Topological stability through tame retractions

A smooth map is said to be stable if small perturbations of the map only differ from the original one by a smooth change of coordinates. Smoothly stable maps are generic among the proper maps between given source and target manifolds when the source and target dimensions belong to the so-called nice dimensions, but outside this range of dimensions, smooth maps cannot generally be approximated by stable maps. This leads to the definition of topologically stable maps, where the smooth coordinate changes are replaced with homeomorphisms. The topologically stable maps are generic among proper maps for any dimensions of source and target. The purpose of this thesis is to investigate methods for proving topological stability by constructing extremely tame (E-tame) retractions onto the map in question from one of its smoothly stable unfoldings. In particular, we investigate how to use E-tame retractions from stable unfoldings to find topologically ministable unfoldings for certain weighted homogeneous maps or germs. Our first results are concerned with the construction of E-tame retractions and their relation to topological stability. We study how to construct the E-tame retractions from partial or local information, and these results form our toolbox for the main constructions. In the next chapter we study the group of right-left equivalences leaving a given multigerm f invariant, and show that when the multigerm is finitely determined, the group has a maximal compact subgroup and that the corresponding quotient is contractible. This means, essentially, that the group can be replaced with a compact Lie group of symmetries without much loss of information. We also show how to split the group into a product whose components only depend on the monogerm components of f. In the final chapter we investigate representatives of the E- and Z-series of singularities, discuss their instability and use our tools to construct E-tame retractions for some of them. The construction is based on describing the geometry of the set of points where the map is not smoothly stable, discovering that by using induction and our constructional tools, we already know how to construct local E-tame retractions along the set. The local solutions can then be glued together using our knowledge about the symmetry group of the local germs. We also discuss how to generalize our method to the whole E- and Z- series.

Contributions to the Theory of Finite-State Based Grammars

This dissertation is a theoretical study of finite-state based grammars used in natural language processing. The study is concerned with certain varieties of finite-state intersection grammars (FSIG) whose parsers define regular relations between surface strings and annotated surface strings. The study focuses on the following three aspects of FSIGs: (i) Computational complexity of grammars under limiting parameters In the study, the computational complexity in practical natural language processing is approached through performance-motivated parameters on structural complexity. Each parameter splits some grammars in the Chomsky hierarchy into an infinite set of subset approximations. When the approximations are regular, they seem to fall into the logarithmic-time hierarchyand the dot-depth hierarchy of star-free regular languages. This theoretical result is important and possibly relevant to grammar induction. (ii) Linguistically applicable structural representations Related to the linguistically applicable representations of syntactic entities, the study contains new bracketing schemes that cope with dependency links, left- and right branching, crossing dependencies and spurious ambiguity. New grammar representations that resemble the Chomsky-Schützenberger representation of context-free languages are presented in the study, and they include, in particular, representations for mildly context-sensitive non-projective dependency grammars whose performance-motivated approximations are linear time parseable. (iii) Compilation and simplification of linguistic constraints Efficient compilation methods for certain regular operations such as generalized restriction are presented. These include an elegant algorithm that has already been adopted as the approach in a proprietary finite-state tool. In addition to the compilation methods, an approach to on-the-fly simplifications of finite-state representations for parse forests is sketched. These findings are tightly coupled with each other under the theme of locality. I argue that the findings help us to develop better, linguistically oriented formalisms for finite-state parsing and to develop more efficient parsers for natural language processing. Avainsanat: syntactic parsing, finite-state automata, dependency grammar, first-order logic, linguistic performance, star-free regular approximations, mildly context-sensitive grammars

