance. The praxis - empirical co-operation - engages both supervisor and supervisee and gets them involved in interaction. After reading my study the supervisors will be able to comprehend and analyze this conduct profoundly. Therefore my thesis gives the tools to develop international study and improve supervisor’s professional praxis.
  • Süvari, Liina (Helsingin yliopisto, 2020)
    At birth, the fluid-filled lung must be cleared to enable postnatal air breathing. Fluid clearance is mediated by the ion and water channels at the alveolar epithelium. The sodium-potassium pump—sodium potassium adenosine triphosphatase (NaKATPase)—generates the transepithelial ion gradient, a prerequisite for the functioning of the key players at the apical alveolar epithelium. These players include the epithelial sodium channel (ENaC) and cystic fibrosis transmembrane conductance regulator (CFTR). Impaired ion and fluid transport leads to respiratory problems, the most common of which in late preterm and full-term infants is transient tachypnea of the newborn (TTN). In preterm infants, the leading cause of respiratory problems—respiratory distress syndrome—results from surfactant deficiency, but impaired lung-fluid clearance is also partly involved. This thesis investigated the earliest postnatal changes in the gene expression of the molecules involved in ion and fluid transport in the airway epithelium. In doing so, we attempted to identify associations between cord-blood hormones and gene expressions in preterm and term human infants. Thus, we gathered nasal epithelial samples at birth and on the first day postnatally to determine the gene expression of the molecules involved in the airway epithelial ion and fluid transport. Gene expression was detected through reverse transcription polymerase chain reaction (RT-PCR). We also collected cord blood at birth and measured the glucocorticoid (GC) and catecholamine concentrations using liquid-chromatography tandem-mass spectrometry. In addition, we used a static lung compliance measurement to estimate the fluid content in the lungs. National registries were used to study the associations between early pulmonary maladaptation and hospitalization due to respiratory syncytial virus (RSV) later in infancy. In term infants, we found associations between the gene expression of the molecules involved in the airway epithelial sodium transport and birth stress hormones—that is, cortisol and catecholamines. Vaginally delivered (VD) newborns exhibited higher stress hormone concentrations than infants born via elective cesarean section (CS). Higher stress hormone levels in the umbilical cord-blood correlated positively with the gene expressions of the sodium transporters. A lower gene expression of the chloride channel at birth associated with better static lung compliance during the initial postnatal hours. In preterm infants, we determined the betamethasone (BM) and cortisol levels in the cord blood following antenatal corticosteroid treatment. The BM levels in the cord blood decreased to low levels two days after the last dose. Preterm infants with respiratory distress syndrome (RDS) had lower cord-blood GC concentrations than those without RDS. Additionally, we found that the gene expressions of the airway epithelial sodium transporters associated with the GC concentrations in preterm human infants. These findings in term and preterm infants provide evidence of the promoting effect of stress hormones in the lung-fluid clearance and, thus, for enhanced pulmonary adaptation. Finally, we identified an association between early postnatal pulmonary maladaptation and hospitalization due to RSV, which may reveal the same pathogenetic background behind these two diseases, suggesting that TTN may not be related to the early postnatal phase alone.
