This thesis reports on a study on the ultimate attainment of grammatical intuition in Swedish in 29 adult hearing native signers, bilingual in Swedish Sign Language and Swedish. It is reasoned that measures of such intuition in adults may indicate implicit linguistic entrenchment in Swedish during early language development. Although Sign Language Linguistics and Second Language Research on deaf signers are two established fields of research in Sweden, there is little research on hearing native signers. A few international studies have focused on early child language development in hearing native signers, showing that these children develop their two languages simultaneously from birth even if the signed language dominates the linguistic environment. However, studies focusing on older children indicate that their morphological and syntactic proficiency in the majority language resembles that of second language learners. Deductively this paper rests on neurobiological and psycholinguistic theories claiming that early language development is naturally and genetically constrained within a critical or maturational period. Grammatical intuition was measured through the use of two versions of a GJT-test (written and auditory) and a cloze test. The results showed that the average grammatical intuition of the hearing native signers was comparable to that of a group of early L2 learners of Swedish, but significantly different from that of a group of native speakers of Swedish, indicating that for some of the native signers, Swedish might have been successively learned. This thesis contributes unique data to second language research, while shedding a light on a group of bilinguals that is scarcely known to the study of linguistics. / Denna explorativa och explanatoriska studie testade grammatisk intuition i svenska hos 29 vuxna hörande tvåspråkiga i svenskt teckenspråk och svenska. Vid statistisk analys och jämförelse med testresultat från tidigare andraspråksforskning indikerar denna studie att deltagarna kan ha lärt sig delar av svenskans morfologi och syntax successivt. Teckenspråkslingvistik och svenska som andraspråk för döva är idag två etablerade forskningsområden. Trots en växande kunskap om teckenspråkiga saknas svensk forskning om tvåspråkigheten hos hörande infödda teckenspråkiga. De internationella studier som gjorts har fokuserat på små barn och visar att hörande infödda teckenspråkiga är simultant tvåspråkiga från födseln även om det tecknade språket dominerar den första tiden. Å andra sidan visar studier på lite äldre barn att kunskaper i majoritetsspråket (det talade språket) hos vissa individer, har morfologiska och syntaktiska drag liknande dem som andraspråksinlärare uppvisar.  Med stöd i neurobiologiska och psykolingvistiska teorier om en biologiskt betingad språkinlärningsmekanism som kräver triggning från födseln, undersökte denna studie, hypotes-deduktivt, huruvida deltagarna utvecklat implicita kunskaper i svenska under en kritisk period för språkutveckling. Denna studie bidrar med nya, unika data till tvåspråkighetsforskning och kastar ljus över en inlärarpopulation som tidigare inte uppmärksammats inom språkinlärningsforskningen.

El objetivo general de esta tesis fue producir información científico-tecnológica básica para la implementación de un sistema integrado de control de malezas, que permita reemplazar al sistema mecánico en las plantaciones de álamo (Populus spp.) del centro-norte de la Provincia de Buenos Aires. Los trabajos se agruparon en tres líneas de investigación complementarias, en donde se abordaron grupos específicos de problemas. En la primera línea de trabajo se determinó la composición específica de la comunidad de malezas y la magnitud de su interferencia, se establecieron los niveles de control y fitotoxicidad que producen diferentes herbicidas, y se evaluaron en forma comparada los efectos sobre la supervivencia y el crecimiento del cultivo de distintos tratamientos integrados de control respecto del sistema actual. La segunda línea estudió la variación temporal de la interferencia en busca de la definición del período crítico para el control de malezas, y en la tercera línea de trabajo se evaluó el resultado económico potencial de la implementación de los cambios estudiados en el sistema de control, considerando diferentes escenarios económico-financieros, grados de incorporación de tecnología y de reemplazo de mano de obra. Las distintas líneas comprendieron experiencias en campo llevadas a cabo entre los años 1998 y 2004 en el Establecimiento Forestal "María Dolores", Partido de Alberti, Provincia de Buenos Aires (34° 50' Lat. Sur; 60° 30' Long. Oeste; 55 msnm). Los trabajos se efectuaron siguiendo una estrategia progresiva de experimentación: en una primera etapa se realizaron ensayos exploratorios y posteriormente los resultados iniciales obtenidos fueron evaluados en ensayos a escala de producción y parcelas demostrativas de 5 hectáreas de superficie.

