Submitted by Fernando Souza (fernandoafsou@gmail.com) on 2017-09-20T13:22:58Z No. of bitstreams: 1 arquivototal.pdf: 6673725 bytes, checksum: 5a6f8ff251599fe900848838a3d9ced8 (MD5) / Made available in DSpace on 2017-09-20T13:22:58Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 6673725 bytes, checksum: 5a6f8ff251599fe900848838a3d9ced8 (MD5) Previous issue date: 2017-04-07 / This study has the purpose presenting the result of a research on unconventional segmentations of words performed with children of the second year of elementary school. Because it is a work developed with children in the process of literacy and thinking about the contribution to a more significant study, we decided to use parlendas, as well as working through children's popular games, it greatly facilitates the study of nonconventional segmentation: hyper segmentation and hypo segmentation because parlendas are attractive texts and have small verses, easy to memorize. We observed that, in the literacy process, students have a lot of difficulty in segmenting words, and therefore end up joining or separating words differently from the ones proposed by the standard, precisely because they transpose the knowledge of orality into writing without any or few teacher's intervention. The separation between the words of a sentence can cause doubts in students who are beginning to have contact with the written language, therefore, are difficulties that once unresolved in the base, in the initial years, can be dragged into the later school years. We understand, based on Kleiman (1996); Soares (2009); Ferreiro (1999; 2011); PCN (1997), that exploits the reading and writing through playful activities, directed to the initial years, helps the students' learning, since it allows the adequate contact with the textual diversity since the first steps in the work with writing. And, in fact, we could verify that of the total of 10 children who participated in our practice, 06 understood the formalization of the segmentation in writing after the sequence of activities applied. / Este estudo tem como propósito apresentar o resultado de uma pesquisa sobre segmentações não convencionais de palavras realizadas com crianças do 2º ano do ensino fundamental. Por ser um trabalho desenvolvido com crianças no processo de alfabetização e pensando em contribuir com um estudo mais significativo, resolvemos utilizar o gênero parlenda, pois além de trabalhar a linguagem através das brincadeiras populares infantis, facilita bastante o estudo da segmentação não convencional: hipersegmentação e hipossegmentação, já que as parlendas são textos atrativos e que possuem versos pequenos, fáceis de memorizar. Observamos que, no processo de alfabetização, os alunos apresentam muita dificuldade de segmentação de palavras, e, por isso, terminam juntando ou separando as palavras de forma distinta do proposto pelo padrão, justamente porque transpõem os conhecimentos da oralidade para escrita sem nenhuma ou pouca intervenção do professor. A separação entre as palavras de uma frase pode causar dúvidas nos alunos que estão começando a ter contato com a língua escrita, portanto, são dificuldades que uma vez não solucionadas na base, nos anos iniciais, poderão ser arrastadas para as os anos escolares posteriores. Entendemos, com base em Kleiman (1996); Soares (2009); Ferreiro (1999; 2011); PCN (1997), que explorar a leitura e a prática da escrita por meio de atividades lúdicas, voltadas aos anos iniciais, auxilia a aprendizagem dos alunos, uma vez que possibilita o adequado contato com a diversidade textual desde os primeiros passos no trabalho com a escrita. E, de fato, pudemos comprovar que do total de 10 crianças que participaram da nossa prática, 06 conseguiram compreender melhor a formalização da segmentação na escrita após a sequência de atividades aplicadas em sala.

