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  • Huhtamäki, Martina (Helsingin yliopisto, 2015)
    This thesis explores the prosodic features of questions in conversations among speakers of Helsinki Swedish. The aim is to find out how the participants used such features to design and ascribe utterances as questions, as well as to signal turn endings in them. The research contributes to the current understanding on how prosodic and other features are used in combination to create meanings in conversation. This work is a compilation thesis comprising four papers and a summarizing report. The data consist of six recordings of everyday conversations among Swedish speakers from the capital region of Finland. The conversations are multi-person conversations. The participants comprise 29 females and males between the ages of nine and approximately 60. Utterances in the data are defined as questions in line with the following criteria: 1) they belong to the epistemic domain of the recipient, and 2) they form the first pair-part of an adjacency pair consisting of a question and the response. This definition includes declarative clauses that are used to request information when the topic is in the epistemic domain of the recipient. However, it excludes rhetorical questions (because the questioner then has more knowledge than the recipient), as well as questions that are used to request action. The questions are all one-unit, syntactically complete utterances. The focus varies in each of the four studies: in the first one it is on 240 questions with varying syntax; in the second it is on 110 questions with non-interrogative syntax; in the third it is on 191 questions with a non-falling final intonation; and in the fourth it is on 52 questions consisting of the free-standing va, what . The theoretical and methodological framework is interactional linguistics, and the methods used are both conversation analysis and phonetic analysis. The research is qualitative. The data are transcribed according to the traditions of conversation analysis, with some added signs indicating prosodic features. The phonetic analysis, for which the Praat program was used, includes both auditory and acoustic elements. The identity of the participants is protected through the anonymization of all recognizable information in the transcripts. The participants were aware that their conversations were being recorded, and gave their permission for the recording to be used in research. The results show the many functions for which questions are used, and that prosodic features are employed for various purposes. Most questions have a final falling intonation in these conversations in Helsinki Swedish, but there are also instances of final rising and level intonation. Final intonation has several functions, and is used together with other features to distinguish between utterances inside the question category. For example, a rising final intonation can be used in a question that paves the way for another action, and a wide pitch span can be used to signal an affective stance. The syntax, the lexical choices and the relation of the question to the conversational context are also indicative of its function, as are the epistemic relations between the participants. However, prosodic features are not used to signal questions as a sentence type that is separate from assertions, for example. In sum, final intonation is just one of several prosodic features projecting a possible point of completion. The other features include a slower rate of speech and diminished loudness, possibly a focal accent and a changed voice quality. Key words: questions, prosody, intonation, Helsinki Swedish, interactional linguistics, conversations
  • Tuovinen, Hanna (Helsingin yliopisto, 2015)
    Northern Fennoscandia has experienced an unparalleled mineral exploration boom since around 2005. At the same time, there has been increasing awareness of the potential environmental impact of non-nuclear industries that extract and/or process ores containing naturally occurring radionuclides. Industrial activities may result in significant environmental problems if the waste generated during ore processing is not adequately managed. In 2010, a new project was launched with an objective to study the mobility of uranium series radionuclides from diverse mill tailings in a northern boreal environment in Finland. Three sites were investigated: the Talvivaara Ni-Cu-Zn-Co mine in central Finland, a former phosphate mine at Sokli, Finnish Lapland, and a former pilot-scale uranium mine at Paukkajanvaara, eastern Finland. The mobility of radionuclides from the mill tailings at Sokli was examined in order to assess the potential environmental impact of past and future mining activities. Mineralogical studies did not indicate that uranium or thorium have been mobilized from altered pyrochlore-group minerals in the Sokli ore or tailings. In the tailings pond, no clear trends were observed in the activity concentrations of uranium, radium or thorium isotopes in the surface layers of the mill tailings. In subsurface samples, an increase in the concentration of these isotopes can be seen when approaching the pond at the distal end of the sludge field. However, this increase is most likely to a consequence of compositional changes in material discharges. The results of the sequential extraction tests suggested that neither uranium nor thorium is in an exchangeable form and could potentially be released to the environment. Uranium (4% of the total concentration) was partly soluble under weakly acidic conditions, whereas thorium was tightly bound in mineral phases. At the former Paukkajanvaara uranium mine in Eno, the aim of the study was to examine the potential for further mobilization of radionuclides after remediation of the site in early 1990s. There are two primary sources of contamination at the site, the waste rock pile and the tailings. The results indicate that Ra-226 has been leached from the waste rock pile and accumulated in surrounding soil. In run-off sediment samples collected from a dry stream bed near the waste rock pile, the activity concentrations of Ra-226 and U-238 are higher than in soil samples. From the tailings, radionuclides can leach directly to the lake and to another small stream, which flows to the east of the waste rock pile. The results from the soil samples collected between the tailings area and the stream indicate leaching of U-238 and Ra-226 with the surface flow. Sediment samples collected from the bottom of the lake display pronounced uranium series disequilibrium with fractionation of Pb-210 and Ra-226 relative to the parent U-238. The results therefore indicate that leaching and accumulation of at least Ra-226 from the waste rock pile and possibly tailings is still ongoing. At Talvivaara, the aim of the study was to generate new data leading to a better understanding of the fate of radiotoxic uranium daughter nuclides, primarily Ra-226, Pb-210 and Po-210, in the mining process. In heap leaching, uranium is dissolved from uraninite to the pregnant leach solution. Uranium is probably transported as uranyl ions and uranyl sulfate complexes in the acid pregnant leach solution (PLS), and finally ends up in precipitates of the gypsum pond tailings via iron removal and final neutralization processes during the removal of residual metals. In terms of radiation safety, the U-238 activity concentration in the gypsum pond is partly above the exemption value (1000 Bq/kg) for natural radionuclides of the U-238 series. Radium and thorium mostly stay in the heaps during heap leaching. In addition, Pb-210 and Po-210 stay mainly in the heaps but slight mobilization of these nuclides was indicated. Secondary sulfate minerals, such as gypsum and jarosite, are precipitated from the sulfate-rich and acid PLS at Talvivaara. These minerals can incorporate radium in their crystal lattices, limiting Ra-226 mobility. Therefore, it can be assumed that most of radium and possibly part of Pb-210 and Po-210 are co-precipitated with poorly soluble sulfates in the Talvivaara heaps.
