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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

「意」的多義現象研究:以語料庫為本 / A Corpus-based Semantic Analysis of Mandarin Polysemy /Yi4/

莊舜雯, Chuang, Shun Wen Unknown Date (has links)
本研究以「意」的雙字詞彙為主要研究範圍,由詞彙內部結構及上下文切入以釐清「意」的多義現象。前人關於「意」的多義現象討論不多,僅有歷時的探源研究、與內在身體部位「心」的比較以及心理學認識活動的相關論述,至今尚未有關於「意」之共時性語料庫研究。於彙整《中文詞彙網路2.0》與《教育部重編國語辭典修訂本》中「意」的義項,並清楚制定「認知」、「情感」、「意志」三個語意類別後,本研究分析了《中央研究院現代漢語平衡語料庫4.0》一千萬詞條版本中的相關語料。研究結果包含了兩個面向的討論:「意」的詞彙內部結構和語意分佈之間的關係以及「意」的意象圖式。 首先,研究發現「意」在構詞上屬於名詞性黏著詞根詞素,可同時作為詞在句子中自由移動的情形不多;「意」在語意上則屬於「心理集合名詞」,而心理集合名詞為一多義詞素,詞彙語意的完整有賴其共現成分。其次,「*意」結構的詞類包含了名詞、狀態動詞、動作動詞、副詞四種詞類,而「意*」結構僅包含名詞、狀態動詞、動作動詞三種。其中,「*意」的構詞能力較「意*」強,語意分佈上則皆以「意志」類為主。 最後,從雙音詞的上下文中發掘了「意」的三條刺激反應路徑,統整出「意」的意象圖式,得知「意」的雙字詞多用於「報導」方面。若刺激類別為「文章/話語」或「外在景色」通常由「當局經驗者」報導概念內涵或刺激為其帶來之感覺,若刺激類別為「人際客體」則通常由「旁觀經驗者」報導當局經驗者理解概念之過程、心理狀態或意志狀態。華語教師在講解「意」之詞彙時,可透過解釋其共現成分之詞意為學生建立語意類別的概念,亦可運用刺激類別及報導的方式讓學生知道「意」的雙音詞使用上的差別。 關鍵字: 「意」、多義名詞、詞彙內部結構、意象圖式、中研院現代漢語平衡語料庫 / Key word: Yi4,polysemy, word component structure, image schema, Mandarin Corpus This thesis reports the polysemous usage of the disyllabic words containing Yi4 ‘meaning’ with the emphasis on their internal structure and co-text. Previous studies on Mandarin polysemy Yi4 mostly focused on the classic manuscripts, the comparison between Xin1 ‘heart’ and Yi4 ‘meaning’, or the philosophical system of knowing. However, none of them was based on real texts from the corpus. Based on the senses taken from the Chinese Wordnet 2.0 and the Revised Mandarin Chinese Dictionary, we categorized the usage of Yi4 as FEELING, COGNITION and INTENTION. Using these as the criteria, we analyzed the data from the Sinica Corpus 4.0. The results were discussed based on two aspects, the interrelationship between the internal structures and meaning distribution, and the image schema of Yi4. For the internal structures, we discovered that Yi4 serves not only as a bound-root morpheme at the syntactical level but also as a semantically polysemous psycho-collection morpheme which needs the co-occurred morpheme to fulfill its word meaning. We also found that most instances in both ‘X+Yi4’ and ‘Yi4+X’ structures belong to INTENTION, and these include nouns, action verbs, and stative verbs. However, only the ‘X+Yi4’ structure, with its stronger word-forming ability, contains adverbial use. In addition to internal structures, for the analysis of co-texts, we came up with the image schema of Yi4 which contains three stimulus-response routes. If the stimulus is article/speech/scenery, Yi4 tends to have a direct experiencer conducting a first-hand report about his/her feeling. If the stimulus comes from a human body, Yi4 prefers having an indirect experiencer conducting a second-hand report about the direct experiencer’s emotion, cognitive process or willing. Finally, this thesis also offers some pedagogical suggestions and application based on the findings.
352

