Väitöskirjat

Recent Submissions

  • Athukorala, Kumaripaba (Helsingin yliopisto, 2016)
    We use information retrieval (IR) systems to meet a broad range of information needs, from simple ones involving day-to-day decisions to complex and imprecise information needs that cannot be easily formulated as a question. In consideration of these diverse goals, search activities are commonly divided into two broad categories: lookup and exploratory. Lookup searches begin with precise search goals and end soon after reaching of the target, while exploratory searches center on learning or investigation activities with imprecise search goals. Although exploration is a prominent life activity, it is naturally challenging for users because they lack domain knowledge; at the same time, information needs are broad, complex, and subject to constant change. It is also rather difficult for IR systems to offer support for exploratory searches, not least because of the complex information needs and dynamic nature of the user. It is hard also to conceptualize exploration distinctly. In consequence, most of the popular IR systems are targeted at lookup searches only. There is a clear need for better IR systems that support a wide range of search activities. The primary objective for this thesis is to enable the design of IR systems that support exploratory and lookup searches equally well. I approached this problem by modeling information search as a rational adaptation of interactions, which aids in clear conceptualization of exploratory and lookup searches. In work building on an existing framework for examination of adaptive interaction, it is assumed that three main factors influence how we interact with search systems: the ecological structure of the environment, our cognitive and perceptual limits, and the goal of optimizing the tradeoff between information gain and time cost. This thesis contributes three models developed in research proceeding from this adaptive interaction framework, to 1) predict evolving information needs in exploratory searches, 2) distinguish between exploratory and lookup tasks, and 3) predict the emergence of adaptive search strategies. It concludes with development of an approach that integrates the proposed models for the design of an IR system that provides adaptive support for both exploratory and lookup searches. The findings confirm the ability to model information search as adaptive interaction. The models developed in the thesis project have been empirically validated through user studies, with an adaptive search system that emphasizes the practical implications of the models for supporting several types of searches. The studies conducted with the adaptive search system further confirm that IR systems could improve information search performance by dynamically adapting to the task type. The thesis contributes an approach that could prove fruitful for future IR systems in efforts to offer more efficient and less challenging search experiences.
  • Tähkäpää, Satu (Helsingin yliopisto, 2016)
    After a series of food incidents in the 1990s, the food business sector has become one of the most heavily regulated sectors in the European Union (EU), with ever-evolving regulations regarding both official food control and food business operators (FBOs). The regulatory framework is meaningless if the regulation is not implemented promptly according to transitional provisions and in a unified way. Dissenting implementation of food safety legislation may also endanger the equal treatment of FBOs and the principle of free trade of foodstuff in the EU. This research provides a new perspective on the challenges of implementing food legislation, with the phenomenon surveyed from the viewpoints of both control officials and FBOs. Resources and organization of food control affect actual control work and were thus included. Varying ways of reporting and handling food frauds on the local, national and EU levels were also investigated. Fulfilling food control requirements set in food legislation necessitates an adequate quantity and quality of personnel, whereas organization of food control can differ between countries or areas depending on socio-economic and political factors. In Finland, municipalities alone or as a joint control unit are responsible for local food control in their respective areas. According to the results, this may lead to varying implementation and interpretation of food legislation, endangering equal treatment of FBOs. There is an alarming shortage of food control personnel in some regions in Finland. Even when food safety is the responsibility of FBOs, scarce resources in food control result in a lower percentage of approved in-house control systems among FBOs. This research revealed a connection between the number of approved in-house control systems and the number of reported food- or waterborne outbreaks in the area, especially in regions with inadequate food control resources. EU legislation concerning quality systems, food control plans and food control fees are implemented in Finland at regionally different time points and with different contents directly influencing FBOs in regionally variable ways. Control officials support larger control units, with the rationale that they will increase equal treatment of FBOs. Both control officials and FBOs have problems in implementation of food legislation, and FBOs are also challenged with varying interpretation of legislation and requirements of control officials. As food safety is the responsibility of the FBOs, they need to understand and carefully comply with legislation. The challenges of fish and meat FBOs in implementation of legislation were therefore evaluated. According to this study, the most common problems concerning food safety legislation are related to layout of production premises and transport routes, control fees, requirements concerning in-house control and structures and maintenance of premises. Risk evaluation is problematic for both control officers and FBOs. Traditional food control measures are challenged, when requirements set by law are intentionally violated for financial gain by FBOs, with food deliberately placed on the market with the intention of deceiving the consumer (food fraud). Uniform methods to detect and report food fraud are needed. Hence patterns of food frauds published in the EU Rapid Alert System for Food and Feed (RASFF) in 2008-2012, recalls of notifications published by the Finnish Food Safety Authority Evira in 2008-2012 and local Finnish food fraud cases in 2003-2012 were analysed. Patterns of food fraud and manners of reporting frauds at the local, national and EU levels differ significantly. If the detection and reporting of frauds and the legal consequences incurred by FBOs for frauds differ among member states, it may create distortion of competition.
