Väitöskirjat

Recent Submissions

  • Saarela, Svetlana (Helsingin yliopisto, 2015)
    Over the past decades it has been shown that remotely sensed auxiliary data have a potential to increase the precision of key estimators in sample-based forest surveys. This thesis was motivated by the increasing availability of remotely sensed data, and the objectives were to investigate how this type of auxiliary data can be used for improving both the design and the estimators in sample-based surveys. Two different modes of inference were studied: model-based inference and design-based inference. Empirical data for the studies were acquired from a boreal forest area in the Kuortane region of western Finland. The data comprised a combination of auxiliary information derived from airborne LiDAR and Landsat data, and field sample plot data collected using a modification of the 10th Finnish National Forest Inventory. The studied forest attribute was growing stock volume. In Paper I, remotely sensed data were applied at the design stage, using a newly developed design which spreads the sample efficiently in the space of auxiliary data. The analysis was carried out through Monte Carlo sampling simulation using a simulated population developed by way of a copula technique utilizing empirical data from Kuortane. The results of the study showed that the new design resulted in a higher precision when compared to a traditional design where the samples were spread only in the space of geographical data. In Paper II, remotely sensed auxiliary data were applied in connection with model-assisted estimation. The auxiliary data were used mainly in the estimation stage, but also in the design stage through probability-proportional-to-size sampling utilizing Landsat data. The results showed that LiDAR auxiliary data considerably improved the precision compared to estimation based only on field samples. Additionally, in spite of their low correlation with growing stock volume, adding Landsat data as auxiliary data further improved the precision of the estimators. In Paper III, the focus was set on model-based inference and the influence of the use of different models on the precision of estimators. For this study, a second simulated population was developed utilizing the empirical data, including only non-zero growing stock volume observations. The results revealed that the choice of model form in model-based inference had minor to moderate effects on the precision of the estimators. Furthermore, as expected, it was found that model-based prediction and model-assisted estimation performed almost equally well. In Paper IV, the precision of model-based prediction and model-assisted estimation was compared in a case where field and remotely sensed data were geographically mismatched. The same simulated population as used in Paper III was employed in this study. The results showed that the precision in most cases decreased considerably, and more so when LiDAR auxiliary data were applied, compared to when Landsat auxiliary data were used. As for the choice of inferential framework, it was revealed that model-based inference in this case had some advantages compared to design-based inference through model-assisted estimators. The results of this thesis are important for the development of forest inventories to meet the requirements which stem from an increasing number of international commitments and agreements related to forests. Keywords: design-based, Landsat, LiDAR, model-based, multivariate probability distribution, sampling.
  • Levänen, Jarkko (Helsingin yliopisto, 2015)
    The circular economy is a topical issue in public policy and environmental social science. This dissertation offers a critical study of operations intended to develop a circular economy and industrial recycling of materials. The study identifies obstacles that prevent or delay the development of industrial recycling and seeks new solutions for overcoming these obstacles. Institutional obstacles are at the core of this work. They can be identified either as formal obstacles, such as legal or administrative problems, or as informal obstacles, such as problems related to routines or established practices. Traditionally, institutional obstacles have been considered either formal or informal. This dissertation challenges that conception and claims that often the most difficult obstacles are those that operate between the formal and the informal. Operating in between disconnects formal (administrative) institutional reality from informal (operative) institutional reality. It is challenging, if not impossible, to develop formal rules or ways of doing things related to a particular issue once the connection related to that issue has been cut off, because formal and informal realities are structurally dependent on one another. At the same time the dissertation points out that once the disconnection has been identified, it is possible to reunite formal and informal realities. This can be done by means of an institutional feedback mechanism that fits the local circumstances. Institutional feedback means maintenance of knowledge exchange between actors and groups of actors operating in different realities. In an industrial context, institutional feedback may, for example, enable the development of new kinds of recycling opportunities and continuous intensification of the materials utilization. Novel institutional feedback mechanisms may also offer new possibilities for overcoming obstacles in the development of recycling and the promotion of the circular economy in different sectors of society. This dissertation consists of four case studies that investigate the management of materials and other resources in industrial units located in the Bothnian Arc region of northern Finland. The industrial units studied cover the fields of Finland s traditional basic industries: the metal, wood-processing, and chemical industries. The primary data for this study consist of interview materials, questionnaires, and documentary sources. The main points of interest are two types of recycling: 1) the utilization of different leftover materials as replacements for existing products or as raw materials, and 2) the development of completely new kinds of recycling products and innovative recycling processes. Both types are considered especially from the perspectives of institutional obstacles and feedback mechanisms aimed at overcoming the obstacles. The key result of this study is a theoretical presentation of the structure and functioning of an institutional feedback mechanism. To function in a complex operational environment, an institutional feedback mechanism should consist of two components: the production of the right kind of knowledge (knowledge networking) and the management and maintenance of a network of actors that are central to the specific aims (network governance). This dissertation shows different ways to identify, conceptualize, and study these two components of institutional feedback mechanisms. By means of an example, the study also demonstrates how an institutional feedback mechanism can be constructed and how it can be utilized to overcome practical problems and profound institutional obstacles. Policy recommendations for the management of complex operational environments and for the promotion of a circular economy and material efficiency are also presented.