Les troubles musculo-squelettiques (TMS) liés au travail sont des maladies qui interrogent la formation du geste professionnel. Il est admis que ces maladies plurifactorielles nécessitent pour leur prévention des approches interdisciplinaires. Notre action s'inscrit dans le cadre de la théorie historico-culturelle de l'activité (Vygotski, 1978). La recherche en clinique de l'activité organise l'action d'appropriation par les sujets de nouveaux moyens d'agir sur eux-mêmes et sur la situation de travail. Elle débute toujours par une intervention dans un milieu professionnel donné. Nous avons répondu à la demande du service de médecine du travail d'une grande ville française. Des TMS au niveau des épaules et des lombalgies ont été diagnostiqués chez des fossoyeurs municipaux. Nous avons conduit cette intervention en psychologie du travail dans un cadre méthodologique clinique de l'activité ouvert aux coopérations interdisciplinaires avec l'ergonomie de l'activité et l'analyse biomécanique. La co-analyse de gestes techniques au sein de trois collectifs de fossoyeurs a pu bénéficier des apports méthodologiques de l'interdisciplinarité. L'intervention a aussi permis des avancées dans l'action de prévention initiée par les membres de la direction et les préventeurs réunis en comité de pilotage. Au plan conceptuel, le geste est une unité physiologique, psychologique et sociale. Dans l'analyse psychologique et sociale du mouvement (Clot & Fernandez, 2005) cette unité est appréhendée dans la complexité de sa dynamique inter fonctionnelle (Luria, 1973). Le développement du geste est pensé en termes de réorganisation qualitative des rapports internes entre automatisme et geste et entre geste et mouvement (Fernandez, 2004). Cette modélisation est construite sur le modèle des rapports inter fonctionnels entre opération et action et entre action et activité (Léontiev, 1984) ainsi que sur le modèle de l'activité dirigée (Clot, 1999). Ce parcours théorique et nos résultats empiriques font apparaître que les TMS sont des maladies de l'hypo-socialisation du mouvement par défaut d'interférences entre les contextes de sa réalisation. La dynamique des controverses gestuelles entre professionnels et l'organisation d'interférences inter-contextuelles sont analysées comme des méthodes indirectes favorisant la socialisation du mouvement en vue de prévenir les troubles musculo-squelettiques. / Work related musculoskeletal disorders (WRMSD) are diseases that question the making of the professional gesture. It said that the prevention of these multifactorial diseases needs interdisciplinary approaches. Our action is in line with the historico-cultural theory of activity (Vygotski, 1978). Research in clinic of activity organizes the subjects' action of appropriation of new means of action both on themselves and on the work situation. It always begins by an intervention within a specific professional environment. We answered the demand of the occupational medicine department of a big French city. WRMSD on the region of the shoulders and lumbers troubles have been diagnosed among municipal gravediggers. We led this intervention in psychology of work within a clinic of activity methodological frame open to interdisciplinary cooperation with ergonomics of activity and biomechanical analysis. Co- analysis of technical gestures within three gravedigger collectives has benefited from the methodological contributions of interdisciplinarity. The intervention has also allowed advances in the action of prevention initiated by managers and preventors together in a piloting committee. From a conceptual viewpoint the gesture is a physiological, psychological and social unit. In the psychological and social analysis of movement (Clot & Fernandez, 2005) this unit is comprehended in the complexity of its interfunctional dynamics (Luria, 1973). The development of the gesture is thought of in terms of qualitative reorganization of internal relations between automatism and gesture and between gesture and movement. This modelling is built on the model of the interfunctional relationships between operation and action and between action and activity (Léontiev, 1984) as well as on the model of directed activity (Clot, 1999). This theoretical route and our empirical findings show that the WRMSD are diseases linked to hypo-socialization of movement by lack of interferences between contexts of its realization. The dynamic of gestural controversies between professionals and the organization of inter-contextual interferences are analysed as indirect methods facilitating the socialization of the movement in order to prevent musculoskeletal disorders.

La modélisation des renforts fibreux combine la prise en compte d'une architecture tridimensionnelle enchevêtrée de mèches et de leur comportement élémentaire anisotrope, résultant, lui-même, d'une microstructure complexe. Notre travail consiste en la mise au point de modèles éléments finis en grandes transformations permettant de caractériser numériquement le comportement des cellules élémentaires représentatives afin de simuler les procédés de mise en forme. Un modèle géométrique de la maille de tricot à l'échelle mésoscopique est construit afin de supporter un modèle éléments finis 3D cohérent. Le comportement, orthotrope et hypo-élastique, est formulé à l'aide de l'outil tensoriel. Cela nous permet de proposer et d'analyser un nouveau modèle : le Milieu Continu Equivalent Orthotrope Fibreux. Enfin, des perspectives pour des modèles de Milieux Continus Equivalents Anisotropes Fibreux, où les directions fortes d'anisotropie sont non-orthogonales, sont développées.

