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  • Özcan-Ketola, Nergiz (Helsingin yliopisto, 2015)
    In this thesis, structural effects on magnetic response properties: magnetically induced ring currents, the ESR g-tensor and hyperfine coupling tensor, and NMR chemical shifts, are investigated computationally with DFT methods, using various exchange-correlation functionals and basis sets. Magnetically induced currents are calculated for thieno-bridged porphyrins with the emphasis on the aromatic character of the systems, the degree of which is investigated for varying molecular modifications. The ESR g-tensor, as well as the hyperfine coupling tensors for Sn and O nuclei in the vicinity of a positively charged oxygen vacancy in solid tin dioxide, are reported with finite cluster methods using different cluster embedding techniques to define the structural environment. The NMR spectral trends for increasing-size nanoflakes of graphenic materials are predicted as functions of the size and boundary geometry of the flakes. Finally, a number of dye molecules are subjected to NMR chemical shift calculations where the intermolecular interaction effects present in liquid solution are studied with dynamic simulation techniques. The magnetically induced currents calculated for thieno-bridged porphyrins show that the changes in the molecular structure such as the direction of the thiophene ring or the substitution by Zn^2+ do not change the aromatic character of the molecule. It is possible to confirm the experimental assignment of the ESR signal with the g-factor around 2.00 to the positively charged vacancy in tin dioxide, whereas the other experimental assignment of a signal at g=1.89 is not supported by our calculations. Distinct characteristic NMR spectral patterns are found for graphene nanoflakes reflecting the effects of increasing size and different boundary geometries on the NMR shifts. Solvent effects on the NMR of dye molecules are found to be location-specific: nuclei from different regions of the systems display distinct response to solvation.
  • Niemi, Jarkko (Helsingin yliopisto, 2015)
    This study examines conceding as a social practice in Finnish conversation as well as the linguistic structures that are used to implement it, such as "voihan se olla" it may (well) be . The four case studies that are analysed are connected by a concessive sequence of turns at talk. In this sequence, the concessor concedes the prior speaker s point of view as (potentially) correct and either implies reserve or subsequently asserts a contrastive point of view. The data consist of telephone calls and video-recorded conversations between acquaintances and family members, as well as conversations from internet forums and a chat room. This study applies the method of Conversation Analysis and adopts the orientation of Construction Grammar on linguistic structures as holistic combinations of form and function. The central research questions of this analysis are 1) what gets done with the linguistic structures that the study examines, 2) what are the social, interactional, and sequential factors involved in the choice of a specific format, and 3) what is the relationship between linguistic constructions and social interaction. The functions of the linguistic structures analysed in this study differ in several ways. The concessor may comment on the truthfulness of the prior speaker s statement or its implied consequences. He or she may modify the prior speaker s statement or assert agreement without modification. In addition, concession can imply either independent knowledge about the subject at hand, or a lack of that knowledge. In the data, the more minimal concessive structures (such as "voi olla" may be and "se voi olla" it may be ) are crystallized so that even a small difference in form results in a difference in function. By contrast, more elaborated clausal concessions allow for variation in their lexical form while retaining their function. This study reveals the two faces of conceding in interaction. While conceding may advance the speakers agreement and mutual understanding, it also may serve as a resource to express disagreement and to represent the other speaker s point of view as rather foolish. In addition, this study demonstrates that concessive structures carry a frame semantic meaning of a larger concessive sequence. The recipients of a concession can therefore anticipate disagreement on the basis of the concessive move. As a result, constructions are to be understood as established practices through which speakers perform and interpret social actions as well as projections of upcoming actions.
  • Kupari, Helena (2015)
    This study examines the lived religion of elderly Finnish Orthodox Christian women in present-day Finland. It discusses the women s everyday religious practice within the domestic environment. Furthermore, it also traces the ways in which their religion had been affected by their life histories, the changing status of the Orthodox community, and the modernization of Finnish society in the course of the 20th century. The primary research material for this study consists of interviews of 24 women. Finland is a Lutheran-dominated country; today, about one percent of Finns belong to the Orthodox Church. Traditionally, most of the Orthodox resided in Finnish Karelia. After the Second World War, Finland had to cede large areas of Karelia to the Soviet Union. In the process, two thirds of the Finnish Orthodox lost their homelands. All the interviewees, or their parents, had been among the evacuees from Karelia. The theoretical-methodological approach made use of in the study is based on practice theory. In particular, the concept of habitus as developed by the sociologist Pierre Bourdieu is applied to analyze the women s interview accounts. The concept captures Bourdieu s understanding of the reciprocal dynamic between practice, subjectivity, and structures of power. The analysis demonstrates that the interviewees religion was characterized by a movement between routine and reflexive action. Judging from the material, they mostly did religion in a habitual fashion. Nevertheless, they could also perform their practices more intentionally, to reinforce their identity against specific others. These two aspects of the women s religion are traced, respectively, to their childhood religious socialization and their social trajectories as minority religious practitioners in Finnish society. Ultimately, the analysis forms an account of the women s religion as habitus. The informants religious habitus constituted an embodied and practical sense of religion, which informed both their routine religious practices and more conscious and creative religious actions. This study provides a description and a theoretical representation of one particular style of contemporary religiosity: the lifelong religion of older lay women. Within recent scholarship on religion, the religion of women of the inter-war generation has not received much attention. This study, moreover, offers a reading of Bourdieuan social theory as applied to the lived religion of minority practitioners. As such, it illustrates the explanatory potential that a Bourdieuan approach can bring to analyses of relatively stable religion.
