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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.
1

Figuras emblemáticas na área arqueológica da Serra da Capivara – São Raimundo Nonato – Piauí - Brasil

OLIVEIRA, Sarah Cavalcante de 29 August 2013 (has links)
Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2016-02-26T13:33:52Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Sarah Cavalcante de Oliveira.pdf: 8538347 bytes, checksum: 63ab2e7cf108dae14604e9b126f9c036 (MD5) / Made available in DSpace on 2016-02-26T13:33:52Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Sarah Cavalcante de Oliveira.pdf: 8538347 bytes, checksum: 63ab2e7cf108dae14604e9b126f9c036 (MD5) Previous issue date: 2013-08-29 / CNPq / Atualmente a análise do material gráfico dos painéis de pinturas rupestres no Nordeste do Brasil tem buscado especificidades nas figuras representadas pelos grupos pré-históricos. Busca-se padrões entre as diferentes representações que formam o acervo gráfico, principalmente da área arqueológica de São Raimundo Nonato no Estado do Piauí, com o objetivo de tentar detectar as diferentes escolhas de cada grupo cultural que tenha realizado essas pinturas. Sob essa perspectiva, nesta dissertação procurou-se estudar um dos principais grafismos emblemáticos da Tradição Nordeste, a figura dorso-contra-dorso, observando suas características a partir dos parâmetros das dimensões temática, técnica e cenográfica. As figuras foram analisadas separadamente, considerando-as unidades analíticas, para posteriormente compreender o conjunto da dupla de antropomorfos representadas. Estes procedimentos analíticos culminaram nesta primeira apresentação que permitiu inferências sobre os padrões de apresentação destas figuras dentro da classe Complexo Estilístico Serra Talhada, estabelecida para a área Arqueológica da Serra da Capivara. / Currently the analysis of the graphic material of the panels of rock art in the northeast of Brazil has been searching specificities on the figures represented by the prehistoric groups. Patterns are sought between different representations that form the graphic collection, especially of the archaeological area of São Raimundo Nonato in the state of Piauí, with the objective of try to detect the different choices of which cultural group that have done these paintings. Under this perspective, in this work we tried to study one of the major emblematic graphisms of the Northeast tradition, the back-to-back figure, observing its characteristics from parameters of the thematic, technical and scenographical dimensions. The figures were analyzed separately, considering them as analytical units, to understand later the set of the anthropomorphic pair represented. These analytical procedures culminated in this first presentation that allows inferences about presentation patterns of these figures inside of the class Stylistic Complex Serra Talhada, established for the Archaeological area of Serra da Capivara.
2

Biochemical studies of the signal transduction pathway mediated by the Drosophila Toll receptor

Kubota, Ken January 1994 (has links)
No description available.
3

Evaluation de l'excitabilité corticale par électroencéphalographie pour l'optimisation de la stimulation magnétique transcrânienne répétée chez les patients souffrant de troubles de l'humeur / Optimisation of repetitive transcranial magnetic stimulation using electroencephalographic measurements in patients suffering from mood disorders