  • Wolf, Jana (Helsingin yliopisto, 2016)
    Abstract Size is a feature that is often connected to different life history-traits and individuals can vary in many fitness aspects related to size, such as reproductive strategies, dispersal and mating behaviour, dominance and many more. If size variation is not continuous in a species, individuals can be divided into two or more distinct size morphs. In social insects, queen size dimorphism (QSD) is an interesting phenomenon as it separates queens into two different morphs, with macrogynes defined as the larger and microgynes as the smaller morph. The aim of this thesis is to improve our understanding of this phenomenon in social insects with a special focus on a palaeartic ant species, Myrmica ruginodis. This thesis demonstrates how several taxa differ in their cause, prevalence and evolutionary processes involved in QSD. Four different hypotheses have been identified as reasons to QSD. First, intraspecific polymorphism in connection with alternative reproductive strategies. Second, inquilinism, where microgynes mainly produce sexual offspring and forego worker production. Third, speciation, where the two morphs represent separate species with intraspecific polymorphism as an ancestral state and speciation processes often combined with inquilinism. Fourth, selfish larval development, which has only been observed in stingless bees so far. This thesis shows how the first three scenarios represent transitional stages and are valid in ants, which provide the necessary evolutionary framework via high levels of obligate secondary polygyny. This thesis also examines the cause for QSD in Myrmica ruginodis by analyzing several traits. These are morphology, offspring production, dispersal and mating behaviour, as well as gene flow. Overall my results suggest that macrogynes and microgynes in the ant M. ruginodis represent an intraspecific polymorphism with alternative reproductive strategies without inquilinism involved in it. Incomplete mating isolation among morphs indicate that this species is at a very early transitional stage from intraspecific polymorphism along the divergence continuum.
  • Ahola, Salla (Helsingin yliopisto, 2016)
    Laypeople’s stances towards expert knowledge and the relationships of personal values to such stances are little studied and remain less than clear. The purpose of this dissertation was to shed more light on these stances and their relationships to personal values, and thereby to contribute to a greater understanding of them. More specifically, this study focusses on the readiness of laypeople to question experts’ views, their non-adherence to doctors’ instructions, and their preferences to seek health advice or treatment from either medical experts (i.e. doctors) or from practitioners of complementary and alternative medicine (CAM) as well as the associations of personal values with each of these. This study used population-based samples from a range of European countries. One of the three sub-studies used survey data collected in Finland for the specific purposes of this study and the other two sub-studies used open-access data from the European Social Survey. The data was mostly quantitative and was analysed using statistical methods, such as logistic regression analysis. The first of the three sub-studies examined the ten values specified in Schwartz’s (1992) theory of basic human values as well as the values of rational truth and non-rational truth proposed by Wach and Hammer (2003b). The results showed that the values of rational truth and power were positively associated with the readiness to question experts’ views (RQEV), whereas the values of security, conformity and tradition were negatively associated with RQEV. Moreover, the analysis of laypeople’s reasons for not disagreeing with experts indicated that these reasons were related to individual factors (personal characteristics, unwillingness to disagree and trust in experts), situational factors (importance of the issue and practical realities), social risks and views on experts. The results of the second sub-study indicated that endorsing openness-to-change values (vs. conservation values) was positively associated with non-adherence to doctors’ instructions. In the third sub-study, endorsing conservation values (vs. openness-to-change values) was found to be positively associated with preferring doctors’ consultations and negatively associated with preferring other practitioners and with the use of CAM treatments. It was also found that valuing self-transcendence (vs. self-enhancement) was positively associated with CAM use. Furthermore, a context-specific factor, namely country-level personal freedom, was found to be negatively associated with the preference to consult doctors, and positively associated with preferring other practitioners and the use of CAM. This study demonstrates that taking into account motivational constructs, such as personal values, contributes to an understanding of how laypeople relate to expert knowledge.