  • Holopainen-Mantila, Ulla (Helsingin yliopisto, 2015)
    Barley (Hordeum vulgare L.) is a globally important grain crop. The composition and structure of barley grain is under genotypic and environmental control during grain development, when storage compounds (mainly starch and protein), are accumulated. Grain structure plays a significant role in malting and feed- and food-processing quality of barley. Hordeins, the major storage proteins in barley grains, are centrally located in the endosperm forming a matrix surrounding starch granules, but their role in the structural properties of barley grain is not completely understood. Thus, the main aim of the current study was to demonstrate the role of hordeins in barley grain structure. The dependence of the grain structure on the growth environment, in particular with respect to day-length and sulphur application relevant to northern growing conditions, was studied. The effects of the grain structure on end use properties in milling as well as in hydration and modification during malting were characterized. The longer photoperiod typical to latitudes in Southern Finland resulted in a C hordein fraction, entrapped by aggregated B and D hordeins, being more deeply located in the endosperm of barley cultivar Barke. Thus the impact of the growing environment on hordein deposition during grain filling was observed both at the tissue and subcellular level. However, the mechanism behind the differential accumulation of C hordein remains unclear. The deeper localization of entrapped C hordein was linked to improved hydration of grains during malting in three barley cultivars. Thus, the role of the subaleurone region in barley grain was found to be significant with respect to end use quality. Moreover, the results suggest that the growing environment affects the end-use properties of barley and that especially the northern growing conditions have a positive impact on barley processing quality. The influence of sulphur application on hordein composition in the Northern European growing conditions was demonstrated for the first time. Asparagine and C hordein served as nitrogen storage pools when the S application rate was lower than 20 mg S / kg soil, whereas total hordein and B hordein contents increased with higher S application rates. The current study also showed that even when sulphur is sufficiently available in field conditions, the hordein composition may react to sulphur application. The observed sulphur responses were in accordance with those reported earlier for hordein composition. This indicates that the more intensive growth rhythm induced in northern growing conditions does not alter greatly the effect of sulphur on grain composition. The current study confirmed that the main grain components: starch, protein and β-glucan, influence grain processing properties including milling, hydration and endosperm modification. However, their influence on endosperm texture (hardness or steeliness), which also affects the performance of barley grains in these processes, cannot be directly derived or estimated on the basis of the grain composition. The results obtained suggest that hordeins should also be taken into account in the evaluation of the processing behaviour of barley grains.
  • Mainio, Aleksi (Omakustanne, 2015)
    The October Revolution in 1917 led to Europe being divided into two camps. The turmoil in Russia also affected Finland, the territory of which became a safe haven for different counterrevolutionary organisations. It is possible to even talk about an invisible war between Finland and the Soviet Union although officially the countries had reached a peace agreement in 1920. This doctoral thesis examines how different White Russian intelligence and military organisations used the territory of Finland for counterrevolutionary activities between 1918 and 1939. It also discusses the relations of the Finnish Security Police and the Military Intelligence of the General Staff with the underground organisations and the attitude of Finnish authorities towards their illegal activities. No comprehensive research has previously been made on these activities. Nor have the groups operating in Finland been formerly examined in a broader international context. Research on these movements and their operations in Finland has therefore remained fragmented and unconnected with the broader picture of the anti-Bolshevistic activity in Russia and the whole of Europe. One of the main conclusions of this thesis is that the territory of Finland served as a significant base for counterrevolutionary operations. Between 1918 and 1939, White Russian emigrants organised intelligence operations and even terrorist attacks against the Soviet Union from the territory of Finland. These events resulted from the previous history of the country and its geopolitical location close to Leningrad and Moscow as well as from the traditions of Finnish activism. This thesis also shows that the White Russian emigrant organisations were closely linked with Finnish security authorities. Arranging terrorist and intelligence operations against the Soviet Union would have been almost impossible without their active or at least passive support. The General Staff, in particular, and the Finnish Security Police to a certain extent, were ready to tolerate and even support the secret activities of White Russian emigrants under certain conditions. This resulted from their desire to affect the developments in the Soviet Union but also from the great demand for intelligence on the neighbouring country. Without close cooperation with the emigrant organisations this would have been difficult to achieve. Such cooperation was a major risk for Finland and its relations with the Soviet Union. From time to time it might even have brought the countries onto the verge of a military conflict. Soviet propaganda used the support of Finnish authorities to emigrant activists involved in terrorist attack plans to harm the reputation of Finland and to justify the shift towards an increasingly totalitarian system.