Wozniak-Kwasniewska, Agata 07 October 2013 (has links)
La stimulation magnétique transcranienne (SMT) est une technique non invasive qui permet de stimuler le cerveau. Les SMT répétitives (SMTr), c'est-à-dire l'application de nombreuses impulsions magnétiques, sont capable d'induire des modifications de longue durée de l'excitabilité neuronale. La SMT s'est développée dans un but thérapeutique et scientifique. Les effets après la SMTr sur le cortex moteur sont bien documentés chez les individus sains, mais on en sait moins sur la stimulation du cortex préfrontal dorso-latéral (DLPFC).L'objectif de cette thèse était de comparer différents protocoles SMTr sur des sujets sains et de trouver des marqueurs électroencéphalograpiques (EEG) de la réponse ou pas à la thérapie SMTr dans la dépression majeure et bipolaire. La principale originalité de la méthode présentée est la comparaison intra-sujet d'effets entre-protocoles et le développement de techniques de localisation de sources.Nous avons étudié chez 20 sujets sains comment les oscillations corticales sont modulées suite à quatre protocoles SMTr actifs différents, et à un protocole sham utilisé comme contrôle, du DLPFC gauche et en comparant la puissance spectrale d'EEG avant et après SMTr de durée de 15 minutes. Le spectre EEG a été estimé grâce à la transformée de Fourier rapide (FFT) et partitionné en bandes de fréquence selon la classification commune.Nous avons trouvé pour chaque protocole actif une diminution significative de puissance delta et theta sur les électrodes préfrontales gauches, principalement localisées dans le DLPFC gauche. Dans des bandes de fréquences plus hautes, la diminution de puissance dans le DLPFC a été de plus observée dans le DLFPC controlatéral et dépend du protocole de stimulation. Parce que les activités delta et theta sont généralement associées à l'inhibition corticale, ces résultats suggérent que la SMTr du DLPFC diminue transitoirement l'inhibition corticale locale. Aussi, les oscillations d'EEG rapides sont associées à l'excitabilité corticale et on peut conclure que des diminutions observées non spécifiques dans l'activité rapide localisée dans le DLPFC suggérent également une réduction de l'excitabilité corticale.Dans la deuxième expérience, nous avons travaillé sur groupe de patients, souffrant de trouble dépressif majeur (MDD) et de trouble bipolaire (BP). Dans cette étude ouverte, nous avons cherché à déterminer s'il existe des différences d'EEG de repos dans l'activité cérébrale entre patients BP et MDD, et entre les répondeurs et non-répondeurs à la SMTr à 10 Hz en étudiant des biomarqueurs d'EEG. Le protocole SMTr à 10 Hz étaient le même entre patients MDD et BP. Les propriétés EEG dans les deux troubles dépressifs ont été étudiées, en comparant la puissance spectrale des enregistrements pré- et post-SMTr EEG au cours des sessions thérapeutiques chez les patients répondeurs et non-répondeurs.La conclusion est qu'il est possible de distinguer les répondeurs des non-répondeurs au traitement SMTr. Les répondeurs avaient une puissance en basse fréquence plus importante. Une augmentation de puissance alpha a aussi été observée au niveau du cortex cingulaire ventral dans les deux groupes. La comparaison des MDD et BP a révélé une activité significativement plus élevée dans la puissance des bandes thêta et bêta chez les patients BP, principalement localisée dans le cortex préfrontal. / Transcranial magnetic stimulation (TMS) is a non-invasive technique for stimulating the brain. A brief electric current passing through a magnetic coil produces a brief, high-intensity magnetic field which stimulates the brain. Repetitive TMS, application of many magnetic pulses, is able to induce relatively long-lasting excitability changes and nowadays is being developed for various therapeutic and scientific purposes. The after-effects of rTMS over motor cortex are well documented in healthy individuals, however less is known about the stimulation of dorso-lateral prefrontal cortex (DLPFC). The aim of this PhD thesis was to compare different rTMS protocols in healthy subjects and to find neurophysiological EEG biomarkers characteristic for response or not to rTMS therapy in major and bipolar depression. The main originality of presented method is within-subject comparison of between-protocols effects. Additionally, source localisation was performed in both analyses. Here, we studied in 20 healthy subjects how cortical oscillations are modulated by four different active rTMS protocols (1 Hz, 10 Hz, cTBS and iTBS) of the left DLPFC, and by a sham-1Hz protocol used as a control condition, by comparing the spectral power of pre- and post-rTMS electroencephalographic (EEG) recordings of 15 minutes duration. EEG spectrum was estimated with the Fast Fourier transform (FFT) and partitioned using the common physiological frequency. We found for every active protocol a significant decrease of delta and theta power on left prefrontal electrodes, mainly localised in the left DLPFC. In higher frequency bands (beta and gamma), the decrease of power in the DLPFC was also observed additionally in the contralateral DLFPC and depended on the stimulation protocol. Because large delta and theta activity is usually associated with cortical inhibition, these results suggest that rTMS of DLPFC transiently decreases local cortical inhibition. Furthermore, fast EEG oscillations are associated to cortical excitability and it can be concluded that observed decreases in fast activity, unspecific to protocol, localised in the DLPFC also suggest reduced cortical excitability, which accompanies a decrease in cortical inhibition. In the second experiment we worked on two subgroups of patients, with major depressive disorder (MDD) and bipolar disorder (BP). In this open study we aimed to examine whether there are EEG differences in resting brain activity between BP and MADD patients, and between responders and non-responders to 10 Hz repetitive transcranial magnetic stimulation (rTMS) by studying EEG biomarkers. Eight MDD (6 females) and 10 BP patients (6 females) were included. The 10 Hz rTMS protocol was the same for MDD and BP. The different patterns of EEG activity in both depressive disorders were studied, by comparing spectral power of pre- and post-rTMS EEG recordings throughout the therapeutic sessions in responders and non-responders.The most important finding is that it is possible to distinguish responders from non-responders to the rTMS treatment. Responders showed significantly higher power of low frequencies. Therefore, an increase of alpha power was observed in ventral cingulate cortex in both groups. The comparison of MDD and BP disorders revealed significantly higher activity in theta and beta bands power in BP patients, mainly localised in prefrontal cortex.
4

