Dissertations / Theses on the topic 'Allophagy'

Bien que nous ne distinguions qu'un nombre fini et restreint de catégories de sons (les phonèmes d'une langue donnée), les sons des messages que nous recevons ne sont jamais identiques. Etant donnée l'ubiquité des processus allophoniques à travers les langues et le fait que chaque langue dispose de son propre inventaire phonémique, quels types d'indices les nourrissons, par exemple anglophones, pourraient-ils exploiter pour découvrir que [siŋki ] et [θiŋki ] (sinking vs. Thinking) ne peuvent pas dénoter la même action ? Le travail présenté dans cette thèse prolonge les travaux initiés par Peperkamp et al. (2006) concernant la définition de mesures de dissimilarité phone à phone indiquant quels phones sont des réalisations d'un même phonème. Nous montrons que résoudre la tâche proposée par Peperkamp et al. (2006) concernant la définition de mesures de dissimilarité phone à phone indiquant quels phones sont des réalisations d'un même phonème. Nous montrons que résoudre la tâche proposée par Peperkamp et al. (2006) concernant la définition de mesures de dissimilarité phone à phone indiquant quels phones sont des réalisations d'un même phonème. Nous montrons que résoudre la tâche proposée par Peperkamp et al. N'apporte pas une réponse complète au problème de l'acquisition des phonèmes, principalement parce que des limitations empiriques et formelles résultent de sa formulation phone à phone. Nous proposons une reformulation du problème comme un problème d'apprentissage automatique non-supervisé par partitionnement reposant sur le positionnement multidimensionnel des données. Les résultats de diverses expériences d'apprentissage supervisé et non-supervisé indiquent systématiquement que de bons indicateurs d'allophonie ne sont pas nécessairement de bons indicateurs de phonémicité. Dans l'ensemble, les résultats computationnels présentés dans ce travail suggèrent qu'allophonie et phonémicité ne peuvent être découvertes à partir d'informations acoustique, temporelle, distributionnelle ou lexicale que si, en moyenne, les phonèmes présentent peu de variabilité<br>Although we are only able to distinguish between a finite, small number of sound categories -a given language's phonemes- no two sounds are actually identical in the messages we receive. Given the pervasiveness of sound-altering processes across languages -and the fact that every language relies on its own set of phonemes- what kind of cues may, for example, English-learning infants rely on to learn that [siŋki ] and [θiŋki ] (i. E. Sinking thinking) can not refer to the same action ? The work presented in this dissertation builds upon the line of computational studies initiated by Peperkamp et al; (2006), wherein research efforts have been concentrated on the definition of sound-to-sound dissimilarity measures indicating which sounds are realizations of the same phoneme. We show that solving Peperkamp et al. 's task does not yield a full answer to the problem of the discovery of phonemes, as formal and empirical limitations arise from its pairwise formulation. We proceed to circumvent these limitations, reducing the task of the acquisition of phonemes to a partitioning-clustering problem and using multidimensional scaling to allow for the use of individual phones as the elementary objects. The results of various classification and clustering experiments consistently indicate that effective indicators of allophony are not necessarily effective indicators of phonemehood. Altogether, the computational results we discuss suggest that allophony and phonemehood can only be discovered from acoustic, temporal, distributionall, or lexical indicators at low allophonic complexities, i. E. When -on average- phonemes do not have many allophones in the quantized representation of the input

A typological peculiarity that West Greenlandic and other Inuit languages exhibit is that they have very few underlying segments. This is especially true for the vowels, of which there are only three. However, the allophonic variation of these three vowels is considerable. In this thesis I investigate the different vowel qualities arising through allophonic variation in West Greenlandic, and propose phonological patterns that are subsequently analysed in the framework of Optimality Theory. The analysis will show that the allophonic variation the vowels exhibit can be explained by the place of articulation of the consonants surrounding the vowel. In addition to this I will compare the phonological structures of Element Phonology with other thories of representation.

