Our research is in the general area of String Algorithms and Combinatorics on Words. Specifically, we study a generalization of square-free strings, shuffle properties of strings, and formalizing the reasoning about finite strings. The existence of infinitely long square-free strings (strings with no adjacent repeating word blocks) over a three (or more) letter finite set (referred to as Alphabet) is a well-established result. A natural generalization of this problem is that only subsets of the alphabet with predefined cardinality are available, while selecting symbols of the square-free string. This problem has been studied by several authors, and the lowest possible bound on the cardinality of the subset given is four. The problem remains open for subset size three and we investigate this question. We show that square-free strings exist in several specialized cases of the problem and propose approaches to solve the problem, ranging from patterns in strings to Proof Complexity. We also study the shuffle property (analogous to shuffling a deck of cards labeled with symbols) of strings, and explore the relationship between string shuffle and graphs, and show that large classes of graphs can be represented with special type of strings. Finally, we propose a theory of strings, that formalizes the reasoning about finite strings. By engaging in this line of research, we hope to bring the richness of the advanced field of Proof Complexity to Stringology. / Thesis / Doctor of Philosophy (PhD)

I föreliggande studie undersöktes kommunikativa resurser i samtal mellan tre personer med afasi och deras respektive logoped/anhörig. Syftet var att identifiera och analysera resurser som samtalsdeltagarna gemensamt använde för att uppnå intersubjektivitet. Vidare undersöktes om det, utifrån vem personen med afasi samtalade med, fanns någon inverkan på hur de kommunikativa resurserna användes. Sex dyader spelades in och samtalsanalys användes för att studera materialet. Samtalsämnen valdes fritt av samtalsdeltagarna. Analysen resulterade i identi¬fie¬ring av tre bevarade resurser hos personerna med afasi; upprepningar, gester och skratt. Det gemensamma för dessa resurser var; att de förekom i den naturliga sekventialiteten i samtalet, att deras kommunikativa funktioner uppstod i samarbetet mellan samtalsdeltagarna och att de bidrog till intersubjektiviteten. Resurserna visade även på en social kompetens hos deltagarna med afasi som ofta döljs av de språkliga hindren. Då de kommunikativa resurserna fick liknande funktioner i de olika dyaderna, är resultatet troligen generaliserbart till annan interaktion där personer med afasi deltar. Resursernas kommunikativa funktioner föreföll inte bero på vem samtalspartnern var. Slutsatsen var att språklig kompetens hos personer med afasi framför allt bör ses ur ett inter¬aktivt perspektiv och att ett sådant förhållningssätt är önskvärt i logopediskt behandlingsarbete. / Analysis of Talk-in-Interaction involving People with Aphasia and Speech and Language Pathologists/Spouses: The Use of Communicative Resources in Collaboration toward Intersubjectivity. In the present study, communicative resources in conversations involving three persons with aphasia and their speech and language pathologists/spouses were investigated. The main purpose was to identify and analyse collaboratively used resources for achieving intersubjectivity. In addition, possible changes in the use of the communicative resources depending on conversational partner were investigated. The conversations of six dyads were recorded and analysed. Conversational topics were chosen by the participants. Through the analysis three preserved resources for participants with aphasia could be identified; repetitions, gestures and laughter. All resources occurred within the natural sequentiality of the conversation, their communicative functions emerged in collaboration of the participants and contributed to intersubjectivity. The social competence of the persons with aphasia, often concealed by the language impairment, was also revealed. The results may possibly be generalised to other communicative activities where persons with aphasia participate, since similar communicative functions were achieved through the same resources in different dyads. The functions of the resources were not determined by conversational partner. To conclude, it may be argued that linguistic competence of persons with aphasia should mainly be considered in an interactive perspective and that this view is preferred in language therapy.

