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L’influence de la gravité sur le développement des capacités motrices a été étudiée chez la souris C57Bl/6J. Nous avons voulu savoir s’il existait des périodes critiques dans l’adaptation à la gravité. Nous avons utilisé pour cela l’hypergravité par centrifugation chronique, seul moyen de modifier la pesanteur durant l’embryogenèse des mammifères. Des groupes de souris ont été centrifugés (a) pendant le développement pré et périnatale (de la conception jusqu’à l’âge de 10 jours), (b) pendant le développement post-natal (du 10e jour au 30e) ou (c) sur l’ensemble de ces deux périodes. Nous avons étudié, à l’âge de 2 et 6 mois, (i) les mouvements compensateurs des yeux dans la stabilisation du regard par vidéo-oculographie et les réactions vestibulaires ; (ii) la dépense énergétiques par calorimétrie indirecte, et (iii) les paramètres cinématiques de la locomotion par vidéo-radiographie. Seules les souris centrifugées pendant l’ensemble du développement présentent, au moins transitoirement, des réactions otolithiques perturbées. Ce résultat nous conduit à rejeter l’hypothèse d’une période critique vestibulaire, mais l’observation de déficits dans certains tests de réactions vestibulaires des souris centrifugées à partir de P10 pourrait confirmer l’hypothèse d’une période critique dans l’établissement des connexions vestibulo-cérébelleuses et vestibulo-spinales. L’analyse du métabolisme a montré que seules les souris élevées prénatalement en hypergravité présentaient une dépense énergétique accrue à l’âge de 2 et 6 mois. L’analyse de la cinématique articulaire au cours de la locomotion a montré que l’ajustement du contrôle postural a lieu, en partie, avant que les animaux ne commencent à marcher. En revanche, l’ajustement des allures se fait après le 10e jours post-natal quand les animaux font l’expérience de la marche. L’ensemble de ces résultats démontrent l’existence d’une succession de périodes critiques dans l’ontogenèse des capacités motrices. / The influence of gravity on the development of motor skills was analysed on the mice C57Bl/6J. Our goal was to evaluate the hypothesis of critical periods in the adaptation to gravity. We used the chronic centrifugation that is the only available technique to modify the gravity during mammals embryogeny. Several groups of mice were centrifuged (a) during the early perinatal development (from conception to tenth postnatal day), (b) during the postnatal development (from day 10 to 30) or (c) during the whole periods. We analysed, at the age of 2 and 6 months, (i) the compensatory eye movements during the gaze stabilization by video-oculography, and the vestibular reactions; (ii) the energetic expanse by indirect calorimetry, and (iii) the kinematic parameters of locomotion by video-radiography. Only the mice centrifuged during their whole development showed at least transitory impairment of otolithic reactions. This result was inconsistent with a vestibular critical period, but the observation of impairments in some vestibular reactions of postnatally centrifuged mice could support the hypothesis of a critical period in the establishment of vestibulo-cerebellar or vestibulo-spinal connections. The metabolic analysis showed an increased energetic expense in mice exposed to hypergravity when 2 or 6 months old. The kinematic analysis of joints during locomotion showed that postural adjustment occurred, at least partly, before the mice started walking. On the other hand, the gait adjustment occured after tenth postnatal day, when the mice experiment walking. As a whole these results show the existence of several critical periods in the ontogenesis of motor capabilities.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