Sound systems are a basic building block of any human language. An integral part of the acquisition of sound systems is the learning of allophony. In sound systems, some segments are used as allophones, or contextually-conditioned variants of a single phoneme, and learners need to figure out whether given segments are different phonemes or allophones. There is a growing interest in the question of how allophony is learned from speech input (e.g., Seidl and Cristia, 2012). This dissertation investigates the mechanisms behind the learning of allophony. Whether given segments are different phonemes or allophones of a single phoneme is partly determined by the contextual distribution of the segments. When segments occur in overlapping contexts and their occurrences are not predictable from the contexts, they are likely to be different phonemes. When segments occur in mutually exclusive contexts, and their occurrences are predictable from the contexts (i.e., they are in complementary distribution), the segments are likely to be allophones. This dissertation starts with the hypothesis that allophony can be learned from the complementary distribution of segments in input. With data collected in a series of laboratory experiments with adult English speakers, I make the following claims. First, adults can learn allophony from the complementary distribution of segments in input. The results of Experiment 1 showed that participants learned to treat two segments as something like allophones when they were exposed to input in which the segments were in complementary distribution. Second, the learning of allophony is constrained by the phonetic naturalness of the patterns of complementary distribution. The results of Experiment 2 showed that the learning of allophony happened only when participants were exposed to input in which relevant segments occurred in phonetically natural complementary contexts. Third, the learning of allophony involves the learning of the context-dependent perception of relevant segments. The results of Experiment 3 showed that, through exposure to input, participants’ perception of the relevant segments became more dependent on context such that they perceived the segments as being more similar to each other when they heard the segments in phonetically natural complementary contexts.<br>Arts, Faculty of<br>Linguistics, Department of<br>Graduate

Imogolite and allophane are nanosized aluminosilicates with high value in industrial and technological applications, however it remains unclear what factors control their formation and abundance in nature and in the lab. This work investigated the complex system of physical and chemical conditions that influence the formation of these nanominerals. Samples were synthesized and analyzed by powder x-ray diffraction, in situ and ex situ small angle x-ray scattering, and high-resolution transmission electron microscopy. Multivariate regression analysis combined with linear combination fitting of pXRD patterns was used to model the influence of different synthesis conditions including concentration, hydrolysis ratio and rate, and Al:Si elemental ratio on the particle size of the initial precipitate and on the phase abundances of the final products. The developed models described how increasing Al:Si ratio, particle size, and hydrolysis ratio increased the proportion of imogolite produced, while increasing the concentration of starting reagents decreased the final proportion. The model confidences were >99%, and explained 86 to 98% of the data variance. It was determined from the models that hydrolysis ratio was the strongest control on the final phase composition. The models also were able to consistently predict experimentally derived results from other studies. These results demonstrated the ability to use this approach to understand complex geochemical systems with competing influences, as well as provided insight into the formation of imogolite and allophane.<br>Master of Science<br>Allophane and imogolite are nanosized aluminosilicate minerals and strongly control the physical and chemical behavior of soil. They hold promise for use in technological applications. In nature, allophane and imogolite are often observed together in varying proportions. Similarly, laboratory synthesis by various methods usually does not result in pure phases. These observations suggest they form at the same time, at a wide range of solution chemical conditions. It remains unclear what factors determine how and when these phases form in solution, which limits our understanding of their occurrence in nature and the laboratory. The objective of this study is to understand and explain what solution chemical and physical conditions control the formation of synthetic imogolite and allophane. We did this by utilizing a unique approach where we systematically varied starting conditions of formation of these particles, and then used analytic and statistical methods to develop a model that describes the relationship between each of the starting conditions – concentration, size, pH, atomic ratios, and hydrolysis ratios, and how those affect the phase abundance of the particles.