  • Hotti, Hannu (2016)
    Coniine, a piperidine alkaloid, is known from poison hemlock (Conium maculatum L.), twelve Aloe species and Sarracenia flava L. Its biosynthesis is not well understood, although a possible route starts with a polyketide formed by a polyketide synthase (PKS). This study focused on identification and characterization of PKS-genes involved in coniine formation, induction of callus from plants containing hemlock alkaloids and investigation of the possibility to elicitate the alkaloid pathway in cell culture in order to understand coniine biosynthesis. Plant materials involved in different stages of this study were investigated for their alkaloid content using gas chromatography-mass spectrometry. A novel type of PKS, CPKS5, was identified as the starter candidate for the initiation of coniine biosynthesis by catalysing the synthesis of the carbon backbone from one butyryl-CoA and two malonyl-CoA moieties. When elicitated, poison hemlock cell cultures produced furanocoumarins but no piperidine alkaloids. The hemlock alkaloids are wider distributed than previously has been thought among Sarracenia, and Aloe spp. contain a new alkaloid for the genus. These results together pave the way towards possible utilization of hemlock alkaloids.
  • Marttila, Jouko (Helsingin yliopisto, 2016)
    The doctoral thesis of Jouko Marttila, Master of Social Sciences, in the field of political history puts in the historical context the convergence of economic policies of the National Coalition Party and the Social Democratic Party. The study focuses on party programmes with their ideological objectives and on two chronological phases in the post war economic policy of these two parties. The first phase deals with the economic policy after Korpilampi conference in the late 1970 s. The second phase concentrates on co-operation between conservatives and social democrats in prime minister Harri Holkeri´s government in 1987-1990. The study describes how the National Coalition Party and the Social Democratic Party converged their economic policies despite of opposite starting points and ended in favour of common economic policy limited market economy. The Coalition Party transformed its policy from people's capitalism and the market economy towards welfare state ideology. SDP aspired to reconcile the socialist planned economy with the market economy. In practise the solution for both parties was restrained market economy within the Nordic welfare model. The traditional ideological ideals and objectives were left behind. The dissertation shows how the global economy, changes in social and economic structures, and the internal political power struggle affected the implementation of economic policies. SDP had to adjust their policies in an environment where international oil crisis did not eventually lead to the overthrow of capitalism, but instead made the centralized economic planning and state control as well as implementation of Keynesian policies redundant. At the same time the growth of middle class voters strengthened the support for the Coalition Party. Based on the dissertation SDP's ideological transformation was deeper than Coalition Party's. SDP abandoned the goal of full employment and democratic socialism and accepted the basic principles of market economy. The Coalition Party distanced itself from capitalism and employers agenda when it defended the working life reforms that strengthened the position of employees. The partial privatization of state-owned companies served the goals of both parties. For the Coalition Party it meant extension of shareholding society, for the social democrats it meant democratisation of capital in limited market economy.