LIMA JÚNIOR, Ronaldo Mangueira. A influência da idade na aquisição da fonologia do inglês por brasileiros. 2012.188f. – Tese (Doutorado) – Universidade de Brasília, Programa de Pós-Graduação em Linguística, Brasília (DF), 2012. / Submitted by anizia almeida (aniziaalmeida80@gmail.com) on 2016-06-21T12:40:59Z No. of bitstreams: 1 2012_tese_rmlimajr.pdf: 4530239 bytes, checksum: 0b1e8835e5cd84322b62adf650080726 (MD5) / Approved for entry into archive by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2016-06-27T21:05:50Z (GMT) No. of bitstreams: 1 2012_tese_rmlimajr.pdf: 4530239 bytes, checksum: 0b1e8835e5cd84322b62adf650080726 (MD5) / Made available in DSpace on 2016-06-27T21:05:50Z (GMT). No. of bitstreams: 1 2012_tese_rmlimajr.pdf: 4530239 bytes, checksum: 0b1e8835e5cd84322b62adf650080726 (MD5) Previous issue date: 2012 / This study sought to investigate how the factor ―age at the beginning of acquisition‖ influences the phonological acquisition of English by Brazilian learners who acquired the foreign language exclusively in Brazilian language classrooms and who were in the last semester of their English courses when the data were collected. Research participants were 10 learners who had begun studying English before age 12, 10 between 12 and 15, 10 after 16, and 10 native speakers of American English. All participants were recorded reading a carrier sentence containing words with the vowels [], reading a paragraph, and speaking spontaneously. The vowels were analyzed acoustically in relation to their duration and spectral quality (F1 and F2), and the other two recordings were judged in terms of intelligibility and degree of foreign accent by nine judges. In addition, all learners completed a survey that assessed extralinguistic characteristics such as motivation, desire to sound like a native speaker, degree of identification with the L2 culture, search for extra exposure to the L2, etc. The data were analyzed under the assumptions of the Complex and Dynamic Systems approach to second language acquisition (e.g. LARSEN-FREEMAN, 1997; DE BOT, 2008; CAMERON, 2003; ELLIS, 1998) and of (Acoustic-)Articulatory Phonetics (BROWMAN; GOLDSTEIN, 1987, 1993; ALBANO, 2001). The results of all analyses showed a large decrease in the quality of phonological production between native speakers and early beginners. Among the learners, though, the results did not reveal a single critical period after which L2 phonology is equally difficult or impossible to acquire, but rather a gradual tendency of greater difficulty to acquire the L2 phonology accurately as ages of onset increased. A few exceptional learners, who had phonological productions close or equal to those of native speakers, were found. / O presente estudo buscou investigar como o fator ―idade no início da aquisição‖ influencia a aquisição da fonologia do inglês por alunos brasileiros que adquiriram essa língua estrangeira exclusivamente em salas de aula no Brasil e que estavam no último semestre de seus cursos de inglês no momento da coleta de dados. Participaram da pesquisa 10 alunos que começaram a estudar inglês antes dos 12 anos de idade, 10 que começaram entre 12 e 15, 10 que começaram após os 16, e 10 falantes nativos de inglês americano. Todos foram gravados lendo uma frase veículo com palavras que continham as vogais [], lendo um parágrafo, e falando espontaneamente. As vogais foram analisadas acusticamente com relação à duração e à qualidade espectral (F1 e F2), e as outras gravações foram julgadas em inteligibilidade e grau de sotaque estrangeiro por nove juízes. Ademais, todos os alunos responderam a um questionário que suscitou características extralinguísticas dos aprendizes, tal como motivação, vontade de soar como um falante nativo do inglês, grau de identificação com a cultura da L2, busca por exposição extra à L2, etc. Os dados foram analisados com base na Teoria de Sistemas Complexos e Dinâmicos para a aquisição de segunda língua (e.g. LARSEN-FREEMAN, 1997; DE BOT, 2008; CAMERON, 2003; ELLIS, 1998) e na fonética (acústico-)articulatória (BROWMAN; GOLDSTEIN, 1987, 1993; ALBANO, 2001). Os resultados de todas as análises mostraram uma grande queda na qualidade da produção fonológica entre os falantes nativos e os aprendizes que começaram mais cedo. Entre os aprendizes, contudo, os resultados não revelaram um único período crítico após o qual a aquisição fonológica seja igualmente dificultosa ou impossível, e sim uma tendência gradual de dificuldade em adquirir a fonologia do inglês-L2 acuradamente conforme a idade de início da aquisição aumenta. Alguns alunos de desempenhos excepcionais, com produções próximas ou iguais às de falantes nativos, foram encontrados.