  • Klenberg, Liisa (Helsingin yliopisto, 2015)
    Executive functions (EFs) are essential for coordination and controlling of other cognitive functions and behavior. EFs are involved in all purposeful activity, and for children, they are important for learning and functioning in school environments. Difficulties in EFs are common in school-age children with developmental disabilities, such as attention deficit disorder (ADHD). This thesis consists of three studies addressing EFs in school-age children. The first study employed neuropsychological tests from the Developmental Neuropsychological Assessment NEPSY to examine age-related differences in EFs in a sample of 400 children. The second study investigated the methodological factors related to EF measures in a sample of 340 children using response inhibition tasks from the NEPSY-II, the second edition of the Developmental Neuropsychological Assessment. The third study aimed at constructing a new instrument, the Attention and Executive Function Rating Inventory ATTEX, for the clinical assessment of EFs and verifying the psychometric properties of the rating scale in a sample of 916 children. Age-related improvement in EF task performance continued throughout the school-age period, proceeding from inhibition to attention control, and further to fluency of actions. A closer examination of response inhibition showed developmental variation even within this EF domain. The developmental change was apparent at school age, but different outcome measures and the cognitive requirements of tasks had an effect on how the development of response inhibition was depicted. In the assessment of everyday EF behaviors, the ATTEX rating scale demonstrated high internal consistency reliability and good criterion and discriminant validity for ADHD. The EF profiles were different for the ADHD subtypes, and children with predominantly inattentive symptoms showed more wide-ranging difficulties in EFs than children with combined symptoms of inattention and hyperactivity-impulsivity. Carefully examined, reliable, and valid measures are essential for both the scientific research and clinical assessment of EFs. Factors related to the measures, e.g., materials, stimuli, and the selected outcome measure, and the cognitive processes involved in tasks have effect on how development of EFs is depicted. Close examination of these factors can help to attain a more consisted account on EF development. In the clinical assessment of EF difficulties, the measures need to be sensitive to the actual difficulties that arise in every-day situations. These are best assessed with standardized rating scales. The new rating scale presented in this thesis proved to be a suitable measure both for screening and examining the detailed EF profiles of children in school situations.
  • Kohonen, Jukka (Helsingin yliopisto, 2015)
    Clustering is a central task in computational statistics. Its aim is to divide observed data into groups of items, based on the similarity of their features. Among various approaches to clustering, Bayesian model-based clustering has recently gained popularity. Many existing works are based on stochastic sampling methods. This work is concerned with exact, exponential-time algorithms for the Bayesian model-based clustering task. In particular, we consider the exact computation of two summary statistics: the number of clusters, and pairwise incidence of items in the same cluster. We present an implemented algorithm for computing these statistics substantially faster than would be achieved by direct enumeration of the possible partitions. The method is practically applicable to data sets of up to approximately 25 items. We apply a variant of the exact inference method into graphical models where a given variable may have up to four parent variables. The parent variables can then have up to 16 value combinations, and the task is to cluster them and find combinations that lead to similar conditional probability tables. Further contributions of this work are related to number theory. We show that a novel combination of addition chains and additive bases provides the optimal arrangement of multiplications, when the task is to use repeated multiplication starting from a given number or entity, but only a certain kind of function of the successive powers is required. This arrangement speeds up the computation of the posterior distribution for the number of clusters. The same arrangement method can be applied to other multiplicative tasks, for example, in matrix multiplication. We also present new algorithmic results related to finding extremal additive bases. Before this work, the extremal additive bases were known up to length 23. We have computed them up to length 24 in the unrestricted case, and up to length 41 in the restricted case.
  • Airila, Auli (Helsingin yliopisto, 2015)
    In today´s work life, employees are expected not only to be reasonably healthy, but also to be highly engaged and work efficiently. However, at the same time, the prevalence of mental health disorders and diseases of the musculoskeletal systems is high. Therefore, understanding and enhancing employee well-being as a whole is essential. This study examined the longitudinal effects of work characteristics, personal resources, and lifestyle on employee well-being by applying three theoretical frameworks Job Demands-Resources (JD-R) model, Conservation of Resources (COR) theory, and Broaden-and-Build (BaB) theory. Employee well-being was understood as a multidimensional construct covering affective, cognitive, and health-related components. The data was collected with questionnaires among Finnish firefighters during a 13-year period with three measurement points (i.e., 1996, 1999, and 2009). Two slightly different datasets were used in the four sub-studies (dataset 1: n = 403; dataset 2: n = 360). The study showed that a positive state of work engagement was significantly associated with work ability even after adjusting for various individual and work characteristics. Secondly, job and personal resources had long-term effects on work engagement, and consequently on work ability, thus expanding the potential positive outcomes of the motivational process included in the JD-R model. Thus, the dual role of work ability both as a predictor (i.e., health-related resource) that may foster engagement, and as an outcome of the motivational process was found. Moreover, this study showed that different developmental paths in positive (i.e., vigor) and negative (i.e., fatigue) affective states are possible and these paths differently predicted well-being. Although both vigor and fatigue were rather stable over time, some changes occurred over the 13-year follow-up period. The results suggest both the possibility and need to foster positive developmental paths in affective states in order to maintain and improve employee well-being. Similarly, different developmental paths in multisite musculoskeletal pain and depressive symptoms were observed, and changes over time proved to be possible. Job demands, job and personal resources as well as lifestyle were partly differently related to pain-depression trajectories. This needs to be acknowledged when planning interventions for preventing musculoskeletal pain and depressive symptoms. To conclude, the beneficial role of job resources and personal resources, and similarly the detrimental effects of job demands in explaining employee well-being were shown, and thus, proving further support for the assumptions of the JD-R model, COR theory, and BaB theory. Evidently, a motivated and energetic worker, who has a resourceful job and not too high mental and physical demands has better well-being than a co-worker who is less engaged and experiences a more unfavourable situation in terms of demands and resources. Moreover, a good level of self-esteem, an optimistic view of the future and healthy lifestyle habits may increase the likelihood of being healthy and happy. As such, work organizations have good opportunities to reinforce and maintain well-being of their employees, and consequently prevent ill-health and promote long work careers.