Résumé L’hypothèse de la période critique, émise par Lenneberg dans les années 60, affirmait qu’un enfant pouvait acquérir une langue seconde, sans difficulté, environ jusqu’à l’âge de la puberté. Après cette période, l’apprentissage d’un autre idiome serait difficile, dû à la latéralisation du cerveau. En même temps, les travaux de Chomsky enrichirent cette théorie avec l’idée de la Grammaire universelle, laquelle établit que nous possédons tous, dès la naissance, les éléments linguistiques universels qui nous permettent d’acquérir une langue maternelle. Tant que la Grammaire universelle est active, notre langue maternelle se développe et c’est pourquoi, si nous apprenons une autre langue pendant cette période, l’acquisition de celle-ci se produit de manière presque naturelle. Pour cette raison, plus une langue est apprise tôt, plus elle sera maîtrisée avec succès. En nous appuyant sur ce cadre théorique ainsi que sur l’Analyse d’erreurs, outil qui permet au professeur de prédire quelques erreurs avec la finalité de créer des stratégies d’apprentissage d’une langue seconde, nous tenterons de vérifier dans le présent travail si l’âge est un facteur qui influence positivement ou négativement l’apprentissage d’une langue seconde, l’espagnol dans ce cas-ci, par le biais de l’analyse comparative des prépositions a/ en dans deux groupes d’étudiants différents. / Abstract According to Leeneberg's critical period hypothesis from the sixties, a child can acquire a second language approximately until puberty, for afterwards the lateralization of the brain takes place and the acquisition of second language becomes more difficult. Further on, Chomsky’s research would contribute to this theory with the Universal Grammar idea or the inborn universal linguistic elements that we use in order to acquire mother tongue. While the Universal Grammar is still on, the already acquired Mother Tongue continues to develop. As a result, the acquisition of another language during this period becomes a natural process, leading to the conclusion that the earlier a child starts learning a second language, the better its acquisition will be. Therefore and for the purpose of this research, a theoretical framework and the error analysis, the tool allowing the teacher to predict some error in order to create the adequate language strategies for effective second language acquisition, are used. I will try to verify the age-factor influence positively or negatively in the acquisition of a second language, in this special case the Spanish language, by means of the comparative analysis of the a/ en prepositional pair with two different groups of apprentices.