<p>I föreliggande studie undersöktes kommunikativa resurser i samtal mellan tre personer med afasi och deras respektive logoped/anhörig. Syftet var att identifiera och analysera resurser som samtalsdeltagarna gemensamt använde för att uppnå intersubjektivitet. Vidare undersöktes om det, utifrån vem personen med afasi samtalade med, fanns någon inverkan på hur de kommunikativa resurserna användes. Sex dyader spelades in och samtalsanalys användes för att studera materialet. Samtalsämnen valdes fritt av samtalsdeltagarna. Analysen resulterade i identi¬fie¬ring av tre bevarade resurser hos personerna med afasi; upprepningar, gester och skratt. Det gemensamma för dessa resurser var; att de förekom i den naturliga sekventialiteten i samtalet, att deras kommunikativa funktioner uppstod i samarbetet mellan samtalsdeltagarna och att de bidrog till intersubjektiviteten. Resurserna visade även på en social kompetens hos deltagarna med afasi som ofta döljs av de språkliga hindren. Då de kommunikativa resurserna fick liknande funktioner i de olika dyaderna, är resultatet troligen generaliserbart till annan interaktion där personer med afasi deltar. Resursernas kommunikativa funktioner föreföll inte bero på vem samtalspartnern var. Slutsatsen var att språklig kompetens hos personer med afasi framför allt bör ses ur ett inter¬aktivt perspektiv och att ett sådant förhållningssätt är önskvärt i logopediskt behandlingsarbete.</p> / <p>Analysis of Talk-in-Interaction involving People with Aphasia and Speech and Language Pathologists/Spouses: The Use of Communicative Resources in Collaboration toward Intersubjectivity.</p><p>In the present study, communicative resources in conversations involving three persons with aphasia and their speech and language pathologists/spouses were investigated. The main purpose was to identify and analyse collaboratively used resources for achieving intersubjectivity. In addition, possible changes in the use of the communicative resources depending on conversational partner were investigated. The conversations of six dyads were recorded and analysed. Conversational topics were chosen by the participants. Through the analysis three preserved resources for participants with aphasia could be identified; repetitions, gestures and laughter. All resources occurred within the natural sequentiality of the conversation, their communicative functions emerged in collaboration of the participants and contributed to intersubjectivity. The social competence of the persons with aphasia, often concealed by the language impairment, was also revealed. The results may possibly be generalised to other communicative activities where persons with aphasia participate, since similar communicative functions were achieved through the same resources in different dyads. The functions of the resources were not determined by conversational partner. To conclude, it may be argued that linguistic competence of persons with aphasia should mainly be considered in an interactive perspective and that this view is preferred in language therapy.</p>

This essay investigates the feminist philosophy of Rosi Braidotti with particular focus on the alternative feminine feminist nomadic subject that she creates. I also introduce Braidotti’s theoretical inspiration from Gilles Deleuze and Luce Irigaray. I argue that Braidotti creates an alternative figuration for feminism through synthesizeing Deleuze’s concept of ”becoming” with Irigaray’s sexual difference-theory. Braidotti highlights the importance of understanding the concept of difference differently. She also argues for the difference between subjectivity and identity, for the materialistic foundation of the subject, for the fundamental asymmetry between the sexes and for the nomadic mode of thinking. Braidottis suggests that the way out of the phallogocentric system, which she means we are encapsulated in, consist in working through the images that patriarchy has produced of women, through mimetic repetitons, in order to create new representations of women. I argue that the feminist philosophy of Braidotti is both humble and subversive which makes it an interesting and useful alternative for everyone who is interested in alternative, complex and thrilling ways of theorizing female feminist subjectivity.