The dichotomy of contrastive and allophonic phonological relationships has a long-standing tradition in phonology, but there is a growing body of research (see Hall, 2013, for a review) that points to phonological relationships that fall between contrastive and allophonic. The criteria most commonly used to define phonological relationships or resolve cases of ambiguous phonological relationships – namely (a) predictability of distribution, and (b) lexical distinction – are not always able to account for observed sound patterns. The main goal of this dissertation is to identify and apply quantitative measures (relative frequency and minimal pair counts) to the traditional criteria in order to better account for cases of intermediate phonological relationships or, in other words, to account for different strengths and degrees of contrast. Twenty native speakers of Laurentian French (LF) participated in Experiment 1, an AX discrimination task, and Experiment 2, a four-interval AX (4IAX) task, which tested the broader relationships of allophony and contrast. It was hypothesized, based on previous experiments (Boomershine et al., 2008; Dupoux et al., 1997; Ettlinger & Johnson, 2009; Johnson & Babel, 2010; Kazanina et al., 2006; Peperkamp et al., 2003; Pruitt et al., 2006), that phones in an allophonic relationship would be more difficult to perceive than phones in a contrastive relationship. Results confirmed previous findings, with longer reaction times for allophonic pairs as compared to contrastive pairs in the AX task (p<.001), as well as in the 4IAX task (p = .004). For Experiments 3, 4 and 5, thirty native speakers of LF participated in an AX, a 4IAX and a similarity rating task. Measures of functional load, frequency and acoustic similarity were applied to pairs of phones in allophonic and phonemic relationships in order to quantify the degree of contrast between pairs. If a gradient view of contrast was supported, it was hypothesized that High Contrast vowels [a-ɔ] would yield higher accuracy, faster reaction times and lower similarity ratings; Low Contrast vowels [y-ʏ] would yield lower accuracy, slower reaction times and higher similarity ratings; and Mid Contrast vowels [o-ʊ] would yield results that fell between the two extremes. If, on the other hand, a strict binary interpretation of contrast was supported, High Contrast vowels and Mid Contrast vowels should yield similar results since these vowels are considered to be in a phonemic relationship, with higher accuracy, faster reaction times and lower similarity ratings, while Low Contrast vowels [y-ʏ], in an allophonic relationship, should yield lower accuracy, slower reaction times and higher similarity ratings. The results from Experiments 3 (AX) and 4 (4IAX) show that the High Contrast pairs yielded significantly higher accuracy scores and faster reaction times than both Mid and Low Contrast pairs (Experiment 3: p<.001 for both High vs. Mid and High vs. Low comparisons; Experiment 4: p = .039 for High vs. Mid, p = .055 for High vs. Low comparisons). However, no significant differences were found between Mid and Low Contrast pairs in these two experiments. The results from Experiment 5 matched gradient predictions, showing significant differences between High, Mid and Low conditions, with similarity being judged highest for Low pairs, lowest for High pairs, and ratings for Mid pairs falling exactly between the other two levels (p<.001 for all comparisons). While results do not perfectly match gradient predictions, the findings provide evidence counter to a strict binary interpretation of contrast since traditionally phonemic pairs (High [a-ɔ] and Mid [o-ʊ]) were significantly different from one another in all experiments. The lack of difference between Mid and Low Contrast pairs could be due to the measures of functional load and frequency for Mid pairs being closer to those of Low pairs, and thus did not reflect a level of contrast that was equidistant between High and Low Contrast. Nevertheless, taken together with the results from Experiment 5, the results appear to support a gradient view of phonological relationships rather than a strictly dichotomous view. Quantitative measures therefore show promise in accounting for cases of intermediate phonological relationships.