[en] LET S TALK ABOUT IT LATER…: REFUSAL STRATEGIES IN THE BRAZILIAN PORTUGUESE AND IN MANDARIN CHINESE WITH APLICABILITY IN PORTUGUESE FOR SPEAKERS OF MANDARIN / [pt] OUTRA HORA A GENTE FALA SOBRE ISSO...: ESTRATÉGIAS DE RECUSA NO PORTUGUÊS BRASILEIRO E NO MANDARIM CHINÊS COM APLICABILIDADE EM PORTUGUÊS PARA FALANTES DE MANDARIM

GUO TIANWEI 27 April 2018 (has links)
[pt] O presente trabalho estuda, à luz do conceito de interculturalismo, da sociologia linguística interacional, bem como das filosofias confucianas, como é realizado o ato de fala de recusa no português do Brasil e no mandarim da China Continental. De modo geral, o ato de recusa pode representar descortesia e falta de interesse do falante; pode ainda causar desentendimento entre os interlocutores, sobretudo quando são de países de culturas diferentes. Entretanto, tanto no português quanto no mandarim, existem vários fatores e estratégias envolvidas na enunciação de tal ato, além de semelhanças e diferenças presentes nesses recursos. O corpus utilizado nesta pesquisa é construído pelas cenas selecionadas de dois programas televisivos: A Grande Família (2001-2011, Rio de Janeiro/Brasil) e Mamãe Tigre Papai Gato (2015, Beijing/China). Através desses dados, apresentamos as principais estratégias de recusa presentes nas duas línguas, bem como os fatores interculturais que interferem na escolha de tais estratégias. / [en] The purpose of this research is to investigate how the speech act of refusing is realized in Brazilian Portuguese and in Mandarin of Mainland China from the perspectives of the concept of interculturalism, linguistic sociology and some Confucian thoughts. In general, refusals present discourtesy and lack of interest on the part of the speaker; this speech act can even cause misunderstandings between people, especially when they come from different culture origins. Nevertheless, several factors and strategies can be identified in refusal speech act in both Portuguese and Mandarin, besides some similarities and differences, which can be verified in those strategies. The corpus used in this study is formed of analysis of scenes collected from two television programs: The Big Family/A Grande Família (2001-2011, Rio de Janeiro/Brazil) and Tiger Mother Cat Father(2015, Beijing/China). By observing these data, we present the main strategies of refusing identified in the two languages, as well as the intercultural factors which interfere in the selection of these strategies.
353

Communicating about stress : modulation of vocalisations in the zebra finch / Communiquer son stress : modulation des vocalisations chez le diamant mandarin