Toiminta ja tarkoite : Tutkimus suomen pronominista

The study describes the use and meaning of the Finnish demonstrative pronouns, focus being on the pronoun "tämä" (roughly 'this'). The Finnish demonstrative system is a three way one, the other two demonstratives are "tuo" ('that') and "se" ('it'). The data consisted of 12 half hours of video- and tape-recorded face-to-face and telephone conversations. The method for the study was ethnomethodological conversation analysis (CA); in addition to CA, the theoretical framework consisted of functional linguistics and linguistic anthropology. First, the study dealt with the syntactic distribution of the three demonstratives. The pronouns were analysed according to whether they are before or after the verb, and whether they compose an NP on their own or are determinants of a lexical NP. The study suggested that the form and the placement of the NP presents the referent as continuous/discontinuous or given/new. Givenness of a referent was defined as "identified adequately for the purposes of the on-going action". The so-called dislocated utterances were considered separately. It was found that left-dislocations are used for inserting referents in a particular relation to the on-going activity. Right-dislocations offer a solution for the sometimes competing motivations of newness and continuity: they are used for securing the identifiability of a referent that is implied to be continuous. Second, the study focussed on analysing the meaning of the pronouns according to three dimensions of reference: referential, indexical and relational. It was found that the demonstratives can organize interactional or spatial context. When organizing interactional context, the demonstrative pronouns express the role of identifying the referent in relation to the on-going activity. The pronoun "tämä" expresses that the referent is referentially open and the characterization of the referent is given in the on-going turn. Furthermore, it expresses asymmetry of the indexical ground: it expresses that the participants of a conversation do not share a mutual understanding of the activity at that particular time. In addition, the referent of the pronoun "tämä" is central for understanding the on-going action. Centrality could be understood as the relational feature of the pronoun. However, it is a consequence of the referential and indexical features of "tämä". The pronoun "tuo" also expresses referential openness, but it implies indexical symmetry. The pronoun "se" implies that the referent is known enough, and implies indexical symmetry. When used spatially, the pronouns may refer to a physical space or to a situation. They express or imply that the speaker is inside or outside the referent. The pronoun "tämä" implies inclusion, and the pronoun "tuo" expresses exclusion.

Nonverbal predication in Erzya : Studies on morphosyntactic variation and part of speech distinctions

This dissertation consists of four articles and an introduction. The five parts address the same topic, nonverbal predication in Erzya, from different perspectives. The work is at the same time linguistic typology and Uralic studies. The findings based on a large corpus of empirical Erzya data, which was collected using several different methods and included recordings of the spoken language, made it possible for the present study to apply, then test and finally discuss the previous theories based on cross-linguistic data. Erzya makes use of multiple predication patterns which vary from totally analytic to the morphologically very complex. Nonverbal predicate clause types are classified on the basis of propositional acts in clauses denoting class-membership, identity, property and location. The predicates of these clauses are nouns, adjectives and locational expressions, respectively. The following three predication strategies in Erzya nonverbal predication can be identified: i. the zero-copula construction, ii. the predicative suffix construction and iii. the copula construction. It has been suggested that verbs and nouns cannot be clearly distinguished on morphological grounds when functioning as predicates in Erzya. This study shows that even though predicativity must not be considered a sufficient tool for defining parts of speech in any language, the Erzya lexical classes of adjective, noun and verb can be distinguished from each other also in predicate position. The relative frequency and degree of obligation for using the predicative suffix construction decreases when moving left to right on the scale verb adjective/locative noun ( identificational statement). The predicative suffix is the main pattern in the present tense over the whole domain of nonverbal predication in Standard Erzya, but if it is replaced it is most likely to be with a zero-copula construction in a nominal predication. This study exploits the theory of (a)symmetry for the first time in order to describe verbal vs. nonverbal predication. It is shown that the asymmetry of paradigms and constructions differentiates the lexical classes. Asymmetrical structures are motivated by functional level asymmetry. Variation in predication as such adds to the complexity of the grammar. When symmetric structures are employed, the functional complexity of grammar decreases, even though morphological complexity increases. The genre affects the employment of predication strategies in Erzya. There are differences in the relative frequency of the patterns, and some patterns are totally lacking from some of the data. The clearest difference is that the past tense predicative suffix construction occurs relatively frequently in Standard Erzya, while it occurs infrequently in the other data. Also, the predicative suffixes of the present tense are used more regularly in written Standard Erzya than in any other genre. The genre also affects the incidence of the translative in uľ(ń)ems copula constructions. In translations from Russian to Erzya the translative case is employed relatively frequently in comparison to other data. This study reveals differences between the two Mordvinic languages Erzya and Moksha. The predicative suffixes (bound person markers) of the present tense are used more regularly in Moksha in all kinds of nonverbal predicate clauses compared to Erzya. It should further be observed that identificational statements are encoded with a predicative suffix in Moksha, but seldom in Erzya. Erzya clauses are more frequently encoded using zero-constructions, displaying agreement in number only.