  • Miroshnikov, Ivan (Helsingin yliopisto, 2016)
    It is no secret that Christian dogmatic theology adopted a generous number of its concepts from Platonist philosophy; by the time of the Cappadocian fathers, it was customary to talk about divine matters in Platonist terms. It is, however, much more difficult to track the Platonist influence during the formative centuries of Christianity. In the last decades, the academic community has gradually come to realize that research into the Platonizing tendencies of early Christian texts may shed new light both on their meaning and their historical context. This study advances along this path. Its focus is on the Gospel of Thomas, an early Christian sayings collection. The core hypothesis of the study is that Platonism in its “Middle” form had a significant impact on this text. An inquiry into the Gospel of Thomas with this particular viewpoint has not been done systematically prior to this dissertation. At least nineteen Thomasine sayings (i.e. one-sixth of the entire collection) were in some way influenced by the Platonist tradition: ● Sayings 56 and 80 make use of the Platonist notions that the world is a body and that every human body is a corpse in order to express a view of the world that is essentially anti-Platonist: the world is nothing but a despicable corpse. ● The opposition of the body to the soul portrayed in sayings 29, 87, and 112 presupposes a stark dualism of the corporeal vs. the incorporeal and appears to be indebted to Platonist anthropology. ● The Thomasine notion of being/becoming oua (sayings 11 and 106), oua ouōt (saying 4, 22, and 23), and monakhos (sayings 16, 49, and 75) has the closest parallels within Platonist speculation about oneness as an attribute of a perfect human, a perfect society, and God. ● The expression ōhe erat⸗ in sayings 16, 18, 23, and 50 reflects the Platonist usage of the Greek verb ἵστημι as a technical term for describing the immovability of the transcendent realm. ● Thomas 61 appropriates the opposition of being equal (to oneself) vs. being divided from the Platonist metaphysics of divine immutability and indivisibility. ● The imagery of the lion and the man in saying 7 portrays the struggle between reason and anger and is derived from Plato’s allegory of the soul, reinterpreted from a Middle Platonist perspective. ● The notion of the image in sayings 22, 50, 83, and 84 should be interpreted against the background of the Middle Platonist metaphysics, where the Greek term εἰκών came to designate both the model (= παράδειγμα) and its imitation (= ὁμοίωμα). These nineteen sayings and, consequently, the Gospel of Thomas as a whole bear testimony to the fact that, during the nascent years of Christianity, certain individuals acknowledged de facto that the Platonist tradition possessed theoretical principles, concepts, and terminologies that could adequately describe and convincingly explain the nature of ultimate reality. Although the Gospel of Thomas is neither the first nor the only early Christian text with Platonizing tendencies, it appears to be an important witness to the early stages of the process that eventually led to the formulation of Christian dogmas in Platonist terms.
  • Silfverberg, Miikka (Helsingin yliopisto, 2016)
    A morphological tagger is a computer program that provides complete morphological descriptions of sentences. Morphological taggers find applications in many NLP fields. For example, they can be used as a pre-processing step for syntactic parsers, in information retrieval and machine translation. The task of morphological tagging is closely related to POS tagging but morphological taggers provide more fine-grained morphological information than POS taggers. Therefore, they are often applied to morphologically complex languages, which extensively utilize inflection, derivation and compounding for encoding structural and semantic information. This thesis presents work on data-driven morphological tagging for Finnish and other morphologically complex languages. There exists a very limited amount of previous work on data-driven morphological tagging for Finnish because of the lack of freely available manually prepared morphologically tagged corpora. The work presented in this thesis is made possible by the recently published Finnish dependency treebanks FinnTreeBank and Turku Dependency Treebank. Additionally, the Finnish open-source morphological analyzer OMorFi is extensively utilized in the experiments presented in the thesis. The thesis presents methods for improving tagging accuracy, estimation speed and tagging speed in presence of large structured morphological label sets that are typical for morphologically complex languages. More specifically, it presents a novel formulation of generative morphological taggers using weighted finite-state machines and applies finite-state taggers to context sensitive spelling correction of Finnish. The thesis also explores discriminative morphological tagging. It presents structured sub-label dependencies that can be used for improving tagging accuracy. Additionally, the thesis presents a cascaded variant of the averaged perceptron tagger. In presence of large label sets, a cascaded design results in substantial reduction of estimation speed compared to a standard perceptron tagger. Moreover, the thesis explores pruning strategies for perceptron taggers. Finally, the thesis presents the FinnPos toolkit for morphological tagging. FinnPos is an open-source state-of-the-art averaged perceptron tagger implemented by the author.