Perez, Emilie 17 December 2013 (has links)
Chez les espèces sociales, les vocalisations transmettent des informations qui participent au maintien et à la survie du groupe. Alors que de nombreuses études se sont intéressées aux informations stables portées par les vocalisations telles que l’identité, peu d’études se sont interrogées sur le rôle des signaux vocaux dans la transmission des informations plus labiles, telles que l’état émotionnel de l’émetteur. Le stress est un bon candidat pour l’étude de l’expression des émotions chez les animaux, puisqu’il est directement mesurable via un dosage de la concentration plasmatique en glucocorticoïdes. Le stress est connu pour modifier les paramètres acoustiques des vocalisations chez les mammifères, mais peu d’études ont traité ce processus chez les oiseaux, qui présentent pourtant des réseaux sociaux complexes. Le but de cette thèse est de déterminer de quelle manière les oiseaux expriment vocalement leur stress, et d’évaluer dans quelle mesure la corticostérone, hormone de stress principale chez l’oiseau, est impliquée dans le phénomène. Je me suis intéressée au Diamant mandarin (Taenopygia guttata), un oiseau chanteur australien au comportement grégaire qui forme des liens d’appariements à vie et prodigue des soins biparentaux à sa progéniture. En administrant de la corticostérone exogène à des oiseaux et en utilisant également des évènements sociaux stressants, nous montrons que les mâles adultes et les poussins expriment leur stress à travers l’émission de cris modifiés dans leur structure, ce qui suggère que la flexibilité des cris chez les oiseaux est plus importante que l’avaient montré des études précédentes. Par une analyse complète des paramètres temporels et spectraux des cris, nous montrons pour la première fois que le stress, par un effet direct de la corticostérone, déclenche l’émission de vocalisations présentant un spectre de fréquence déplacé vers les hautes fréquences. De plus, les receveurs du signal (respectivement les partenaires femelles et les parents) semblent capables de décoder l’information portée par ces cris de stress car ils modifient leur comportement en conséquence. Les processus physiques impliqués dans l’émission de cris modulés par le stress sont également discutés en appliquant la théorie « source-filtre » généralement utilisée chez les mammifères. Enfin, les valeurs adaptatives de ces cris sont également envisagées, en rapport avec le réseau social du Diamant mandarin et les risques de prédation encourus par l’émetteur du signal. Ce travail apporte de nouvelles preuves sur l’expression du stress chez les oiseaux, et propose une étude complète, des signaux physiologiques impliqués dans le stress aux modifications de comportement de l’émetteur, qui déclenchent une réponse adaptative des receveurs du signal / In social species, vocalisations convey information that participates in the maintenance and the survival of the group. While many studies were interested in stable information carried by vocal signals, like identity, fewer studies dealt with their potential role in informing about labile information such as the senders’ emotional state. Stress is a good candidate for the study of the expression of emotions in animals, as it is directly measurable by the plasma levels of glucocorticoïds. Stress is known to modify acoustic parameters of vocalisations in mammals, but few studies studied the process in birds, that also show complex social networks. The aim of this thesis is thus to determine how birds can vocally express their stress and to what extent corticosterone, the main stress hormone in birds, is implicated in this expression. I focused my research on the zebra finch (Taenopygia guttata), a gregarious Australian songbird that form lifelong pairbond and provides biparental care to its young. Using oral administration of exogenous corticosterone but also social stressful events, we show that both adult males and nestlings can express their stress through modulations of their calls’ structure, suggesting that flexibility in birds’ vocalisations is higher than previously expected. With a complete analysis of temporal and spectral parameters of calls, we show for the first time that stress evokes the emission of vocalisations with up-shifted frequency spectrum via a direct effect of corticosterone. Moreover, we show that females and parents are able to decode the information carried by stressed-induced calls of respectively their male partner and their young, as they exhibit modifications of behaviour in accordance with the context. The physical processes leading to the emission of stressed-induced vocalisations are discussed by applying the source-filter theory usually used in mammals. Adaptive values are also proposed, in regards with the zebra finch social network and predation risks for the caller. This work gives new evidences about the expression of stress in birds, and proposes a comprehensive study, from the physiological signals involved in stress to the resulting modifications of communication behaviour for the sender, that leads to an adaptive response from the receivers
354

Rôle de la sélection intersexuelle dans l’évolution de la cognition mâle et femelle : approche observationnelle et théorique