En hög andel repetitioner är ett av de utmärkande dragen i barnriktat tal. Tidigare forskning har visat att andelen repetitioner i barnriktat tal varierar beroende på barnets ålder. Dessutom tyder forskningen på att repetitioner i barnriktat tal kan vara främjande för språkutvecklingen. Syftet med studien var att undersöka eventuella variationer över tid i andelen repetitioner i barnriktat tal under det första levnadsåret, samt försöka hitta ett samband mellan detta och barnens språkliga utveckling. Repetitionerna i föräldrarnas tal hos tio förälder-barn-dyader då barnet var 3, 6, 9 och 12 månader undersöktes kvantitativt. Exakta och varierade självrepetitioner samt exakta och varierade repetitioner av barnens yttranden undersöktes och jämfördes med samma barns språkliga nivå vid 18 månader. Resultatet visade att andelen exakta självrepetitioner var cirka en tredjedel lägre vid 12 månaders ålder än vid de tre tidigare inspelningstillfällena. Den totala andelen repetitioner av barnens yttranden mer än fyrdubblades från 3 till 12 månader. Ett samband kunde påvisas mellan repetitionerna under det första levnadsåret och barnens språkutveckling, där en låg andel exakta självrepetitioner vid 6 till 9 månader korrelerade med en hög språklig nivå vid 18 månader. Som en tolkning av resultatet föreslogs kopplingar mellan barnens aktiva språkbruk och repetitionerna i föräldrarnas tal. / A high proportion of repetitions is one of the distinctive features of child-directed speech (CDS). Research has shown that the percentage of repetitions in CDS varies over time depending on the age of the child. In addition, it is suggested that repetitions in CDS correlate with child language development. The aim of the study was to investigate the possible variations over time in the percentage of repetitions in CDS during the child’s first year, and to try to find a connection between repetitions and the child’s language development. Repetitions in parent speech in ten parent-child dyads as the children were 3, 6, 9 and 12 months old were investigated quantitatively. Exact and varying self-repetitions and exact and varying repetitions of the child’s utterances were investigated and compared to the same children’s linguistic level at 18 months of age. The results showed that the percentage of exact self-repetitions was more than 30 percent lower at the age of 12 months than at 3, 6 and 9 months of age. The total percentage of repetitions of the child’s utterances increased more than four times from 3 to 12 months of age. A connection was found between the repetitions during the child’s first year and the child’s language development, indicating that a low percentage of exact self-repetitions at 6 to 9 months of age correlated with a high vocabulary at 18 months of age. A link between the expressive language of the child and the repetitions in parents’ speech was suggested. / MINT: Modelling infant language acquisition from parent-child interaction (MAW 2011.007)

Nos travaux sur 26 gènes de la famille des WDR a permis d’en identifier sept (Atg16l1, Coro1c, Dmxl2, Herc1, Kif21b, Wdr47, Wdr89) associés à des anomalies cérébrales majeures. Cette grande famille de protéines reste pourtant peu explorée quant à ses rôles dans le développement du système nerveux central. Nous avons choisi d’étudier WDR47, dont la fonction est totalement inconnue en dépit d’une très grande similarité structurale avec LIS1, protéine à l’origine de la lissencéphalie. En combinant trois modèles expérimentaux (souris, siRNA et levure), nous avons démontré que Wdr47 est essentiel pour la survie de l’organisme et est impliqué dans la coordination motrice et le maintien de l’homéostasie énergétique avec une origine probablement centrale. Au niveau cellulaire, Wdr47 assure un rôle clé dans la dynamique des microtubules et la stabilisation du cône de croissance au travers d’interaction protéiques avec Reelin et SCG10. En outre, Wdr47 est aussi impliqué dans la prolifération neuronale et la macroautophagie. Ces résultats ont permis d’établir un lien de causalité entre une duplication de 200 kb contenant Wdr47 et des troubles de coordination motrice et une obésité hyperphagique chez un jeune patient. / WD40-repeat (WDR) proteins are one of largest eukaryotic family, however little is known about their role in neurodevelopment. We investigated 26 WDR genes, and found 7 (Atg16l1, Coro1c, Dmxl2, Herc1, Kif21b, Wdr47, Wdr89) with a major impact in brain structure when inactivated in mice. We chose WDR47 for further investigation, as it is a completely unknown protein that shares striking domain similarity with LIS1. Using three independent model systems (mice, siRNA and yeast), we found an essential role of Wdr47 in survival, and key neuronal processes involving microtubule dynamics such as proliferation, autophagy and growth cone stabilization. Next we identified Reelin and superior cervical ganglion 10 (SCG10) as top interacting proteins of WDR47. Interestingly, a 200-kb duplication encompassing WDR47 was linked to poor coordination in one patient, recapitulating mouse behavioural anomalies. Together our data help unravel for the first time a key role of Wdr47 in brain.