  • Ding, Yi (Helsingin yliopisto, 2015)
    Due to the popularity of smartphones and mobile streaming services, the growth of traffic volume in mobile networks is phenomenal. This leads to huge investment pressure on mobile operators' wireless access and core infrastructure, while the profits do not necessarily grow at the same pace. As a result, it is urgent to find a cost-effective solution that can scale to the ever increasing traffic volume generated by mobile systems. Among many visions, mobile traffic offloading is regarded as a promising mechanism by using complementary wireless communication technologies, such as WiFi, to offload data traffic away from the overloaded mobile networks. The current trend to equip mobile devices with an additional WiFi interface also supports this vision. This dissertation presents a novel collaborative architecture for mobile traffic offloading that can efficiently utilize the context and resources from networks and end systems. The main contributions include a network-assisted offloading framework, a collaborative system design for energy-aware offloading, and a software-defined networking (SDN) based offloading platform. Our work is the first in this domain to integrate energy and context awareness into mobile traffic offloading from an architectural perspective. We have conducted extensive measurements on mobile systems to identify hidden issues of traffic offloading in the operational networks. We implement the offloading protocol in the Linux kernel and develop our energy-aware offloading framework in C++ and Java on commodity machines and smartphones. Our prototype systems for mobile traffic offloading have been tested in a live environment. The experimental results suggest that our collaborative architecture is feasible and provides reasonable improvement in terms of energy saving and offloading efficiency. We further adopt the programmable paradigm of SDN to enhance the extensibility and deployability of our proposals. We release the SDN-based platform under open-source licenses to encourage future collaboration with research community and standards developing organizations. As one of the pioneering work, our research stresses the importance of collaboration in mobile traffic offloading. The lessons learned from our protocol design, system development, and network experiments shed light on future research and development in this domain.
  • Stén, Johan Carl-Erik (Springer / Birkhäuser, 2015)
    The Finnish mathematician and astronomer Anders Johan Lexell (1740-1784) was a long time close collaborator and the academic successor of Leonhard Euler at the Imperial Academy of Sciences in Saint Petersburg. Lexell was invited in 1768 from his native town of Åbo (Turku) in Finland to Saint Petersburg to assist in the laborious mathematical processing of the astronomical data from the forthcoming transit of Venus of 1769. A few years later he became an ordinary member of the Academy. Lexell was the first mathematician and astronomer of international renown from Finland. This thesis is the first full-length intellectual biography devoted to Lexell and his prolific scientific output. Using his numerous publications, we trace the development of his scientific thought. In close collaboration with Euler, he contributed especially to infinitesimal calculus and geometry. In astronomy his work pertains mainly to the parallax and longitude problems, as well as to orbit calculations. He is known for having recognised that Herschel's new "comet" of 1781 moves in a nearly circular orbit and must therefore be a planet. Lexell also predicted the extraordinary motion of the comet of 1770 ("Lexell's comet"), which constitutes an example of a restricted three-body problem. Lexell had wide scientific interests. Being internationally minded and well-connected, he entertained a rich correspondence not only with astronomers and mathematicians but also with natural historians and administrators. His detailed letters especially from his grand tour to Germany, France and England in 1780-1781 reveals him as a lucid observer of the intellectual landscape of enlightened Europe.
  • Sova, Susanna (2015)
    The evolution of biominerals, including teeth, has been an important step in the evolutionary diversification of organisms. For an organism, biominerals allow various advantages, such as ion storage, protection, food capture and processing, and locomotion. In mammals, tooth enamel is the hardest and most mineralized part of the body. Although tooth development is better known than that of many other organs, the maturation of enamel is still not completely understood. Enamel formation is a slow process biologically. In humans, the mineralization of the enamel in the first permanent molars starts at the time of birth, and the process continues even after the eruption of the teeth at the age of six years. Any disturbances during the enamel formation or other damage later in life will become permanent, as enamel does not reform. The aim of this work is to document the maturation of domestic pig molars, and use mineralogical and physics research methods to study enamel growth. The domestic pig (Sus scrofa domesticus) is a plant-dominated herbivore with large, bunodont molars. The relatively fast development of pig teeth together with their large size makes pig teeth a suitable model for comparisons of different methods. One of the methodological interests was to test if mineral grains can be used in computational microtomography for relative calibration of the absorption models. Three minerals (fluorapatite, quartz and siderite) were chosen by their physical and chemical features. The calibrated absorption models were compared with the results of more traditional methods, such as thin sections and hardness tests. X-ray diffraction and scanning electron microscopy were also used for structural studies. The results show that the microtomography is a valuable starting point for the traditional destructive methods used in the study of biomineralization, but does not substitute for the other methods. The mineral calibration was an efficient method for the microtomography-absorption models. Additionally, the calibration minerals allowed detection of microtomography artifacts better than using teeth only.
  • Kivisaari, Heli (2015)
    The occurrence of high-aluminum orthopyroxene megacrysts (HAOMs) has been used to argue for polybaric crystallization of Proterozoic anorthosites. In this study, the petrography, geochemistry, and petrologic significance of HAOMs discovered from the 1.64 Ga Ahvenisto rapakivi granite – massif type anorthosite complex were studied. Fieldwork in the northwestern flank of the Ahvenisto complex revealed new outcrops with two different types of HAOM embedded in leucogabbroic rocks. Type 1 HAOM are autonomous, euhedral to subhedral, and up to 15 cm in diameter. Type 2 HAOMs occur in pegmatitic pockets with megacrystic (up to 30 cm long) laths of plagioclase. Especially the type 1 HAOMs are surrounded by complex rim structures comprised of plagioclase, low-Al orthopyroxene, iddingsite (after olivine), and sulphides. A quantitative electron microprobe wavelength dispersive spectroscopy analysis (EMPA-WDS) of orthopyroxene, plagioclase, and olivine was conducted on nine samples. Also, a bulk-analysis (WD-XRF) was performed on a set of twelve whole-rock and mineral samples. The precision and applicability of these methods in the HAOM research is briefly discussed. The geochemical data was used to evaluate the crystallization pressures of orthopyroxene in the system with an ”Al-in-orthopyroxene” geobarometer. A relatively clear three-stage compositional evolution is observed. The Al content decreases significantly from the core regions of the HAOM (4.4–7.6 wt. % Al2O3), through the rims (1.3–3.6 wt. %), into the host rock (0.5–1.5 wt. %). Enstatite compositions overlap but are generally higher in the cores (En~60–70) and rims (En~50–70) of the HAOMs than in the host rock (En~45–60) orthopyroxenes. The highest recorded Al abundances in the HAOM cores correspond to crystallization pressures of up to ~1.1 GPa and depths of ~34 km. The HAOM rims have crystallized in lower pressures (maximum of ~0.5 GPa/20 km). The highest pressure-estimates within barometer calibration for the host rock orthopyroxene were ~0.2 GPa (<10 km). The observations made in this study suggest that the inner parts of the HAOMs have crystallized in high-pressure conditions at lower crustal levels. The reaction coronas between the HAOM and the host rock were most likely formed during initial igneous cooling and in the presence of some melt, followed by subsequent hydration of the system. The occurrence of magmatic olivine within the rim may reflect the effects of pressure decrease in the ternary Fo-An-Si system, which stabilized olivine over orthopyroxene in the late stages of crystallization. Groundmass orthopyroxene composition is concurrent with late low-pressure crystallization at intrusion depth. This information is concordant with the latest research from the Ahvenisto area, which suggest that the anorthosistic rocks have a mantle origin.