  • Gruber, Christina (Helsingin yliopisto, 2015)
    Both the ability to gain a high dominance status and having an efficient immune defence are favourable qualities that typically increase fitness in social and host-parasite interactions. Individuals with a high dominance status are predicted to gain fitness-related benefits from prior access to limited, defensible resources, such as food and matings. Immune defence mechanisms, on the other hand, have evolved to minimize the fitness costs of parasitic infections. The relative significance of a high dominance status and strong immune defence for individual fitness is, however, affected by the quality of the environment. The aim of this thesis is to improve the understanding of environmentally determined variation in dominance status, immune defence and their consequences for individual fitness. I use the native noble crayfish (Astacus astacus), the invasive signal crayfish (Pacifastacus leniusculus) and the highly virulent, invasive Aphanomyces astaci, the causative agent of the crayfish plague, as my study models. I first experimentally test theoretical predictions on how major ecological factors, including food availability, predation risk and population density, influence behavioural decision-making in fight contests, especially with regard to the maintenance of dominance hierarchies between size-matched crayfish. Using natural noble crayfish subpopulations with different crayfish plague history, I then explore whether variation in immune defence and crayfish plague resistance is potentially explained by local adaptation to the disease, or alternatively by geographical divergence. By keeping noble crayfish experimentally under constant environmental conditions, I finally determine whether seasonal variation in immune defence is endogenously regulated. My results show that individuals that had achieved dominant status in non-resource fight contests have an advantage in monopolising a limited, defendable food resource in a future contest. Furthermore, I find evidence that as population density increases, the division of the resource between dominants and subdominants becomes more unequal. Generally, my results suggest that due to ecological factors the dominance status of individuals can be more dynamic than theory predicts, especially when the contestants have similar fighting ability. For example, in line with the asset-protection principle, individuals having achieved dominant status in a non-predation risk contest increase their submissive behaviours in the presence of a predation threat, giving subdominants the opportunity to win a larger percentage of bouts in the predation risk contest. My results also reveal evidence for geographical variation in resistance to the crayfish plague and immune defence that is, however, independent of historical disease outbreaks in the study subpopulations. Furthermore, for the first time in invertebrates, my results demonstrate reproduction-related endogenous seasonal variation in the immune defence of noble crayfish. Overall, my results suggest that ecological factors, such as population density, predation risk and disease history, have to be taken in to account to better understand the causes and consequences of dominance status and immune defence in any individual species.
  • Hovi, Aarne (Helsingin yliopisto, 2015)
    This thesis presents basic research on how airborne LiDAR measurements of forest vegetation are influenced by the interplay of the geometric-optical properties of vegetation, sensor function and acquisition settings. Within the work, examining the potential of waveform (WF) recording sensors was of particular interest. Study I focused upon discrete return LiDAR measurements of understory trees. It showed that transmission losses influenced the intensity of observations and echo triggering probabilities, and also skewed the distribution of echoes towards those triggered by highly reflective or dense targets. The intensity data were of low value for species identification, but the abundance of understory trees could be predicted based on echo height distributions. In study II, a method of close-range terrestrial photogrammetry was developed. Images were shown as being useful for visualizations and even the geometric quality control of LiDAR data. The strength of backscattering was shown to correlate with the projected area extracted from the images. In study III, a LiDAR simulation model was developed and validated against real measurements. The model was able to be used for sensitivity analyses to illustrate how plant structure or different pulse properties influence the WF data. Both simulated and real data showed that WF data were able to capture small-scale variations in the structural and optical properties of juvenile forest vegetation. Study IV illustrated the potential of WF data in the species classification of larger trees. The WF features that separated tree species were also dependent on other variables such as tree size and phenology. Inherent between-tree differences in structure were quantified and the effects of pulse density on the features were examined. Overall, the thesis provides basic findings on how LiDAR pulses interact with forest vegetation, and serves to link theory with real observations. The results contribute to an improved understanding of LiDAR measurements and their limitations, and thus provide support for further improvements in both data interpretation methods and specific sensor design.