Barou-Dagues, Marie 08 1900 (has links)
Choisir un partenaire sexuel est une décision importante pour un animal. Parce que cette décision va considérablement affecter son succès reproducteur, l’individu doit se baser sur un ensemble de traits qui reflètent la qualité du partenaire. Depuis peu, une attention particulière est portée sur l’importance de la cognition dans le contexte de choix de partenaire. En effet, la capacité à percevoir, intégrer, mémoriser et utiliser l’information disponible dans l’environnement permet aux individus de répondre de manière appropriée aux problèmes qu’ils rencontrent et d’ajuster leur comportement en conséquent. Si les femelles retirent un bénéfice à s’apparier avec des mâles capables de répondre aux changements de leur environnement, ces derniers pourraient avoir un accès privilégié à l’appariement lors du choix de partenaire des femelles. Certaines évidences appuient cette idée en démontrant notamment des relations positives entre les capacités cognitives des mâles et leur succès d’appariement et reproducteur et en révélant des préférences sexuelles femelles pour des traits cognitifs mâles. Cependant, ces résultats restent très contrastés, particulièrement chez les animaux non humains où l’importance du choix de partenaire dans l’évolution de la cognition n’est pas encore clairement définie. L’objectif de ma thèse était donc d’explorer le rôle du choix de partenaire dans l’évolution de la cognition mâle et femelle en combinant l’approche observationnelle sur une espèce d’oiseaux monogame et l’approche théorique en utilisant un modèle à base d’agents. Plus précisément, en réalisant des expériences en laboratoire sur le Diamant mandarin (Taeniopygia guttata), j’ai notamment testé si les femelles démontrent une préférence pour des mâles capables d’ajuster leur comportement d’approvisionnement en réponse à un changement environnemental. J’ai ensuite examiné, dépendamment de leurs propres capacités cognitives, si les femelles expriment des préférences pour des mâles performants dans quatre tests psychométriques différents. J’ai finalement exploré les rôles respectifs de la sélection naturelle et intersexuelle en simulant l’évolution de la cognition sous différents scénarios environnementaux. Les résultats de cette thèse ont révélé que les femelles diamants mandarin exprimaient une préférence pour les mâles capables d’ajuster leur comportement d’approvisionnement ainsi que les mâles performants dans certaines tâches cognitives. Cependant, ces préférences n’étaient pas unanimes et dépendaient des propres capacités cognitives des femelles à performer dans ces différentes situations. À l’échelle évolutive, la sélection intersexuelle à travers le choix de partenaire modifiait les patrons d’évolution de la cognition prédits lorsque la sélection naturelle opérait seule. En effet, elle favorisait l’évolution de bonnes capacités cognitives lorsque les contraintes environnementales étaient faibles, mais maintenait de la diversité cognitive lorsque ces contraintes étaient élevées. Dans l’ensemble, ces résultats suggèrent que le choix de partenaire jouerait un rôle important dans l’évolution et le maintien de diversité cognitive au sein des populations. Néanmoins, les conséquences évolutives du choix de partenaire sur les capacités cognitives des individus dépendraient de l’avantage adaptatif à s’apparier avec un mâle plus performant, c’est-à-dire de la capacité cognitive mâle considérée, des caractéristiques des femelles et de l’environnement dans lequel ce choix est fait. / Choosing a mate is an important decision for an animal. Because this decision significantly affects an individual’s reproductive success, it must base its choice according to different traits that reflect the quality of potential mates. Recently, a particular attention has been given to cognitive traits in mate choice context. Indeed, the ability to perceive, integrate, memorize and use the information available in the environment allows individuals to act properly when facing a problem and to adjust their behaviours accordingly. Given that females could benefit from choosing males capable of responding to environmental changes, those with good cognitive abilities should have privileged access to females in mate choice contexts. Some evidence supports this idea by revealing positive relationships between males’ cognitive abilities and their mating and reproductive success as well as female mating preference for male cognitive abilities. However, these results stay contrasted, particularly in non-human animals for which the importance of mate choice in the evolution of cognition is still not clearly defined. The objective of my PhD was to explore the role of mate choice in the evolution of male and female cognition by combining an observational approach using a monogamous bird species and a theoretical approach using an agent-based model. Specifically, by running laboratory experiments on zebra finches (Taeniopygia guttata), I tested whether females demonstrated a mate preference for males able to adjust their foraging behaviour following an environmental change. Then, I investigated whether females, depending on their own cognitive abilities, demonstrated a mate preference for better performers in four different psychometric tests. I finally explored the relative role of natural and sexual selection by simulating the evolution of cognition under different environmental scenarios. The results of this PhD project revealed that zebra finch females preferred males exhibiting greater behavioural plasticity in their foraging tactic use as well as males performing better in several cognitive tasks. However, females’ preference for cognitive abilities was not unanimous but depended on females’ own abilities to perform in these tasks. At the evolutionary scale, intersexual selection through mate choice changed the evolutive patterns observed under natural selection alone. In fact, intersexual selection promoted good cognitive abilities under most favourable environments but maintained cognitive diversity under the harsher ones. Taken together, these results suggest that mate choice plays an important role in the evolution and maintenance of cognitive diversity within populations. Nevertheless, the evolutive consequences of mate choice on individual cognitive abilities should depend on i) the adaptive value of mating with a male with better performance, and thus, on the cognitive ability considered, ii) the female characteristics and iii) the local environment during mate choice.
355

Between Verb and Preposition: Diachronic Stages of Coverbs in Mandarin Chinese

Jones, Glynis 03 April 2023 (has links)
Mandarin Chinese has long been known to possess a category of words known as ‘coverbs’ in the literature, which sit in the gray area between verb and preposition. Li and Thompson (1974) describe the historical origins of Mandarin coverbs to be full transitive verbs, despite their modern state being decidedly less verbal. They also note that coverbs are a non-homogenous class. This thesis works to establish categories of coverbs in Mandarin Chinese and their distance from true verbhood in order to understand the diachronic shift that coverbs are currently undergoing before our very eyes. I will draw on the work of scholars of Atlantic-Congo languages, Oceanic languages, and other languages of mainland Southeast Asia, to create semantic, syntactic, and morphological testing for Mandarin coverbs. Using the results of this three-pronged testing approach, I will map the results on a six-pointed verb-preposition matrix in order to visualize the space between verb and preposition and how Mandarin coverbs inhabit it. I will then use these diagrams to create a numerical score for each category of coverb and place them on a linear progression between verbhood and prepositionhood. Lastly, this work will analyze the theta roles assigned by Mandarin coverbs in each category and propose stages of diachronic development for Mandarin coverbs.
356