Cortical processing of speech and non-speech sounds in adults and newborns

Comprehension of a complex acoustic signal - speech - is vital for human communication, with numerous brain processes required to convert the acoustics into an intelligible message. In four studies in the present thesis, cortical correlates for different stages of speech processing in a mature linguistic system of adults were investigated. In two further studies, developmental aspects of cortical specialisation and its plasticity in adults were examined. In the present studies, electroencephalographic (EEG) and magnetoencephalographic (MEG) recordings of the mismatch negativity (MMN) response elicited by changes in repetitive unattended auditory events and the phonological mismatch negativity (PMN) response elicited by unexpected speech sounds in attended speech inputs served as the main indicators of cortical processes. Changes in speech sounds elicited the MMNm, the magnetic equivalent of the electric MMN, that differed in generator loci and strength from those elicited by comparable changes in non-speech sounds, suggesting intra- and interhemispheric specialisation in the processing of speech and non-speech sounds at an early automatic processing level. This neuronal specialisation for the mother tongue was also reflected in the more efficient formation of stimulus representations in auditory sensory memory for typical native-language speech sounds compared with those formed for unfamiliar, non-prototype speech sounds and simple tones. Further, adding a speech or non-speech sound context to syllable changes was found to modulate the MMNm strength differently in the left and right hemispheres. Following the acoustic-phonetic processing of speech input, phonological effort related to the selection of possible lexical (word) candidates was linked with distinct left-hemisphere neuronal populations. In summary, the results suggest functional specialisation in the neuronal substrates underlying different levels of speech processing. Subsequently, plasticity of the brain's mature linguistic system was investigated in adults, in whom representations for an aurally-mediated communication system, Morse code, were found to develop within the same hemisphere where representations for the native-language speech sounds were already located. Finally, recording and localization of the MMNm response to changes in speech sounds was successfully accomplished in newborn infants, encouraging future MEG investigations on, for example, the state of neuronal specialisation at birth.

Kilpailukykyvaltion koululainsäädännön rakentuminen : Suomen eduskunta ja 1990-luvun koulutuspoliittinen käänne

Finnish education policy, educational legislation and the entire education system changed significantly during the 1990s as part of a general restructuring of public administration. There has been a clear divergence from the former tradition of a system of regulation, founded on detailed legislation and the principle of equality. The new governance, which is based more on individual choice, efficiency and evaluation, emphasizes that the development of a high standard of education is a necessity in the light of global competition. This study explores the legislative process regarding education policy in the Finnish Parliament during the 1990s, and highlights in particular how the international discourse on education policies was restructured in the context of Finnish legislation. The research material consists of all the public parliamentary documents relating to education, including government proposals, minutes from the discussions in the chamber and archive material (final protocols, reports and statements) for the Committee for Education and Culture. The discourse on the process of drafting and passing education legislation is modelled on three interrelated policy technologies (market, management and performance), which are understood here as mechanisms connecting general political ideas to normative legislation. The changes in the regulation of education were part of a general public administration reform instigated during the mid 1980s. The research results will prove that during the left-right coalition cabinet of PM Harri Holkeri, new policy technologies affected the parliamentary discourse on education policy. This was particularly influenced by a change in the preconditions for the management of education that was created as a result of the numerous demands to deregulate and delegate decision-making authority to the local and school levels while rendering the whole education system more effective. At the turn of the decade, market-type mechanisms were more indirectly manifested in the forms of individuality and freedom of choice, which were reflected, for example, in proposals to “lower the hurdles” by separating general from vocational secondary education with a view to encouraging students to select courses from other educational establishments, in addition to relaxing the requirements for establishing private schools and abolishing a hundred-year-old strict national catchment-area system. Later, in the course of the 1990s, after the subjects, players, and methods of evaluation had been more precisely defined, evaluation based on performance would result in the active measurement of the attainment of set objectives. In the spring of 1991, from the outset of PM Esko Aho's right-centre coalition cabinet, the education budget suffered cutbacks as a result of a global recession and this influenced the legislative work of, and discourses in, parliament. Representatives of the parties in power regarded the recession solely as an external factor that was remote from the political arena. In their view, the education system should rise to the challenge by ensuring the efficient and innovative use of the resources available and by developing new forms of indicators for evaluating results. Representatives of the opposition opposed the cabinet’s standpoint as a result of the recession, criticized the measures taken by pointing out the harmful effect of constantly cutting the budget and argued that the government had made political capital out of the recession by using it as an opportunity to give more room to market, management and performance technologies within the Finnish education system. Criticism of the new education policy became even stronger during PM Paavo Lipponen's first “rainbow” coalition cabinet with critical views being expressed not only from the opposition but also from representatives within the government. Representatives from the left demanded legislative restrictions and the instigation of measures to relieve the presumed negative effects of market, management and performance in the name of educational equality. The new management by results steering method within the university sector and the introduction of commercial education services in compulsory education were fiercely criticized. The argument over “setting outer limits” including, for example, the demands for more detailed legislation and earmarked state subsidies was characteristic of Parliament’s legislative discourse in the latter part of the 1990s. Keywords: education policy, education legislation, Parliament of Finland