  • Rolando, Sara (Helsingin yliopisto, 2015)
    The aim in this study is to narrow the gap in knowledge about how young people understand their direct (personal) and indirect (others ) drinking experiences by investigating images of alcohol (Sulkunen, 2007) among Italian and Finnish adolescents and young people on the threshold of adulthood. Italy and Finland are considered examples of geographies (Sulkunen, 2013) characterised by different social values and socialisation practices, but also facing common global challenges (Beck, 2005). The concept of individualistic and collectivistic cultures is used as a framework to describe the variations observed in young people s images of the risks related to alcohol consumption and responsible drinking. Individualistic cultures represent a socio-cultural system in which individuals are expected to develop an independent personality, and autonomy and self-maximisation are the prominent values, whereas collectivistic cultures encourage adherence to norms, values, roles and familial authority (Dwairy 2002). Within this framework, Finnish and Italian cultures are perceived as exemplifying individualism and family-oriented collectivism, respectively. The six published research articles, which together with this summary comprise the whole work, were co-authored by various Italian and Finnish researchers and are based on three main sets of data collected in focus-group (FG) interviews: 1) 32 FGs involving 191 participants from four different cohorts organised in Helsinki (FI) and Turin (IT); 2) 40 mixed-gender FGs involving 220 pupils aged 15-16 organised in Turin and Cosenza (IT) and Helsinki, and 10 FGs involving 30 parents and 32 teachers organised in Italy; 3) 32 FGs including 105 male and female pupils aged 13-14 and 15-16 and living in urban (Milan and Helsinki) and rural areas (Ciriè and Orivesi). The Reception Analytical Group Interview (RAGI) technique was used for collecting most of the data (sets 2 and 3), with visual images as stimuli, the aim being to enhance comparability in qualitative research (Sulkunen and Egerer 2009). Data set 1) was collected by means of verbal questioning and photographic stimuli. The results indicate that collectivistic, and particularly family-oriented cultures have thus far contributed to shaping less risky drinking patterns among young people. There are many reasons for this, including the more coherent and active role of parents in the socialisation process, the presence of shared social norms, and a greater awareness of the risks of drinking that are beyond the individual s control. Conversely, a parenting model that places more emphasis on independence and self-efficacy, which is typical of the more individualistic geographies, conveys trust in an individual s own competence to handle drinking, which in turn leads to a lack of attention to risks that are beyond the individual s control, in other words risks that are contextual, social and inherent in the substance. However, the global trend towards individualisation and the complex nature of the transition to adulthood could soon undermine the more protective collectivist images of alcohol.
  • del Amo Páez, Eva María (Helsingin yliopisto, 2015)
    Drug discovery and development is a long process: it takes usually 12 to 15 years before a drug candidate reaches the market. The pharmacokinetics of the drug is an important aspect of drug discovery and development, because the drug must reach its target site and exert the therapeutic response. The pharmacokinetic parameters of new compounds should be investigated early in drug discovery. Pharmacokinetic predictions can be made with Quantitative Structure-Property Relationships (QSPR) which are computational models that correlate chemical features with pharmacokinetic properties. The correlations are based on in vivo or in vitro pharmacokinetic data and molecular descriptors. QSPR models can be used to predict the pharmacokinetic parameters even before any actual drug synthesis and can be exploited to guide drug discovery. Pharmacokinetic models can also simulate concentration profiles of drugs during the drug discovery and development process. It was decided to develop QSPR models of pharmacokinetic parameters of drugs to be delivered by the systemic or ocular routes. A combination of Principal Component Analysis and Partial Least Square multivariate statistical methods was used to obtain QSPR equations for volume of drug distribution and fraction of unbound drug in plasma. Parallel modelling of these parameters resulted in acceptable R2 (0.58 - 0.77) and Q2 values (0.55 - 0.58). These models are based on a large set of structurally unrelated compounds, they are open and they have a defined applicability domain. Charge and lipophilicity related descriptors were the relevant ones which influenced the volume of distribution and free fraction of drug in plasma. Pharmacokinetics is an important factor in the development of ocular medications, because the ocular drug targets are difficult to reach, particularly in the posterior tissues such as retina and choroid. Therefore, drugs need to be injected intravitreally in the treatment of retina and choroid diseases (e.g. in exudative age-related macular degeneration) and thus prediction of intravitreal pharmacokinetics would be especially advantageous in ocular drug discovery and development. The first comprehensive collection of intravitreal volume of distribution and clearance values of compounds was collated based on extensive rabbit eye data from the literature. Moreover, predictive QSPR models for intravitreal clearance and half-life were created which had R2 and Q2 values of 0.62 0.84 for clearance and 0.61 - 0.80 for half-life. LogD7.4 and hydrogen bonding capacity defined the intravitreal clearance and half-life of compounds with a molecular weight below 1500 Da. The intravitreal volumes of drug distribution lay within a narrow range (80% within 1.18 - 2.28 ml). The QSPR models for intravitreal clearance and the typical values for intravitreal volumes of distribution were implemented in pharmacokinetic simulation models; the simulated profiles based on the real and predicted pharmacokinetic parameter values were similar. Thus, a combination of QSPR and pharmacokinetic models can be used in drug discovery and development to aid in the design of drugs and drug delivery systems. A comprehensive comparison of intravitreal pharmacokinetic data between rabbit and human was carried out to clarify the translational value of the rabbit model. The analysis revealed that the rabbit can be considered as a clinically predictive animal model for intravitreal pharmacokinetics of small molecules (18 Da - 1500 Da) and macromolecules (7.1 kDa - 149 kDa). There was a correlation between the intravitreal clearance values in human patients and healthy rabbits; they showed similar, but not identical, absolute values. The intravitreal pharmacokinetics of small molecules is mainly governed by permeability-limited clearance across blood-ocular barriers and occurs via the posterior route, whereas large molecules are cleared mostly via the anterior route. Although the literature contains some claims about the significance of the viscosity of the vitreous, it seems that this is not a major factor in drug elimination from the eye. In conclusion, new in silico tools were generated for systemic and ocular pharmacokinetics and drug delivery. These models can be exploited in industrial drug discovery and will hopefully speed up the development of new medications.