[pt] Comunidades surdas são compostas por populações com alto nível de variabilidade de proficiência (NIEDLE et al, 2000), o que dificulta a estruturação de amostras de participantes para a obtenção de dados em estudos sobre a gramática internalizada (Língua-I) por falantes dessas comunidades. Tal variabilidade está relacionada diretamente à idade de aquisição de uma língua de sinais (LS), à qualidade e à quantidade do insumo linguístico recebido pelas crianças surdas no período de aquisição de linguagem. Em diversos estudos sobre LS, sinalizantes surdos filhos de pais surdos sinalizadores (SFPS) são considerados como nativos, ou seja, possuidores de competência gramatical plena (Chomsky, 1986). Todavia, devido à escassez de informantes SFPS, pesquisas têm ampliado a caracterização de sujeitos que, de fato, possuem conhecimento pleno da gramática de uma LS, incluindo também surdos filhos de pais não surdos (SFPnS) como informantes. Contudo, estudos evidenciam a que há um período sensível para a aquisição dos aspectos estruturais de uma gramática e, tal sensibilidade tende a ser reduzida gradativamente até o início da puberdade (Lenneberg, 1967). Assim sendo, parte-se da hipótese de que em Libras, SFPnS que tiveram exposição tardia à gramática não apresentam competência gramatical plena. Fazer a verificação dessa hipótese é o objetivo principal deste trabalho, que se caracteriza como um estudo teórico-experimental sobre competência morfossintática em Libras. O foco da pesquisa foi concordância verbal e o experimento consistiu em uma tarefa de julgamento de aceitabilidade, em que sinalizantes de Libras (20 SFPS e 45 SFPnS (15 com exposição à Libras antes dos 4 anos; 15 com exposição entre 5 e 7 anos; 15 com exposição a partir de 8 anos de idade)) do Rio de Janeiro julgaram a aceitabilidade de 32 sentenças/vídeos alvos com uso de Escala Likert de cinco pontos, em que 1 = ruim e 5 = ótimo. Tomamos como variáveis independentes o tipo de concordância verbal (regular vs. reversa), verbo auxiliar (presença vs. ausência) e a manifestação morfologia da concordância (parcial (apenas com o objeto) vs. neutra (sem marca de concordância tanto com o sujeito como com objeto)). Os dados foram estatisticamente tratados (ANOVA com medidas repetidas) e os resultados interpretados à luz da Teoria Gerativa e da literatura sobre concordância verbal em língua de sinais. Os resultados não evidenciam nenhuma diferença muito marcada entre SFPS e SFPnS. Tanto SFPS como SFPnS possuem sensibilidade quanto ao tipo de concordância verbal (regular vs. reversa), apresentando uma preferência pela concordância regular, e menor preferência pela presença do verbo auxiliar mesmo quando a concordância verbal é neutra, como sugerido em Lourenço (2014). Contudo, SFPS apresentaram menor aceitação de sentenças com concordância verbal regular parcial na presença de auxiliar, como observado em Quadros e Quer (2008, 2010). / [en] Deaf communities display high level of variability in language proficiency (NIEDLE et al, 2000), which makes it difficult to structure samples for studies about the Grammar (I-language) in sign languages (SL). Such variability is directly related to the age of acquisition, the quality and quantity of the linguistic input received by deaf children during the acquisition period. Deaf signers whose parents are also deaf signers (DsDsP) are considered to be native signers. That is, these signers are considered to have full grammatical competence (Chomsky, 1965, 1986) on their native languages. However, due to shortage of DsDsP informants, researchers tend to leave open the set of signers with full grammatical knowledge, including deaf signers with non-deaf parents (DsNonDsP) as informants in their research. Studies suggest, however, the existence of a sensitive period for the acquisition of the structural properties of any given grammar. This sensitivity tends to be gradually reduced until the onset of puberty (Lenneberg, 1967). Therefore, we should, by hypothesis, expect that DsNonDsP with late exposure to any SL, including Brazilian Sign Language (Libras), do not have the same grammatical competence as DsDsP. Investigating this hypothesis is the main goal of our research, a theoretical-experimental study on grammatical competence in Libras. We focused on the morphosyntax of verbal agreement in Libras and we conducted an acceptability judgment take, in which signers (20 DsDsP and 45 DsNonDsP (15 with exposure to Libras before 4 years; 15 with exposure between 5 and 7 years; 15 with exposure from 8 years old)) used a 5-point Likert Scale (1 = Not acceptable, 5 = fully acceptable) to judge 32 target sentences/videos. The independent variables were: type of verbal agreement (regular vs. backwards), auxiliary verb (presence vs. absence) and morphological manifestation of agreement on the verb (partial (with the object only) vs. neutral (no agreement at all)). The data collected were statistically treated (ANOVA with repeated measures) and the results were analyzed taking into consideration the literature on language acquisition within Generative Grammar and the literature on verbal agreement in SL. The results did not show any strikingly difference between DsDsP and DsNonDsP. Both DsDsP and DsNonDSP seem to be sensitive to the type of verbal agreement, displaying a preference for regular verbal agreement and a lower preference for the presence of auxiliary verb even in sentences with neutral verbal agreement, in accordance with Lourenço (2014). However, DsDsP showed less acceptance of partial regular verbal agreement in the presence of auxiliary in accordance with Quadros and Quer (2008, 2010).