  • Lagus, Heli (Helsingin yliopisto, 2020)
    Although the use of split thickness skin grafts (STSGs) is the gold standard to cover excised deep burns, relatively little is known about how regenerating dermal connective tissue underneath the STSGs affects wound healing and ultimately the outcome from grafting. We compared three ways to treat a wound bed of a deep burn after excision onto fascia. The recipient sites before transplanting the STSGs were: a plain excised wound as a control, a site treated with permanent artificial dermal template (Integra®), and a site with granulation tissue promoted by cellulose sponge (Cellonex™). In study I ten adult burn patients with deep burns covering 22-45 % of total body surface-area were included. Test areas were divided into three equal sections (5 x 10 cm each) that were covered in random order with one of the aforementioned materials. After two weeks, the artificial dermal template and the wound bed under the viscose cellulose sponge were also covered with STSGs. At each site the wound healing process was followed-up for up to one year. Histological analysis from punch biopsy samples and clinical scar assessments were performed using the Vancouver Scar Scale at 3 and 12 months. Study II concentrated on the healing process of STSGs one week and 3 months after grafting from the material retrieved from study I. Healing was assessed using immunohistochemistry of late inflammation, angiogenesis/vascularity, and proliferation . In study III, samples from study I were analysed using proteomics. The differentially expressed proteins (DEPs) were further analysed using Ingenuity Pathway Analysis. Based on the results of pathway analysis the potential role and function of DNAH10 (a motor protein usually found in cilia and flagella) was assessed in a group of patients with psoriasis as well as healthy controls. This thesis has five main findings: 1) A valuable experimental model was designed for objective comparative studies of different treatment modalities with-in a patient-controlled study protocol. 2) In study I, inflammation was more distinctive in the granulation tissue promoted by cellulose sponge. In contrast to expectations, more pronounced inflammation combined with granulation tissue formation did not jeopardize the outcome in terms of scarring problems when the wound bed was covered in a timely fashion. 3) After one year, the clinical outcome and the histological findings of the artificial template site did not differ from the two other test sites. 4) In study III, at one-year follow-up, approximately 12% of all proteins detected demonstrated differential expression across comparisons between the different wound bed treatments, and 5) the biggest differences were found in the expression of the axonemal heavy chain dynein DNAH10. STSGs on pre-treated wound beds demonstrated higher expression of DNAH10 than STSGs of control sites. The expression of DNAH10 was also higher in intra-lesional psoriasis skin samples than non-lesional or healthy control skin samples. The dermal composition of the wound bed has an impact on cellular behaviour during wound healing, and it affects functions such as proliferation and angiogenesis. Surprisingly by the end of the follow-up period, healthy granulation tissue resulted in as little scarring as dermal substitute in the STSGs. Despite the lack of clinical and histological differences with those assessment methods used, clear differences were found in protein levels at the long-term follow-up.
  • Korhonen, Janne (Helsingin yliopisto, 2020)
    Nitrogen (N) and associated carbon (C) cycling were studied in an N-limited boreal Scots pine (Pinus sylvestris L.) forest in Hyytiälä, southern Finland and were compared to two N-rich temperate forests, the Speulderbos Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) forest in the Netherlands and the Sorø European beech (Fagus sylvatica L.) forest in Denmark. Nitrogen and carbon cycling in the Scots pine forest were modelled. These results were compared to continuous year-round observations to obtain an overall understanding of nutrient cycling in the forest. The N balance of the Scots pine forest was calculated based on direct measurements, measurement-based estimations and model results. Nitrogen uptake and resorption by trees were estimated based on continuous measurements. Litter fall dynamics of the Scots pine and Douglas fir forest were compared. Scots pine needle N dynamics were compared between the three forests. Soil was the main N storage in the boreal Scots pine forest and most of this N was in recalcitrant form. Scots pine trees were very efficient at saving and recycling N. This together with atmospheric N deposition, potential N uptake by the canopy and organic N uptake mean that the importance of mineralization as the process driving N cycling may have been overestimated. Most of the N was allocated simply to replace dead tissue in the Scots pine forest. This means that the additional N received via N deposition may significantly increase the N pool size that trees have for extending their biomass N (net growth). Because Scots pine trees were found to be dependent on efficient N use and recycling, this adversely also means that even slight snow and storm damages may cause foliar biomass to decrease due to reduced relocation on top of the direct effect of losing the foliage due to damage, affecting forest carbon sink strength.
  • Rauma, Ville (Helsingin yliopisto, 2020)
    Lung cancer is a nefarious disease causing more deaths than any other cancer worldwide. It is also among the most common cancers in Finland and the leading cause of cancer-related deaths, with 5-year survival rates of only 10-15%. However, more cases are being diagnosed at an earlier, possibly curable stage – radical surgery being the main curative treatment. As more patients survive the disease, long-term results, including quality of life, have attained more weight as treatment outcome measures. Thus, less invasive video-assisted thoracoscopic surgery (VATS) has largely replaced the more invasive thoracotomy as the standard treatment for operable local non-small cell lung cancer (NSCLC) patients. This study assessed the long-term health-related quality of life (HRQoL) among surgically treated NSCLC survivors, determining possible patient and treatment factors affecting the long-term HRQoL and survival among these patients, and comparing the effects of VATS and thoracotomy on the long-term HRQoL. For Studies I and II, we gathered patient and operational characteristics on 579 patients operated on for NSCLC in our clinic at Helsinki University Central Hospital between January 2000 and June 2009. The 276 survivors received two HRQoL questionnaires, the generic 15D and the cancer-specific EORTC QLQ-C30, in 2011. The HRQoL of our 230 respondents was compared with that of the age- and gender-standardized general population. Study II utilized the same data to determine factors predicting survival and long-term HRQoL among NSCLC survivors via regression analyses. Study III compared long-term HRQoL between 88 thoracotomy and 92 VATS patients undergoing lobectomy for local NSCLC in our clinic from January 2006 to January 2013. All of the studies were retrospective in nature. The NSCLC survivors reported significantly lower long-term HRQoL than the general population, with the most severe deterioration observed on the dimensions of mobility and breathing. Long-term survival proved to be moderately predictable by objective patient, disease, and treatment features, such as age, disease stage, and perioperative complications, but the regression models failed to notably predict long-term HRQoL. VATS patients reported significantly lower long-term HRQoL than thoracotomy patients, although the groups had comparable pre- and perioperative characteristics, and particularly no differences favouring the thoracotomy group were observed. The apparent long-term reduction in HRQoL should be considered in patient counselling, and more resources directed to the pre- and postoperative rehabilitation of the most severely affected functions. Long-term postoperative HRQoL seems poorly predictable, or at least the commonly measured clinical features fail to have a marked effect on HRQoL.