  • Nikula, Karoliina (Helsingin yliopisto, 2015)
    Keywords: goodness, capability, choice, ethics, deaf, sign language, cochlear implant, clinical practice, medicalization. Lapsen hyvää edistämässä. Syntymäkuurojen lasten sisäkorvaistutehoitokäytännön sosiaalieettistä tarkastelua. [Promoting The Good of The Child. A Social-Ethical Analysis of Cochlear Implants in Children Born Deaf]. Karoliina Nikula, University of Helsinki. In 1995, after a long period of lobbying and political action, sign language was granted a legal status in Finland. In 1997, the first cochlear implant surgeries were performed on children in Finland. At present, 90 percent of deaf children undergo cochlear implant surgery. The use of sign language as a first language is diminishing. The majority of deaf children are born to hearing parents, and they are being asked to make the choice whether their children should receive cochlear implants or not. Previous empirical studies have shown that some parents feel that their choices are not always respected. The aim of this research project is to study cochlear implant clinical practices using the concepts of goodness, capability, and choice, as well as to analyse whether the shift in clinical practices from sign language to spoken language is based on careful deliberation and reasonable arguments. This study helps us to better understand the parents process of deciding whether or not to obtain cochlear implants for their children, and the family s journey through treatment options and standard clinical practices. In addition, this study provides tools for parents of deaf children to assist their decision-making and to medical practitioners who advise these parents. The study is focused around the following research questions: (1) What constitutes medical goodness for a child born deaf? (2) In what ways do cochlear implants and sign language promote a deaf child s capabilities? (3) Is it adequate to speak of choice when thinking about the dilemmas of parents of children born deaf? The research methodology is philosophical concept and argumentation analysis along with analysis of the construction of the concept of choice. The research data consists of various sources and literature. The sources can be divided into the following: 1) Avaintietokansio [materials made available to families of the deaf]; 2) publications of the Satakieli seminars; 3) brochures and other information provided by device manufacturers; 4) DVD and video recordings; 5) Internet pages; and 6) legislation. The literature is comprised of (1) previous empirical studies on the parents of deaf children obtaining treatment for their children. Empirical studies on family experience include materials published by the Finnish Association of the Deaf and the Institute for the Languages of Finland, e.g., Suomen viittomakielten kielipoliittinen ohjelma (2010); a publication of the Ombudsman for Children Hei, kato mua! (Johanna Kiili and Kirsi Pollari, eds., 2012); and Riia Celen s documentary Sanoja sormenpäissä (2009) and Minna Luukkainen s Viitotut elämät: Kuurojen nuorten aikuisten kokemuksia viittomakielisestä elämästä Suomessa (2008). These provide information on the experiences of families whose deaf children are being treated. Internationally, Stuart Blum s The Artificial Ear (2010) also provides information on the experiences of families. (2) Ethical and medical discourse on cochlear implants in deaf children. (3) Previous philosophical and ethical work, particularly the following: a) Martha Nussbaum s capability approach; b) Georg Henrik von Wright s The Varieties of Goodness (1963, Finnish translation 2001); and c) rational choice theory, especially in the work of Jon Elster. In addition, (4) methodological handbooks (e.g., literature about the conceptual tools) were used. The study is organized as follows. Chapter two examines deafness from two points of view: audiological and socio-cultural. I also introduce topics often associated with deafness, such as sign language and deaf culture. Here I also discuss the technical aspects of cochlear implants and provide a brief history of the deaf in Finland. In chapters 3 5 I examine the three main concepts goodness, capabilities, and choices with reference to the research questions. These provide essential conceptual tools when analysing the issue, as the processes connected to cochlear implants are centred around the question of what constitutes a good life for the child, the child s ability to develop, and the choices that parents in this situation must make. My research demonstrates the following: (1) The transition from sign language to spoken language is not based on sound arguments. This study did not find a solid rationale for reducing the use of sign language in order to rehabilitate hearing. Giving up sign language cannot be said to promote the child s good, capabilities, or opportunities to make independent choices in the future. On the contrary, it may indeed interfere with them. (2) In conjunction with the cochlear implant treatment process, it sometimes seems that the ideas of promoting choice and increasing capabilities are more of an illusion. We can also speak of language as an illusion in the sense that in the literature I surveyed (as well as in this discourse), language is often used synonymously with spoken language. The rhetoric used directs choice and creates impressions. We cannot speak of a family s autonomous, rational choices if the situation does not meet the criteria for choice. (3) Occasionally, the process seems to be about audism, i.e., valuing spoken language over signed language, medicalization, technological imperatives, and the treatment of cochlear implants as an ideological issue. All of these can have an effect on the decision-making processes of parents. (4) Cochlear implant clinical practices differ from general health care practices in the sense that implant practices are not always based on evidence (e.g., there is no evidence of the advantages of choosing not to learn sign language; there is as yet no knowledge of the long-term effects of cochlear implants). Furthermore, health care usually focuses only on areas within the medical field, but a language is not only a medical issue. Health care practices are usually based on research results, limited to areas in which medical authorities have competence and designed to maximize the patient s capabilities. (5) Legislation, different schools of thought, and treatment practices create different ways of understanding deafness. Legislation treats the deaf in terms of language and handicap. Different schools of thought lead to polarized discourse about deafness. Finally, according to the reports of parents, current clinical practices require them to choose one language for their child, although it would be possible to choose both sign language and spoken language. These divisions in the discourse may affect the decision-making of parents. (6) The idea of choice is not the best way to promote the well-being of deaf children. Focusing instead on capabilities would free parents and health care practitioners from the burden of predicting outcomes which will only come with time: that is, if all capabilities are promoted, it is not necessary to know how hearing or speech will develop, what the child would like to do or be when s/he grows up, or what sort of future the child will have. A discourse of choice creates an either/or, rather than a both/and situation. Both/and is a better platform from which to develop a child s full capabilities. (7) The concepts of goodness, capabilities, and choice provide useful tools to examine cochlear implant clinical practices and the dilemma of families with deaf children. These concepts can also be used more generally in thinking about ethical considerations in medical practice, as they represent fundamental issues in terms of both ethics and health care practice. (8) Cochlear implant clinical practices need to be developed. This study shows that written materials supporting parental decisions need to be improved, and care needs to be taken that space is given to different alternatives. In addition, more multi- and cross-disciplinary co-operation needs to be developed to improve the prospects for deaf children. Based on this study, I suggest that in the future we need to focus on four issues. First, we must pay attention to the rhetoric used in legislation, in information packets for families of the deaf, and in the research literature. Second, instead of talking about choice, we must take into consideration the child s strengths and skills on many levels. Third, we should consider the possibilities offered by multiculturalism, which includes different types of language choices, as well as multi- and cross-disciplinary clinical teams. If advice is being given on language, the treatment team should include a language specialist as well as a member who knows sign language. This study affirms the need for further multi- and cross-disciplinary co-operation. Fourth, deaf children should be treated as a whole person, not simply through their hearing or lack thereof.