  • Viitamäki, Mikko (Helsingin yliopisto, 2015)
    This study discusses poetic communication in the context of maḥfil-i samāʿ (an assembly of listening to sung poetry) among South Asian Sufis. Drawing from both textual and ethnographic materials, the study explores the relationship between Sufi practice, poetic expression, and musical performance. It presents a context-sensitive reading of a multilingual (Persian, Hindi, Urdu) poetic corpus that takes into account its literary characteristics, the framework of Sufi practice, as well as the various techniques the qawwali musicians utilize in delivering the meaning of a poetic text. The study comprises three parts that are distinguished by their sources and methodological approaches. The first part discusses the dynamics of samāʿ as a meditative and ecstatic Sufi practice, and it is based on close reading of textual sources in Arabic, Persian and Urdu, written between the fourteenth and twentieth centuries. Throughout these texts, the authors have characterized samāʿ as a spiritual practice whose transformative effect is sudden, even violent. The second part examines twentieth-century anthologies of qawwali poetry and shows the extreme fluidity of the poetic repertoires; the performers are fairly free to choose the texts they sing as long as they bring about the desired effect in the listeners. The study of poetry in samāʿ, however, is bound to remain suggestive, if it is solely based on textual sources. Each performance of a poetic text is uniquely shaped in the interaction between the listeners and singers. For this reason, the third part of the study covers an ethnographic analysis of four samāʿ assemblies that took place in Delhi and Hyderabad. While the focus is on the poetic text, the analysis takes into account the physical settings of the occasions, the hierarchies that regulate the interaction of the participants, as well as the economics involved. The analysis reveals how the qawwals intertwine musical and poetic conventions in order to continuously alternate between tension and release during maḥfil-i samāʿ. In this manner, they intensify the listenersʼ feelings and emotions which are then ideally integrated into their spiritual practice. The impassioned poetic expression that addresses god as the beloved also constitutes a significant religious discourse that complements the more systematic approach found in Islamic theological and legal prose writings.
  • Virtanen, Susanna (Helsingin yliopisto, 2015)
    The dissertation consists of four articles published in peer-reviewed linguistic journals and an introduction. The aim of the study is to provide a description of the formal means of expressing semantic transitivity in the Eastern dialects of the Mansi language (EM), as well as of the variation between the different means. The study is connected to Uralic studies and functional-linguistic typology. Mansi is a Uralic language spoken in Western Siberia. Unfortunately, its Eastern dialects died out some decades ago, but there are still approximately 2700 speakers of Northern Mansi. Because it is no longer possible to access any live data on EM, the study is based on written folkloric materials gathered by Artturi Kannisto about 100 years ago. From the typological point of view, Mansi is an agglutinative language with many inflectional and derivational suffixes. The study is based on information structural analysis, particularly the terminology and definitions proposed by Lambrecht (1994). The approach is based on three main pragmatic functions, primary topic, secondary topic and focus, and on how they correlate with syntactic functions and how their morphological markedness or unmarkedness is due to information structural factors. Further, the notion of topicality is connected to the concept of Differential Object Marking (DOM) and the observations of Iemmolo (2010/2011). According to the data of this study, DOM is based on topicality in EM. Finally, the analysis is expanded to include variation between the active voice and the passive voice and variation in three-participant constructions. The topic of the study can be divided into three different sub-topics: 1) marking of the DO, 2) variation in three-participant constructions and 3) variation between the active voice and the passive voice. The main result of the study is a complex description of how the whole system of expressing semantic transitivity in EM is based on the same principles. Among others, the results of the study also show some new aspects that differ from the recent studies: for example, possessive marked direct objects do not always trigger the objective verb conjugation.