  • Viilo, Marjut (Helsingin yliopisto, 2020)
    The present aims of educational policy making and curricular guidelines are calling for collaborative inquiry and knowledge creation skills, which are considered to be a fundamental future competency. In order to participate in the future society and to be able to bring creative opportunities to living, students will need to have experience of creative knowledge work practices from an early stage of their education. However, there is still a need to clarify how the students’ processes of creation and improvement should be organized, and little by little, how to support students’ growth on the way to gradually taking responsibility for their learning. The teacher operates in a decisive position when guiding this process, but there has been little research about the teacher’s actual process when supporting collective object-oriented inquiry. The main purpose of the present study was to concentrate on the pedagogical guidance process in knowledge creation setting from the teacher’s perspective, and clarify how the teacher organizes and orchestrates the longitudinal collaborative inquiry and design learning activities in elementary level. Methodologically, this study is an example of design-based research. In the intervention, a longitudinal investigative one-and-half-year-long learning project, “The Artefact Project”, was organized at a Finnish elementary school in Helsinki. The project was designed with the class teacher and researchers, but the teacher implemented and adapted the plans in practice. During the project, the students (N=32) were guided to analyze artefacts within the cultural context, to study physical phenomena related to them, and to design future artefacts. The intervention was supported with the help of progressive inquiry and learning by collaborative design approaches. Knowledge Forum, a collaborative learning environment, facilitated the activities. The data used in the study consisted of the teacher’s project diaries that had two parts, video recordings, and the Knowledge Forum database. The teacher’s activity diary part created the overall picture from the project. The overall picture was complemented with the results from the database. The teacher’s reflective diaries offered a view of the teacher’s process, interpretations and designing in the background of the project. The teacher’s realized practice was detected with the help of video recordings. The data were analyzed through iterative cycles of qualitative content analyses. Each of the data sources offered a complementary perspective to the teacher’s longitudinal orchestration process, strengthening the reliability of the interpretations. The findings highlighted how the teacher’s orchestration was longitudinally oriented. Her disciplined improvisation was not only momentary spontaneity. It was characterized in the trajectory that she maintained and balanced pursuing the longitudinal, object-oriented inquiry in the background of the activities and sustaining the activities in presence. The teacher’s understanding of the inquiry practices, in conjunction with constant assessment of project achievements, created the basis for focusing and structuring the process and the opportunity for the improvisational enactment collectively. Using the Knowledge Forum enabled longitudinally emergent knowledge advancement through which the members were building the process onwards, based on each other’s contributions. The database showed how the learning activities were organized around the creation of collective artefacts. The results suggest that in order to orchestrate and focus the knowledge creating process, the teacher needs to act as a link between the several levels, tasks, and processes by orchestrating the interplay between different activities and social processes. In addition, it is critical to engage students in work with object-oriented artefacts and to improve their ideas. However, along with the epistemic process with its practices, it is also essential to develop and keep the other processes going along: the reflective, social, and pragmatic practices that maintain the ongoing development of the process. Maintenance of these processes helps the teacher to interlink the efforts across extended time frames, the different lines of inquiry, and results of the ongoing discussions.