La structure et la dynamique des molécules d'eau confinées dans des aluminosilicates de formes tubulaire (imogolite) et sphérique (allophane) ont été étudiées à l'échelle microscopique par la méthode de la dynamique moléculaire. Pour ce faire, des modèles structuraux de ces aluminosilicates ainsi que des modèles d'interactions ont été développés. La simulation de la dynamique vibrationnelle de l'imogolite fournit des résultats en accord avec ceux expérimentaux. Ainsi, certaines bandes des spectres infrarouge et Raman ont pu être attribuées. Les spectres Raman calculés pour ces structures montrent une bande située aux basses fréquences dont la position varie en fonction du diamètre du nanotube. Cette bande est attribuée à la vibration de respiration radiale de la structure. Les résultats des simulations sur les systèmes eau/imogolite montrent des caractères hydrophile et hydrophobe respectivement pour les surfaces interne et externe de l'imogolite. Par conséquent, les molécules d'eau proches de ces surfaces ont des comportements différents. Alors que les molécules d'eau entre les nanotubes se comportent de façon similaire aux molécules d'eau dans l'eau liquide, les caractéristiques structurales et dynamiques des molécules à l'intérieur de l'imogolite sont fortement influencées par la surface Bien que la composition chimique de la surface interne de l'imogolite et de l'allophane soit similaire, une plus grande mobilité des molécules d'eau est constatée dans le cas de la structure sphérique traduisant des interactions eau/surface plus faibles que pour le système eau/imogolite

Les Imogolites (OH)3Al2O3Si(OH) sont des minéraux naturels découverts en 1962 dans des sols volcaniques japonais qui présentent une structure analogue à celle des nanotubes de carbone. Leur synthèse, décrite depuis 1977, permet l'obtention de tubes bien calibrés et monodisperses. La récente mise en évidence de la possibilité de synthétiser des analogues au germanium en grande quantité en a fait un matériau de choix dans le cadre de mon sujet de thèse visant à préparer des matériaux mésoporeux à base de nanoparticules anisotropes. Lors de la caractérisation de ces imogolites par diffusion de rayons X aux petits angles (SAXS) et microscopie électronique en transmission (MET) et à force atomique (AFM), nous avons montré que ces analogues d'Imogolite sont bien des nanotubes, mais qu'ils existent sous deux formes : des tubes à paroi unique mais également des tubes à paroi double jamais observés à ce jour. La concentration importante utilisée pour cette synthèse a également permis de mieux définir l'espèce précurseur de ces nanotubes appelée proto-imogolite et mal connue jusqu'ici. Après une identification du paramètre déterminant la formation de l'une ou l'autre des structures, nous avons étudié en détail le mécanisme et la cinétique de croissance de ces imogolites. Enfin, des premiers tests sur l'organisation de ces nanotubes en forte concentration ou au sein de microgouttes permettent d'observer leur tendance à s'organiser, propriété prometteuse pour le développement futur d'applications.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-08-04T20:54:32Z No. of bitstreams: 2 Dissertação - Isadora Massad Giani Pinheiro - 2016.pdf: 2015934 bytes, checksum: d6e918e92682e48b46f6170a6b396b1d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-05T12:17:08Z (GMT) No. of bitstreams: 2 Dissertação - Isadora Massad Giani Pinheiro - 2016.pdf: 2015934 bytes, checksum: d6e918e92682e48b46f6170a6b396b1d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Made available in DSpace on 2016-08-05T12:17:08Z (GMT). No. of bitstreams: 2 Dissertação - Isadora Massad Giani Pinheiro - 2016.pdf: 2015934 bytes, checksum: d6e918e92682e48b46f6170a6b396b1d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-09-29<br>Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq<br>This work presents the description of some phonological aspects in the southern region of Goiás State, in the cities of Orizona, Pires do Rio, Ipameri, Catalão, Três Ranchos, Corumbaíba, Buriti Alegre, Caldas Novas, Mineiros, Rio Verde, Jataí, Itumbiara, Cachoeira Dourada, Quirinópolis, São