  • Soininen, Antti (Helsingin yliopisto, 2015)
    Hydrogen free diamond-like carbon (DLC) coatings have been the subject of investigation all around the world for the last 30 years. One of the major problems in producing of thick high-quality DLC coatings has been the inadequate adhesion of the deposited film to the substrate. This obstacle is finally overcome by depositing an intermediate adhesion layer produced with high energy (>2 keV) carbon plasma before application of a high-quality coating produced with a low energy unit. To the best of our knowledge, this can be achieved (with reasonable yield for industrial purposes) only with the filtered pulsed arc discharge (FPAD) method developed by our group. In this thesis a new combination of in situ surface oxide reduction method with FPAD is presented. Novel anti-soiling DLC polymer hybrid coatings (DLC-p-h) can be deposited using a slightly modified FPAD system. Both the coatings and their deposition method are recent innovations invented in our research group. This method makes possible to combine diamond and polymer properties in the resulting coatings. Two novel hybrid coatings have been developed: DLC polytetrafluoroethylene hybrid (DLC-PTFE-h) and DLC polydimethylsiloxane hybrid (DLC-PDMS-h). These hybrid coatings are highly hydrophobic and oleophobic (dirt repelling). Therefore these novel coatings could probably be used as antifouling and wear resistant coatings to which pathogenic bacteria would adhere less than to conventional biomaterials in biomedical applications. These DLC-p-h coatings are not produced anywhere else in the world. In this thesis bacterial adhesion to DLC was studied under dynamic conditions. Our experiments demonstrated that the bacterial adhesion to DLC was similar to the adhesion to AISI 316L surgical steel commonly used in medical applications. This suggested that DLC coating can be used on implants made from AISI 316L or other materials without increasing the risk of implant-related infections. Adhesion of bacteria and human cells (hMSC, hOB, Saos-2) to our novel DLC-p-h coatings was also studied. Bacterial adhesion tests showed a potential application of DLC-PTFE-h coating as a less biofouling surface than DLC, titanium and oxidized silicon surfaces. Cell adhesion studies showed less adhesion on DLC-PDMS-h surfaces than on DLC or titanium surfaces and some of the cells even underwent programmed cell death caused by lack or loss of adhesion. Osteogenic differentiation study on DLC-PDMS-h surface showed impaired or delayed osteogenesis. Cytocompatibility and cytotoxicity tests proved that DLC-PTFE-h and DLC-PDMS-h coatings are biocompatible. In summary, these studies suggest that DLC-PTFE-h coatings could be used in medical applications where bone integration would be preferred while DLC-PDMS-h coating in orthopedic applications where an implant or implant-facet should be protected against bone overgrowth.
  • R. Labafzadeh, Sara (Helsingin yliopisto, 2015)
    Worldwide research is focused on the use of renewable and biodegradable raw materials due to the limited existing quantities of fossil supplies and the environmental degradation caused by global warming. Cellulose, derived from natural resources such as wood, annual plants and microbes, represents the most abundant renewable polymeric material on earth. Due to its low cost and functional versatility, cellulose has been a key feedstock for the production of chemicals with various properties and applications over the past century. It has found a wide range of applications in food, printing, cosmetics, pharmacy, therapeutics, paper making and in the textile industry. This partly crystalline polymer has not yet reached its full application potential due to its essential insolubility in most common solvents. Many investigations focus on the development of novel media for efficient and economically feasible functionalization of cellulose. The chemical modification of cellulose overcomes this obstacle and offers considerable opportunities for preparing cellulose-based polymeric materials. The modification could adjust the properties of the macromolecule for different purposes and meet the environmental requirements by using green reagents and recyclable solvent systems. Synthesis of new cellulose-based polymers and their thorough characterization and increasing the usefulness of cellulose by altering its properties have been of growing research interest for the past few years. The objective of this research was to investigate new paths for the preparation of cellulose-based materials with a variety of structural features to obtain advanced materials suitable for different applications. Most of the research has focused purely on the synthesis of cellulose derivatives in new and economically feasible solvent systems, but it also has general relevance for the material properties of the obtained derivatives. Also, the potential application of synthesized cellulose derivatives as barrier films for packaging was investigated. Highly substituted cellulose esters, carbamates and carbonates were prepared using various recyclable reaction solvents. Biomaterials with the potential for use in the packaging sector should provide high mechanical properties, in addition to good barrier properties for oxygen and water vapour. Some derivatives showed good barrier properties being promising for packaging application.
  • Ahvenniemi, Rasmus (Helsingin yliopisto, 2015)
    The thesis consists of an introduction and 3 essays presenting stochastic dynamic optimization models concerning decision making in the banking sector. The first two essays consider individual banks in an environment where financial crises may occur. The third essay considers the whole banking sector as one entity which is a part of the economy, and thereby the process of money creation in the banking system becomes a central issue. The first essay presents a model for analyzing the optimal dynamic decision making of a bank, which adjusts the size and composition of its balance sheet over time. The model considers the development of the bank's balance sheet in a situation involving the risk of a financial crisis which may or may not materialize, and the timing of which is uncertain. The crisis may involve defaulting of loans and a reduction in the availability of funding. The maturing of loans and deposits taking place in each period is explicitly modeled, assuming maturity mismatch. The outcomes of the model show e.g. a tendency of the bank to deleverage its balance sheet in preparation for an anticipated financial crisis, as well as a tendency to accumulate cash reserves in order to maintain sufficient liquidity. The second essay presents a portfolio model for analyzing a bank making decisions over time in a stochastic environment. The bank is assumed to make decisions regarding the amount of new loans given out in each period, thus affecting the allocation of its funds between liquid cash and non-liquid loans. The model involves maturity mismatch and the risk of a liquidity crisis during which the availability of new funding is restricted. Simulations of the model show that a positive amount is allocated to cash even though cash pays zero returns and no credit risk or investment risk is present in the model, as long as maturity mismatch and the risk of a liquidity crisis are both present. The third essay presents a model of an economy consisting of a central bank, a commercial banking sector, and a real economy experiencing stochastic productivity shocks. A stochastic dynamic programming model is formulated for modeling the policy decisions of the central bank, which dynamically adjusts the size of the monetary base, attempting to keep inflation close to a target. It is assumed that reserve requirements may or may not be binding at a given time. When reserve requirements are not binding, money creation is endogenous, i.e. determined by lending decisions of commercial banks. These lending decisions are affected by the condition of the real economy and, to some extent, by central bank policies acting through transmission channels such as the portfolio rebalance effect. Lending stimulates the real economy while also accelerating inflation as it causes the money supply to grow. The outcomes show that during a recession lending by commercial banks is reduced, deflation prevails, and the central bank carries out expansionary monetary policy. When the recession ends, lending increases and there is a period of increased inflation, while at the same time contractionary monetary policy is carried out.