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No. of bitstreams: 2 Dissertação - Cesar Augusto Sam Tiago Vilanova Costa - 2006.pdf: 1500361 bytes, checksum: 3401843db66da8f77a90a41b7a08f826 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2006-09-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Hypo pharynx is the under region of pharynx and serves both respiratory and digestive tract, acting as a passageway to air and food. It’s composed by squamous nonkeratinized epithelial tissue. Statistical studies indicates that 85 to 90% of neoplasies rush pyriform sinus and are characterized by fast dissemination and metastization. Epidemiological trends of hypo pharynx cancer in Goiania on period 1998 to 2003 analyzing data derived from Cancer Registry of Association for Cancer Combat of Goias, shows that the relative survival rate for men diagnosed with hypo pharynx cancer was 38% past 60 months while women presented a survival rate of 100%. Surgery was the treatments that present fewer rates (34%) and chemotherapy was associated to the most survival rate (54%). Patients that use tobacco presented a survival rate of 43% while non-tabagists present a rate of 60% of surviving. Relative survival rate for patients diagnosed with hypo pharynx tumor was 38% and estimated censure for 5 years was just 5%. Survival rate was extremely decreased due to 45% of cases were diagnosed in advanced stages of disease. It is important to point out that preventive campaign is important to evade the increasing of these pathologies that are related to behavior of tabagism and etilism. Present study also evaluates cytogenetically individuals diagnosed with hypo pharynx cancer. Cytogenetic analysis of exfoliated cells is largely used to evaluate cytotoxic and genotoxic alterations on people exposed to potentially mutagens. A number of 36 individuals were analyzed, representing case group, and 36 healthy individuals composed control group. Data was collected and analysis was performed to estimate main nuclear alterations. Standard protocols were adopted to collect and counting cells. Micronuclei test was used to determinate the frequency of cytotoxic and genotoxic alterations. Besides than micronuclei others alterations like broken-eggs, binucleated cells and piknotic nuclei are good markers of cell alterations because they are resulted from cytotoxic events frequently related to occupational exposure. Behaviors like tabagism, etilism and exposition time were also investigated to correlate cells alterations. The correlation between micronuclei frequencies of case and control group test doesn’t show statistic difference. Broken egg and binucleated cells were the most observed anomalies on case group and showed up significant statistic difference (p=0.03). Results indicates a high grade of cytotoxic anomalies on individuals with hypo pharynx cancer, specially in tabagists and chronic etilists individuals, behaviors that are correlated to induct and promote tumors in susceptible people due their capabilities to affect cell cycle. Studies about relationship between Human Papillomavirus (HPV) and cancer development are performed since 80’s. Although the correlation of HPV and cervical cancer are well established, the possible role of HPV and head and neck cancer are still unclear. Among controversial factors of HPV and carcinogenesis of squamous epithelial cells, there is a viral incidence that oscillates from 0 to almost 100% on studies that includes a myriad of viral genome detect methods, such Blotting and PCR. Importance of HPV infection and epithelial carcinogenesis is related to capabilities of High risk HPV 16 and 18 to promote cell alterations, by tumor suppressor proteins inactivation, tumor suppressor genes blockage and insertions of HPV oncogenes. On present study, HPV detection and typing was performed on tumors derived from hypo pharynx of 24 patients diagnosed with cancer (CID-O: C12,0 to C13,9). All samples was submitted to PCR with generic primers MY09/11 and GP05/06, as specific primers to HPV 6, 11, 16, 18, 33, 35, 45 and 58. Results shows that on 9 of 24 samples, HPV were detected by generic primers (a rate of 37,5%) and HPV types 16, 18 and 45 were identified, with a sample presenting coinfection of HPV 16 and 18. / A hipofaringe, região inferior da faringe, também chamada de laringofaringe ou faringolaríngea, serve aos sistemas respiratório