  • Markula-Patjas, Kati (Helsingin yliopisto, 2015)
    Children with juvenile idiopathic arthritis (JIA) are predisposed to compromised bone health and alterations in body composition because of chronic inflammation, nutritional and hormonal disturbances, limited physical activity and glucocorticoid (GC) therapy. Compromised bone health may present as pathological vertebral compression fractures, but data on their prevalence and risk factors in children are limited. Excess fat, and especially adipose tissue-derived adipokines leptin and adiponectin, may also contribute to impaired bone health. Furthermore, adipokines modulate immunity and inflammation in adults with rheumatic diseases, but their role in JIA has not been explored. We evaluated bone health in patients with severe JIA and investigated body composition and adipokines and their contribution to bone health and disease activity in JIA. We recruited two cohorts of patients for cross-sectional studies. The Severe JIA Cohort comprised 50 patients with severe polyarticular or systemic JIA. The GC-treated Cohort included 50 patients with JIA with mostly mild to moderate disease severity and at least three months' exposure to systemic GC. The results were compared with those of sex-and age-matched healthy controls. The study protocol included clinical and laboratory assessments, evaluation of bone mineral density (BMD) and body composition by dual-energy X-ray absorptiometry (DXA), spinal radiography and spinal magnetic resonance imaging (MRI). Spinal radiography showed vertebral compression fractures in 22% of the patients with severe JIA. Patients with fractures had higher weight-adjusted cumulative GC dose, higher disease activity and higher body mass index than those without fractures. Bone age-corrected BMD Z-scores for lumbar spine and whole body were similar between those with and without fractures. On spinal MRI, altogether 28% of patients with severe JIA showed vertebral fractures and several other vertebral changes, including end plate irregularities in 26%, anterior vertebral corner lesions in 16% and disc changes in 46%. Based on concentrations of bone turnover markers, the patients with severe JIA had increased bone resorption, but normal bone formation. Further, patients with severe JIA had increased body adiposity, and their serum leptin was increased even independently of fat mass. Leptin showed an inverse association with bone turnover markers in patients, while in controls the association was dependent on fat mass. In the GC-treated Cohort, fat mass, lean mass and serum leptin and adiponectin were similar to those of controls, but patients had slightly lower BMD values than controls. Those patients with lumbar spine BMD Z-score -1.0 tended to have higher serum leptin values than those with higher BMD Z-scores, but in regression analysis leptin was not associated with BMD. Adipokines did not correlate with current disease activity in either patient cohort. Patients with severe JIA have compromised bone health based on high prevalence of compression fractures. Risk factors include high GC exposure, high disease activity and high body mass index. BMD, as measured by DXA, is unable to differentiate between those with and without compression fractures. According to spinal MRI findings, patients with severe JIA have, besides compression fractures, several other changes involving intervertebral discs and vertebral end plates; the clinical relevance of these remains uncertain. Patients with severe JIA are prone to high adiposity, whereas those with less severe disease have normal body composition despite previous GC exposure. Leptin may negatively contribute to bone metabolism in severe JIA, but larger and longitudinal studies are needed to prove causality and to evaluate whether these preliminary findings are generalizable to other JIA groups. We did not observe a correlation between leptin or adiponectin and disease activity in either JIA cohort. The possible role of adipokines as a modulator of immunity and inflammation in JIA remains to be evaluated.