  • Riihijärvi, Sari (Helsingin yliopisto, 2016)
    Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in the western world. It is an aggressive disease and rapidly fatal if left untreated. With immunochemotherapy, a combination of chemotherapy and CD20 antibody rituximab, 70% of the patients can be cured. DLBCL comprises several distinct molecular subgroups, which differ in the expression of specific gene signatures and in the oncogenic pathways involved, corresponding to discrete prognostic categories. Research on biological prognostic factors and targeted therapies is active and it is likely that in the near future the patients will be treated according to risk-adapted and biomarker driven therapies. The aim of this study was to identify novel prognostic factors in the immunochemotherapy era. The study population comprised tumor tissue, blood samples and clinical data of DLBCL patients treated with immunochemotherapy. Methods included immunohistochemistry, ELISA and gene expression microarrays. PKCβII is an enzyme involved in cellular proliferation and it is overexpressed in cancer, including DLBCL. We observed that the patients with high tumor PKCβII expression had poorer survival than the patients with low expression. Consistently, high PKCβII gene expression correlated with inferior survival in an independent patient set. PKCβII is also known for its ability to stimulate tumor angiogenesis. We found no association between tumor microvessel density and survival data. Vascular endothelial growth factor (VEGF) is a signalling protein which stimulates angiogenesis. It is overexpressed in cancer and essential in tumor growth and development. We observed that high pretreatment serum VEGF levels are associated with inferior survival after therapy. However, VEGF mRNA levels correlated neither with the survival nor the serum VEGF levels. Thus, it is possible that the serum VEGF is not derived from the tumor itself but may be a host response instead. Tumor associated macrophages (TAMs) reprogrammed by malignant cells are a major source of angiogenic factors. Also, mechanism of rituximab is partly mediated by macrophages. The function of TAMs is known to be controversial: they have both anti-tumor and pro-tumor features. In our study, tumor macrophage counts correlated with favorable outcome. The findings were validated in independent cohorts of immunochemotherapy-treated patients. In contrast, in patients treated with chemotherapy, high macrophage count was associated with inferior survival. We also measured serum levels of CCL18 and CD163, proteins commonly expressed in M2 type macrophages. A significant association with inferior survival and low CCL18 serum levels was observed. To summarize, high PKCβII expression, low tumor TAM content, high serum VEGF and low serum CCL18 levels serve as prognostic factors for inferior outcome in immunochemotherapy-treated DLBCL. Their use as prognostic biomarkers in the clinical setting, however, calls for further study. The results underline the complex biology of DLBCL and the interplay between the tumor microenvironment, host responses and the malignant cells.
  • Miihkinen, Santeri (Helsingin yliopisto, 2016)
    The topic of this dissertation lies at the intersection of analytic function theory and operator theory. In the thesis, compactness and structural properties of a class of Volterra-type (integral) operators acting on analytic function spaces are investigated. The Volterra-type operator is obtained by integrating a product of two analytic functions, where one of these functions, the so-called symbol of the operator, is fixed and the other one is considered to be a variable. This integral operator was introduced by C. Pommerenke in 1977 in connection to exponential integrability of BMOA-functions. A systematic research of Volterra-type operators was initiated by Aleman and Siskakis in the mid-1990s when they characterized the boundedness and compactness of these operators on the Hardy spaces and weighted Bergman spaces. In the first article of the thesis, we derive estimates for the essential and weak essential norms of a Volterra-type operator in terms of its symbol when the operator is acting on the Hardy spaces, BMOA and VMOA. The essential and weak essential norms of a linear operator are its distances from compact and weakly compact operators respectively. In particular, it follows from our estimates that the compactness and weak compactness of Volterra-type operator coincide when its domain is the non-reflexive Hardy space, BMOA, or VMOA. In the second article, a notion of strict singularity of a linear operator is investigated in the case of the Volterra-type operator acting on the Hardy spaces. An operator between Banach spaces is strictly singular if its restriction to any closed infinite-dimensional subspace is not a linear isomorphism onto its range. We construct an isomorphic copy M of the sequence space of p-summable sequences and show that a non-compact Volterra-type operator restricted to M is a linear isomorphism onto its range. This implies that the strict singularity and compactness of this operator coincide in the Hardy space case. In the third article, we provide estimates for the operator norms and essential norms of the Volterra-type operator acting between weighted Bergman spaces, where the weight function satisfies a doubling condition.