e digestivo, funcionando como passagem para o ar e os alimentos. É composta de tecido epitelial escamoso estratificado não-queratinizado, com grande quantidade de glândulas seromucosas. As estatísticas mostram que entre 85 e 90% dos cânceres que acometem a hipofaringe são carcinomas espino-celulares. A lesão inicial no seio piriforme apresenta-se macroscopicamente sob o aspecto de um nódulo ou úlcera, tendo como característica principal, a rápida disseminação pela submucosa. Atualmente, com a associação de cirurgias radicais e radioterapia pós-peratória aumentou-se o controle locorregional destes tumores, contudo, a sobrevida global não sofreu alterações em decorrência das metástases à distância, o que não representa uma falha no tratamento realizado e sim uma evolução natural devido à característica invasiva desse tipo de neoplasia. Os tumores malignos de hipofaringe não são freqüentes, representando entre 5 a 10% das neoplasias das vias aerodigestivas superiores e apenas 0,5 % de todos os cânceres. Porém, do conjunto das neoplasias malignas da região da cabeça e pescoço, tumores de hipofaringe apresentam o pior prognóstico. A avaliação das tendências epidemiológicas apresentadas pelo câncer de hipofaringe em Goiânia no período de 1998 a 2003, analisando os dados disponíveis pelo Registro de Câncer de Base Populacional da Associação de Combate ao Câncer em Goiás, mostrou uma sobrevida relativa dos pacientes do sexo masculino diagnosticados com câncer de hipofaringe foi de 38% após 60 meses de segmento, enquanto que para o feminino apresentou-se uma sobrevida máxima de 100%, com todas as pacientes curadas. Dentre os tratamentos realizados, a cirurgia apresentou a menor taxa de sobrevida (34%) ao passo que para a quimioterapia foi associada uma sobrevida de 54%. A sobrevida dos pacientes tabagistas (43%) se mostrou muito inferior à dos indivíduos que não eram tabagistas (60%). Em fim, ao longo de cinco anos de segmento deste estudo, a taxa de sobrevida relativa para portadores de tumores malignos da hipofaringe foi de aproximadamente 38%, estimada para cinco anos com uma censura de apenas 5%. A taxa de sobrevida relativa é diminuída uma vez que cerca de 45% dos casos, o diagnóstico é feito tardiamente. O presente estudo também avaliou as alterações citogenéticas nucleares de pacientes portadores de câncer na região da hipofaringe. Foram analisados 36 indivíduos do grupo de casos, constituído de pacientes diagnosticados com tumores de hipofaringe, e 36 indivíduos saudáveis do grupo controle. Para obtenção dos dados foram considerados hábitos de consumo como tabagismo e etilismo e principalmente o tempo de exposição. Foram contadas 5000 células por indivíduo e as freqüências de micronúcleo, binucleadas, broken eggs e demais aberrações nucleares, foram calculadas para ambos os grupos. A freqüência de micronúcleo mostrada entre o grupo controle e o de casos não apresentaram diferença estatística. Porém, foi observado, por parte do grupo de casos, um grande número de células com broken eggs e binucleadas. Tais resultados demonstraram diferença estatística (p = 0,03). A binucleação e a formação de dois núcleos em forma de broken egg sugere que agentes como o tabaco e o alcoolismo crônico podem estar relacionados com a indução e progressão de tumores em pessoas susceptíveis, devido à capacidade desses mutágenos afetarem o ciclo celular. Dentre os fatores que geram controvérsias, podemos destacar o achado freqüente de variados tipos de HPV em mucosa oral normal, numa incidência que varia de 0% a quase 100% em diversos estudos, com numerosos métodos de identificação, incluindo entre eles um método altamente sensível, a PCR. A importância da infecção pelo HPV na carcinogênese de células epiteliais é suportada pela capacidade dos HPVs de alto risco, principalmente os tipos 16 e 18, de imortalizar os queratinócitos orais, quando em análise in vitro. O processo de imortalização pode envolver a desativação de proteínas supressoras de tumores pré-formadas pelas oncoproteínas virais, o bloqueio da transcrição de genes supressores de tumores como resultado da inserção do oncogene do HPV, ou a estimulação da transcrição do oncogene celular pela inserção de seqüências ativadoras de transcrição derivadas do próprio genoma do HPV. No presente estudo, o grupo amostral foi constituído de 24 pacientes diagnosticados com carcinoma de hipofaringe. Os casos foram