Aivojen jännitevasteiden rekisteröinti useaan äänen piirteeseen yhdellä mittauskerralla terveillä musiikkileikkikoulua käyvillä kaksivuotiailla

The early detection of hearing deficits is important to a child's development. However, examining small children with behavioural methods is often difficult. Research with ERPs (event-related potentials), recorded with EEG (electroencephalography), does not require attention or action from the child. Especially in children's ERP research, it is essential that the duration of a recording session is not too long. A new, faster optimum paradigm has been developed to record MMN (mismatch negativity), where ERPs to several sound features can be recorded in one recording session. This substantially shortens the time required for the experiment. So far, the new paradigm has been used in adult and school-aged children research. This study examines if MMN, LDN (late discriminative negativity) and P3a components can be recorded in two-year-olds with the new paradigm. The standard stimulus (p=0.50) was an 80 dB harmonic tone consisting of three harmonic frequencies (500 Hz, 1000 Hz and 1500 Hz) with a duration of 200 ms. The loudness deviants (p=0.067) were at a level of +6 dB or -6 dB compared to the standards. The frequency deviants (p=0.112) had a fundamental frequency of 550 or 454.4 Hz (small deviation), 625 or 400 Hz (medium deviation) or 750 or 333.3 Hz (large deviation). The duration deviants (p=0.112) had a duration of 175 ms (small deviation), 150 ms (medium deviation) or 100 ms (large deviation). The direction deviants (p=0.067) were presented from the left or right loudspeaker only. The gap deviant (p=0.067) included a 5-ms silent gap in the middle of the sound. Altogether 17 children participated in the experiment, of whom the data of 12 children was used in the analysis. ERP components were observed for all deviant types. The MMN was significant for duration and gap deviants. The LDN was significant for the large duration deviant and all other deviant types. No significant P3a was observed. These results indicate that the optimum paradigm can be used with two-year-olds. With this paradigm, data on several sound features can be recorded in a shorter time than with the previous paradigms used in ERP research.

Soil carbon modelling as a tool for carbon balance studies in forestry

Soils represent a remarkable stock of carbon, and forest soils are estimated to hold half of the global stock of soil carbon. Topical concern about the effects of climate change and forest management on soil carbon as well as practical reporting requirements set by climate conventions have created a need to assess soil carbon stock changes reliably and transparently. The large spatial variability of soil carbon commensurate with relatively slow changes in stocks hinders the assessment of soil carbon stocks and their changes by direct measurements. Models therefore widely serve to estimate carbon stocks and stock changes in soils. This dissertation aimed to develop the soil carbon model YASSO for upland forest soils. The model was aimed to take into account the most important processes controlling the decomposition in soils, yet remain simple enough to ensure its practical applicability in different applications. The model structure and assumptions were presented and the model parameters were defined with empirical measurements. The model was evaluated by studying the sensitivities of the model results to parameter values, by estimating the precision of the results with an uncertainty analysis, and by assessing the accuracy of the model by comparing the predictions against measured data and to the results of an alternative model. The model was applied to study the effects of intensified biomass extraction on the forest carbon balance and to estimate the effects of soil carbon deficit on net greenhouse gas emissions of energy use of forest residues. The model was also applied in an inventory based method to assess the national scale forest carbon balance for Finland’s forests from 1922 to 2004. YASSO managed to describe sufficiently the effects of both the variable litter and climatic conditions on decomposition. When combined with the stand models or other systems providing litter information, the dynamic approach of the model proved to be powerful for estimating changes in soil carbon stocks on different scales. The climate dependency of the model, the effects of nitrogen on decomposition and forest growth as well as the effects of soil texture on soil carbon stock dynamics are areas for development when considering the applicability of the model to different research questions, different land use types and wider geographic regions. Intensified biomass extraction affects soil carbon stocks, and these changes in stocks should be taken into account when considering the net effects of forest residue utilisation as energy. On a national scale, soil carbon stocks play an important role in forest carbon balances.