Comparative Analysis of Muscle and Locomotion Patterns in Drosophila Species

Belu, Mirela 28 March 2011 (has links)
No description available.
5

Temporalité de l'initiation des fleurs et contrôle de l'architecture de l'inflorescence / Temporality of Flower Initiation and Control of Inflorescence Architecture

Chaumeret, Anaïs 27 October 2017 (has links)
La phyllotaxie, arrangement d’éléments botaniques autour de l’axe primaire de la plante, suit unpatron spatio-temporel robuste. Elle est établie au niveau du Méristème Apical Caulinaire (MAC),qui est la niche de cellules souches post-embryonnaires des parties aériennes de la plante.L’accumulation locale de la phytohormone auxine déclenche la formation des organes latéraux auniveau du MAC. En même temps, la déplétion d’auxine dans les cellules environnantes crée unchamp inhibiteur, où toute nouvelle organogenèse est impossible. La croissance permet auxanciens organes de constamment s’éloigner du MAC, ce qui libère l’espace nécessaire auxnouvelles organogenèses. C’est un exemple frappant de processus biologique auto-organisé etitératif. Des mécanismes moléculaires et génétiques régulant la phyllotaxie ont été identifiés,majoritairement dans le contexte d’une phyllotaxie commune, qu’est la spirale de Fibonacci. Iln’est pas actuellement démontré que ces mécanismes expliquent aussi d’autres types dephyllotaxies. Nous avons identifié DRB27, un mutant d’Arabidopsis thaliana présentant une fortetendance à générer des pseudo-verticilles. Cela rappelle la phyllotaxie observée chez presquetoutes les fleurs et quelques tiges d’espèces non parentes. La quantification de la phyllotaxie deDRB27 ainsi que des expériences d’imagerie in vivo, ont révélé que ces groupes d’organes ne sontpas des verticilles, mais correspondent à des éruptions d’organogenèses se produisant en croissantà la périphérie du MAC quand, à l’inverse, de larges domaines restent inactifs. Ces observationsvont à l’encontre des règles classiques de positionnement d’organes lors de la mise en place de laphyllotaxie. De façon surprenante, nous avons identifié deux mutations candidates affectant lesrégulateurs abaxiaux FILAMENTOUS FLOWER et MIR166A, potentiellement toutes deuximpliquées dans le phénotype phyllotactique de DRB27. Alors que ces gènes sont exprimés dansles organes en développement, cela suggère des retours d’information sur la phyllotaxie, de façonnon autonome. Nous avons identifié des séries d’anomalies dans le MAC de DRB27, incluant despatrons de signalisation d’auxine anormaux, la perturbation des frontières entre les organes et leméristème, la modification des domaines WUS-CLV3 et de la géométrie du MAC, ainsi qu’unemodification de la dureté de la surface du méristème. Toutes ces données suggèrent que l’identitéet le développement des organes latéraux agissent sur l’homéostasie du MAC et l’établissement dupatron phyllotactique. / Phyllotaxis, the arrangement of botanical elements around plant axis,conforms to a robust spacial-temporal pattern. It is primarily established atthe shoot apical meristem (SAM), the post-embryonic aerial stem-cellniche. Local accumulation of the phytohormone auxin locally triggersorgan formation at the SAM, while depletion of auxin in the surroundingcells creates an inhibitory field, where no new organ can be initiated.Growth constantly moves older organs away from the SAM, clearingspace for new organogenesis. This is a striking example of an iterative and self-organized process driven by inhibitory fields. Molecular and geneticmechanisms regulating phyllotaxis are now being identified, but mostly inthe context of the most common Fibonacci spiral. Whether or not thesame mechanisms explain other types of phyllotaxis remains to beexplored. We identified DRB27, an Arabidopsis thaliana mutant with astrong tendency to generate clusters of organs. This is reminiscent of thewhorled phyllotaxis, observed in almost all angiosperm flowers and insome shoots of unrelated species. Quantification of DRB27 phyllotaxisand live imaging revealed that clusters are not whorls but correspond toburst of organs initiating in crescent domains at the periphery of the SAM.Conversely, large crescent domains remain devoid of organ initiation.Organogenesis in these clusters violates classical rules of organ spacing inphyllotactic systems. Surprisingly, we identified two candidate mutationsaffecting the two abaxial regulators FILAMENTOUS FLOWER andMIR166A, which likely combines to produce DRB27 peculiar phyllotaxis.Since these genes are expressed in developing organs, it suggests non-cellautonomous feedbacks on phyllotaxis. We identify a series of anomaliesin DRB27 SAM, including abnormal patterns of auxin signalling,perturbation of organ boundary formation, modification of CLV3/WUSdomains and SAM geometry and increase in cell wall stiffness. Takentogether our data questions how lateral organ identity and developmentfeedbacks on SAM homeostasis and phyllotaxis patterning.
6