Nous étudions dans cette thèse différents problèmes d'évitabilité des répétitions dans les mots infinis. Soulevée par Thue et motivée par ses travaux sur les mots sans carrés, la problématique s'est développée au cours du XXe siècle, et est aujourd'hui devenue un des grands domaines de recherche en combinatoire des mots. En 1972, Dejean proposa une importante conjecture, dont la validation étape par étape s'est terminée récemment (2009). La conjecture concerne le seuil des répétitions d'un alphabet, i.e., la borne inférieure des exposants évitables sur cet alphabet. La notion de seuil, comme frontière entre évitabilité et non-évitabilité d'un ensemble donné de mots, est le fil directeur de nos travaux. Nous nous intéressons d'abord à une généralisation du seuil des répétitions (nous donnons des encadrements de sa valeur). Cette notion permet d'ajouter, pour décrire l'ensemble des répétitions à éviter, au paramètre de l'exposant, celui de la longueur des répétitions. Puis, nous étudions des problèmes d'existence de mots dans lesquels, simultanément, certaines répétitions sont interdites et d'autres sont forcées. Nous répondons, pour l'alphabet ternaire, à la question : quels réels sont l'exposant critique d'un mot infini sur un alphabet fixé? Nous introduisons ensuite une notion de haute répétitivité, et établissons une description partielle des couples d'exposants paramètrant une double contrainte de haute répétitivité et d'évitabilité. Pour finir, nous utilisons des résultats et techniques issus de ces problématiques pour résoudre une question de coloration de graphes : nous introduisons un seuil des répétitions, calqué sur celui connu pour les mots, et donnons sa valeur pour deux classes de graphes, les arbres et les graphes de subdivisions. / In this thesis we study various problems on repetition avoidance in infinite words. Raised by Thue and motivated by his work on squarefree words, the topic developed during the 20th century, and has nowadays become a principal area of research in combinatorics on words. In 1972, Dejean proposed an important conjecture whose verification in steps was completed recently (2009). The conjecture concerns the repetition threshold for an alphabet, i.e., the infimum of the avoidable exponents for that alphabet. The notion of threshold as a borderline between avoidability and unavoidability for a given set of words is the guiding line of our work. First, we focus on a generalization of the repetition threshold. This concept allows us to include, in addition to the exponent, the length of the repetitions as a parameter in the description of the set of repetitions to avoid. We obtain various bounds in that respect. We then study existence problems for words in which simultaneously some repetitions are forbidden, and others are forced. For the ternary alphabet, we answer the question: what real numbers are the critical exponent of some infinite word over a given alphabet? Also, we introduce a notion of highly repetitive words and give a partial description of the pairs of exponents which parameterize the existence of words both highly repetitive and repetition-free. Finally, we use results and techniques stemming from those problems to solve a question on graph colouring: we introduce a repetition threshold adapted from the thresholds we know for words, and give its value for two classes of graphs, namely, trees and subdivision graphs.

Repetitions in child-directed speech (CDS) have been shown to vary over time, and are suggested to affect first language acquisition. Correlations between verbal contents of repetitions in CDS and children’s language development have been suggested. The verbal contents of repetitions in Swedish CDS have not yet been investigated. The aim of this study was to examine the verbal contents of repetitions in Swedish CDS during the child’s first 2 years and possible changes in proportions of repetitions during the same time span. Verbal contents of repetitions in parents’ speech in 10 parent-child dyads as the children were 3, 6, 9, 12 and 24 months old were investigated focusing on word classes, sentence types and whole-constituent change. The results were compared to the children’s productive vocabularies at the age of 30 months. Possible occurrences of item-based constructions and frequent frames in the repetitions were also examined. The overall results revealed patterns concerning change in verbal contents in repetitions over time and correlations between verbal contents in repetitions and child language development. Two proposals were made: parents adjust the complexity of their speech to linguistic developmental stages of their children, and linguistic variation in the input increases as the child grows older. / Repetitioner i barnriktat tal (BRT) har visat sig variera över tid, och har föreslagits påverka förstaspåksinlärning. Även ett samband mellan det verbala innehållet i repetitioner i BRT och barns språkutveckling har föreslagits. Det verbala innehållet i repetitioner i svenskt BRT har inte undersökts tidigare. Syftet med denna studie var att undersöka det verbala innehållet i repetitioner i svenskt BRT under barnets två första år och möjliga förändringar gällande andelen repetitioner under samma tidsperiod. Det verbala innehållet i repetitioner i föräldrars tal hos tio förälder-barn-dyader då barnen var 3, 6, 9, 12 och 24 månader gamla undersöktes med fokus på ordklasser, satstyper och förändringar gällande konstituenter. Resultaten jämfördes med barnens produktiva ordförråd vid 30 månaders ålder. Även den möjliga förekomsten av typbaserade konstruktioner (item-based constructions) och frekventa ramar (frequent frames) undersöktes. De övergripande resultaten uppvisade mönster gällande förändringar inom det verbala innehållet i repetitioner över tid samt ett samband mellan det verbala innehållet i repetitioner och barns språkutveckling. Två antaganden gjordes: föräldrar justerar komplexiteten i sitt tal efter språkliga utvecklingsfaser hos sina barn, och den språkliga variationen i inputen ökar med barnets ålder. / MINT: Modelling infant language acquisition from parent-child interaction (MAW 2011.007)