  • Mäki-Nevala, Satu (Helsingin yliopisto, 2016)
    Lung cancer is a common cancer with a poor prognosis. Prognostic and predictive molecular markers for lung cancer have become available and along those treatment options have multiplied. Treatments can be targeted to aberrant molecules driving the tumorigenesis. Thus, clarification of molecular characteristics of a tumor is important for the optimized therapy. Further development in this field would be aided by the identification of (novel) significant markers and understanding how their incidence is associated with clinical characteristics. The aim of this thesis work was to examine known and novel molecular markers, more specifically mutations in selected genes which could be potential molecular markers of cancer, and to link findings with clinical data in Finnish lung cancer patients. Mutations were studied in genes encoding ephrin receptors (Ephs), EGFR, and in 22 other lung cancer related genes. In addition, coding regions of the genome, i.e. exons, were studied for mutations potentially associated with asbestos-exposure. The study material consisted of more than 600 patients, their tumor specimens and clinical data. The majority of the specimens were formalin-fixed, paraffin-embedded non-small cell lung cancer (NSCLC) and malignant mesothelioma (MM) samples. Most of the specimens were subjected to next generation sequencing (NGS); the suitability of this technology in cancer diagnostics was also assessed. Mutations in Ephs were common; 18 % of the patients carried one or more novel mutation. In MM, in particular EPHB1 was found to be mutated. The mutations did not associate with any particular clinical characteristic and they were found often concurrently with known pathogenic driver mutations, which points to a probable passenger mutation nature for these mutations. However, when considering their diverse role in cellular function, as well as their oncogenic and tumor suppressive properties, therapeutically they represent a very intriguing group of molecules. Clinically significant EGFR mutations were found in 11 % of tumors from NSCLC patients. The mutations were associated with adenocarcinoma histology, female gender and never-smoking status, as has been reported in previous studies. The incidence of EGFR mutations resembled that described in previous studies conducted on other Western patients. Similarly, screening of mutational hot spot regions in 22 genes revealed the mutation profile to be rather similar to that described in Western NSCLC patients with some exceptions, such as the higher BRAF mutation and lower STK11 mutation frequency. TP53 and KRAS as the most frequently mutated genes, being mutated in 46 % and 26 % of the NSCLC patients, respectively. In particular, TP53 mutations were found to co-occur recurrently with other mutations, also with pathogenic EGFR and KRAS mutations. Of the 425 patients, 77 % carried one or more mutations. Statistically significant associations were found between the following mutated genes and clinical characteristics: TP53 and PIK3CA and squamous cell carcinoma, KRAS and adenocarcinoma, and CTNNB1 and light ex-smoking status. In the study comparing asbestos-exposed and non-exposed lung cancer, eight candidate genes (BAP1, COPG1, INPP4A, MBD1, SDK1, SEMA5B, TTLL6 and XAB2) were found to be recurrently mutated exclusively in the asbestos-exposed patients. Mutations in BAP1 and COPG1 were found exclusively in MM. However, the well-established lung cancer-related, pathogenic clinically relevant mutations, such as EGFR and KRAS, do not associate with asbestos-exposure. Finally, the application of NGS technology proved to be very suitable for cancer diagnostics. One major advantage of this technology is the possibility to test for different alterations in multiple genes simultaneously as well as the ability to detect and characterize both known and novel alterations.