Cantonese in a Mandarin China : Language ideology and nationalism in China’s language policy

Norderstål, Victor January 2023 (has links)
This thesis aims to explain the ideological characteristics of China’s language laws. Using theoretical definitions of language ideology, the study analysed two language provisions, China’s national language law and the language law of Guangdong province, with the goal of understanding the ideology of China’s language policy. The strong status of Cantonese and its role as a marker of identity in Guangdong can be seen as standing in contrast to the overall language goals of the state, as part of a possible struggle between localism and nationalism. The analysis found that both regulations contain articles that are indicative of nationalist language ideology, although differences between the regulations and the different forms of ideologies exist.
357

Mutation Rate and Gene Expression in Genetic Admixtures of Domesticated Citrus

Pérez Román, Estela 23 January 2023 (has links)
Tesis por compendio / [ES] La domesticación de los cítricos es un proceso en gran parte desconocido. Las investigaciones llevadas a cabo hasta la fecha indican que las variedades de cítricos que se comercializan en la actualidad son, en general, el producto de introgresiones ancestrales intraespecíficas e interespecíficas. Las introgresiones de tipo intraespecífico tuvieron lugar entre las poblaciones de dos subespecies antiguas de mandarinas y aportaron el comportamiento apomíctico que la mayoría de las mandarinas actuales y otros cítricos relacionados conservan todavía hoy. Una vez dichas mezclas genéticas o admixtures quedaron establecidas, otras introgresiones interespecíficas de pummelo establecieron nuevas características en el genoma de mandarina. Durante el proceso de domesticación, la variabilidad genética de estos cítricos se adquirió fundamentalmente a través de mutación espontánea, y mediante la práctica del injerto los genotipos carentes de semillas se extendieron rápidamente, acentuándose el papel de las mutaciones en la selección de cítricos como las naranjas y las mandarinas modernas. En este trabajo, mostramos que las mutaciones somáticas en cítricos se propagan siguiendo un patrón iterativo determinado por un modelo de ramificación simpodial y, en consecuencia, se agrupan en sectores a lo largo del árbol, donde algunas mutaciones quedan permanentemente fijadas. En este escenario, un árbol puede considerarse un mosaico genéticamente compuesto de diferentes genomas, en el que las ramas más jóvenes acumulan un número mayor de mutaciones. En promedio, nuestro árbol experimental de Clementina de 36 años muestra una tasa de mutación de 4.4 × 10-10 bp-1 yr-1, pudiendo contener en total entre 1500 y 5000 variantes y producir 1 mutación somática en cada meristemo axilar. Este número relativamente alto de mutaciones está en línea con el gran número de variedades derivadas de mutaciones espontáneas que se comercializan en cítricos. Para identificar caracteres esenciales adquiridos durante la domesticación, se han analizado los transcriptomas de la pulpa de frutos en desarrollo de la variedad silvestre e incomestible papeda de Ichang, la mandarina ácida Sun Chu Sha Kat y tres segregantes comestibles derivados de un cruce entre mandarinas comerciales. Basándonos en los resultados obtenidos, se propone que durante la transición de las papedas incomestibles a las mandarinas ácidas, la domesticación se caracterizó por una primera fase de cambios radicales en la expresión de los genes que regulan rutas fundamentales tanto del metabolismo primario como del secundario. Esta fase estuvo determinada principalmente por la estimulación de los procesos de crecimiento y la reducción de las defensas químicas, constituidas por compuestos de sabores desagradables. También se sugiere que en una segunda fase los atributos asociados a la palatabilidad de las mandarinas, especialmente la acidez, se mejoraron progresivamente a través de modificaciones específicas. Otros cambios de relevancia se relacionaron con la regulación de genes involucrados tanto en la síntesis de sustancias básicas de agradable aroma y sabor, como en la modulación de transportadores de azúcares. Por lo tanto, la transición entre las papedas incomestibles y las mandarinas de tipo ácido se caracterizó esencialmente por una drástica reprogramación de la expresión génica de rutas metabólicas fundamentales, mientras que las mandarinas modernas evolucionaron posteriormente mediante un refinamiento progresivo de las propiedades relacionadas con la palatabilidad. En su conjunto, estas observaciones sugieren que en cítricos, las tasas de mutación de los tejidos somáticos son consistentes con la idea de que las mutaciones desempeñaron un papel importante en las últimas fases de la domesticación. / [CAT] La domesticació dels cítrics és un procés en gran part desconegut. Les investigacions poratades a terme fins al moment indiquen que les varietats de cítrics comercialitzades hui en dia són, en general, el producte de introgressions ancestrals intraespecífiques i interespecífiques. Les introgressions de tipus intraespecífic van tindre lloc entre les poblacions de dues subespècies antigues de mandarina tot aportant el comportament apomíctic que la majoria de les mandarines actuals i altres cítrics relacionats encara conserven. Una vegada que aquestes barreges genètiques o admixtures es consolidaren, diferents introgressions interespecífiques de pummelo establiren noves característiques en el genoma de mandarina. Durant el procés de domesticació, la variabilitat genètica dels cítrics va ser assolida mitjançant mutació espontània i, per mitjà de la pràctica de l'empelt, genotips sense llavors es van estendre ràpidamente, accentuant el paper de les mutacions en la selecció de cítrics com les taronges i les mandarines modernes. En aquest treball, mostrem com les mutacions somàtiques en cítrics es propaguen seguint un patró iteratiu determinat