obtidos do Registro de Câncer de Base Populacional de Goiânia/GO da Associação de Combate ao Câncer em Goiás. Todos os pacientes considerados foram diagnosticados como carcinomas de hipofaringe (CID-O: C12.0 a C13.9). Todas as amostras foram submetidas a uma PCR com os primers genéricos MY09/11 e GP05/06 para detecção em amplo espectro do genoma de HPV. Posteriormente, utilizou-se a mesma abordagem, com os primers tipo-específico para HPVs 6, 11, 16, 18, 33, 35, 45 e 58. Em 9 das 24 amostras utilizadas, foi observada amplificação com os primers genéricos, identificando-se o genoma de HPV em 37,5% (6/24) dos casos. Em 67% (6/9) das amostras, o genoma viral foi detectado por MY09/11 e em 33% (3/9) pelos primers GP05/06. As amostras positivas foram então submetidas a uma segunda PCR para a genotipagem dos HPVs, tendo sido observados os tipos 16, 18 e 45. Os tipos virais mais associados ao câncer da hipofaringe, no presente estudo, foram os HPV 16 e 18, presente em 6 amostras e o HPV45, encontrado em 1 amostra. Em um paciente foi observada a co-infecção de tipos virais de HPVs 16 e 18. Contudo, mesmo diante de tantas pesquisas realizadas, há muito para ser explorado, apesar de uma hipótese possível para a carcinogênese ser a interação sinérgica de carcinógenos químicos, virais, oncogenes e genes supressores de tumores.

Univ., Diss. u.d.T.: Regina Frank "Quantifizierung von Synergiepotentialen im Rahmen der Bewertung von Zusammenschlüssen von Universalbanken"--Bremen, 2002. / Literaturverz. S. 281 - 329.

Vowel hyperarticulation and hyper affect are two characteristics of infant-directed speech (IDS), reported in several studies. Vowel hyperarticulation has been suggested to be a way in which adults subconsciously facilitate infants’ language acquisition, but it has also been argued to be the acoustic by-product of an affective speaking style. The present thesis describes the expression of vocal affect in Swedish IDS at 12 months and investigates the relationship between vocal affect and vowel hypo-/hyperarticulation (VHH) on a speaker level. Naïve listeners (n = 23) rated affect valence in filtered samples of parents’ IDS and adult-directed speech (ADS). VHH was quantified by vowelspace area (VSA) for the same parents. In line with previous studies, IDS contained significantly more positive affect than ADS, illustrating that heightened positive affect is a distinct feature of Swedish IDS. Furthermore, no relationship was found between vocal affect and degree of VHH. However, a significant negative relationship was found between parents’ difference in VSA for IDS and ADS, and the difference in vocal affect for IDS and ADS. The results show that hyper affect was not associated with hyperarticulation of vowels. In general, parents that made affective adjustments in their IDS made smaller adjustments regarding VHH. The results support previous research suggesting that vowel hyperarticulation in IDS is not simply the result of an affective speaking style. / Vokalhyperartikulation och förhöjd positiv röstkänsla är två kännetecken för barnriktat tal (BRT) som har rapporterats i flera studier. Vokalhyperartikulation har föreslagits vara ett sätt vuxna omedvetet underlättar barns språkinlärning. Andra menar att det är en akustisk sidoeffekt av den positiva röstkänslan som används i interaktion med små barn. Den aktuella uppsatsen beskriver uttrycket av röstkänsla i svenskt BRT vid 12 månader och undersöker sambandet mellan röstkänsla och vokalhypo-/hyperartikulation (VHH) på talarnivå. Röstkänslan i föräldrars BRT och vuxenriktade tal (VRT) skattades av vuxna lyssnare (n = 23) och samma föräldrars vokalarea användes som mått på VHH. I linje med tidigare studier innehöll BRT signifikant mer positiv röstkänsla än VRT, vilket illustrerar att förhöjd positiv röstkänsla är ett utmärkande drag för svenskt BRT. Vidare fanns inget samband mellan röstkänsla och grad av VHH. Däremot fanns ett signifikant negativt samband mellan föräldrarnas skillnad i vokalarea för BRT och VRT, och föräldrars skillnad i röstkänsla för BRT och VRT. Resultaten visar att förhöjd positiv röstkänsla inte var associerad med hyperartikulation av vokaler. Generellt gjorde föräldrar som anpassade röstkänsla i hög grad mindre anpassningar gällande VHH. Resultaten stödjer tidigare studier som har visat att vokalhyperartikulation i BRT inte enbart är en effekt av ett positivt uttryckssätt.