Made available in DSpace on 2014-06-11T19:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-09Bitstream added on 2014-06-13T19:44:35Z : No. of bitstreams: 1 cardoso_gd_dr_jabo.pdf: 279202 bytes, checksum: 9e92c9473063ab02a0b348aed72354f8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve como objetivo identificar os períodos de interferência das plantas daninhas no algodoeiro de fibra naturalmente colorida (BRS Safira e BRS Verde), e avaliar o efeito da competição das plantas daninhas na produtividade desta cultura. Dois experimentos foram instalados na área experimental da Embrapa Algodão em Missão Velha, CE, (7º42’07’’ de latitude e 39º24’18’’ de longitude, altitude de 360 m) na safra 2007/2008, utilizando-se o espaçamento de 1,00 x 0,20 m. Utilizou-se o delineamento experimental em blocos ao acaso, com quatro repetições, os tratamentos constaram de duas: modalidades de competição (convivência e controle de plantas daninhas) e períodos de interferência das plantas daninhas. Os períodos iniciais de controle ou de convivência após a emergência da cultura foram 0-20, 0-40, 0-60, 0-80 dias após a emergência (DAE) e 0-colheita (120 dias). Para determinação dos períodos de interferência, considerando-se perdas na produtividade de 2, 5 e 10%; foi realizada análise de regressão do modelo sigmoidal de Boltzmann, utilizando-se os dados de produtividade separadamente dentro de cada modalidade de competição. A comunidade infestante para ambas cultivares, foi composta por 21 espécies, destacando-se: Richardia grandiflora, Amaranthus deflexus, Eleusine indica, Merremia aegyptia, Eragrotis pilosa, Cenchrus echinatus e Waltheria indica. Observou-se para cultivar BRS Safira, que os períodos anteriores a interferência (PAI) foram, respectivamente, 8, 14 e 20 DAE, para perdas na produtividade de 2, 5 e 10%; e os períodos críticos de prevenção a interferências (PCPI), para esses mesmo níveis de perdas, foram respectivamente, 100, 82 e 60 dias. Para cultivar BRS Verde, os PAIs foram, respectivamente, 25, 31 e 35 DAE, para perdas de 2, 5 e 10%; e os PCPIs, para esses mesmo níveis de perdas, foram respectivamente... / This study aimed to determine the late-season presence of weeds in reddish brown cotton and green cotton (cultivars BRS Safira and BRS Verde) and the critical times for removing weeds. And assess the effect of weeds competition in the crop productivity. Two experiments were carried out in the area of Embrapa in Missão Mission-CE, Brazil, the region Cariri, located at 7º42’07’’ S latitude and 39º24’18’’ WGr. longitude, altitude of 360 m, in the 2007/2008 season. The treatments consisted of two control groups: weed-free crop during the initial period after crop emergency, and crop kept with weeds during initial period after plant emergency. Both consisted, 0, 20, 40, 60, 80 e 120 days after crop emergency (DAE). Regression analysis was performed of the model of sigmoidal Boltzmann, using data from productivity separately within each type of competition, to identify the critical periods of competition considering 2, 5 and 10% reduction in yield. The community of weeds, for both cultivars, was composed by 21 predominant species, standing out among them: Richardia grandiflora, Amaranthus deflexus, Eleusine indica, Merremia aegyptia, Eragrotis pilosa, Cenchrus echinatus and Waltheria indica. For cultivar BRS Safira, considering 2, 5 and 10% reduction in yield fiber as acceptable, the period preceding the interference was, respectively, 8, 14 and 20 (DAE). And the critical periods of prevention to interferences, for those same levels of losses, they were respectively, 100, 82 and 60 (DAE). For cultivar BRS Verde, considering 2, 5 and 10% reduction in yield fiber as acceptable, the period preceding the interference was, respectively, 25, 31 and 35 (DAE). And the critical periods of prevention to interferences, for those same levels of losses, they were respectively, 67, 43 and 22 (DAE). The BRS Safira cultivar was more susceptible to interference of the weed community that BRS Verde.