  • Ma, Hairan (VTT Technical Research Centre of Finland Ltd, 2015)
    Milk proteins, sodium caseinate (CN) and whey protein isolate (WPI) are used in food industries as emulsifiers. The stability of an O/W emulsion is dependent on the electrostatic and steric repulsion provided by the interfacial proteins against droplet aggregation or lipid oxidation. Therefore, modifications of the surface charge or the interfacial conformation of protein emulsifiers are expected to enhance their emulsifying properties and emulsion stability. In this present work, sodium caseinate and whey protein isolate were modified by different chemical and enzymatic approaches. The modified proteins were characterized using multiple techniques, and the effect of these modifications on emulsifying properties of proteins and emulsion stability was investigated. Succinylation converts the positively charged amino groups into negatively charged carboxyl groups, lowering the isoelectric point (pI) of protein. The ethylene diamine (EDA) modification worked in the opposite way, leading to an increased pI. The extent of these two modifications was studied using SDS-PAGE and MALDI-TOF mass spectrometry. The pI of succinylated and EDA modified milk proteins was studied using zeta-potential measurement. As a result, the succinylation to full extent altered the pI of CN from 4.2 to 2.7, and the EDA modification shifted the pI of CN and WPI from 4.2 to 9.4 and from 4.9 to 9.5 respectively. The pH stability of emulsion made with the modified milk proteins was monitored by following the increase of particle size during storage. The results suggested that succinylation and EDA modification could enhance the emulsion stability at pH 4 7 by increasing the electrostatic repulsion between droplets. Regarding the enzymatic modification of milk proteins, the laccase and transglutaminase (Tgase) catalyzed cross-linking were applied on WPI and CN respectively. In order to improve the reactivity of WPI towards the laccase, a vanillic acid modification was carried out to incorporate additional methoxyphenol groups into the protein surface. The cross-linking of vanillic acid modified WPI (Van-WPI) by laccase was studied using SDS-PAGE. The extent of cross-linking of Van-WPI was found to be significantly higher compared to the unmodified WPI and the combination of WPI and free phenolic compound as a mediator. The effect of laccase catalyzed cross-linking on storage stability of emulsions was investigated by visual observation and confocal microscopy. The post-emulsification cross-linking was proven to enhance the stability of the emulsions prepared with Van-WPI during the storage. The reduced droplet coalescence could be most likely attributed to an extended interfacial protein layer formed via the interaction between the adsorbed proteins and non-adsorbed proteins in the water phase. In contrast with the limited extent of cross-linking of WPI by laccase, CN was extensively cross-linked by Tgase. The physical stability of emulsions was studied by measuring the increase of particle size during storage, and the oxidative stability was evaluated by following the formation of fatty acid hydroperoxides and volatile compounds in different stages of the lipid oxidation. The pre-emulsification cross-linking showed no obvious influence on the physical stability of CN emulsion but significantly improved its stability against lipid oxidation. The improvement of oxidative stability of emulsions could be contributed to a thicker and denser interfacial protein layer, which thus increases the amount of anti-oxidative groups located at the interface and provides a stronger barrier against competitive adsorption by oil oxidation products.
  • Nevanen, Saila (Helsingin yliopisto, 2015)
    This research focuses on one arts education project which was carried out in Helsinki in early childhood education centres and schools. This study is an evaluation research which concentrates on art education s connections to learning, wellbeing and communality; it views kindergarten and school as arts learning environments and at arts education as a multiprofessional col-laboration between teachers and artists. The arts education project, which was started in Helsinki in 2000, was offered to children who were under school age (3 6 years old) and at ele-mentary school age (7 9 years old). The data consists of interviews of the teachers, artists and principals of the kindergartens (N=23), the narratives of the closing report (N=9) and the follow-up materials of the project. The method of the research was multidimensional evaluation. The research includes five independent articles and a summary that con-nects the entirety of the research. Each theme is included in one independ-ent article, each of which was published in international peer-reviewed journals. Article I analyses the multiprofessional collaboration between teachers and artists. Article II focuses on the possibilities of arts education in developing learning abilities. Article III explores kindergarten and school as learning environments of arts education. Article IV highlights the evalua-tion of the arts education project through a multidimensional evaluation method. The last article, number V, analyses the long-term impacts of the arts education project in kindergartens and schools. The results show that well-executed, long-lasting arts education projects may support and promote children s wellbeing and their learning abilities. It was easy to motivate and direct the children in activities that connected target-oriented work with natural play. Arts education can also be used to strengthen the unity of the community between early childhood education centres, schools and neighbourhoods. The multiprofessional collaboration between the teachers and artists con-nected their skills and professional abilities, but successful cooperation also required the ability to handle additional interests and tensions. The long-term impact evaluation showed that five out of ten participating kindergartens still continue the developmental work started in the project. The project work was also seen as an excellent way to continue or update training.