The question of the asset of early foreign language learning is a frequently discussed topic. Following prevailing opinion in society, that ‚the sooner, the better ', the beginning of compulsory foreign language learning is continually shifting in lower grades at primary school. A lot of children have already started with foreign language learning in kindergarten. Researches, which support the benefits of the approach, focus on a very narrow aspect of foreign language acquisition (pronunciation) or survey these facts with a specific group of inhabitants (immigrants). As experts point out, there is no significant benefit of early instructions ascertained in the Czech Republic. However, the research focused only on adults. We do not have any further evidence of the advantages of starting to learn a foreign language early. Therefore, the author focused on comparing the level of foreign language competences of two groups of pupils after their two-year compulsory instructions of English at primary school. The aim was to compare the level of their language competence in English and the learners' potential difficulties by the learners with early learning experience and by the learners without previous experience of foreign language learning before the beginning of compulsory learning at primary school....

Plusieurs études ont démontré l’impact de divers facteurs sur l’espérance de vie, dont les caractéristiques liées à l’environnement dans l’enfance et à l’âge adulte. L’objectif principal de ce mémoire est de déterminer si l’exposition à une épidémie durant la période fœtale ou pendant la première année de vie a un impact sur la survie après 40 ans pour les Québécois nés entre 1885 et 1901. Durant cette période, nous avons relevé des épidémies de variole et de scarlatine, ainsi qu’une pandémie de grippe, la grippe russe. L’influence d’autres facteurs sur l’âge au décès est également étudiée, celle du sexe, de l’année et de la saison de naissance, du lieu de résidence à la naissance (urbain ou rural) et des régions d’habitation dans l’enfance et à l’âge adulte. Les données sur les Canadiens français nés au Québec à la fin du XIXe siècle, soit l’échantillon de 5% des ménages du recensement canadien de 1901 (Sager 2001) recueilli par le Canadian Families Project, jumelées aux dates de décès à partir de l’index des décès de 1926 à 1996 de l’Institut de la statistique du Québec (ISQ) et de la Société de généalogie du Québec (Pilon-Marien et al. 2009; Gagnon et Bohnert 2012) ont été analysées. Plus spécifiquement, nous avons effectué une analyse descriptive de la population étudiée, puis une analyse multivariée à l’aide de modèles de Cox et de modèles de Gompertz. Il en résulte qu’une exposition à une épidémie avant l’âge d’un an augmente significativement le risque de décéder après l’âge de 40 ans. L’exposition pendant la période fœtale a également un effet négatif sur la longévité, toutefois cet effet n’est pas significatif dans les modèles fournissant le meilleur ajustement aux données. Enfin, une naissance pendant une épidémie, donc une exposition in utero et durant la première année de vie n’a pas d’impact négatif significatif sur l’âge au décès pour ceux qui survivent jusqu’à 40 ans. / Numerous studies have shown the effects on longevity of early life and adult conditions. The purpose of our study is to analyze the impact of exposure to an epidemic disease during the fetal stage or the first year of life on survival after age 40 for people born in Quebec between 1885 and 1901. During this period, we identified epidemics of smallpox and scarlet fever, and the Russian influenza pandemic. The effects on age at death of other environmental conditions have been studied such as the sex, the season of birth and the year of birth, the urban-rural status at birth, the region of residence in early life and the region of residence at death. The dataset used in this study is based on the 5 percent sample of the 1901 Canadian Census, gathered by the Canadian Family Project (Sager 2001). Individuals were matched to their deaths records through the Quebec Consolidated Deaths Index from the Société de Généalogie du Québec and the Index des décès from the Institut de la statistique du Québec (Pilon-Marien and al. 2009). A descriptive analysis of the population studied has been done and a statistical analysis with Cox models and Gompertz models was made. We observe that individuals who were exposed to an epidemic disease during their first year of life had an increased mortality after age 40. In utero exposure to an epidemic hints at an increase of mortality after age 40 but the effect is not significant. Also, a birth during a pandemic, and therefore exposure both in utero and in the first year, apparently has no significant negatives impacts on longevity.