Les réseaux neuronaux sont hautement sensibles aux stimuli sensoriels pendant une fenêtre temporelle dite période critique (PC). Un des acteurs clé de la consolidation de ces réseaux est le Perineuronal Net (PNN), une matrice extracellulaire qui s’accumule au cours de la PC majoritairement autour des interneurones parvalbumin-positifs (PV). La dégradation des PNNs chez l’adulte restaure une plasticité structurale, typique de la PC. Ce projet de recherche vise à déterminer i) les propriétés neurophysiologiques des neurones PV et glutamatergiques dans la couche 4 du cortex visuel primaire de souris au cours du développement ii) de quelle façon ces propriétés sont altérées par l’accumulation des PNN. Nous avons montré, au cours du développement, une augmentation de l’excitabilité des deux types de neurones. La dégradation in vivo des PNN augmente la transmission glutamatergique et GABAergique spécifiquement sur les PV, récapitulant un état juvénile. Dégrader les PNN chez l’adulte n’affecte pas les connections unitaires inhibitrices en couche 4. Afin de comprendre les mécanismes impliqués au niveau du circuit, nous avons exprimé l’opsine sensible à la lumière ChR2 dans les neurones glutamatergiques du thalamus visuel projetant sur la couche 4 du cortex. Ainsi, une absence de PNN augmente le recrutement spécifique des PV par le thalamus, entrainant une augmentation de l’inhibition feedforward. Ces résultats sont en accord avec des expériences réalisées in vivo, au cours desquelles nous avons mesuré les potentiels évoqués en réponse à des stimuli visuels suite à une dégradation des PNN et qui indiquent une augmentation du recrutement de l’inhibition. / The maturation of sensory processing undergoes a critical period (CP), during which cortical neural circuits are sculpted and changed by experience. The closure of CP is paralleled by the accumulation of extracellular perineuronal nets (PNN) around parvalbumin (PV)-positive interneurons. The degradation of PNNs in adult animals was shown to re-open the structural plasticity typical of the CP. We aimed at defining i) the neurophysiological properties of PV cells and principal neurons in layer 4 of primary visual cortex (V1) during the establishment of the CP ii) how these properties are altered by PNN accumulation. We found a robust age-dependent increase of input-output firing relationships in both cell types. Importantly, in vivo PNN removal in adult V1 increased both excitatory and inhibitory transmission selectively onto PV, leaving their excitability intact, and recapitulating younger states. In addition, triggering plasticity in vivo by monocular deprivation did not boost the increased activity onto PV cells. Interestingly, paired recordings in layer 4 showed no changes of inhibitory unitary connections, with or without PNNs. In order to understand the circuit mechanisms underlined, we expressed the light-sensitive opsin ChR2 in the visual thalamus. We found that PNN removal increases the recruitment of PV cells by thalamocortical fibers leading to an increase of feedforward inhibition. These results are in agreement with V1 recordings in vivo of visually evoked potentials in response of increasing contrast. Indeed, PNN disruption caused a reduction of the slope of the contrast sensitivity curve, indicating a higher recruitment of inhibition.