Simão, Edéia, Paraúna and Vianópolis. The analysis resulted from the answers given in the ALINGO (Linguistic Atlas of Goiás). For pedagogical reasons, these aspects were separated regarding the vowels, the syllables and the consonants. The observations performed about the vowels were related to the phonological possibilities for the phoneme /o/ in pretonic position, which analyzed the different productions of words like “armpit” (sovaco), “ankle” (tornozelo), “sob” (soluço) and “dew” (orvalho). The issue concerning the syllables approaches the nasalization and the oralization of the syllable “-gem” in the end of the words. In this analysis, it was used the realization of “rain drought” (estiagem), “swill” (lavagem) and “pod” (vagem). The chapter about the consonants addressed the oscillation between the employment of /g/ and /k/ in the word “corncob” (sabugo) in the south of Goiás speech. As theoretical fundamentals of the hypothesis worked in each phenomenon, it were used, mainly, the Historical Grammar and the Descriptive Linguistics. To introduce these descriptive chapters presented and explained the concepts of vowel sounds, syllable and consonantal sounds in order to facilitate the comprehension of occurred phenomena. Before the descriptive analysis, in the first chapter, there is a historical background of studies related to the sounds, which presents the development of the main theories in this scope, including the ones used as theoretical basis.<br>Este trabalho apresenta a descrição de alguns aspectos fonológicos na região sul do estado de Goiás, nas cidade de Orizona, Pires do Rio, Ipameri, Catalão, Três Ranchos, Corumbaíba, Buriti Alegre, Caldas Novas, Mineiros, Rio Verde, Jataí, Itumbiara, Cachoeira Dourada, Quirinópolis, São Simão, Edéia, Paraúna e Vianópolis. As análises partiram de respostas dadas ao questionário do ALINGO – Atlas linguístico de Goiás. Por questões didáticas esses aspectos foram separados quanto às vogais, às sílabas e às consoantes. As observações realizadas sobre as vogais se relacionaram às possibilidades fonológicas para o fonema /o/ em posição pré-tônica, que analisou as diferentes produções das palavras “sovaco”, “tornozelo”, “soluço” e “orvalho”. A questão referente às sílabas aborda a nasalização e a oralização da sílaba “-gem” em final de palavras. Para essa análise foram utilizadas as realizações de “estiagem”, “lavagem” e “vagem” O capítulo a respeito das consoantes tratou da oscilação entre o emprego de /g/ e /k/ na palavra “sabugo” no falar do sul de Goiás. Como fundamentação teórica das hipóteses trabalhadas em cada um dos fenômenos utilizaram-se, principalmente, aspectos da Gramática Histórica e da Linguística descritiva. Para introduzir esses capítulos descritivos, foram apresentados e explanados os conceitos dos sons vocálicos, das sílabas e dos sons consonantais, a fim de facilitar a compreensão dos fenômenos ocorridos. Antes das análises descritivas, no primeiro capítulo, há um percurso histórico dos estudos referentes aos sons, que apresenta o desenvolvimento das principais teorias desse âmbito, inclusive das que foram utilizadas como aporte teórico.

Cette thèse s'intéresse à l'imitation dans la parole, c'est à dire à la tendance pour un locuteur de parler de façon plus similaire à son interlocuteur. Beaucoup d'entre nous font l'expérience de ce phénomène lorsque que nous conversons avec une personne qui possède un accent différent. Certaines caractéristiques de notre propre parole peuvent changer, pour se rapprocher de celle de notre interlocuteur. L'imitation dans la parole a fait l'objet de récentes études. Notre contribution à ce type de recherches est d'étudier l'imitation au niveau allophonique, c'est à dire au niveau des réalisations phonétiques possibles d'un phonème. Nous voulons savoir si l'imitation d'un son phonétique pour un phonème donné, dans une position de mot donnée, peut influencer les autres réalisations de ce phonème, dans la même position de mot. Nous voulons également savoir si l'imitation d'un son phonétique pour un phonème donné, dans une position de mot donnée, peut influencer la réalisation d'autres allophones de ce phonème, dans une position