Ob es eine 'kritische Periode' beim Spracherwerb gibt oder nicht, wird kontrovers diskutiert. Die Untersuchung zweisprachiger Probanden mit unterschiedlichem Spracherwerbsalter und Sprachleistungsniveau in der Zweitsprache stellt eine gute Möglichkeit dar, diese Frage näher zu beleuchten. In der vorliegenden Studie nutzten wir die funktionelle Magnetresonanztomographie, um den Einfluss der Faktoren Spracherwerbsalter und Sprachleistungsniveau auf die neuronalen Korrelate grammatikalischer und semantischer Verarbeitungsprozesse bei italienisch-deutschsprachigen Probanden mit unterschiedlichem Spracherwerbsalter und Sprachleistungsniveau zu untersuchen. Während das zerebrale Aktivierungsmuster beim semantischen Urteilen größtenteils vom erreichten Sprachleistungsniveau abhängig war, beeinflusste das Spracherwerbsalter hauptsächlich die zerebrale Repräsentation grammatikalischer Verarbeitungsprozesse. Diese Ergebnisse weisen darauf hin, dass beide, das Spracherwerbsalter und das Sprachleistungsniveau, die neuronalen Substrate der Verarbeitung der Zweitsprache beeinflussen, jedoch mit einem unterschiedlichen Effekt auf grammatikalische und semantische Verarbeitungsprozesse. / The existence of a 'critical period' for language acquisition is still controversial. Bilingual subjects with variable age of acquisition and proficiency level constitute a suitable model to study this issue. In the present study, we used functional magnetic resonance imaging to investigate the effects of age of acquisition and proficiency level on neural correlates of grammatical and semantic judgments in Italian-German bilinguals who learned the second language at different ages and had different proficiency levels. While the pattern of brain activity for semantic judgment was largely dependent on the proficiency level, the age of acquisition mainly affected the cortical representation of grammatical processes. These findings support the view that both age of acquisition and proficiency level affect the neural substrates of second language processing, with a differential effect on grammar and semantics.

Au cours du développement du système nerveux, l'activité des cibles post-synaptiques permet le raffinement du nombre et de la force des connexions neuronales. En employant la jonction neuromusculaire de Caenorhabditis elegans comme système modèle, nous avons étudié deux aspects de la mise en place de ces connexions. D'une part, nous montrons que le nombre de récepteurs présents à la jonction neuromusculaire est contrôlé par l'activité musculaire : une augmentation de l'activation synaptique entraîne une régulation différentielle des trois types de récepteurs présents à la jonction neuromusculaire. D'autre part, nous avons étudié les changements de la morphologie de certains motoneurones de la tête du ver, appelés neurones SAB, en fonction de l’activité musculaire. Une diminution de l’activité musculaire durant une période critique du développement entraîne une surcroissance axonale des neurones SAB. À travers différentes approches, nous avons pu identifier la suppression de la surcroissance axonale dans des mutants où la biosynthèse des neuropeptides est perturbée. Enfin, nous avons mis en évidence que la surcroissance axonale apparait également lors de perturbations plus générales de la physiologie cellulaire, telles qu'un choc thermique ou la surexpression d'un transgène, ce qui suggère que le système SAB est plastique et particulièrement sensible au cours du développement / Throughout nervous system development, activity of the post-synaptic targets can regulate the connectivity of neural networks, affecting both the number and strength of synapses. Using the neuromuscular junction of Caenorhabditis elegans as a model system, we studied two processes displaying such plasticity. First, we show that the number of receptors present at the neuromuscular synapse is regulated by muscle activity: an increase in synaptic activity can lead to a differential regulation of the three types of receptors present at the neuromuscular junction. Second, we studied the activity-dependent morphological changes of one type of motor neurons in the worm’s head, called the SAB neurons. A decrease of muscle activity during a critical developmental phase leads to SAB axonal overgrowth. Using several approaches, we were able to observe suppression of SAB axonal overgrowth in mutants with a disruption of neuropeptides biosynthesis. Finally, we give evidence that axonal overgrowth also occurs following more general disruptions of cell physiology, such as a heat-shock or transgene overexpression, which suggest that the SAB system is plastic and sensitive during development