per un model de ramificació simpodial i, en conseqüència, queden agrupades al llarg de l'arbre, on algunes d'aquestes mutacions romanen fixades. En aquest escenari, un arbre pot ser considerat un mosaic genèticament format per diferents genomes, en el qual les branques més joves acumulen un nombre major de mutacions. De mitjana, el nostre arbre experimental de Clementina mostra una ràtio de mutació de 4.4 × 10−10 bp−1 yr−1, arribant a incloure en total entre 1500 i 5000 variants i produint-hi 1 mutació somática en cada meristem axil·lar. Aquest nombre relativament elevat de mutacions està en línia amb el gran nombre de varietats provinents de mutacions espontànies que es comercialitzen en cítrics. Per tal d'abordar la identificació de trets essencials adquirits durant la domesticació, s'ha analitzat el transcriptoma de fruits en desenvolupament de la varietat silvestre i incomestible papeda d'Ichang, la mandarina àcida Sun Chu Sha Kat i tres segregants comestibles derivats d'un creuament entre mandarines comercials. Basant-nos en els resultats obtinguts, s'ha proposat que durant la transició de les papedes incomestibles a les mandariens àcides, la domesticació es va caracteritzar per una primera fase de canvis radicals en l'expressió dels gens que regulen rutes fonamentals del metabolisme primari i secundari. Aquesta fase va estar determinada principalment per l'estimulació dels processos de creixement i la reducció de les defenses químiques de gust desplaent. També es suggereix que en una segona fase atributs associats a la palatabilitat de les mandarines, especialment l'acidesa, van ser millorats progressivament mitjançant modificacions específiques. Altres canvis de rellevància van estar relacionats amb l'estimulació de gens involucrats tant en la síntesi de substàncies bàsiques d'agradable aroma i sabor, com en la modulació de transportadors de sucres. Per tant, la transició entre les papedes incomestibles i les mandarines àcides va estar caracteritzada essencialment per una dràstica reprogramació de l'expressió gènica de rutes metabòliques fonamentals mentre que les mandarines modernes evolucionaren posteriorment mitjançant un refinament progressiu de propietats relacionades amb la palatabilitat. En conjunt, aquestes observacions suggereixen que, en els cítrics, les ràtios de mutació dels teixits somàtics són consistents amb la idea que les mutacions tingueren un paper important en les últimes fases de la domesticació. / [EN] Citrus domestication is a largely unknown process. Research carried out to date indicates that current commercial citrus varieties are, in general, the product of ancestral intraspecific and interspecific introgressions. Intraspecific introgressions took place between the populations of two antique subspecies of mandarins and contributed to the apomictic behavior that most current mandarins and other related citrus still retain today. Once these genetic admixtures were established, interspecific pummelo introgression brought new traits to the admixtured mandarin genome. During domestication, genetic variability of these citrus occurred mainly through spontaneous mutations and with the practice of grafting, seedless genotypes expanded rapidly, emphasizing the role of mutations in the selection of citrus such as oranges and modern mandarins. In this work, we provide evidence that somatic mutations in citrus propagate following an iterative pattern determined by the sympodial branching model and consequently are grouped in sectors along the tree, where some of them remain fixed. In this scenario, a tree can be considered a mosaic genetically composed of different genomes, in which younger branches accumulate greater number of mutations. On average, our 36-yr-old experimental Clementine tree shows a mutation rate of 4.4 × 10-10 bp-1 yr-1, may carry a total of 1,500 to 5,000 variants and produces 1 somatic mutation per axillary meristem. This relatively high number of mutations is in line with the large number of varieties derived from spontaneous mutations that are commercialized in citrus. To identify key traits elicited by citrus domestication, we analyzed transcriptomes from developing fruit pulp of wild inedible Ichang papeda, Sun Chu Sha Kat sour mandarin and three palatable segregants derived from a cross between commercial mandarins. Based on these results, we propose that during the transition from inedible papedas to sour mandarins, domestication involved a first phase of major changes in the expression of genes regulating central pathways of primary and secondary metabolism. This stage was mainly characterized by both the stimulation of growth processes and the reduction of distasteful chemicals defenses. It is also suggested that in a second phase, edible attributes of mandarins, especially acidity, were progressively improved through specific modifications. Other relevant changes included upregulation of genes involved in the synthesis of key substances of pleasant aroma and flavor, and the modulation of sugar transporters. Thus, the transition from inedible papeda to sour mandarin was essentially defined by a drastic reprogramming of gene expression of fundamental metabolic pathways, while modern mandarins evolved later through progressive refinement of palatability properties. Taken together, these observations suggest that the rates of mutations occurring in citrus somatic tissues are consistent with the idea that they have played an important role during the later steps of citrus domestication. / This research is co-funded by the Ministerio de Ciencia, Innovación y Universidades (Spain) through grant RTI2018-097790-R-100 and by the European Union through the European Regional Development Fund (ERDF) of the Generalitat Valenciana 2014- 2020, through grants IVIA 51915 and 52002 / Pérez Román, E. (2022). Mutation Rate and Gene Expression in Genetic Admixtures of Domesticated Citrus [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/191452 / Compendio
358