  • Heinänen, Mikko (Helsingin yliopisto, 2020)
    Severely injured trauma patients and trauma deaths due to severe injury are a burden to the world as these patients are often young, treatment is costly, and outcomes can be unsatisfactory. Trauma registries around the world collect valuable information about these patients, injury mechanisms, sustained injuries, treatment methods, and outcomes. With this information, research can be performed to better understand how to prevent these injuries and how to provide better care for these patients. New treatment modalities can be tested and analyzed with the data. Trauma registry data are also used for resource allocations and administrative decision making in hospitals, hospital districts, and nationally within countries. International comparisons and collaborations are also possible with this data. Therefore, the data must be valid; it must be reliable, complete, and correct. Otherwise, the conclusions made with the data can be misleading or even completely wrong. The Helsinki Trauma Registry (HTR) is a local trauma registry of the Helsinki University Hospital Trauma Unit. Since 2006, data of severely injured patients has been recorded to the registry. Thus far, there are more than 5000 patients in the registry. This study focused on evaluating the quality of the HTR by assessing the case completeness, data completeness, data accuracy, and data correctness. We compared the HTR data to patient files and Finnish Hospital Discharge Registry (FHDR) data. We also compared a patient group with severe chest injury to a similar group of patients from the German trauma registry (TR-DGU) to verify the comparability of the HTR data with international data and to identify possible differences in treatment, outcomes, and resource use with these patients. This was also an external validation of the HTR. Finally, we used the HTR data on road traffic injury patients as a reference to test the accuracy and reliability of an international, EU-recommended, ICD-AIS mapping tool in Finnish patient material. This tool generates injury severity classification scores from commonly used ICD-10 injury diagnosis codes automatically instead of the AIS (Abbreviated Injury Scale) coding performed by an expert coder. We discovered that the HTR yields quality data of seriously injured patients. Case completeness (97%), data completeness (93-99%), data accuracy (90-95%), and data correctness (97%) were excellent and therefore can reliably be used for research, administrative decision making, and national or international comparisons. Comparisons with the TR-DGU could be performed without problems. The treatment results (main outcome was survival) of patients with severe chest injury were similar in Finland and Germany; however, this was managed in Finland with fewer resources. We observed that the ICD-AIS mapping tool is not reliable in Finnish patient material. In the future, we should establish a high-class nationwide Finnish trauma registry that includes the trauma units of the five Finnish University Hospitals and the largest Central Hospitals that treat multiple severely injured trauma patients per year. In this way, we could more effectively unify treatment protocols, learn from each trauma unit, and improve the already good treatment of severely injured trauma patients in Finland. As treating severely injured patients is costly and resource consuming, we must also know the treatment results to ensure that our work among trauma patients is cost effective. This way we can ensure that limited health care resources are prioritized correctly. This is only possible with an effective nationwide Finnish trauma registry.
  • Mäkinen, Jussi (Helsingin yliopisto, 2020)
    The study of geographical ecology is about how species populations are distributed in space and time. Using a model-based approach to study ecological processes controlling species distributions provides us with the means to compare different ecological hypothesis, predict a distribution of a species population in locations we have not sampled, and assess uncertainty of the predictions. Such models are practical tools for environmental management as well. For this doctoral thesis, I studied statistical modeling methodologies to reveal and accommodate model uncertainties, which originate from natural variation of the environment, inconstant surveying, and lack of important ecological covariate data from a model. I apply the methods to improve decision making process in conservation planning. As a case study I examined how Arctic marine environment has changed during the recent decades and how severely the Arctic marine mammals are exposed to stress from environmental change and disturbance from marine traffic in the Siberian Shelf Sea area. First, to assess the magnitude of change of the hydrographic conditions, I applied spatially-explicit prediction method, which accounts for uncertainties especially from strong spatio-temporal variation of the environment. Second, I developed a method for jointly analyzing different types of species observations, generated by heterogeneous sampling methods. Third, I combined species distribution predictions with the locations of marine traffic routes to define the mortality risk marine oil spill accidents pose to different species. Lastly, I developed approaches for further utilizing prior information in ecological models to improve the identifiability of the different processes that control distributions of species populations. I demonstrated this approach on vegetation data in northern Norway. This thesis shows, that the western part of the Siberian Shelf Area has become warmer and less saline during 1980-2000, but the magnitudes of changes are highly uncertain. The Arctic marine mammals in that area have responded to changes in physical environment, particularly diminishing ice cover, by changing their spatial distributions (ringed seal and polar bear), or becoming less abundant in their original distributional area due their inability to change their home ranges (walrus). The risks of the Arctic marine mammals to become exposed to oil spills are uncertain due to predictive variance of the species distribution models and natural variation of the environment. On average, spring is the riskiest season for oil transportation with respect to the hazards posed to the Arctic marine mammals. Lastly, the identifiability and predictive accuracy of species distribution models were improved by steering the inference with prior restrictions on the random effects, which reflect the unobserved ecological processes. This thesis shows that methods for propagating uncertainties into model predictions from data and model structure are essential for testing ecological hypothesis and predicting into novel areas. Random effects may accommodate assumptions about varying sampling methods and unobserved ecological processes, but they need to be restricted appropriately not to allow them to run over the covariate effects. The methods developed here allow to utilize different data sets and help in tackling shortage of observational data in remote areas. They also assist in making more credible predictions for example into novel climatic conditions. Further, this thesis suggests of propagating uncertainties into areal and temporal comparisons of model predictions from predictive variance and natural variation of the environment. These are essential prediction steps to create credible information for comparing different decisions in environmental management. In general, this thesis provides tools to detect ecological and environmental changes and approaches how to adjust environmental management to those changes.