  • Lehto, Elviira (Helsingin yliopisto, 2016)
    Most children consume less fruit and vegetables (FV) than recommended for a healthy diet. FV intake is especially low among boys and children from lower socioeconomic backgrounds. The aims of the study were to clarify which factors could explain socioeconomic and gender differences in children s FV intake and liking for FV. Furthermore, it was of interest to find out how the implementation level of an intervention affects children s FV intake and which factors mediate this association. The study sample consisted of 11-year-old children, who participated in the PRO GREENS project in 2009 and 2010. The cross-sectional data used in Study I was derived from ten European countries (n=8159). Finnish longitudinal data from children in control schools (n=424) was used in Studies II and III and from children in intervention and control schools (n=727) in Study IV and. Children reported their FV intake frequency and several environmental and psychosocial factors. Parents stated their highest level of education and teachers documented the implementation level of the intervention. The results indicate that I) in most studied countries, children with higher socioeconomic background were more likely to eat FV daily. The most important mediators were higher availability of FV at home and greater knowledge of the FV recommendation among children from higher socioeconomic backgrounds. II) Descriptive norms about FV intake among friends were as important as parental descriptive norms in predicting children s FV intake among both girls and boys. III) Girls higher liking for vegetables and greater variety in preferences was partly explained by girls higher previous vegetable intake and fewer perceived barriers. IV) Higher implementation level of the intervention increased children s fruit intake via increasing children s knowledge and liking for fruits. Lower implementation levels were less effective, but increased children s fruit intake via increasing the frequency children brought fruits to school for snacking. In conclusion, schoolchildren s FV intake is intertwined with liking for FV and affected by both parents and friends. Interventions should be implemented at the higher level and target all above-mentioned factors. Plentiful availability of FV and their consumption in a supportive environment should be ascertained, especially for boys and children from lower socioeconomic backgrounds.
  • Jokiniemi, Tapani (Helsingin yliopisto, 2016)
    Energy saving objectives have arisen recently in all sectors of life due to the climate change sce-narios and depletion of fossil energy resources. In boreal and northern temperate climate zone countries one of the most energy intensive operations in arable farming is grain preservation, which in most cases means drying. This work focused on examining the energy use and energy saving possibilities in grain drying, and grain preservation in general, from several aspects. The main focus was in Finnish conditions, but the results can be applied also in other areas, when applicable. In addition to the energy aspect, some economic considerations were conducted, since economic profit is the ultimate decision making factor for farmers. The principal method for grain preservation in Finland is hot-air drying. Energy use and energy savings in drying hence constituted the major part of the research work included herein. The aim of the work was to produce information that could be easily utilized in current farming practices. Therefore all the experiments and measurements were conducted in grain recirculat-ing mixed-flow hot-air dryer, which is the most common grain dryer type in Finland. The energy utilization in dryer was first examined and energy losses identified, and three energy saving methods were chosen for closer consideration: 1) controlling the air flow rate and temperature of the drying air (publications I and II), 2) heat insulation of the dryer device (III) and 3) heat recovery from the dryer exhaust air (IV). The aim of the method 1) was to improve the utilization of the supplied heat energy by increasing the humidity of the dryer exhaust air and thus reducing the energy losses via sensible heat in the exhaust air. Method 2) aimed to eliminate the heat losses from the dryer surfaces by the heat insulation. Method 3) focused on recovering the sensible as well as latent heat from the dryer exhaust air with a passive parallel plate heat exchanger. In addition to the energy saving potential in drying, also the possibilities for enhanced use of alternative moist grain preservation methods and their effects on the energy consump-tion in grain preservation were examined (publication V). While drying is practically the only suit-able preservation method for market quality grain in Finnish conditions, moist grain preservation methods could be applied basically for all home-grown grain used for animal feeding, which rep-resents roughly one third of the total annual grain yield in Finland. The examined moist grain preservation methods were airtight preservation, acid preservation of whole grains and grain crimping (ensiling). The energy saving possibilities with these methods, compared to the current situation, were evaluated by theoretical calculations. The results indicated that considerable energy savings could be achieved by the methods examined in publications I to V. The drying process control method produced energy savings of 5 15%, depending on the grain species, compared to conventional drying method. The energy savings achieved by the heat insulation were 16 21% in the examined dryer. Heat recovery method saved on average 18% energy compared to the conventional system, and energy sav-ings up to 40% were suggested for passive heat recovery by the theoretical model developed in the publication IV. Moist grain preservation methods for preserving home-grown feed grain provided energy savings of 50 90% compared to drying. The combined energy saving potential of the examined methods was 20 43% of the total energy consumption in grain preservation at the present situation, when the realizable potential was considered. It was concluded that significant energy saving possibilities exist in current grain preser-vation practices and their utilization could aid to reduce the energy consumption in the agricul-tural sector and thus to achieve the energy saving objectives set by authorities. Energy savings of 5 11% of the total direct energy use in arable the farming sector could be achieved. However, even the relatively large energy savings would have quite a modest effect on the economy of farming with the current energy prices, which indicates that the direct energy inputs are still relatively cheap, compared to other inputs. While energy prices are expected to rise in the long term, energy saving measures will become more viable for the economy of farms in the future, which is the ultimate incentive for more energy efficient production.