  • Eränpalo, Tommi (Helsingin yliopisto, 2015)
    Abstract This dissertation deals with young people s civic skills and how these competences can be developed particularly in civics education at school by means of gamification. The dissertation consists of four sub-studies written in article form as well as a summary. The articles examine young people s civic behaviour from the perspective of conceptions of democracy, civic competence and civic identity. The current generation of youth and young adults seems to be shunning the traditional structures of civic participation and political decision making. Young people are re-evaluating their own roles in civic discussion and are often choosing methods that are outside the official channels. To further develop civic activism, this state of affairs should be changed, since our future decision makers will ultimately emerge from this group of people. The role of the school is seen as essential in scientific debate on the subject. The dissertation commences with the question of how deceptive the suggestion is that young people are passive, and how civic education didactics need new ways to recognise students involvement in civic matters. This query is addressed by means of finding new methods for civics education, using, for example, gamification and dialogue education. The intention of the dissertation is to answer the following questions: a) What aspects of young people s civic skills can be detected in the deliberation resulting from game playing? b) How should civics education at school be developed to strengthen young people s inclusion in civic affairs? The Grounded theory method is applied in the study. Each dissertation article introduces a new perspective on the research phenomenon, and the analysis of the research material proceeds in stages revealing new information on young people s civic competence. The theoretical conclusions of the study are presented in the summary. The first article focuses on the public image of young people s civic competence, which has been marked by pessimism in the early 21st century. This negative image has been publicly debated in conjunction with international surveys indicating young people s passive behaviour in civic orientation (CIVED 1999 and ICCS 2009). The article looks for a new perspective by ques-tioning the pessimistic interpretations of these surveys. It also presents new research evidence of a more active youth culture. The second and third articles venture deeper into the world of young people s civic competence. The image of young people being passive is often maintained by the conventional discussion culture in schools, one that avoids open ideological and political debate and does not particularly encourage deliberation on civic matters. The articles raise issues concerning the atmosphere in the classroom as well as the role of the student in education and society as a whole. It also presents the Act now! game, developed by the author and the author s students. The game aims to provide a framework for dealing with civic issues by means of deliberation. The fourth article introduces the concept of dialogue in education, and a comparative Scandinavian example of it. The Act now! game was played in Finland, Sweden and Norway. The article focuses on dialogue education as part of young people s civics education, and examines the features that emerge from analysing civic identity among Scandinavian youth. The summary presents the results in a way that is typical to the Grounded theory method. It then provides a summarizing analysis of them. The results justify claiming that teaching methods involving deliberation in civic education stimulate and strengthen young people s participatory civic orientation as well as their civic competence. The summary also speculates on the possibilities of increasing young people s motivation to participate in civic issues. The competences that arise from young people s deliberation indicate how the young are capable of responding to civic responsibility. The results also high-light the democratic-political need to create a forum in which young people may engage in civic deliberation. The ongoing curricular reform in Finnish primary and secondary schools will emphasise student involvement as well as creating a new and more active role for students. Accordingly, the results of this study can be implemented in civics teaching. They also suggest that deliberation instruments such as the Act Now! game could be used as a solution to didactic needs on a wider scale. A game-like method offers an example of dialogical teaching that enables a path to deliberation. Keywords: Civic competence, deliberation, gamification, inclusion
  • Marionneau, Virve (Helsingin yliopisto, 2015)
    Public and academic discussion of gambling has been characterised by numerous contradictions. Although definitions of gambling as a sinful activity or even as a crime are now things of the past, the contemporary debate on whether gamblinkö-g is actually a social problem, an individual problem, a socially beneficial activity or perhaps just another form of consumption has been heated. This study maintains that no such conclusive definition of the social role of gambling can be found because societies discuss gambling differently based on contextual conditions. The research question asks whether the understandings of gambling differ between two European societies, Finland and France, and if so, how these differences are manifested. To answer this question a comparative study has been conducted. The research data consist of group interviews conducted among gamblers in Finland and in France, along with legal texts that regulate gambling in each country. Finland and France were chosen for this study owing to practical constraints but also to represent two European countries with differing gambling traditions but with similar overall availability of gambling opportunities. This made it possible to analyse institutional differences related to provision and legislation, as well as to compare cultural differences related to habits of thought and deep cultural structures. The study argues that social contexts influence not only the kind of gambling offers made available, but also how gambling is discussed, how it is justified, how it is understood and even how ensuing problems are conceptualised. Sociological theory is used to show that the way we understand social concepts such as gambling is specific to a particular cultural and institutional context. The results show that Finland and France differ in terms of how their gambling legislation has been justified and in how gamblers themselves discuss the activity. Differences were found in relation to what was considered an acceptable reason to gamble, what was considered the cause of problem gambling and how well the gambling offers of their respective countries were accepted. It is argued here that these differences reflect separate historical traditions of gambling, varying institutional organisations providing gambling opportunities, cultural differences in how blame is assigned, and varying conceptualisations of individuality in Finland and France. The analysis supports the hypothesis, showing that the way gambling is understood depends on the social context. The comparative analysis also demonstrates that gambling is a social issue and should be treated as such when its consequences, its availability or its importance to societies are discussed.