Les troubles musculo-squelettiques (TMS) liés au travail sont des maladies qui interrogent la formation du geste professionnel. Il est admis que ces maladies plurifactorielles nécessitent pour leur prévention des approches interdisciplinaires. Notre action s'inscrit dans le cadre de la théorie historico-culturelle de l'activité (Vygotski, 1978). La recherche en clinique de l'activité organise l'action d'appropriation par les sujets de nouveaux moyens d'agir sur eux-mêmes et sur la situation de travail. Elle débute toujours par une intervention dans un milieu professionnel donné. Nous avons répondu à la demande du service de médecine du travail d'une grande ville française. Des TMS au niveau des épaules et des lombalgies ont été diagnostiqués chez des fossoyeurs municipaux. Nous avons conduit cette intervention en psychologie du travail dans un cadre méthodologique clinique de l'activité ouvert aux coopérations interdisciplinaires avec l'ergonomie de l'activité et l'analyse biomécanique. La co-analyse de gestes techniques au sein de trois collectifs de fossoyeurs a pu bénéficier des apports méthodologiques de l'interdisciplinarité. L'intervention a aussi permis des avancées dans l'action de prévention initiée par les membres de la direction et les préventeurs réunis en comité de pilotage. Au plan conceptuel, le geste est une unité physiologique, psychologique et sociale. Dans l'analyse psychologique et sociale du mouvement (Clot & Fernandez, 2005) cette unité est appréhendée dans la complexité de sa dynamique inter fonctionnelle (Luria, 1973). Le développement du geste est pensé en termes de réorganisation qualitative des rapports internes entre automatisme et geste et entre geste et mouvement (Fernandez, 2004). Cette modélisation est construite sur le modèle des rapports inter fonctionnels entre opération et action et entre action et activité (Léontiev, 1984) ainsi que sur le modèle de l'activité dirigée (Clot, 1999). Ce parcours théorique et nos résultats empiriques font apparaître que les TMS sont des maladies de l'hypo-socialisation du mouvement par défaut d'interférences entre les contextes de sa réalisation. La dynamique des controverses gestuelles entre professionnels et l'organisation d'interférences inter-contextuelles sont analysées comme des méthodes indirectes favorisant la socialisation du mouvement en vue de prévenir les troubles musculo-squelettiques.

This thesis work deals with the volume changes during the solidification of cast irons and peritectic steels. The volume changes in casting metals are related to the expansion and/or contraction of the molten metal during solidification. Often, different types of shrinkage, namely macro- and micro-shrinkage, affect the casting quality. In addition to that, exposure of the metal casting to higher contraction or expansion during the solidification might also be related to internal strain development in samples, which eventually leads to surface crack propagation in some types of steel alloys during continuous casting. In consequence, a deep understanding of the mechanisms and control of the solidification will improve casting quality and production. All of the experiments during the entire work were carried out on laboratory scale samples. Displacement changes during solidification were measured with the help of a Linear Variable Displacement Transformer (LVDT). All of the LVDT experiments were performed on samples inside a sand mould. Simultaneously, the cooling curves of the respective samples during solidification were recorded with a thermocouple. By combining the displacement and cooling curves, the volume changes was evaluated and later used to explain the influence of inoculants, carbon and cooling rates on volume shrinkages of the casting. Hypoeutectic grey cast iron (GCI) and nodular cast iron (NCI) with hypo-, hyper- and eutectic carbon compositions were considered in the experiments from cast iron group. High nickel alloy steel (Sandvik Sanbar 64) was also used from peritectic steel type. These materials were melted inside an induction furnace and treated with different types of inoculants before and during pouring in order to modify the composition. Samples that were taken from the LVDT experiments were investigated using a number of different  methods in order to support the observations from the displacement measurements:  Differential Thermal Analysis (DTA), to evaluate the different phase present; Dilatometry, to see the effect of cooling rates on contraction for the various types of alloys; metallographic studies with optical microscopy; Backscattered electrons (BSE) analysis on SEM S-3700N, to investigate the different types of oxide and sulphide nuclei; and bulk density measurements  by applying