Power and Authority. Birgitta of Sweden and her Revelations

In the High Middle Ages female saints were customarily noble virgins. Thus, as a wife and a mother of eight children, the Swedish noble lady Birgitta (1302/3 1373) was an atypical candidate for sanctity. However, in 1391 she was canonized only 18 years after her death and became a role model for many late medieval women, who were mothers and widows. The dissertation Power and Authority Birgitta of Sweden and Her Revelations investigates how Birgitta went about establishing her power and authority during the first ten years of her career as a living saint, in 1340 1349. It is written from the perspectives of gender, authority, and power. The sources consist of approximately seven hundred revelations, hagiographical texts and other medieval documents. This work concentrates on the interaction between Birgitta and her audience. During her lifetime Birgitta was already regarded as a holy woman, as a living saint. A living saint could be given no formal papal or other recognition, for one could never be certain about his or her future activities. Thus, the living saint needed an audience for whom to perform signs of sanctity. In this study particular attention is paid to situations within which the power relations between the living saint and her audience can be traced and are open to critical analysis. Situations of conflict that arose in Birgitta s life are especially fruitful for this purpose. During the Middle Ages, institutional power and authority were exclusively in the hands of secular male leaders and churchmen. In this work it is argued, however, that Birgitta used different kinds of power than men. It is evident that she exercized influence on lay people as well as on secular and clerical authorities. The second, third, and fourth chapter of this study examine the beginning of Birgitta s career as a visionary, what factors and influences lay behind it, and what kind of roles they played in establishing her religious authority. The fifth, sixth, and seventh chapter concentrate on Birgitta s exercising of power in specific situations during her time in Sweden until she left on a pilgrimage to Rome in 1349. The central question is how she exercised power with different people. As a result, this book will offer a narrative of Birgitta s social interactions in Sweden seen from the perspectives of power and authority. Along with the concept of power, authority is a key issue. By definition, one who has power also has authority but a person who does not have official power can, nevertheless, have authority. Authority in action is defined here as meaning that a person was listened to. Birgitta acted both in situations of open conflict and where no conflict was evident. Her strategies included, for example, inducement, encouragement and flattery. In order to make people do as she felt was right she also threatened them openly with divine wrath. Sometimes she even used both positive persuasion and threats. Birgitta s power seems very similar to that of priests and ascetics. Common to all of them was that their power demanded interaction with other people and audiences. Because Birgitta did not have power and authority ex officio she had to persuade people to believe in her powers. She did this because she was convinced of her mission and sought to make people change their lives. In so doing, she moved from the domestic field to the public fields of religion and politics.

Towards a Critique of the Concept of the Right to Self-Determination in Africa : A Conceptual Examination and the Cases of Western Sahara, Southern Sudan and Eritrea