de mot différente<br>This dissertation investigates imitation in speech, which is the general tendency shown by a speaker to become more similar to another speaker in the way they speak. Many of us have experienced this while talking to someone who is speaking the same language but with a different accent. Conversing with such a person can affect some characteristics of our speech, so that we come to sound more like them. Imitation in speech has been very extensively studied, especially over recent years. To contribute to this line of research we provide an account of imitation in speech at the allophonic level, that is at the level of the possible phonetic realisations of a phoneme. We are interested in whether imitation of the sound of a given phoneme in a particular word position can influence the other possible realisations of that phoneme in the same word position. We are also interested in determining whether imitation of a speech sound in a particular word position for a given phoneme can affect the realisations of that phoneme in a different word position

La structure et la dynamique des molécules d'eau confinées dans des aluminosilicates de formes tubulaire (imogolite) et sphérique (allophane) ont été étudiées à l'échelle microscopique par la méthode de la dynamique moléculaire. Pour ce faire, des modèles structuraux de ces aluminosilicates ainsi que des modèles d'interactions ont été développés. La simulation de la dynamique vibrationnelle de l'imogolite fournit des résultats en accord avec ceux expérimentaux. Ainsi, certaines bandes des spectres infrarouge et Raman ont pu être attribuées. Les spectres Raman calculés pour ces structures montrent une bande située aux basses fréquences dont la position varie en fonction du diamètre du nanotube. Cette bande est attribuée à la vibration de respiration radiale de la structure. Les résultats des simulations sur les systèmes eau/imogolite montrent des caractères hydrophile et hydrophobe respectivement pour les surfaces interne et externe de l'imogolite. Par conséquent, les molécules d'eau proches de ces surfaces ont des comportements différents. Alors que les molécules d'eau entre les nanotubes se comportent de façon similaire aux molécules d'eau dans l'eau liquide, les caractéristiques structurales et dynamiques des molécules à l'intérieur de l'imogolite sont fortement influencées par la surface. Bien que la composition chimique de la surface interne de l'imogolite et de l'allophane soit similaire, une plus grande mobilité des molécules d'eau est constatée dans le cas de la structure sphérique traduisant des interactions eau/surface plus faibles que pour le système eau/imogolite.

Cette étude vise à déterminer le transfert et la mobilité d'éléments traces métalliques (ETM), dans des sols de la Réunion destinés à l'épandage de déchets urbains. En plus des fortes teneurs naturelles en ETM, ces sols ont la particularité d'avoir une minéralogie très spécifique avec la présence en abondance de nanoparticules naturelles, communément appelés "imogolites" (nanotubes) et "allophanes" (nanosphères, ovoïdes, amorphe ?). Ces aluminosilicates structurés à courte distance sont susceptibles de piéger les ETM pouvant ainsi limiter leur mobilité et leur biodisponibilité. <br /><br />Dans un premier temps, une étude sur des composés synthétiques analogues aux aluminosilicates a permis d'approfondir nos connaissances sur la structure et les mécanismes de formation des imogolites et allophanes. La synthèse de nanotubes de type imogolite (Si-imogolite et Ge-imogolite) a pu être optimisée ouvrant ainsi les portes à de potentielles applications industrielles. Enfin, notre étude a permis de mettre en avant le rôle important des nanoparticules naturelles sur la dynamique du Ni dans un andosol de la Réunion. Ainsi, près de 80% du Ni est lié aux aluminosilicates structurés à courte distance.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008.<br>Source: Dissertation Abstracts International, Volume: 69-11, Section: A, page: 4310. Adviser: Jose Ignacio Hualde. Includes bibliographical references (leaves 149-153) Available on microfilm from Pro Quest Information and Learning.