  • Kangasluoma, Juha (Helsingin yliopisto, 2015)
    Atmospheric aerosols exhibit the largest uncertainties in the radiative forcings of the Earth s climate. A large fraction of the uncertainties originates from the aerosol-cloud in-teractions, a process which is not understood completely. Understanding the processes related to aerosol formation and growth will help to narrow down these uncertainties and understand the anthropogenic fraction of the radiative forcings. Atmospheric new particle formation creates a large fraction of the particles present in the atmosphere. To understand the process thoroughly, direct measurements of the par-ticle concentration and chemical composition are needed. This need has pushed the in-strument development forward, allowing measurements which were not possible five years ago: a direct measurement of the concentration and composition of sub-3 nm particles. The purpose of this thesis was to develop methods to calibrate the instruments to reliably measure sub-3 nm particles. We developed an experimental setup to reproducibly generate well-characterized sub-3 nm particles in the laboratory, with the particular aim to characterize particle counters. During the course of the work the particle generation meth-ods were modified to provide test aerosols smaller than 3 nm, of which chemical composi-tion was monitored simultaneously with a mass spectrometer. Together with the modifica-tion of the generators, commercial fine particle counters were shown to be capable of sub-2 nm particle detection Controlling the properties of the generated particles was found to be extremely important in the measurement of sub-3 nm particles. With the various test particles we studied the importance of the particle size, charging state and chemical composition on their detection, as well as the importance of the particle counter working fluid on the de-tection. The chemical composition of the particles was the most important factor determin-ing the smallest detectable size in the sub-3 nm size range. One of the particle counters, the Particle Size Magnifier (PSM) was characterized more in depth at low pressure conditions and various operation temperatures, providing in depth understanding on the instrument operation. The results provided key aspects on how the instrument should be operated in field experiments in order to obtain reliable data. In laboratory conditions the inversion routine of the particle PSM was experimentally verified against a high resolution differential mobility analyzer and an electrometer. The results of this thesis provide basic knowledge on sub-3 nm particle generation and detection. The utilization of several generation techniques and test aerosols of differ-ent chemical composition, the operation of sub-3 nm particle detectors was improved along with a more in-depth understanding on the parameters governing the particle - vapor interactions. The laboratory instrumentation used in this thesis offer tools for chemical (composition) and physical (electrical mobility, charging state) characterization of the sub-3 nm particles. Overall this thesis improved the methods dealing with sub-3 nm particles from their generation to characterization, and to their detection. The methods are directly applicable to other fields of nanomaterial production and characterization, as well as envi-ronmental and industrial nanoparticle monitoring.
  • Visakko, Tomi (Helsingin yliopisto, 2015)
    The study examines the mediation and evaluation of personhood in light of Finnish online dating advertisements. The main focus is on the performance and interpretation of what has been called self-promotion, or the idealization of the self in relation to others. The study operates with concepts originating from discourse studies and anthropology under the overarching framework of pragmatism-based semiotic anthropology. The online dating advertisement genre is approached as a cultural instrument of personhood and intersubjective interaction in which writers step into a controlled performance of a promotional persona in order to instigate social relations (only) with desirable and ideal others. The primary data consists of 111 Finnish-language online dating advertisements collected from two online dating services in 2007. In addition, a questionnaire was held for a group of university students to elicit examples of actual interpretations. A third set of data consists of cultural metadiscourses that reflect on online dating advertisements as a type of interaction (online dating guidebooks, Internet discussions and articles, a segment of a TV program). Such backstage discourses illuminate the kinds of reflexive metapractices and interpretive assumptions that do not usually come up explicitly in actual advertisement-based interactions. The study shows that stereotypic cultural understandings of self-promotion often focus on specific kinds of evaluative stances and their reliability or appropriateness, whereas many actually occurring phenomena are entirely overlooked. Such biased stereotypes may be one reason for the fact that evaluative stancetaking seems to be an expected but often problematic act in online dating advertisements. The study also illuminates the non-narrative organization of personhood, selfhood, and biography, as taxonomic and hierarchical structures of theoretical representations are one of the most salient textual patterns in the data. More generally, the study draws attention to the importance of the indexical patterning of text-artifacts. Textual patterning at all layers, from macrostructures to orthography, becomes interpreted as signs of personhood contributing, for instance, to particular views of subjectivity, a level of meaning often overlooked in studies of online communication. Moreover, the study stresses the importance of reflexive models and ideologies of interaction. For instance, the nature of online dating advertisements as an intersubjective encounter can be understood in almost entirely opposite ways by different interpreters (e.g., as distant versus intimate, or authentic versus inauthentic ).
