The Membrane Systems Language Class

The aim of this paper is to introduce the class of languages generated by the transitional model of membrane systems without cooperation and without additional ingredients. The fundamental nature of these basic systems makes it possible to also define the corresponding class of languages it in terms of derivation trees of context-free grammars. We also compare this class to the well-known language classes and discuss its properties

Lexico-semantic and morphosyntactic processing in French-speaking adolescents with and without developmental language disorder

CodirectionBien que la communauté scientifique soit toujours à la recherche d'une caractéristique déterminante du trouble développemental du langage (TDL), les difficultés d'accord sujet-verbe, et par extension morphosyntaxiques, ont été identifiées comme un marqueur du TDL chez les enfants anglophones, autant chez les enfants du préscolaire que les plus vieux. Cependant, des études sur les enfants francophones d'âge préscolaire suggèrent que les déficits morphosyntaxiques ne seraient pas un marqueur fiable du TDL. Puisque que certains aspects de la morphosyntaxe en français ne sont acquis que vers l’âge de huit ans chez les enfants au développement typique, tels que l'accord en nombre des verbes sous-réguliers et irréguliers, ci-après SOUSIRR, les déficits morphosyntaxiques pourraient être un marqueur du TDL en français uniquement vers la (pré-)adolescence. Cette thèse a pour objectifs de déterminer si les (pré-)adolescents francophones au développement typique ont acquis l'accord en nombre des verbes SOUSIRR, si les (pré)adolescents francophones avec un TDL ont des déficits d'accord en nombre des verbes SOUSIRR, et à établir si la morphosyntaxe est un domaine de faiblesse par rapport à la lexico-sémantique dans cette population. L'accord en nombre des verbes SOUSIRR et les compétences morphosyntaxiques ont été évalués à l'aide de tâches ciblant les niveaux comportemental et neurocognitif en utilisant des tâches linguistiques et des potentiels évoqués (PÉ). De plus, nous avons développé des prédictions basées sur deux théories touchant les compétences morphosyntaxiques chez les (pré-)adolescents atteints de TDL : l'hypothèse du déficit procédural (Ullman & Pierpont, 2005 ; Ullman et al., 2020), et l'hypothèse du ralentissement généralisé (Kail, 1994). Cette thèse est composée de trois manuscrits pour publication. Le premier évalue les compétences des participants dans plusieurs domaines linguistiques, à l'aide de tâches comportementales typiquement utilisées en orthophonie et dans la recherche sur l’acquisition du langage. Les données révèlent des déficits lexico-sémantiques et morphosyntaxiques chez les participants avec un TDL, mais suggèrent qu'une tâche d'accord en nombre des verbes SOUSIRR était la meilleure pour discriminer les participants avec et sans TDL. Le deuxième article présente une étude innovante de PÉs utilisant uniquement des phrases grammaticales, présentées simultanément avec des images sémantiquement ou grammaticalement congruentes et incongruentes, afin d'évaluer le traitement morphosyntaxique et lexico-sémantique des phrases au niveau neurocognitif. Les résultats provenant de vingt-huit adultes francophones montrent qu'ils ont présenté les composantes PÉs attendues et comparables aux études utilisant des phrases agrammaticales. Ces données ont servi de référence pour établir si nos participants avec et sans TDL avaient un traitement linguistique mature. Le troisième article a testé cette nouvelle expérimentation avec nos participants (pré )adolescents. Les résultats suggèrent que, contrairement à la morphosyntaxe, la lexico-sémantique est une force relative chez les adolescents avec un TDL lors du traitement de l'information linguistique au niveau neurocognitif. Dans l'ensemble, cette thèse révèle que la morphosyntaxe est particulièrement altérée chez les adolescents francophones avec un TDL. Nous discutons les résultats en relation avec la pratique clinique orthophonique et soulignons l'importance d'examiner les processus neurocognitifs dans l'étude du TDL.Although the scientific community is still searching for a defining characteristic of developmental language disorder (DLD), problems with subject-verb agreement, and by extension morphosyntax, have been identified as a hallmark of English-speaking preschoolers and older children with DLD. However, in studies of French-speaking preschoolers with DLD, morphosyntax has not been found to be a specific linguistic weakness. Since there is evidence that some aspects of morphosyntax in French are acquired by children with typical language (TL) development only later in childhood, such as subregular and irregular subject-verb number agreement, henceforth SUBIRR, morphosyntax has been argued to be a French marker for DLD only in older childhood and adolescence. The present thesis aimed to determine if French speaking (pre-)teenagers with TL have acquired SUBIRR number agreement, resolve whether French-speaking (pre-)teenagers with DLD are impaired on SUBIRR number agreement, and establish whether morphosyntax is an area of weakness as compared to lexico-semantics in this population. SUBIRR number agreement and morphosyntactic skills were evaluated with tasks targeting the behavioural and neurocognitive levels using linguistics tasks and event-related potentials (ERP). Furthermore, we contrasted two theories’ predictions on morphosyntactic skills in (pre-)teens with DLD : the procedural deficit hypothesis (Ullman & Pierpont, 2005; Ullman et al., 2020), and the generalized slowing hypothesis (Kail, 1994). This thesis is composed of three manuscripts for publication. The first evaluated our participants’ skills in multiple linguistic domains with behavioural tasks typical of clinical and research settings. Data reveal impairments in the DLD group in both lexico-semantic and morphosyntactic domains but suggest that a SUBIRR number agreement task was best at discriminating DLD from controls. The second article presents a novel ERP experimental design using only grammatical sentences, presented simultaneously with semantically and grammatically congruent or incongruent images, to assess morphosyntactic and lexico-semantic sentence processing at the neurocognitive level. Data from twenty-eight French-speaking adults show that they elicited the expected ERP components found in previous studies using ungrammatical sentences. These data served as a reference to establish whether our participants with and without TL process sentences in a mature way. The third article tested this novel ERP experiment with our (pre-)teen participants. We tested predictions of the procedural deficit hypothesis which states that children with DLD should have impaired morphosyntax due to an underlying procedural memory deficit, and the generalized slowing hypothesis, which proposes that all linguistic domains should be impaired due to an underlying processing deficit. This experimental design was run on teens with and without DLD. Although some processing delays were found in the DLD group, results on most conditions better fit the procedural deficit hypothesis. This study suggests that, in contrast with morphosyntax, lexico-semantics is a relative strength in teenagers with DLD when processing linguistic information at the neurocognitive level. Overall, this thesis reveals that morphosyntax, tested through SUBIRR number agreement, is especially impaired in French-speaking teens with DLD when compared to their TL peers. We discuss the findings in relation to clinical practice and highlight the importance of examining neurocognitive processes in language assessment