Archimedes' principle. Furthermore, the experimental volume expansion during solidification was compared with the theoretically calculated values for GCI and NCI. It was found that the casting shows hardly any shrinkage during early solidification in GCI, but in the eutectic region the casting expands until the end of solidification. The measured and the calculated volume changes are close to one another, but the former shows more expansion. The addition of MBZCAS (Si, Ca, Zr, Ba, Mn and Al) promotes more flake graphite, and ASSC (Si, Ca, Sr and Al) does not increase the number of eutectic cells by much. In addition to that, it lowers the primary austenite fraction, promotes more eutectic growth and decreases undercooled graphite and secondary dendritic arm spacing (SDAS). As a result, the volume expansion changes in the eutectic region. The expansion during the eutectic growth increase with an increase in the inoculant weight percentage. At the same time, the eutectic cells become smaller and increase in number. The effect of the inoculant and the superheat temperature shows a variation in the degree of expansion/contraction and the cooling rates for the experiments. Effective inoculation tends to homogenize the eutectic structure, reducing the undercooled and interdendritic graphite throughout the structure. In NCI experiments, it was found that the samples showed no expansion in the transversal direction due to higher micro-shrinkages in the centre, whereas in the longitudinal direction the samples shows expansion until solidification was complete.   The theoretical and measured volume changes agreed with each other. The austenite fraction and number of micro-shrinkage pores decreased with increase in carbon content. The nodule count and distribution changes with carbon content. The thermal contraction of NCI is not influenced by the variation in carbon content at lower cooling rates. The structural analysis and solidification simulation results for NCI show that the nodule size and count distribution along the cross-sections at various locations are different due to the variation in cooling rates and carbon concentration. Finer nodule graphite appears in the thinner sections and close to the mold walls. A coarser structure is distributed mostly in the last solidified location. The simulation result indicates that finer nodules are associated with higher cooling rate and a lower degree of microsegregation, whereas the coarser nodules are related to lower cooling rate and a higher degree of microsegregation. As a result, this structural variation influences the micro-shrinkage in different parts. The displacement change measurements show that the peritectic steel expands and/or contracts during the solidification. The primary austenite precipitation during the solidification in the metastable region is accompanied by gradual expansion on the casting sides. Primary δ-ferrite precipitation under stable phase diagram is complemented by a severe contraction during solidification. The microstructural analysis reveals that the only difference between the samples is grain refinement with Ti addition. Moreover, the severe contraction in solidification region might be the source for the crack formation due to strain development, and further theoretical analysis is required in the future to verify this observation. / <p>QC 20170228</p>

A acidez do solo é um dos principais fatores limitantes à produção vegetal. A toxicidade por alumínio, que ocorre apenas a pH baixo, tem sido extensamente investigada, enquanto o estresse causado pelo pH baixo tem recebido pouca atenção. Os estudos nesta área quase sempre presumem efeitos aditivos, e portanto independentes, da toxicidade por Al3+ e H+. Este provavelmente não é o caso, sendo que o pH baixo pode ser um fator de predisposição das células ao Al3+. As evidências indicam que o pH baixo causa desarranjos na parede de células em crescimento, gerando estresse que pode comprometer a sua funcionalidade e integridade. É provável que a susceptibilidade a este estresse deve ser dependente da pressão de turgor. Por sua vez, o metabolismo oxidativo e a geração de espécies reativas de oxigênio (ROS) na parede celular podem modular a sua extensibilidade por romper ou criar ligações dentro ou entre cadeias de polissacarídeo. Há grande interesse em se conhecer se, à semelhança do que ocorre em leveduras, as células vegetais possuem um sistema de percepção e resposta a estresse da parede. Os pêlos radiculares em crescimento são sensíveis a pH baixo e estresse hipo-osmótico e constituem um bom modelo experimental para estes estudos. Os objetivos deste trabalho foram: a) Otimizar um sistema experimental para o estudo de pêlos radiculares de tomateiro (Solanum lycopersicum L. cv