  • Holopainen, Sari (Helsingin yliopisto, 2015)
    The boreal biome harbours a large share of the world s wetlands, and is the main breeding area for several duck species. Breeding habitats strongly influence duck reproduction. In this study, the habitat use of ducks and their breeding success was estimated in a boreal landscape in southern Finland. A review of duck habitat use in boreal wetlands was additionally made. Boreal forest lakes are normally considered stable environments, but from a duck s point of view both resource abundance and habitat quality in the lakes may differ from one year to another. In this study the vegetation of boreal freshwater lakes was found to slowly change during the 20-year study period. Beavers (Castor canadensis) caused pronounced alterations in the lakes by flooding them. Flooding rendered lake vegetation structure more luxuriant and increased the lake use by ducks. In general, duck brood lake use was positively associated with both the coverage of wide belts of tall emergent plants and the abundance of emerging insects and aquatic invertebrates. The relative importance of these factors varied between species. The brood production of common goldeneyes (Bucephala clangula) was regulated by density dependence per se, but fluctuated with food availability per capita. No spatial density-dependent effects were found for the common teal (Anas crecca), but the breeding success was instead explained well by habitat quality variation. Both food and flood abundance had a positive effect, but different variables seemed to operate during different phases of the breeding season. Many aspects of boreal breeding ducks are still poorly studied. Especially lacking are studies concerning duckling survival and the effects of anthropogenic actions on duck habitat use. This research underlines the importance of high quality habitats for breeding duck populations in the boreal landscape. The varying habitat requirements of duck species should be considered when implementing wetland management.
  • Nyholm, Elina (Helsingin yliopisto, 2015)
    The research question relates to the content of the ex post supervision provisions of the Finnish Environmental Protection Act (EPA) under the currently valid legislation. The study particularly focuses upon single control orders (EPA Section 180), indirect administrative compulsion (EPA Sections 175 through 176) and direct administrative compulsion (EPA Section 181). The objective is to systematize the mutual delineation of the scopes of application of the said provisions. The study utilizes the method of legal dogmatics. Furthermore, the aim is to present views on how the ex post control provisions of the EPA should be developed. A particular methodical characteristic entails the ample utilization of also unpublished case law, primarily in highlighting the problematic issues. For this reason, the study also exhibits characteristics of empirical legal research. This is also why the study is additionally distinctly connected to administrative procedural law, albeit it is categorized under environmental law, or, more precisely, under environmental protection law. The study examines the instances when activities causing the threat of environmental pollution can be targeted with a single control order, when the activities are in breach of the EPA, a decree or regulation issued under it in such a manner that it can be targeted with indirect administrative compulsion, and what are the prerequisites that need to be met for the causing of the pollution to be capable of being addressed by means of direct administrative compulsion, i.e. the immediate suspension of the activities. The study systematizes the obligations contained in the various provisions of the EPA, and those contained in the decrees and regulations issued under the EPA, compliance with which can be enforced by means of indirect administrative compulsion. The pivotal finding comprises the systematization of the provisions of the EPA in such a manner that the situations entitling to the application of the various ex post supervisory measures and the mutual boundaries of the ex post supervisory measures scopes of application become less ambiguous. An additional finding entails the provision of some individual legislative recommendations relating, inter alia, to the regulation of the competent authority and the degree of the obligatory nature at which the prohibitions contained in the legislation should be set.
  • Pahkin, Krista (Helsingin yliopisto, 2015)
    The overarching aim of the thesis was to identify work-related and personal factors which support employee well-being during working career and organizational restructuring. The empirical part of this thesis was based on a prospective cohort study of employees in the Finnish forest industry. Data included responses to questionnaires (N up to 4279) and records from organizational and national registers, all collected between 1986 and 2009. The data covered a period of stable growth, strong international expansion and organizational downsizing. The findings first of all show that the level of employee well-being was relatively stable over time. Employees who reported feeling unwell at work at follow-up worked in considerably worse working conditions (compared to people with good well-being) already 10 years before the follow-up. Their personal resources were weaker both at the 10-year follow-up and at baseline. Furthermore, the resources seemed to increase among those feeling well, whereas the development trend was vice versa among those feeling less well. There was an overall trend of decreasing mental well-being through the restructuring process, irrespective of the type of changes. The findings showed that the same factors which helped individuals to stay well over the long run also helped them during the turbulence of work life. Strong sense of coherence and strong social support were also associated with indices of employee well-being during organizational restructuring as well as a more positive view of the restructuring and its consequences. However, pre-change social support from co-workers did not provide a buffer against the detrimental effect of negative change experience on employee well-being. There was an association between the change appraisal and employee well-being, both health and mental well-being, during organizational restructuring: A negative appraisal of the restructuring process increased the risk of lower employee well-being. The findings showed that also the positive, motivational aspects of mental well-being can be damaged if the change appraisal is negative. Finally, the findings showed that by offering opportunities to participate in the planning of the changes related to one s own work and through the actions of top management and the immediate superior s organizations can support the development of positive change experience.