  • Lahén, Natalia (Helsingin yliopisto, 2020)
    Interactions and mergers between galaxies are among the most spectacular astrophysical phenomena that drive morphological transformations of galaxies as they evolve throughout cosmic times. Specifically, galactic encounters induce star formation due to the compression of the interstellar medium through tidal torques, ram pressure and shocks. The in-situ star formation process is in turn self-regulated by various stellar feedback processes, such as ultraviolet radiation from young massive stars and energetic supernova explosions. The thermodynamical processes in the interstellar gas with temperatures ranging from a few degrees to millions of Kelvins, coupled with the stellar lifecycle, are therefore the subjects of a wide range of ongoing observational and numerical studies. Significant technological advances in recent decades have resulted in a general framework for the formation and evolution of galaxies, but the complete astrophysical picture still remains incomplete. Here we study the evolution of galaxies undergoing mergers by running high-resolution hydrodynamical simulations. We use state-of-the-art numerical methods, post-processing methods, and observational data analysis tools. The simulations presented here span a wide range of initial conditions from gas-rich dwarf galaxies, through Milky Way-like disk galaxies, to massive early-type galaxies which include central supermassive black holes. The employed simulation methods include some of the most sophisticated astrophysical models available for galactic-scale simulations. The cooling of the star-forming gas is modelled in detail using a chemical network, and the newly formed stars sample a mass resolution down to the masses of individual massive stars. We also follow the spatially and the temporally evolving interstellar radiation field emanating from the individually modelled stars into the surrounding interstellar medium, while simultaneously accounting for dust attenuation and gas self-shielding. In this thesis we investigate how the extreme star formation environment produced by a gas-rich, low-metallicity dwarf galaxy merger can be used as a proxy for the turbulent star formation conditions present in the high-redshift Universe. Specifically, we follow the formation of a population of young star clusters during the interactions of dwarf galaxies. We show that the star cluster formation proceeds most efficiently during the starburst phase. Young star clusters are, however, already present with an observationally consistent power-law mass function after the first pericentric passage. We take special interest in the formation and early evolution of the three most massive star clusters, which form hierarchically during the most intense starburst. These objects are shown to evolve in terms of their sizes and surface mass densities to resemble the present-day globular clusters observed in the Local Group. Another simulation, specifically set up to reproduce the observed properties of the Antennae galaxy merger (NGC 4038/4039), is in turn used to study the spatially extended star formation during a disk galaxy merger. The simulation output is post-processed using radiative transfer and the results are reduced with observational data analysis methods. We compare the spatial star formation properties and the metallicity distribution to the observed present-day Antennae. We further follow the enrichment of the interstellar medium through stellar winds and supernovae, and show how the merger remnant evolves into a red and dead elliptical galaxy. We continue simulating the Antennae merger for a prolonged period of time after the coalescence of the galactic disks, and use the surface brightness and kinematic properties of the simulated remnant to search for an observational counterpart to the possible future fate of the present-day Antennae galaxies. The outputs of our numerical simulations are used as well to discern how long a period a galaxy merger can be identified in optical images of observed mergers, and the results are used in building a comprehensive picture of the origin of post-starburst galaxies. Finally, we show how the supermassive black holes, found in the centres of all massive early-type galaxies, end in binaries at the centres of merger remnants of elliptical galaxies. The binaries scour the galactic centres while producing cored surface brightness profiles often observed in ellipticals, and coalesce as a result of gravitational wave driven binary evolution.

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