DNA Computing: Modelling in Formal Languages and Combinatorics on Words, and Complexity Estimation

DNA computing, an essential area of unconventional computing research, encodes problems using DNA molecules and solves them using biological processes. This thesis contributes to the theoretical research in DNA computing by modelling biological processes as computations and by studying formal language and combinatorics on words concepts motivated by DNA processes. It also contributes to the experimental research in DNA computing by a scaling comparison between DNA computing and other models of computation. First, for theoretical DNA computing research, we propose a new word operation inspired by a DNA wet lab protocol called cross-pairing polymerase chain reaction (XPCR). We define and study a word operation called word blending that models and generalizes an unexpected outcome of XPCR. The input words are uwx and ywv that share a non-empty overlap w, and the output is the word uwv. Closure properties of the Chomsky families of languages under this operation and its iterated version, the existence of a solution to equations involving this operation, and its state complexity are studied. To follow the XPCR experimental requirement closely, a new word operation called conjugate word blending is defined, where the subwords x and y are required to be identical. Closure properties of the Chomsky families of languages under this operation and the XPCR experiments that motivate and implement it are presented. Second, we generalize the sequence of Fibonacci words inspired by biological concepts on DNA. The sequence of Fibonacci words is an infinite sequence of words obtained from two initial letters f(1) = a and f(2)= b, by the recursive definition f(n+2) = f(n+1)*f(n), for all positive integers n, where * denotes word concatenation. After we propose a unified terminology for different types of Fibonacci words and corresponding results in the extensive literature on the topic, we define and explore involutive Fibonacci words motivated by ideas stemming from theoretical studies of DNA computing. The relationship between different involutive Fibonacci words and their borderedness and primitivity are studied. Third, we analyze the practicability of DNA computing experiments since DNA computing and other unconventional computing methods that solve computationally challenging problems often have the limitation that the space of potential solutions grows exponentially with their sizes. For such problems, DNA computing algorithms may achieve a linear time complexity with an exponential space complexity as a trade-off. Using the subset sum problem as the benchmark problem, we present a scaling comparison of the DNA computing (DNA-C) approach with the network biocomputing (NB-C) and the electronic computing (E-C) approaches, where the volume, computing time, and energy required, relative to the input size, are compared. Our analysis shows that E-C uses a tiny volume compared to that required by DNA-C and NB-C, at the cost of the E-C computing time being outperformed first by DNA-C and then by NB-C. In addition, NB-C appears to be more energy efficient than DNA-C for some input sets, and E-C is always an order of magnitude less energy efficient than DNA-C