  • Jokinen, Tuija (Helsingin yliopisto, 2015)
    We live in a world full of aerosols and witness their existence constantly. Changes in visibility, road dust and pollen filling the air in the spring time and even dosing some medicines are all related to aerosols. The most important aspect for this thesis is however, the formation of aerosol precursor molecules and clusters and their possible effects on aerosol properties. Different types of aerosols e. g. organic and inorganic, ice and pollen, biogenic and anthropogenic, when acting as cloud condensation nuclei (CCN), can change the optical properties of clouds and thus have different climate effects via changes in precipitation or cloud cover. Also the mechanism how the small cloud seeds are formed can have a major effect on the cloud properties. Clouds reflect and scatter radiation cooling the atmosphere but to this day aerosol effects still form the largest uncertainty in estimates of the climate of the future. Low-volatility compounds in the ambient air are the most important components in both aerosol formation and their growth to sizes that can affect cloud properties such as their reflectivity. The vapours in the atmosphere form around half of the first precursors of aerosol particles via nucleation, still molecular in size. The rest is released directly into the air e.g. by the traffic or from the oceans as sea salt. Neutral molecular size precursor substituents are difficult to detect because they lack electric charge and their concentrations rarely exceed the detection limits of the used measurement instruments. This is one of the reasons why the first steps of nucleation process are still partly unsolved after decades of research. This thesis concentrates first in development of selective methods and ultrasensitive instrumentation for the detection of acidic aerosol precursor molecules and clusters. These compounds include sulphuric acid, which is known to be highly important precursor for new particle formation. This thesis presents the first ambient measurements with the new instrumentation and even though sulphuric acid was detected in relative high concentrations during a particle formation event, no ambient cluster formation was yet observed. The same instrumentation was further used in an ultraclean chamber experiment were sulphuric acid and dimethyl amine formed growing clusters and they were detected from the smallest clusters all the way up to ~2 nm size. These compounds are likely to dominate the new particle formation with low-volatility organic compounds. Tens of thousands of volatile organic compounds (VOC) are emitted in the atmosphere by terrestrial vegetation, marine environments and anthropogenic sources, making the search for the meaningful compounds for new particle formation extremely difficult. In this thesis a new group of extremely low-volatility organic compounds (ELVOC) from terpene oxidation are introduced. They form a large source of secondary organic aerosol (SOA) and might help explaining the former big gap between the measured and the modelled SOA loads in the atmosphere. Formation of these compounds from RO2 radicals via rapid autoxidation process to stable molecules is also studied in details in laboratory experiments. This thesis also utilizes a global modelling framework, where the measurement results are applied. According to this thesis, ELVOC in particular are in crucial role when estimating SOA and CCN formation in the air. All together this thesis is a comprehensive study of both organic and inorganic low-volatility precursor molecules and clusters in the atmosphere, from their origin, formation mechanisms, and measurement techniques to their possible effects on climate now and in the future.
  • Tumiati, Manuela (Helsingin yliopisto, 2015)
    Breast cancer is the second most common cancer in the world and the most common cancer among women. Germ-line mutations in the DNA repair gene RAD51C (RAD51 paralog C) predispose women to breast and ovarian cancers, yet the mechanisms by which a lack of RAD51C causes tumorigenesis are poorly understood. RAD51C deficiency is thought to promote cancer by preventing correct repair of DNA double-strand breaks, leading to accumulation of somatic mutations and genomic instability, a cancer hallmark. Similarly, defects in other genes involved in repair of DNA double-strand breaks, such as BRCA1 (breast cancer 1, early onset), BRCA2 (breast cancer 2, early onset), or PALB2 (partner and localizer of BRCA2), are linked to breast cancer, suggesting that the mammary gland is particularly susceptible to genomic instability. We know that RAD51C-null cells from several organisms present a number of chromosomal aberrations, and Rad51c knockout mice die during early embryogenesis from massive Trp53-mediated apoptosis. A previously generated mouse model demonstrated that when Rad51c is lost together with Trp53, multiple tumors develop approximately at one year of age. However, while Trp53 knock-out mice predominantly develop osteo- and myosarcomas, a spontaneous loss of both Rad51c and Trp53 in double-mutant mice leads mostly to development of epithelial-derived carcinomas, especially in mammary glands, skin, and skin-associated specialized sebaceous glands. While suggesting a possible role for Trp53 in the Rad51c-mediated tumorigenesis, this study left several questions unaddressed. First, the ability of Rad51c loss to induce tumor formation independently of Trp53 stood as an open question. Second, the mechanisms by which Rad51c might cause malignant transformation remained unclear. Last, there was complete absence of information about the role of RAD51C in the mammary gland. We set out to fill these gaps by generating a skin and skin-associated Rad51c knock-out mouse model. For this purpose, we conditionally deleted Rad51c and/or Trp53 from basal cells of the epidermis and ectodermal-derived glands using Keratin 14 Cre-mediated recombination. With this model, we demonstrated that deletion of Rad51c alone is not sufficient to drive tumorigenesis but impairs the proliferation of sebaceous cells and causes their transdifferentiation into terminally differentiated keratinocytes. In addition, we reported that Rad51c/p53 double mutant mice develop multiple tumors in skin and mammary and sebaceous glands at around six months of age, while Trp53-mutants have a tumor-free survival of 11 months and a lower tumor burden. We also observed that in situ carcinomas are detectable in Rad51c/p53 double mutant mice as early as four months of age, which provided a tool for studying the early phases of tumorigenesis. Notably, we reported that mouse mammary tumors recapitulate several histological features of human RAD51C-associated breast cancers, especially a luminal-like, hormone receptor-positive status. Finally, we described that loss of RAD51C causes chromosomal aberrations in both mouse and human cells, providing a direct translational link between the phenotype observed in the two species.