  • Tolonen, Hannele (Suomalainen Lakimiesyhdistys, 2015)
    This dissertation, which belongs to the field of procedural law, focuses on the procedural standing of children in custody proceedings and care proceedings. In the Finnish legal system, these proceedings are allocated to separate court systems. This study investigates the effects of this dual court system in situations where child welfare measures and the determination of custody, residence or contact overlap. The dissertation has two main goals: to systemize and compare the legal framework on children s standing in these court proceedings and to evaluate the procedural rights and the right to protection in each proceeding. The research is mainly based on legislative material, case law from the European Court of Human Rights and the national courts, and legal scholarship. In order to examine the effects of overlap of the proceedings at the level of individual cases and to illuminate children s participation in detail, court documents from 34 custody proceedings and 32 care proceedings were qualitatively studied. One of the main results of the study is that the overlap in the proceedings may cause several complications at the level of individual proceedings. In the cases that were studied, many children were affected by both the child welfare system and custody proceedings. In an acute situation, where concerns are raised for the safety of the child, but where the private and public parties disagree on the course of action, the dual process system adds to the complexity. The dual role of social agencies seemed problematic in the overlapping cases, where strong claims of partiality were voiced by the parties in the custody proceedings. In the studied care proceedings, the children who were assisted by a legal counsel participated most effectively and directly. To ensure that children are able to participate effectively in legal decision making, assistance should be provided for them in care proceedings. Especially for older children and in cases where the measures are motivated by the child s conduct, a lawyer should be appointed for the child. In the studied custody proceedings, children rarely participated directly in the proceedings. To enable individual assessment of the means of participation in light of the circumstances in each case, a more flexible approach should be adopted in determining children s procedural standing in custody proceedings. The need for impartial assistance should be considered, for example, in complicated custody cases or when a child is claimed to be at risk.
  • Joensuu, Emmi (Helsingin yliopisto, 2015)
    Cancer usually arises through mutational changes in the genome but also epigenetic changes can contribute to tumorigenesis. In this research we studied both sporadically occurring and familial colorectal, endometrial and gastric tumors. Sporadic tumors were divided into separate categories depending on the microsatellite instability status of the tumor. In addition to sporadic tumors we studied tumors from patients with different cancer syndromes: Lynch syndrome, Familial colorectal cancer type X and Familial site-specific endometrial cancer. Lynch syndrome patients have a predisposing germline mutation in one of the mismatch repair genes (MLH1, MSH2 or MSH6) and the tumors are typically microsatellite unstable. Despite the extensive research efforts, the genetic or epigenetic background of the other studied syndromes is not known and remains to be molecularly characterized. We therefore explored the possible epigenetic basis of cancer susceptibility in these syndromes. First we studied the promoter methylation of 24 established tumor suppressor genes. Hypermethylation patterns were found to be characteristic of each tissue and diversely dependent on the microsatellite instability status of the tumor, or family category. The CpG island methylator phenotype (CIMP) in which multiple loci are silenced by promoter methylation, was most evident in sporadic microsatellite unstable tumors (P less than 0.001) and was present in 38% of all of the studied colorectal, 19% of endometrial and 29% of gastric tumors. In these tumors the CIMP phenotype can contribute to the genomic instability and the progression of cancer. In addition, despite being microsatellite stable, 50% of Familial colorectal cancer type X tumors displayed the CIMP phenotype. Our results of global hypomethylation confirm that tumors have significantly lower methylation levels compared to normal tissues in most of the studied patient groups (P less than 0.05) and that the hypomethylation levels depend significantly on the microsatellite instability status of the tumors (P = 0.042 for colorectal and P = 0.018 for gastric tumors). The significant decrease in the methylation levels, observed especially in the normal tissues of Familial colorectal cancer type X patients, could function as a premalignant field defect, where a large area of tissue is affected by carcinogenic alteration, and hence promote cancer development by facilitating the accumulation of other lesions such as genetic mutations or other epigenetic changes in the affected areas. After the characterization of different DNA methylation aberrations in distinct tumor categories, we studied the possible mechanisms behind the observed methylation changes. We evaluated the association of the expression of DNA methyltransferases DNMT1 and DNMT3B and histone methyltransferase EZH2 with CIMP+ phenotype and global hypomethylation patterns. Compared to the normal tissues, all the studied methyltransferases were significantly overexpressed in colorectal tumors (P less than 0.001) and DNMT3B also in endometrial tumors (P less than 0.001). EZH2 overexpression was shown to associate with CIMP+ phenotype especially in sporadic colorectal tumors and the finding was statistically significant (P = 0.003). The overall aim of this research was to elucidate epigenetic mechanisms in cancer, including cancers of different organs and also different familial cancers. Available information on the epigenetic events of cancers is increasing and although the topic is under continuous study, our understanding of it is still limited. New knowledge in the field can increase the understanding of the basic tumorigenic mechanisms and thereby facilitate more specific and earlier diagnosis and treatment of different types of cancer. Also the potential reversibility of epigenetic states offers interesting possibilities for drug development.
  • Ropponen, Jussi (Helsingin yliopisto, 2015)
    Chronic lung allograft dysfunction (CLAD) is the major life-limiting factor after lung transplantation and bronchiolitis obliterans syndrome (BOS) is the most common subtype and best-characterized form of CLAD. Pathologically, BOS presents as obliterative bronchiolitis (OB) and it is characterized by peribronchial inflammation, epithelial damage, and obliteration of small and medium-sized bronchioli by fibrotic plaques. BOS is the leading cause mortality after the first post-operative year. In this study, we hypothesized that inhibiting innate immune activation through different pathways influences the development of experimental OB. To test our hypothesis, we investigated different factors and pathways leading to experimental OB using both rat and mouse heterotopic tracheal allograft models. In the presence of alloantigens, early ischemic injury induced both innate and adaptive immune responses followed by Th17 activation and afterwards by a sustained Th1 immune response. This was accompanied by infiltration of the allograft with proinflammatory effector cells and lead to progressive fibroproliferation and total tracheal occlusion. Interestingly, recipient treatment with simvastatin, a cholesterol-lowering drug with lipid-independent immunomodulatory properties, enhanced early epithelial recovery after transplantation in the allografts. It also inhibited the infiltration of inflammatory cells and the expression of lymphocyte chemokines and proinflammatory cytokine mRNA. Most importantly, simvastatin inhibited the development of experimental OB in the absence of other immunosuppression. The cellular responses to hypoxia are regulated by transcription factors called hypoxia inducible factors (HIFs). HIF-1 is a principle regulator of hypoxic adaptation. In this study, we found that continuous HIF-1 expression in myeloid cells improved epithelial recovery, reduced inflammatory cell accumulation, and increased regulatory FoxP3 mRNA expression in mouse tracheal allografts. Importantly, these effects led to better preservation of tracheal epithelium and a decrease in the development of experimental OB suggesting a protective role of HIF-1 in this constellation.