The Representation, Organization and Access of Lexical Tone by Native and Non-NativeMandarin Speakers

Wiener, Seth 29 May 2015 (has links)
No description available.
359

A comparative study of the provision of Mandarin as foreign language in higher education in China and South Africa

Wang, Yuhua (Educator) 11 1900 (has links)
The importance of China as world power has led to a growing interest in and demand for learning Mandarin as a Foreign Language (MFL) worldwide. This study focuses on a comparative study of the provision of MFL in higher education in China and in South Africa. A conceptual framework was provided by examining theories of language policy planning and second language or foreign language acquisition as well as an overview of MFL provision in Chinese and South African higher education. MFL policy in China is characterised as a diffusion policy driven by economic globalisation, „soft power‟ and culture, and supported by legislation, funding and implementation. In South Africa, no specific policy underlies MFL, although motivation for MFL provision is given through strategic economic relations between South Africa and China. Against this background, a mixed-method inquiry conducted in two phases examined MFL at three purposefully selected universities in China and at the four university providers in South Africa. Phase One investigated lecturer perceptions of MFL tuition using a researcher-designed questionnaire; Phase Two explored student experiences of MFL using semi-structured interviews with purposefully selected MFL students in both countries. Findings indicated similarities in lecturer profile and differences in lecturers' perceptions regarding institutional support for MFL, particularly in institutions offering degrees in MFL, the MFL classroom environment and the curriculum. Student participants identified differences in studying MFL abroad in China and at home in South Africa in terms of class scheduling, peer and tutor support, student enrolments and design of educational programmes. All language skills were acquired more rapidly in the immersion learning context in China than in the first language dominant South African context, especially communication skills. Similarities were demonstrated in the emotional dimension of learning a new language, the main needs of MFL students, the opportunity to use or speak Mandarin, motivation to study Mandarin, and the challenges characteristic of Mandarin as a language. Recommendations for improvement of practice were given in terms of immersion context creation, opportunity to learn support, Confucius Institute facilities and exchange programmes for study abroad, lecturer and tutor improvement, and the establishment of an incentive to learn mechanism in South Africa. / Educational Studies / D. Ed. (Comparative Education)
360