Micro-Tom); b) Avaliar as respostas dos pêlos radiculares ao estresse por pH baixo e hipo-osmolaridade; c) Examinar o papel da modulação oxidativa da parede celular nestas respostas; e d) Avaliar a resposta de diferentes mutantes hormonais de Micro-Tom a estes fatores de estresse. Os principais parâmetros avaliados foram a taxa de alongamento (µm.min-1) e a freqüência de rompimento dos pêlos. Tanto o estresse por pH baixo quanto choques hipo-osmóticos resultaram em taxas de alongamento significativamente diminuídos e o rompimento de pêlos radiculares, mas os efeitos dos tratamentos hipo-osmóticos foram mais marcantes. Uma curva de resposta frente à osmolaridade da solução externa revelou que a taxa de alongamento aumentou com a diminuição da osmolaridade até alcançar um limiar em que houve redução drástica da taxa de alongamento e começou-se a observar o rompimento de pêlos. Também se observou uma interação entre hipo-osmolaridade e pH baixo. O emprego do inibidor difenileno iodônio não forneceu evidências do envolvimento de NADPH oxidases da membrana plasmática na resposta de pêlos radiculares a choque hipo-osmótico ou pH baixo. Já no caso do inibidor ácido salicilhidroxâmico, encontrou-se evidências do envolvimento de peroxidases da parede. Nos mutantes hormonais dgt (pouco sensível a auxina) e epi (super produtor de etileno), mas não em not (deficiente em ácido abscísico), os pêlos radiculares apresentaram uma melhor resposta de ajustamento a choque hipo-osmótico do que Micro-Tom, reduzindo o alongamento e o rompimento dos pêlos. Este trabalho fornece fortes evidências de que os pêlos radiculares possuem um mecanismo de percepção e resposta a estresse da parede visando à manutenção de sua integridade e que apresentam bom potencial como sistema modelo nesta linha de pesquisa / Soil acidity is a major factor limiting plant growth worldwide. Aluminum toxicity, which occurs only at low pH, has been extensively studied, whereas low pH stress has received much less attention. Studies on Al3+ and H+ toxicity make the underlying assumption that the effects of these stress factors are additive, and, therefore independent of each other. However, this is most likely not the case and low pH may be a factor which increases susceptibility to further injury by Al3+. There is evidence that low pH causes disruption in cell wall structure of growing cells, which might jeopardize cell wall functionality and integrity. It is likely that turgor pressure plays an important role in cell wall stress caused by low pH. The apoplastic metabolism of reactive oxygen species (ROS) can modulate cell wall extensibility by making or breaking bonds within and between cell wall polysaccharides. A major question is whether, similarly to yeast, plant cells have a cell wall integrity signaling and response system. Growing root hairs are sensitive to low pH and hypo-osmotic stress and are potentially good experimental systems for such investigations. The objectives of this study were: a) Optimize an experimental system to examine tomato (Solanum lycopersicum L. cv Micro-Tom) root hairs; b) Examine the response of root hairs to low pH and hypo-osmotic stress; c) Examine the role of oxidative modulation of the cell wall in these responses; and d) Evaluate the response of different hormonal mutants of Micro-Tom to these stress factors. Root hair elongation rates (µm.min-1) and the frequency of cell bursting were the major experimental parameters which were evaluated. Both low pH and, more markedly, hypo-osmotic stress caused significant reductions in elongation rates and the bursting of root hair tips. In a response curve to varying osmolarities of the external medium, root hair elongation rates increased with decreasing osmolarities until a threshold was reached and elongation rates decreased drastically and the bursting of root hairs began to be observed. Interactions between low pH and hypo-osmolarity were observed. The use of the inhibitor diphenylene iodonium (DPI) did not provide evidence for the involvement of plasma membrane NADPH in the response of root hairs to low pH and hypo-osmotic shock. However, a role for cell wall peroxidases was provided by use of the inhibitor salicylhydroxamic acid (SHAM). Root hairs of the hormonal mutants dgt (low sensitivity to auxin) and epi (ethylene super producer), but not not (deficient in abscisic acid), displayed a more effective response to hypo-osmotic shock than Micro-Tom, by decreasing elongation rates and cell bursting to a greater degree. This study provides strong evidence to suggest that root hairs have a cell wall integrity response system and that root hairs are potentially good cell model systems for such research

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