  • Milardi, Marco (Helsingin yliopisto, 2015)
    Fish introductions, unlike many other clades, are often carried out purposefully. This is a worldwide practice, which has been ongoing since ancient times and has found new powerful ways to increase in magnitude and scope through the development of more effective transport and with increasing population wealth. Even though the literature is building up pace fast with this relatively recent phenomenon, information is still lacking on the mechanisms and results of the impact that introduced fish have on freshwater ecosystems. Remote small lakes at high-latitudes can be used to evaluate some of these impacts, as they are of limited size and often host relatively simple food webs with a single species of introduced fish, which makes them ideal model systems. Many areas are not as easy to investigate, as they present much more complex ecosystems where complex species interactions take place. For example, artificial lotic systems with a high number of species interactions can be particularly challenging to tackle as other anthropogenic/environmental stressors might be challenging to disentangle. This thesis focused on three main themes which addressed the reliance of introduced fish on terrestrial energy, their cascading effects on the food web and their interaction with native species. The first two themes used brown trout introduced in remote small lake ecosystems at high latitudes as a model, whereas the last theme used a complex lotic system at low latitudes where multiple species were introduced at different times. The chapters of this thesis used neo- and paleolimnological techniques to investigate the impacts of introduced fish, sometimes in combination. In particular, the first theme was tackled through the use of stomach content, fatty acids and stable isotopes to unravel the feeding ecology of introduced brown trout. The second theme was instead addressed through multiple paleo-proxies in combination with neolimnological analyses and models. The last theme was investigated through the analysis of long-term environmental and fish-assemblage data. Our findings suggest that terrestrial sources could be highly important in supporting introduced brown trout populations in small lakes at high latitudes. Despite challenges inherent to the turnover rates of fish liver and muscle tissues, which were longer than previously thought, this support did not vary across different years or fish densities, but was affected by seasonal factors over the course of the open-water season. Our results also suggest that introduced brown trout affect the food web of host lakes through trophic cascades, altering the abundance of pelagic and benthic micro- and macroinvertebrates, probably through a modification of the distribution of macro-invertebrate communities. According to a bioenergetic and a mass balance model, introduced brown trout nutrient regeneration should have increased lake productivity; however paleo-proxies indicated no such change but rather a shift from pelagic to benthic productivity. Finally, our results suggest that, in artificial lotic systems at low latitudes, environmental chemistry did not play a role in the decline of the native fish species communities. Rather, this was a result of the interaction between some of the introduced fish species and the native ones, enhanced by the habitat simplification and the peculiar water fluctuation regime.
  • Ramiadantsoa, Tanjona (Helsingin yliopisto, 2015)
    Habitat loss and fragmentation is the main culprit behind the current decline in biodiversity. The estimated current rate of extinction is two or three orders of magnitude higher than the background extinction rate. This thesis analyzes existing data and develops models to improve our understanding of the role of spatial processes in the dynamics of populations and communities. This work is focused on the features of habitat destruction that causes decline of biodiversity as well as the traits that make species vulnerable to habitat loss. First, I attempt to infer relationships between spatial heterogeneity, rate of diversification (speciation and extinction), and the dynamics of geographical ranges from a reconstructed phylogeny. I build a flexible comparative method to analyze adaptive radiation and range dynamics that extends the current models in two directions by allowing more than two regions and by assuming diversity-dependent diversification rates. In a five-region system stimulated by the biogeography of Madagascar, processes that increase and decrease diversity are strongly correlated. Therefore, it is not possible to estimate independently region-specific speciation and extinction rates, though their ratios can be successfully estimated. When applied to Malagasy dung beetles, we found that diversification rate is highest in the northern (very heterogeneous) and lowest in the southern (most homogeneous) parts of Madagascar. Thus it appears that landscape heterogeneity promotes diversification and thus biodiversity. The two other chapters investigate the consequences of habitat loss and fragmentation for generalist and specialist species. We aim to understand how generalist and specialist species respond to habitat loss and fragmentation. In particular, we ask why generalist species often increase in abundance following an intermediate level of habitat destruction. I develop a modular modeling approach that allows one to switch on and off various mechanisms as needed. This approach one to assess the marginal and joint effects of different mechanisms by comparing model outcomes. Our analyses confirm that a high level of specialization leads to high sensitivity to habitat loss and fragmentation. When landscape quality is high, specialists are competitively superior, but when landscape degrades, generalists gradually become superior. In previous models, competitive hierarchy is usually thought to be an intrinsic property of species, but we show that a shift in competitive capacity is caused by extrinsic factors. Comparing deterministic versus stochastic models, we find that a key extrinsic factor is increase in demographic stochasticity in degraded landscapes that affects specialists more than generalists. In the third chapter, I ask about the role of large- scale habitat corridor for biodiversity conservation. We analyzed a community of 300 species belonging to 6 taxonomic groups inhabiting more than 2000 km2 forest, composed of two large national parks in Madagascar, Ranomafana and Andringitra, and connected by a corridor. We found that in 2000 the corridor was still functional, but since then it has degraded substantially and may lose its corridor function in the coming decades. Our spatially realistic simulations show that species with passive mode of dispersal suffer the most from corridor destruction. This thesis emphasizes the role of different mechanisms that should be considered while analyzing species responses to changes in habitat structure. The most important ones are the mode of dispersal, ecological specialization, temporal and spatial stochasticity, and competition. As such, tropical regions, like Madagascar, are in double trouble due to high ecological specialization of most species and high rates of habitat destruction. Effective measures need to be enforced to ameliorate the conditions within and outside protected areas so they can truly enhance biodiversity protection.