This thesis examines the right to self-determination which is a norm used for numerous purposes by multiple actors in the field of international relations, with relatively little clarity or agreement on the actual and potential meaning of the right. In international practice, however, the main focus in applying the right has been in the context of decolonization as set by the United Nations in its early decades. Thus, in Africa the right to self-determination has traditionally implied that the colonial territories, and particularly the populations within these territories, were to constitute the people who were entitled to the right. That is, self-determination by decolonization provided a framework for the construction of independent nation-states in Africa whilst other dimensions of the right remained largely or totally neglected. With the objective of assessing the scope, content, developments and interpretations of the right to self-determination in Africa, particularly with regard to the relevance of the right today, the thesis proceeds on two fundamental hypotheses. The first is that Mervyn Frost s theory of settled norms, among which he lists the right to self-determination, assumes too much. Even if the right to self-determination is a human right belonging to all peoples stipulated, inter alia, in the first Article of the 1966 International Human Rights Covenants, it is a highly politicized and context-bound right instead of being settled and observed in a way that its denial would need special justification. Still, the suggested inconsistency or non-compliance with the norm of self-determination is not intended to prove the uselessness or inappropriateness of the norm, but, on the contrary, to invite and encourage debate on the potential use and coverage of the right to self-determination. The second hypothesis is that within the concept of self-determination there are two normative dimensions. One is to do with the idea and practice of statehood, the nation and collectivity that may decide to conduct itself as an independent state. The other one is to do with self-determination as a human right, as a normative condition, to be enjoyed by people and peoples within states that supersedes state authority. These external and internal dimensions need to be seen as complementary and co-terminous, not as mutually exclusive alternatives. The thesis proceeds on the assumption that the internal dimension of the right, with human rights and democracy at its core, has not been considered as important as the external. In turn, this unbalanced and selective interpretation has managed to put the true normative purpose of the right making the world better and bringing more just polity models into a somewhat peculiar light. The right to self-determination in the African context is assessed through case studies of Western Sahara, Southern Sudan and Eritrea. The study asks what these cases say about the right to self-determination in Africa and what their lessons learnt could contribute to the understanding and relevance of the right in today s Africa. The study demonstrates that even in the context of decolonization, the application of the right to self-determination has been far from the consistent approach supposedly followed by the international community: in many respects similar colonial histories have easily led to rather different destinies. While Eritrea secured internationally recognized right to self-determination in the form of retroactive independence in 1993, international recognition of distinct Western Sahara and Southern Sudan entities is contingent on complex and problematic conditions being satisfied. Overall, it is a considerable challenge for international legality to meet empirical political reality in a meaningful way, so that the universal values attached to the norm of self-determination are not overlooked or compromised but rather reinforced in the process of implementing the right. Consequently, this thesis seeks a more comprehensive understanding of the right to self-determination with particular reference to post-colonial Africa and with an emphasis on the internal, human rights and democracy dimensions of the norm. It is considered that the right to self-determination cannot be perceived only as an inter-state issue as it is also very much an intra-state issue, including the possibility of different sub-state arrangements exercised under the right, for example, in the form of autonomy. At the same time, the option of independent statehood achieved through secession remains a mode of exercising and part of the right to self-determination. But in whatever form or way applied, the right to self-determination, as a normative instrument, should constitute and work as a norm that comprehensively brings more added value in terms of the objectives of human rights and democracy. From a normative perspective, a peoples right should not be allowed to transform and convert itself into a right of states. Finally, in light of the case studies of Western Sahara, Southern Sudan and Eritrea, the thesis suggests that our understanding of the right to self-determination should now reach beyond the post-colonial context in Africa. It appears that both the questions and answers to the most pertinent issues of self-determination in the cases studied must be increasingly sought within the postcolonial African state rather than solely in colonial history. In this vein, the right to self-determination can be seen not only as a tool for creating states but also as a way to transform the state itself from within. Any such genuinely post-colonial approach may imply a judicious reconsideration, adaptation or up-dating of the right and our understanding of it in order to render it meaningful in Africa today.

The Soviet Union, Finland and the Cold War : The Finnish Card in Soviet Foreign Policy, 1956-1959