Cette thèse questionne les manifestations de la convergence (i.e. le rapprochement entre les productions des participants) au niveau interactionnel. Pour cela, les termes d'alignement (défini en rapport avec l'activité en cours) et d'affiliation (l'expression d'un même stance par les participants) sont empruntés à l'Analyse Conversationnelle. Le corpus utilisé est le CID-Corpus of Interational Data, corpus de conversation (interaction non-contrainte, hautement coopérative et globalement symétrique).Nous interrogeons le lien entre la convergence et la similarité lexicale, grâce à l'analyse d'une collection de 300 hétéro-répétitions (recueillie grâce à un outil d'aide au repérage des répétitions). Nous proposons ensuite une analyse quantitative de l'évolution des réponses des auditeurs, puis une analyse qualitative de discours rapportés directs, phénomènes susceptibles de faire émerger de l'affiliation. Nous montrons que les hétéro-répétitions lexicales et les discours rapportés « en écho » (discours rapportés produits par l'auditeur de la narration) peuvent être utilisés (entre autres) pour exprimer l'alignement et l'affiliation, ce qui, en cas de ratification, crée les conditions propices à l'émergence d'un moment de convergence interactionnelle. Nous montrons également que ces mêmes phénomènes peuvent servir à créer le désalignement temporaire nécessaire à l'engagement dans une séquence oblique convergente. Ainsi, ce travail décrit l'établissement et le fonctionnement de séquences convergentes, à travers l'étude de phénomènes interactionnels méconnus. / This thesis investigates the manifestations of convergence (i.e. the rapprochement between the participants' productions) at the level of interaction. With this aim, the terms of alignment (defined in relation to the current activity) and affiliation (display of the same stance by both participants) are borrowed from Conversation Analysis. The conversational corpus (non-constrained, highly cooperative and globally symmetrical interaction) used is the CID-Corpus of Interactional Data. Firstly, the link between convergence and lexical similarity is investigated thanks to the analysis of a collection of 300 other-repetitions (collected using a tool to assist in the detection of OR). Secondly, storytelling is studied and a quantitative analysis of the evolution of listeners' responses is proposed together with a qualitative analysis of direct reported speech phenomena, which are likely to make affiliation emerge. These analyses show that lexical other-repetitions and "echo" reported speech (reported speech which is produced by the listener of the narrative) can be used by participants to, inter alia, express alignment and affiliation, which, in case of ratification, creates the adequate conditions for the emergence of interactional convergence. The same phenomena can be used to create the temporary disalignment necessary to engage in an oblique (and potentially convergent) sequence. This work then describes the establishment and the conduct of convergent sequences through the analysis of interactional phenomena.

The main aim of this thesis is to introduce issue of averaging of biological signals. The first part of the thesis deals with the principles of individual averaging methods (constant, floating and exponential window) and describes their basic features. Moreover, the principle of filtered residue, detection of QRS complex, and stretching/shrinking the length of RR-interval to the standardized length are explicated. In the second part of the thesis the outcomes of practically realized (Matlab and GUI) methods of averaging (by final signal-to-noise ratio) are evaluated. Signals from MIT-BIH database are used.