  • Laaksonen, Antti (Helsingin yliopisto, 2015)
    This thesis studies two problems in music information retrieval: search for a given melody in an audio database, and automatic melody transcription. In both of the problems, the representation of the melody is symbolic, i.e., the melody consists of onset times and pitches of musical notes. In the first part of the thesis we present new algorithms for symbolic melody search. First, we present algorithms that work with a matrix representation of the audio data, that corresponds to the discrete Fourier transform. We formulate the melody search problem as a generalization of the classical maximum subarray problem. After this, we discuss algorithms that operate on a geometric representation of the audio data. In this case, the Fourier transform is converted into a set of points in the two-dimensional plane. The main contributions of the first part of the thesis lie in algorithm design. We present new efficient algorithms, most of which are based on dynamic programming optimization, i.e., calculating dynamic programming values more efficiently using appropriate data structures and algorithm design techniques. Finally, we experiment with the algorithms using real-world audio databases and melody queries, which shows that the algorithms can be successfully used in practice. Compared to previous melody search systems, the novelty in our approach is that the search can be performed directly in the Fourier transform of the audio data. The second part of the thesis focuses on automatic melody transcription. As this problem is very difficult in its pure form, we ask whether using certain additional information would facilitate the transcription. We present two melody transcription systems that extract the main melodic line from an audio signal using additional information. The first transcription system utilizes as additional information an initial transcription created by the human user of the system. It turns out that users without a musical background are able to provide the system with useful information about the melody, so that the transcription quality increases considerably. The second system takes a chord transcription as additional information, and produces a melody transcription that matches both the audio signal and the harmony given in the chord transcription. Our system is a proof of concept that the connection between melody and harmony can be used in automatic melody transcription.
  • Pérez Vera, Cristina (Helsingin yliopisto, 2015)
    The incidence of arthropod-borne infections is increasing worldwide and Fennoscandia is no exception. In the last decades, infections transmitted by ticks are being diagnosed more frequently in people living in the Nordic countries. Ixodes ricinus, the sheep or castor bean tick, which is the most common tick in North-Western Europe, is widely distributed in Finland. Ixodes ticks are vectors of a broad spectrum of pathogens of medical and veterinary importance, such as Babesia spp., Borrelia spp., Anaplasma phagocytophilum (Ap), Bartonella spp., tick-borne encephalitis virus (TBEV), and Francisella tularensis. To date, there is limited information regarding the prevalence of many vector borne diseases in companion animals in Finland, and therefore the majority of available data come from human medicine studies. Infections caused by Bartonella species are considered an emerging zoonosis. One peculiarity of this genus of bacteria is its ability to cause long lasting bacteremia in reservoir hosts. Also, it appears that no other infectious agent is transmitted by more vectors. The deer ked, Lipoptena cervi, is an ectoparasite of moose (Alces alces), which carries Bartonella DNA. Deer keds, which are a nuisance for people, can occasionally bite humans and cause deer ked dermatitis. Whether or not the deer ked can successfully transmit bartonellae to ruminants or humans has not been determined. Because many of the arthropod-borne infections that affect dogs can cause serious disease in people, dogs are considered to be effective sentinel animals to assess the risk of human infection. Also, pets represent a large reservoir for human Bartonella infection because most of the species that infect them are zoonotic. The objective of the present research project was threefold: first, to establish the serological and molecular prevalence of selected tick borne diseases in a large group of dogs in Finland; second, to retrospectively compare different diagnostic approaches and clinicopathologic findings in dogs infected with Bartonella spp.; and third, to explore the role of the deer ked in the transmission of Bartonella spp. to Finnish moose. The serological results from dogs in this study indicate that Finnish dogs are exposed to at least one of four tested arthropod borne pathogens. Dogs were most frequently exposed to Ap (5.3%) followed by Bb (2.9%). Exposure rates were significantly higher in dogs living in Åland. No Finnish dog in this study was infected with Bartonella spp, based on PCR. Bartonella-infected dogs from the USA were most often infected with B. henselae, based on BAPGM enrichment PCR. Interestingly, for most of these dogs, no positive antibodies against Bartonella spp were detected. Clinicopathologic abnormalities in dogs with Bartonella infection were similar to those dogs suspected to have other vector-borne infection. The presence of Bartonella DNA (B. schoenbuchensis and B.bovis) was demonstrated in deer ked pupae samples and in one winged adult, which indicates transstadial transmission of this bacterium in the deer ked. The same Bartonella species were identified in blood samples from free ranging moose in Finland. Furthermore, a high prevalence of Bartonella infection was found in moose, which was significantly lowest in northern Lapland, a region considered deer-ked free. These findings further support the potential of L.cervi as vector of Bartonella.
  • Klimeski, Aleksandar (Helsingin yliopisto, 2015)
    Deterioration in the quality of surface waters worldwide is associated with losses of phosphorus (P) from diffuse sources. Controlling such losses is rather difficult, but their significance in reducing the effects of eutrophication is crucial. Phosphorus losses from diffuse sources represent a significant share of total P transfers to surface waters. Researchers have studied and implemented numerous methods to curb non-point P losses during the past decades, but such studies have generally been insufficient to change the impact of agriculture on the course of surface waters eutrophication. For example, even though inputs of P and nitrogen (N) into the Baltic Sea have significantly decreased over the past two decades, the Baltic Sea still represents a eutrofied body of water. To further reduce P losses from agriculture, current P abatement methods must be amended with additional techniques. One such technique involves the use of P-retaining materials as filters placed in ditches within agricultural areas. This study encompasses a set of laboratory, meso- and large-scale set-ups to identify potential P-retaining materials available in Finland for the treatment of agricultural runoff. The laboratory studies investigated the P retention potential of fresh and weathered Ca-rich (Sachtofer PR®, steel slag, Filtra P®, Filtralite P®) as well as Fe-rich materials (mine drainage residual - MDR) in flow-through tests when applying a high influent P concentration of 50 mg/l. The weathering process served to leach out soluble species such as Ca2+ and OH-, thus mimicking aged filters. In addition, desorption/dissolution tests involved the placement of P-saturated materials in solutions of variable pH as well as one-month extraction with large volumes of water. Sachtofer PR®, steel slag, Filtra P® and MDR retained relatively large amounts of P, varying between 12 and 24 mg P/g material. As desorption/dissolution tests show, two distinct mechanisms controlled the materials retention of P: precipitation of Ca-phosphates and sorption of P onto Fe-hydroxide surfaces. As the most promising material, Sachtofer PR® was further employed in meso- (20 kg) and large-scale (7 tons) filters that treated influents with significantly lower P concentrations, up to 6 mg/l and 0.25 mg/l, respectively. The feed solution in the meso-scale filter alternated between P-enriched tap and river waters, whereas the large filter treated agricultural runoff from 17 ha of cropland. As the application of Sachtofer was scaled up, and influent P concentration declined, cumulative P retention decreased from 19 mg P/g in the laboratory to 0.06 mg P/g in the field. The meso-scale experiment indicated that the P removal efficiency decreased also due to the presence of dissolved organic carbon (DOC) in the influents; the filter retained about 10% of the total amount of DOC added to the system. As for the large filter, the formation of preferential water pathways resulting from material decomposition and freezing-thawing cycles greatly reduced its efficiency. Moreover, in high flow conditions during spring snowmelts or high rainfalls, the large filter treated only a small portion of the incoming flow; the estimated treated flow during the entire test period was about 20%. Maintaining a low effluent limit is rather challenging, and such techniques should instead serve to remove a significant part (e.g., 30-40%) of the dissolved mass of P in agricultural runoff. To justify the potential P recovery from spent filters and to ensure cost-efficiency, the P-retaining material should reach a significant P saturation. In addition, P removal structures should be coupled with other best management practices to minimize losses of P from agriculture. Keywords: P-retaining materials, P retention, precipitation, sorption, upscaled application, dissolved organic carbon, material alteration, preferential flows, high flows, filters, permeable reactive barriers