During an incident, which is critical in nature, sense-making by the individuals involved are essential in ensuring an optimal response to the incident. The incident management systems employed to manage the allocation of resources to an incident allow for the visualisation of the incident and its constituents, and this visualisation supports sense-making by improving knowledge transfer. Knowledge visualisation contains pitfalls that can be avoided by implementing knowledge visualisation criteria. The purpose of this study is to identify the knowledge visualisation criteria that optimise the knowledge transfer by visual artifacts in incident management systems like emergency medical or fire-response systems. This study used the design science research (DSR) methodology and was conducted in the context of critical incident response management. A review of the existing literature was done to identify an initial set of knowledge visualisation criteria. The initial set was evaluated by content experts (using questionnaire driven interviews) and usability experts (using questionnaire driven interviews, usability testing with eye tracking and a survey) in the context of an emergency incident management system. The main contribution of this study is a validated set of knowledge visualisation criteria to guide knowledge transfer in incident management systems. / School of Computing / M. Sc. Computing

This thesis explores the role of age in second language (L2) acquisition and first language (L1) attrition. The focus is on Voice Onset Time (VOT) in the production and categorical perception of word-initial L1 and L2 stops in highly advanced L1 Spanish learners of L2 Swedish. Using as the point of departure a maturational constraints perspective and the Critical Period Hypothesis (CPH), Study I examines the impact of age of onset (AO) of L2 acquisition on the production of L2 Swedish voiceless stops. The results show that there are AO effects even in the speech of highly advanced L2 learners and that the incidence of nativelike L2 learners is considerably lower than earlier assumed. However, conclusions like these are only possible when speaking rate is accounted for, thereby highlighting the importance of speaking rate effects on VOT as a measure of nativelikeness. Like Study I, Study II reveals age effects on the same L2 learners’ categorical perceptions of L2 Swedish stops. Moreover, after combining the results with the data from Study I, the incidence of nativelike behavior drops remarkably with no late L2 learner performing within the range of native-speaker production and perception. The results suggest that L2 acquisition of phonetic/phonological aspects is especially sensitive to AO effects. It is concluded that theories on maturational constraints, including the CPH, cannot be refuted on the basis of the present data. Study III concerns the same participants’ production and perception of L1 Spanish stops. Age of reduced contact (ARC) is identified as an important predictor for L1 attrition and retention of voiceless stop production, although not of stop perception. This discrepancy is related to different activation thresholds as proposed by the Activation Threshold Hypothesis (ATH). It is further suggested that early bilinguals are more dependent on high-frequency L1 use than late bilinguals when compensating for age effects, but only in production. / <p>At the time of doctoral defence the following papers were unpublished and had a status as follows: Paper 1: Accepted. Paper 2: In press. Paper 3: Manuscript.</p> / Age of onset and ultimate attainment in second language acquisition, The Bank of Sweden Tercentenary Foundation, grant no. 1999-0383:01 / First language attrition in advanced second language speakers, Swedish Research Council, grant no. 421-2004-1975