  • Seppänen, Henri (Helsingin yliopisto, 2015)
    Tethers are key elements in the electric solar wind sail (E-sail). In this thesis I claim that E-sail tether manufacturing on km scale is possible. The E-sail is a space propulsion method for interplanetary missions. It uses long, thin and conductive, tethers to create thrust from the solar wind. Based on simulations a full scale E-sail using one hundred 20 km long tethers could create a continuous 1 N thrust. Compared to state of the art ion engines the proposed E-sail produces 10 100 times more specific impulse over the device lifetime. The E-sail is estimated to lower costs of interplanetary missions by reducing the payload mass needed to launch to orbit and by shortening the travel time. Manufacturing is an important technical challenge to the E-sail. A multifilament tether structure is needed to provide micrometeoroid tolerance to the tether. To address the challenge we combined an industrial ultrasonic wire bonder and a custom-built tether factory for tether production. A customized 3-wire bonding wedge enabled 4-wire multifilament tether manufacturing. The tether comprises 25 and 50 µm in diameter (Ø) aluminum wires that are ultrasonically welded together. The main result of this thesis is that we showed the feasibility of large-scale device manufacture by producing a continuous 1.04 km long multifilament tether comprising 90 704 wire-to-wire bonds. The measured bonding yield of the manufacture was 99.9%. Wire-to-wire bond pull strength was measured in a separate test on a 97 m long tether produced subsequent to the 1 km tether production. The maximum sustainable pull force of the tether bonds should exceed the estimated 50 mN centrifugal force of the spinning full scale E-sail. The measured average maximum sustainable pull force of 252 bonds along the 97 m test tether was (99 ± 8) mN with a minimum recorded value of 80 mN. This result shows that E-sail tether production on km scale is possible and thus supports the main claim of this thesis. Before this PhD project, no E-sail tether existed. The development of tether production and the results achieved brings the implementation of the most important E-sail component into the practical engineering realm and thus significantly advances the E-sail development. The produced 1 km tether was the most important objective of the ESAIL EU FP7 -framework project.
  • Tonttila, Juha (Helsingin yliopisto, 2015)
    Clouds, aerosols and the interactions between them are some of the most important uncertainties in climate modelling. The scales of spatial variability related to clouds are generally too small to be resolved using a typical climate model grid resolution. This work comprises studies about the small-scale variability of the vertical wind component, which significantly contributes to the process of cloud droplet formation. In addition, more elaborate methods for describing the small-scale variability of cloud properties in climate models are developed. The key questions that are investigated include: 1) What are the statistical properties of the turbulent vertical wind variability in the boundary layer and can they be represented accurately by atmospheric models? 2) How does parameterizing the small-scale variability in cloud microphysical processes affect the simulated cloud properties in climate models? 3) How does accounting for the small-scale variability in cloud properties affect the model-based estimates of the aerosol indirect radiative effects? The most important tool used in this work was the ECHAM5-HAM2 aerosol-climate model. The model simulates not only the atmospheric circulation and thermodynamics, but also the global distribution of aerosols and the physical processes between particles that affect the aerosol particle population. This allows the model to represent the interactions between clouds and aerosols. In addition, parts of this work also make use of measurement data based on remote sensing methods as well as high-resolution output from a numerical weather prediction model. The results show that the small-scale variability of the vertical wind associated with cloud droplet formation must be parameterized even in models with relatively high grid resolution. This highlights especially the importance of such methods for lower-resolution climate models. The variability of vertical wind can be described using a probability density function (PDF), the shape of which may vary significantly depending on the atmospheric conditions. The intricacies of the PDF include many uncertainties which can only be reduced by more extensive observations. With a simplified representation of the vertical velocity PDF, a new version of the climate model is constructed in this work, which can be used to study the climate effects due to the small-scale variability in vertical wind and clouds. It is noted that earlier methods that try to account for the variability in vertical velocity and cloud formation are somewhat insufficient. More attention should be paid on treating the small-scale variability self-consistently for entire chains of processes rather than separately for individual processes. This was accomplished in this work with the newly developed method, comprising the chain of processes from cloud formation to radiative transfer. The new method has a strong impact on the number of cloud droplets and drizzle formation as compared to the default model version, where the small-scale variaiblity of clouds is not as accurately accounted for. Moreover, the response of the model-simulated cloud properties to anthropogenic changes in aerosol emissions is found to be considerably weaker in the new model version than in the default model version. In effect, when compared with the default model version, the aerosol indirect radiative effect estimated with the new model version is closer to the best observation-based estimate. The results of this work contribute to improving our understanding of the aerosol-cloud interactions and to guide the work towards further reducing the uncertainties related to modelling clouds and climate.