  • Korpunen, Heikki (Helsingin yliopisto, 2015)
    Finnish forest industry purchases 50 million cubic meters of wood annually. This means that the economic importance of the business is significant to forest owners. Sawmills, pulp and paper industry, and energy production are most common targets of the wood raw material. It is in mutual interest of both forest owners and the industry that the wood is allocated to right use according to the highest possible value-adding. The path of wood from forest to customers can be described as a value chain where the links are formed of harvesting and forwarding, long distance transportation, wood processing and energy use, and delivery to final customers. This dissertation focuses on the links of wood processing and energy use of the wood value chain by modelling production and costs of sawmill, pulp mill, paper mill, and combined heat and power (CHP) plant. The modelling was done by using activity-based costing (ABC), where the production is divided into processes and the production costs of each process are allocated to products or services according to resource consumption. Finally, all process costs are summed for total production costs of each cost object. The production and cost models were tested with virtual mills. The processes, the resources and the necessary cost factors of production were determined for test calculations. Finally, the capital, the labor, and the energy costs were allocated to the cost objects, which were both the raw materials and the end products. When comparing different mills and their production processes, it was noticed clearly that drying was an expensive process in sawmilling, pulping and papermaking. When focusing on cost factors of each mill, it was noteworthy that the sawing pattern affects the costs of a sawmill, energy production affects the costs of pulp and paper industry, and, likewise the utilization rate affects the combined heat and power plant. Profitability analyses were also made on the pulp mill, the paper mill and the CHP plant in varied market situations. One key finding was that in papermaking, the change of market price of paper was more significant to economics of the mill than a similar change in the market price of energy. The results of this dissertation can be used in estimating the economic performance of forest industry. Process-based approach helps in finding possible bottlenecks and in developing the production systematically. The findings of this study can also be used in finding the most profitable route for wood from the forest to customers.
  • Aivelo, Tuomas (Helsingin yliopisto, 2015)
    Parasite community dynamics is one of the central themes in contemporary parasitology. While between-host dynamics has been studied for a long time, within-host dynamics is less well studied. My aim was to identify which factors affect the parasite community during the lifetime of individual hosts by following longitudinally several individuals from a long-living species. Specifically, I was interested in how the dynamics of infra- and component communities differ from one another and which traits explain the variation in infracommunities. I studied rufous mouse lemur (Microcebus rufus), which is a primate living in the eastern montane rainforests of Madagascar. Mouse lemur is a well-suited study species as it can live for up to ten years in the wild. Due to its small size, the population density is high and trapping straightforward. Nematodes are the most common helminths found in mouse lemurs, but their identification is difficult. Typically, the nematodes are identified from adult specimens, but for longitudinal studies, this is not possible, as we cannot dissect the host individuals. In addition, morphological differences between species are small and we expected to encounter previously undescribed species. These difficulties led to the development of a new method, based on metabarcoding, to identify parasitic nematodes from fecal samples. The method I developed encompasses all steps from fieldwork to sequence analysis. Despite numerous confounding factors, the method managed to amplify and analyze half of the samples collected. Whilst there is room for further improvements, the main advantage is that the method works well for different host species, for example mouse lemurs and gastropods. In principle, this method works for all species of nematode, including free-living soil nematodes. Nevertheless, the resolution of identification do not allow for species-level identification. The variation in the parasite community inside individual hosts was extensive, but at the population level remained stable. Most of the parasites belonged to the putative species thought to be Strongyloides sp. The reason for this species success might be its lifecycle, the parasite can live in the intestine or as a free-living form in the soil. Due to the limited number of samples, the factors affecting the dynamics in individual mouse lemurs are difficult to analyze. It appears that sex and age do not have an effect on either parasite load or variation in parasite dynamics. Nevertheless, body condition appears to bear a consequence with the individuals in better condition having more parasite species in addition to higher fecal egg loads. The reason may be that those individuals are able to sustain larger populations of parasites, or that they are more tolerant to parasites. Hibernation could lead to the extinction of the nematode community, whereas higher precipitation appeared to lead to higher prevalences. This work gives insights into the dynamics of parasite communities both at the host individual and population level. It highlights the need for longitudinal studies as parasite community dynamics in host individual-level cannot be inferred from the host population-level The method I have developed can be used to perform more efficient and faster surveys of previously unknown parasite communities, though further development is necessary for better reliability.
  • Hoppania, Hanna-Kaisa (Helsingin yliopisto, 2015)
    This dissertation investigates the politics of care. Providing care, particularly for the elderly, is becoming a major problem in many European countries. Dependency ratios are weakening while resources for the welfare state appear to be limited in the prevailing economic conditions. In this research I analyze how this situation was acknowledged and addressed in Finland through the Act on Care Services for Older People (Act on Supporting the Functional Capacity of the Older Population and on Social and Health Care Services for Older Persons [980/2012]) which came into force in 2013. The research explores the subtext and roots of the issue, and examines why the law turned out the way it did by analyzing the processes whereby the Act was initiated, drafted and finally passed. It considers how care and the problems around it were represented in the political process following media scandals which highlighted serious problems regarding the quality of elder care. This case study is situated in its wider historical context, and the nature of the subject matter itself care is investigated to illuminate what is at stake in the reforms of elder care service provision. I argue that this reform project, and the situation it stemmed from, presented a moment of political openness to debate, and an opportunity to transform the societal commitments regarding elder care. This potential however was lost. A problem which was largely about resource scarcity became one of regulation, thus limiting the issues on the political agenda and the scope of the legislation passed. A seemingly apolitical governance of care is becoming the key site in which power over care relations is exercised, effectively undermining democratic control of care policy. Theoretically and methodologically the research links Nancy Fraser s framework of recognition, redistribution and representation and Michel Foucault s concept of governmentality with a post-structuralist discourse approach. It also draws from multidisciplinary feminist care research. Through the deployment of this multidimensional perspective in the analysis of elder care politics in Finland, a discussion of care is brought into the discipline of politics where to date it has not received much attention. The complex character of care is moved from the somewhat abstract ethics of care literature into the specific question of how care is understood and managed in the political process. This research explains how an issue which appeared to have widespread societal support bypassed the central question of redistribution, preventing the Act from leading to any transformative changes in elder care. The nodal points of dwindling resources and the bureaucratic division of labour functioned to limit the scope of the law. The imprecise content of various floating signifiers, such as quality of care, meant that these were understood differently by the various actors involved in the process. Through the functioning of a logic of difference, alternative or challenging framings of the issue at hand were sidelined and contained during the process and within the Act. When finalized, the Act only led to an affirmation of existing levels of care provision albeit with new regulatory procedures. Symbolic recognition, procedural clarifications and preventative measures were emphasized at the expense of securing better resourcing. Despite a rhetorical commitment to welfare state principles across the political spectrum, in the background neoliberal policies were pushed ahead as the solution to the challenges of care. These programmes and schemes, however, rely on the maintenance and reproduction of unequal, gendered care relations.