  • Malinovskaja-Gomez, Kristina (Helsingin yliopisto, 2016)
    Biological variation and poor transport efficacy are the major concerns in the development of novel iontophoretic drug delivery systems for the transdermal administration of therapeutics. One possibility to overcome these limitations would be to load the drug in interest into a reservoir system such as ion-exchange fibers or nanocarriers prior administration. More precise and homogenous control of drug release and the following transdermal iontophoretic permeation could be obtained as the transdermal device/patch would determine the rate of drug transfer instead of the skin, leading to smaller inter- and intrasubject variability. In addition, the range of molecules delivered by iontophoresis can be expanded as charges could be imparted to neutral drugs by encapsulating them in charged drug carriers. Other benefits raising from such combined systems include enhanced drug transport into or across the skin, improved drug stability and decreased local side effects on skin. The aim of this thesis was to study in vitro the applicability of systems that combine iontophoresis and either drug-loaded ion-exchange fibers or nanocarriers for the controlled transdermal delivery of therapeutics. Firstly, drug reservoirs based on cation-exchange fibers were utilized to retard drug release and provide additional control into transdermal transport of a small molecular drug and a peptide. The drug release kinetics could be modified by the choice of the fiber type or the ionic composition of the external solution. The application of pulsed current iontophoresis instead of conventional constant current led to increased transport efficiency of a cationic hydrophobic peptide that has a tendency to adsorb into skin and inhibit electroosmosis as its main transport mechanism. In addition, drug delivery systems combining iontophoresis and nanoencapsulation into polymeric nanoparticles or lipid vesicles for the controlled transdermal delivery of lipophilic or hydrophilic model compound were developed and tested. Although the obtained nanocarriers were considered as suitable for transdermal iontophoretic administration, regarding the colloidal properties, stability and release kinetics, no clear advantage was observed with respect to drug permeation from free drug formulation. Throughout the thesis, the impact of formulation parameters and current type on drug transport efficiency was monitored. Iontophoretic transdermal drug delivery from polymeric nanoparticle-based formulations but not from lipid vesicular nanocarriers was improved by the application of pulsed current. In conclusion, binding the drug molecules prior iontophoresis into reservoir based on ion-exchange material or nanocarriers is a promising approach to be utilized in controlled transdermal delivery, although the comprehensive evaluation of full potential of such systems tailored for specific drug warrants further investigation in the future.
  • Berg, Venla (Helsingin yliopisto, 2016)
    Recently, personality variation has been found to be associated with number of offspring, pace of reproduction, and other components of fitness in humans and other animals. The link between personality and fitness has inspired a surge of theoretical accounts on the evolution of personality. However, the associations between personality and fitness are yet to be sufficiently empirically elaborated for the theoretical advances to be solidly based. This thesis explores the pathways between personality and fertility in three contemporary Western human populations. Specifically, this thesis i) provides further evidence on the phenotypic associations between personality and lifetime reproductive success; ii) examines the differences between a phenotypic and genetic approach to natural selection on personality; iii) investigates whether personality is involved in a trade-off between the number and quality of offspring; and iv) explores possible novel selection pressures on personality. The results are discussed in relation to the theoretical accounts on the evolution of personality. The results suggest that the phenotypic associations between personality and lifetime reproductive success vary by populations. Further, it seems that the phenotypic and genetic approaches to natural selection on personality differ and that modern environments can impose novel selection pressures on personality. Lastly, it seems that personality is similarly associated with number of children and grandchildren, implying no quality quantity trade-offs in modern environments. Crucially, the results show that personality is not associated with fitness in any one way, or because of any one evolutionary mechanism. Further, the results suggest that the behavioural personality differences might not be evolutionarily relevant, but that personality correlates genetically with something else that affects fitness. Thus, future studies should concentrate on the individual personality traits and their genetic correlates, as trying to find a unified evolutionary answer for personality may prove an elusive task.