La condition des larves de hareng des Downs durant la période critique a été caractérisée entre 2008 et 2015, en Manche orientale et dans la Baie sud de la Mer du Nord à partir des données collectées, durant la campagne International Bottom Trawl Surveys (IBTS). Tout d'abord, l'étude de la stratégie alimentaire, à partie de l'observation des proies dans les contenus digestifs par deux méthodes complémentaires (microscopie électronique et mesure de la fluorescence) a montré un changement de régime en fonction de la taille. Les larves inférieures à 13 mm avaient un régime omnivore très diversifié et composé de protistes et de petites proies zooplanctoniques, tandis que les larves plus grandes avaient un régime moins diversifié et composé principalement de plus grandes proies zooplanctoniques. En parallèle du changement de régime alimentaire, la combinaison de quatre indices de condition (taux d'ingestion, rapports ARN/ADN et ADN/C et otolithes) à l'échelle individuelle a également révélé un changement de l'état nutritionnel et de la croissance de ces larves. Les larves inférieures à 13 mm avaient une nutrition et une croissance soutenues, tandis que la croissance des larves plus grandes était faible. Ceci peut traduire un changement dans la stratégie d'allocation de l'énergie à partir de 13 mm, qui serait plus orientée vers du stockage que vers de la croissance. Ces changements ontogéniques dans la condition larvaire suggèrent que le changement de régime alimentaire qui s'opère à partir de 13 mm, pourrait constituer le coeur de la période critique pour les larves de hareng des Downs. / The larval condition of Downs herring during the critical period was investigated between 2008 and 2015 in the eastern English Channel and Southern Bight of North Sea from data collected during the International Bottom Trawl Survey (IBTS). First, the study of the feeding strategy from gut contents analysis using two complementary approaches (electronical microscopy and measure of fluorescence) revealed a shift in the feeding diet occuring at a larval size of 13 mm. Smaller larvae had an omnivorous and a more diversified diet composed of numerous protists and small zooplanktonic preys whereas bigger larvae had a less diversified diet composed mainly of bigger zooplanktonic prey. Along with the diet shift, combination of four condition indices (ingestion rate, RNA/DNA and DNA/C ratios and otoliths) also revealed important changes in the nutritional status and growth of these larvae. Larvae smaller than 13 mm had a sustainable nutrition and growth whereas larger larvae depicted low growth rate. This could reflect a change in the energy-allocation strategy from a growth-oriented strategy towards a more storage-oriented strategy. These ontogenetic changes in the larval condition suggest that the diet shift occurring at 13 mm could constitute the core of the critical period for Downs herring larvae.

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.

ABSTRACT OF THE DISSERTATION PENNSYLVANIA’S LOYALISTS AND DISAFFECTED IN THE AGE OF REVOLUTION: DEFINING THE TERRAIN OF REINTEGRATION, 1765-1800 by René José Silva Florida International University, 2018 Miami, Florida Professor Kirsten Wood, Major Professor This study examines the reintegration of loyalists and disaffected residents in Pennsylvania who opposed the American Revolution from the Stamp Act crisis in 1765 through the Age of Federalism in 1790s. The inquiry argues that postwar loyalist reintegration in Pennsylvania succeeded because of the attitudes, behavior, actions and contributions of both disaffected residents and patriot citizens. The focus is chiefly on the legal battle over citizenship, especially the responses of the disaffected to patriot legislative measures such as treason, oaths of allegiance, attainders, confiscation, and militia service laws that revolutionaries employed to sanction dissent in the state. Loyalists and the disaffected contributed to their own successful reintegration in three ways. First, the departure of loyalist militants at the British evacuation of occupied Philadelphia in June 1778 and later substantially lessened internal political tensions associated with the rebellion. Second, the overwhelming majority of the disaffected who stayed in Pennsylvania adopted non-threatening attitudes and behaviors towards republican rule. And third, the disaffected who remained ultimately chose to embrace the new republican form of government they had earlier resisted. Patriots contributed to the successful reintegration of the disaffected chiefly through the outcome of the factional struggle for internal political supremacy between revolutionary radicals and moderates. Pennsylvania radicals used the rule of law to deny citizenship to opponents of the Revolution and pushed for their permanent exclusion from the body politic. Moderates favored a reincorporation of those who had not supported the rebellion, utilizing the law to foster inclusion. Moderate electoral victories in the decade of the 1780s led to solid majorities in the state assembly that rescinded all repressive measures against former opponents, in particular the 1789 repeal of the Test Act of 1777. The analysis stresses the activities of loyalists and the disaffected, exploring elite loyalist militants such as Joseph Galloway and the sons of Chief Justice William Allen; ordinary loyalist militants like John Connolly and the Rankin brothers of York County; Quaker pacifists such as the Pemberton siblings; loyalists whom patriots perceived as defiant, such as the Doan guerrilla gang and British collaborators Abraham Carlisle and John Roberts; and the Penn family proprietors. Each of these protagonists epitomized a particular strain of loyalism or disaffection in Pennsylvania, ranging from armed resistance to pacifism. Reintegration experiences and outcomes are therefore assessed in relation to these Pennsylvanians’ conduct before, during, and after the Revolutionary War.

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.