Sénescence et longévité : des mécanismes aux processus évolutifs : étude chez les oiseaux et les mammifères / Senescence and longevity : from physiological mechanisms to evolutionary processes : studies in birds and mammals

Guerreiro, Romain 14 December 2012 (has links)
Il existe dans le règne animal une diversité incroyable de durées de vie allant de quelques jours pour les petits vers gastrotriches à plusieurs centaines d’années pour certains bivalves ou tortues terrestres. Cette étonnante diversité a depuis longtemps questionné les chercheurs en biologie. L’intérêt croissant pour le phénomène de vieillissement, notamment dû à l’augmentation de l’espérance de vie chez l’Homme, a conduit les chercheurs à essayer de comprendre les processus qui déterminent les patrons de longévité et de vieillissement. D’une part, les études biomédicales et biogérontologiques ont contribué à décrire nombres de mécanismes physiologiques et cellulaires à l’origine du vieillissement. Parmi ces mécanismes, le stress oxydant a été identifié comme jouant un rôle majeur, à travers l’accumulation au cours de la vie des dégâts générés par la production de radicaux libres lors d’activités métaboliques aérobies. D’autre part, le développement de théories évolutives du vieillissement a contribué à comprendre l’origine ultime du vieillissement et l’évolution de la diversité des traits d’histoire de vie. Cependant, ces approches, bien que complémentaires, sont longtemps restées imperméables et les travaux intégrant les mécanismes physiologiques tels que le stress oxydant dans une perspective évolutive n’ont connu que de récents développements. Dans cette thèse, nous avons étudié comment des mécanismes tels que le stress oxydant et ses coûts associés lors d’évènements comme la reproduction ou la réponse immunitaire pouvaient jouer un rôle dans l’évolution des patrons de vieillissement chez les oiseaux et les mammifères (i) en étudiant le rôle des antioxydants comme ressources clés dans les compromis adaptatifs entre reproduction et survie en fonction de l’âge, (ii) en étudiant les conséquences à long terme de l’environnement périnatal, (iii) en étudiant le lien entre réponse inflammatoire et patrons de vieillissement et de longévité contrastée entre oiseaux et mammifères, (iv) en s’intéressant plus particulièrement aux mécanismes de régulation immunitaire, soulignant leur rôle crucial pour la fitness des hôtes, et notamment tard dans la vie. Nos résultats soulignent l’importance des contraintes physiologiques liées à la limitation en ressources clés (antioxydants) ou aux dégâts engendrés lors d’activités coûteuses et destructrices et sur les patrons de vieillissements à l’échelle intra et inter-spécifique. / There is an incredible diversity of lifespan in the animal kingdom ranging from a few days for small gastrotrichs worms to several hundred of years for some bivalves or tortoises. This amazing diversity has long questioned biology researchers. The growing interest in the phenomenon of aging, mainly due to the increase in life expectancy in humans, has questioned researchers on processes that determine patterns of longevity and ageing. On the one hand, biomedical and biogerontological studies helped describe numerous cellular and physiological mechanisms related to aging. Among these mechanisms, oxidative stress has been identified as playing a major role, through life-time accumulation of damage generated by production of metabolic free radicals. On the other hand, the development of evolutionary theories of aging has contributed to understanding ultimate origins of ageing and of the diversity of life history traits. However, these approaches, although complementary, have long remained separated and works that integrate physiological mechanisms such as oxidative stress in an evolutionary perspective have known only recent developments. In this thesis, we studied how mechanisms such as oxidative stress and its associated costs produced during reproduction or immune response could play a role in the evolution of patterns of ageing in birds and mammals by (i) studying the role of antioxidants as key resources involved in adaptive trade-offs between reproduction and survival through age, (ii) studying the long-term effects of the early environment, (iii) studying the relationship between inflammatory response and contrasted patterns of ageing and longevity between birds and mammals, (iv) focusing particularly on immune regulatory mechanisms, emphasizing their crucial role in fitness of hosts, especially late in life. Overall, our results highlight the importance of physiological constraints in terms of key resources limitation (i.e. antioxidants) or damage caused during costly and destructive activities and on intra-and inter-specific patterns of ageing.

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