From the Soviet point of view the actual substance of Soviet-Finnish relations in the second half of 1950s clearly differed from the contemporary and later public image, based on friendship and confidence rhetoric. As the polarization between the right and the left became more underlined in Finland in the latter half of the 1950s, the criticism towards the Soviet Union became stronger, and the USSR feared that this development would have influence on Finnish foreign policy. From the Soviet point of view, the security commitments of FCMA-treaty needed additional guarantees through control of Finnish domestic politics and economic relations, especially during international crises. In relation to Scandinavia, Finland was, from the Soviet point of view, the model country of friendship or neutrality policy. The influence of the Second Berlin Crisis or the Soviet-Finnish Night Frost Crisis in 1958-1959 to Soviet policy towards Scandinavia needs to be observed from this point of view. The Soviet Union used Finland as a tool, in agreement with Finnish highest political leadership, for weakening of the NATO membership of Norway and Denmark, and for maintaining Swedish non-alliance. The Finnish interest to EFTA membership in the summer of 1959, at the same time with the Scandinavian countries, seems to have caused a panic reaction in the USSR, as the Soviets feared that these economic arrangements would reverse the political advantages the country had received in Finland after the Night Frost Crisis. Together with history of events, this study observes the interaction of practical interests and ideologies, both in individuals and in decision-making organizations. The necessary social and ideological reforms in the Soviet Union after 1956 had influence both on the legitimacy of the regime, and led to contradictions in the argumentation of Soviet foreign policy. This was observed both in the own camp as well as in the West. Also, in Finland a breakthrough took place in the late 1950's: as the so-called counter reaction lost to the K-line, "a special relationship" developed with the Soviet Union. As a consequence of the Night Frost Crisis the Soviet relationship became a factor decisively defining the limits of domestic politics in Finland, a part of Finnish domestic political argumentation. Understood from this basis, finlandization is not, even from the viewpoint of international relations, a special case, but a domestic political culture formed by the relationship between a dominant state, a superpower, and a subordinate state, Finland.

Structural and Functional Studies on Trimeric Autotransporters

Trimeric autotransporters are a family of secreted outer membrane proteins in Gram-negative bacteria. These obligate homotrimeric proteins share a conserved C-terminal region, termed the translocation unit. This domain consists of an integral membrane β-barrel anchor and associated α-helices which pass through the pore of the barrel. The α-helices link to the extracellular portion of the protein, the passenger domain. Autotransportation refers to the way in which the passenger domain is secreted into the extracellular space. It appears that the translocation unit mediates the transport of the passenger domain across the outer membrane, and no external factors, such as ATP, ion gradients nor other proteins, are required. The passenger domain of autotransporters contains the specific activities of each protein. These are usually related to virulence. In trimeric autotransporters, the main function of the proteins is to act as adhesins. One such protein is the Yersinia adhesin YadA, found in enteropathogenic species of Yersinia. The main activity of YadA from Y. enterocolitica is to bind collagen, and it also mediates adhesion to other molecules of the extracellular matrix. In addition, YadA is involved in serum resistance, phagocytosis resistance, binding to epithelial cells and autoagglutination. YadA is an essential virulence factor of Y. enterocolitica, and removal of this protein from the bacteria leads to avirulence. In this study, I investigated the YadA-collagen interaction by studying the binding of YadA to collagen-mimicking peptides by several biochemical and biophysical methods. YadA bound as tightly to the triple-helical model peptide (Pro-Hyp-Gly)10 as to native collagen type I. However, YadA failed to bind a similar peptide that does not form a collagenous triple helix. As (Pro-Hyp-Gly)10 does not contain a specific sequence, we concluded that a triple-helical conformation is necessary for YadA binding, but no specific sequence is required. To further investigate binding determinants for YadA in collagens, I examined the binding of YadA to a library of collagen-mimicking peptides that span the entire triple-helical sequences of human collagens type II and type III. YadA bound promiscuously to many but not all peptides, indicating that a triple-helical conformation alone is not sufficient for binding. The high-binding peptides did not share a clear binding motif, but these peptides were rich in hydroxyproline residues and contained a low number of charged residues. YadA thus binds collagens without sequence specificity. This strategy of promiscuous binding may be advantageous for pathogenic bacteria. The Eib proteins from Escherichia coli are immunoglobulin (Ig)-binding homologues of YadA. I showed conclusively that recombinant EibA, EibC, EibD and EibF bind to IgG Fc. I crystallised a fragment of the passenger domain of EibD, which binds IgA in addition to IgG. The structure has a YadA-like head domain and an extended coiled-coil stalk. The top half of the coiled-coil is right-handed with hendecad periodicity, whereas the lower half is a canonical left-handed coiled-coil. At the transition from right- to left-handedness, a small β-sheet protrudes from each monomer. I was able to map the binding regions for IgG and IgA using truncations and site-directed mutagenesis to the coiled-coil stalk and identified residues critical for Ig binding.