  • Luomaranta, Anna (Helsingin yliopisto, 2015)
    Risk-stratification is an essential step in planning of the treatment of patients with endometrial carcinoma, as it allows the omission of lymphadenectomy and/or adjuvant treatments in patients who are at low risk for extrauterine spread and have a good prognosis. This thesis consists of three cohort studies and one meta-analysis that were conducted to evaluate the reliability of methods that are currently available for the risk-stratification of endometrial carcinoma, and to develop new methods that might be clinically applicable. Cohort studies were based on a sample of 1166 women who were surgically treated for endometrial carcinoma at the Department of Obstetrics and Gynecology, Helsinki University Hospital, between January 2007 and December 2013. In the first study, previously recognized risk factors for an advanced stage and poor outcome were used to create a calculatory score to predict lymph node and distant metastasis in endometrial carcinoma. The score combining weighted risk factors was: (2 x leukocytosis) + (3 x thrombocytosis) + (7 x elevated CA125) + (4 x preoperative high-risk histology, defined as grade 3 endometrioid or nonendometrioid carcinoma). Depending on the number of risk factors of an individual patient, the score ranged from 0 to 16 points. Using six as the cut-point for positive and negative test results, the area under curve for this total score was 0.823, with 71.6% sensitivity, 75.2% specificity, 25.9% positive predictive value, and 95.7% negative predictive value. In the second study, the reliability of macroscopic pelvic lymph node findings at surgery in predicting para-aortic metastasis was evaluated. Lymph nodes were considered grossly positive based on size and morphology. In patients who underwent comprehensive lymphadenectomy (n = 117), grossly positive pelvic nodes predicted para-aortic metastasis with a sensitivity of 52.4% and specificity of 93.8%. The positive and negative likelihood ratios were 8.4 and 0.51, respectively. The whole sample of 854 patients was employed for Bayesian calculations. Grossly positive pelvic nodes at surgery predicted para-aortic metastasis with a negative predictive value of 99.7% in patients with superficial grade 1-2 endometrioid carcinomas and 98.0% in patients with deeply invasive grade 1-2 endometrioid carcinomas. For patients with grade 3 endometrioid and nonendometrioid carcinomas, negative predictive values were 97.3% and 92.2%, respectively. The value was 98.4% for all 854 patients. The third study compared two surgical treatment strategies: 1) routine pelvic lymphadenectomy, and 2) selective pelvic lymphadenectomy for women with high-risk carcinomas according to preoperative histology and magnetic resonance imaging. The combination of preoperative histology and magnetic resonance imaging detected high-risk carcinomas with a sensitivity of 85.7%, specificity of 75.0%, positive predictive value of 74.4%, and negative predictive value of 86.1%. The area under curve was 0.804. In the routine lymphadenectomy algorithm, 54.1% of lymphadenectomies were performed in patients with low-risk carcinoma. In the selective lymphadenectomy algorithm, 14.3% of patients with high-risk carcinoma did not receive lymphadenectomy. Missed positive pelvic nodes were estimated to occur in 2.1% of patients in the selective lymphadenectomy strategy. Similarly, the estimated risk for isolated para-aortic metastasis was 2.1%, regardless of treatment strategy. In conclusion, the risk-scoring model that was developed may provide a cost-effective approach to the risk-stratification of endometrial carcinoma, as it allows prediction of high-risk cases prior to surgery without advanced technology. Selective para-aortic lymphadenectomy, based on gross findings of pelvic nodes, is feasible for patients with grade 1-2 endometrioid carcinomas, regardless of the depth of myometrial invasion. Similarly, gross findings of pelvic nodes can be used to evaluate the need for paraaortic lymphadenectomy in the strategy of routine pelvic lymphadenectomy. The combination of preoperative histology and magnetic resonance imaging is moderately sensitive and specific in detecting high-risk endometrial carcinomas. However, the clinical utility of the method is hampered by the relatively high proportion of high-risk cases that remain unrecognized preoperatively. Considering the poor-to-moderate sensitivity of magnetic resonance imaging in detecting high-risk features of endometrial carcinoma, patients with negative findings may not safely forego lymphadenectomy unless the findings are confirmed by a backup method. The high specificities allow targeting of staging procedures by magnetic resonance imaging alone in patients with positive findings.
  • Rennicke, Iiris (Helsingin yliopisto, 2015)
    The main objective of this dissertation is to describe the current state and classhood of rhotics in the Minas Gerais variety of Brazilian Portuguese (BP), explore the factors behind sound change, and discuss the direction of change. The hypothesis is that changes in various subsystems of the language contribute to a general sound change trajectory, which takes place mostly through articulatory reduction and retiming in frequently used words and constructions (as predicted by Exemplar Models). Language is seen as a Complex Adaptive System that consists of several subsystems, all of which undergo change and can contribute simultaneously to gradual changes in the overall system. Semi-structured interviews and a sentence completion task with 14 speakers from southwestern Minas Gerais yielded a total of 7,765 contexts for rhotics. The rhotics of BP were found to include trills, taps, fricatives, approximants and aspirated approximants in alveolar, palatal, retroflex/bunched, uvular, and glottal places of articulation. Deletions also form a considerable part of the data. BP rhotics have followed two diverging lenition trajectories: one anterior (alveo-palatal) and one posterior (uvular and glottal). Both trajectories can ultimately lead to deletion. Factors that promote lenition include post-tonic position, adjacency to the voiceless fricative [s] and/or the high vowels [i u], and coda position which involves more lenited r-variants and deletion than any other context. Once sound change begins to generalize in these attractors, it can also spread to other r-contexts. BP rhotics are best modelled as a network of language-specific family relationships, in which chains of articulatory reductions and retimings establish diachronic connections between synchronically distant variants. As a class, rhotics are featurally, articulatorily, and phonetically unspecified, and phonetic overlap between contexts makes the contrast between r-variants incomplete. For this reason, the phonological representation of rhotics consists of fuzzy positional categories that encompass a variety of phonetic forms and that are constantly updated through language use.