abstract: Chemical and mineralogical data from Mars shows that the surface has been chemically weathered on local to regional scales. Chemical trends and the types of chemical weathering products present on the surface and their abundances can elucidate information about past aqueous processes. Thermal-infrared (TIR) data and their respective models are essential for interpreting Martian mineralogy and geologic history. However, previous studies have shown that chemical weathering and the precipitation of fine-grained secondary silicates can adversely affect the accuracy of TIR spectral models. Furthermore, spectral libraries used to identify minerals on the Martian surface lack some important weathering products, including poorly-crystalline aluminosilicates like allophane, thus eliminating their identification in TIR spectral models. It is essential to accurately interpret TIR spectral data from chemically weathered surfaces to understand the evolution of aqueous processes on Mars. Laboratory experiments were performed to improve interpretations of TIR data from weathered surfaces. To test the accuracy of deriving chemistry of weathered rocks from TIR spectroscopy, chemistry was derived from TIR models of weathered basalts from Baynton, Australia and compared to actual weathering rind chemistry. To determine how specific secondary silicates affect the TIR spectroscopy of weathered basalts, mixtures of basaltic minerals and small amounts of secondary silicates were modeled. Poorly-crystalline aluminosilicates were synthesized and their TIR spectra were added to spectral libraries. Regional Thermal Emission Spectrometer (TES) data were modeled using libraries containing these poorly-crystalline aluminosilicates to test for their presence on the Mars. Chemistry derived from models of weathered Baynton basalts is not accurate, but broad chemical weathering trends can be interpreted from the data. TIR models of mineral mixtures show that small amounts of crystalline and amorphous silicate weathering products (2.5-5 wt.%) can be detected in TIR models and can adversely affect modeled plagioclase abundances. Poorly-crystalline aluminosilicates are identified in Northern Acidalia, Solis Planum, and Meridiani. Previous studies have suggested that acid sulfate weathering was the dominant surface alteration process for the past 3.5 billion years; however, the identification of allophane indicates that alteration at near-neutral pH occurred on regional scales and that acid sulfate weathering is not the only weathering process on Mars.<br>Dissertation/Thesis<br>Ph.D. Geological Sciences 2011

Chaque année, un nombre considérable d’élèves récemment immigrés intègrent les écoles du Québec. Pour ces jeunes, les risques de faire face à des difficultés socioscolaires sont potentiellement élevés, en particulier chez ceux pour qui des facteurs tels que l’allophonie et la défavorisation s’additionnent. De nombreuses recherches soulignent la réussite de l’adaptation socioscolaire de plusieurs de ces élèves, mais il demeure que d’autres jeunes éprouvent des difficultés et il est capital de chercher à mieux comprendre comment les accompagner à travers ce processus. L’objectif général de cette recherche est de décrire le phénomène de la résilience scolaire chez des jeunes allophones du primaire récemment immigrés dans le but de savoir comment mieux soutenir leur intégration sociale ainsi que leur réussite scolaire. Le concept de la résilience a été employé comme cadre théorique afin de capter le caractère systémique de l’intégration socioscolaire de ces élèves immigrants qui, à leur arrivée, ne maîtrisent pas le français. Les résultats de l’analyse de nos données révèlent que les caractéristiques qui ont soutenu l’adaptation socioscolaire des jeunes que nous avons rencontrés appartiennent à quatre catégories : l’élève (motivation scolaire et importance accordée aux études en général, volonté d’apprentissage du français), son environnement familial (intérêt porté par les parents à l’éducation de l’enfant, discours positif du parent quant à l’éducation), son environnement extra-familial (lieux de culte et espaces d’épanouissement socioculturel pour le jeune, organismes communautaires, adultes significatifs qui peuvent soutenir la résilience du jeune) et son vécu scolaire (enseignants engagés, disponibles, qui inspirent confiance et qui sont outillés, climat psychosocial positif en classe et à l’école).<br>Every year a considerable number of recently immigrated students attend the schools of Quebec. For these students, the risk of facing socio-educational difficulties is potentially high, particularly for those who are allophones and living in deprivation. Several studies highlight success of socio-educational adaptation of numerous students, but it still remains that others have difficulties and it is capital to look into better understanding how to best support them through this journey. The general objective of this research is to describe the phenomenon of educational resilience in young allophones in elementary schools who have recently immigrated in order to know how to better foster and support their social integration and educational success. The concept of resilience was used as the theoretical framework in order to capture the systemic character of socio-educational integration of these immigrant students, who at their arrival do not master the French language. The results of the data analysis show that the characteristics that have supported the socio-educational adaptation of the students we have met with, can be organized in four categories: the student (educational motivation and the importance placed on education in general, the will to learn French), his/her family environment (parents’ interest in the child’s education, parents’ positive discourse in regards to education), his/her environment outside the family (places of worship and spaces for socio-cultural development, community organisations, significant adults who can support the child’s resilience) and his/her school experience (involved and available teachers, who inspire trust and are appropriately equipped, positive psychosocial climate in class and in school).