  • Hakojärvi, Mikko (Helsingin yliopisto, 2015)
    Precision farming is a set of advanced technologies and cultivation practices that aim to enhance crop growing conditions in a site-specific manner. Current machinery offers many technical tools for such actions, but information about when and where it is necessary to use the developed machinery effectively is lacking. The use of crop models has been proposed to combine the effects of growing season conditions and field spatial properties. However, in a timely and spatially variable environment, which a field often is, much information about site-specific growing conditions should be available in order for an advanced crop model to reproduce the site-specific growth in a detailed manner. Unfortunately the information from fields has often been very limited, and insufficient for such purposes. Furthermore the set of precision farming tools and the number of growth factors that can be managed is limited. For describing maximal biomass accumulation, a simple crop model was introduced and evaluated in this thesis. The model is mechanistic, and it uses a minimal number of parameters that all are based on physics, chemistry or physiology. The model can be used for calculating the radiation or radiation and water limited biomass accumulation of a C3-crop. A field experiment equipped with continuous measurements was used for model establishment and after model establishment the model was evaluated with a field experiment with various radiation, nitrogen fertilization and precipitation conditions. In both the studies the crop model was found to produce the maximal biomass accumulation when parameter values measured in the experiment were used. The model was applied in a study evaluating the effects of selected site- and depth-specific soil properties on yield variation on three different clay soil fields located in southern Finland. In order to evaluate the effects of selected soil properties under various weather conditions a Monte Carlo method was used with the biomass accumulation model and generated precipitations. The yield variation was evaluated according to temporal mean biomass yield and temporal standard deviation of the biomass yield. For studying the use of the model in a spatial environment, the introduced biomass accumulation model was applied in a simulator built for simulating a fully automated crop farm. In addition, the use of continuous soil moisture measurements for measuring the crop water use and further for biomass accumulation was tested. According to the results, the crop model was capable of simulating the highest biomass accumulation of the crops used in the experiments. This was the case for all radiation-limited simulations and for most of the water-limited simulations. In a few cases the values of the observed soil properties were found to cause too low biomass accumulation in simulations but in such cases the problem was also present in the comparisons of observed soil properties and observed soil water content during the growing season. For future research with the model, the next phase will be to test the model use in precision farming-related decision making. The structure of the model enables its use with other C3-crops than small grain cereals. Therefore testing of the model with other C3-crops could be performed in future research.
  • Karhula, Kati (Helsingin yliopisto, 2015)
    Health care personnel often have irregular working hours and stressful work characteristics, which may challenge employees possibilities to sleep and recover sufficiently. The aim of this study was to examine the association of stressful work characteristics, measured as job strain, with sleep and psychophysiological recovery in shift working health care professionals. As part of the Finnish Public Sector Study, 95 participants were recruited from hospital wards that belonged to the top (high job strain, HJS, n=42) or bottom quartiles on job strain (low job strain, LJS, n=53) as determined by the average job strain score among the employees of the ward. These participants experienced job strain at least as high (HJS group) or as low (LJS group) as the average on their ward. Measurements included a Trier Social Stress Test (TSST), and 3-week field measures of sleep-wake rhythm with sleep diary and actigraphy. The 3-week rosters included three pre-selected, circadian rhythm and recovery controlled measurement days, one morning shift, one night shift and a day off, and the following measurements: ratings of sleepiness (Karolinska Sleepiness Scale), Psychomotor Vigilance Test (PVT), 24h heart rate variability (HRV) measurements and saliva samples of stress biomarkers (cortisol and alpha-amylase). The rosters of the HJS group included more single days off and quick returns than the rosters of the LJS group. Severe sleepiness (KSS score of ≥7) was more common in the HJS group in quick returns. The HJS group reported poorer recovery from all work shifts and after morning shifts than the LJS group. High job strain was not associated with extended working hours. The HJS group had more difficulties in initiating sleep after evening shifts, more often reduced sleep efficiency before morning shifts, and took fewer and shorter naps before the first night shift than the LJS group. Additionally, the HJS group had more often lapses in the PVT during night shifts. Insufficient sleep (31%) and sleep complaints (often 68%) were common in shift workers regardless of the job strain group. The TSST resulted in, on average, a 2.27-fold increase in cortisol concentration in the HJS group and a 1.48-fold increase in the LJS group (non-significant group difference). The HJS group also had higher salivary alpha-amylase levels 30 minutes after awakening in the morning shift. Apart from that, the salivary cortisol and alpha-amylase levels, profiles and total secretion showed no statistically significant stress group differences. Heart rate and HRV, before and during sleep, were similar in both job strain groups. Shift work contributed to impaired sleep in both the high and low job strain groups, although the sleep impairments were more pronounced in the HJS group. Associations between job strain and psychophysiological stress-related reactions and recovery were modest. Intervention studies are needed to determine whether increasing recovery time by reducing the number of quick returns and single days off would also reduce job strain and improve sleep quality among shift workers. Emphasising the importance of sufficient sleep might promote shift workers´ recovery and well-being.