Correlações macroscópicas e ultrassonográficas das dimensões prostáticas no cão / Correlation of macroscopic and ultrasonographic prostate size in the dog

Pinto, Manuela Martins 13 August 2010 (has links)
A proposta desse estudo foi verificar a acurácia das fórmulas, previamente estabelecidas em outros estudos, em determinar valores das dimensões prostáticas e sugerir uma nova fórmula que considere outras características do animal além do peso para fornecer uma análise quantitativa da próstata. Realizou-se a avaliação ultrassonográfica das próstatas de 63 cães hígidos, saudáveis com até 6 anos, em seguida obteve-se o peso, a altura e comprimento do dorso dos animais. Imediatamente após o óbito os animais foram submetidos à prostatectomia e determinou-se o volume glandular real por meio do deslocamento da coluna de àgua e a massa do órgão com a utilização de uma balança analítica. Calculou-se por meio de fórmulas previamente estabelecidas os valores de medidas prostáticas como a altura, comprimento, volume e peso. Os valores de peso e volume obtidos por meio das fórmulas foram comparados com os obtidos após pesagem e deslocamento da coluna de àgua respectivamente. Os valores das medidas de altura e comprimento obtidos por meio das fórmulas foram comparados aos obtidos ultrassonograficamente. Verificou-se o erro quadrático médio (EQM) e percentual ao testar a aderência dessas fórmulas. Após regressões lineares observou-se uma maior correlação ao se ultilizar medidas do animal como varíaveis explicativas em fórmulas para calcular os valores das medidas de comprimento e altura da próstata. Medidas de comprimento (CL) e altura (AL) da próstata podem ser estimadas por meio das fórmulas: CL = 1,59 + (0,06 * P) + (0,01 * CD) (0,01 * AA) (cm) e AL = 1,06 + (0,05 * P) + (0,003 * CD) + (0,04 * AA) (cm). / The purpose of this study was to verify the accuracy of the formulas previously established in other studies to determine values of prostate size and suggest a new formula that considers other characteristics of the animal besides the weight to provide a quantitative analysis of prostate. Prostatic ultrasonographic evaluation were performed in 63 non-castrated and healthy dogs of 6 years old in maximun. We obtained the animal\'s weight, height and length of the back. Immediately after death the animals underwent prostatectomy and the actual glandular volume was determined through water column displacement and its mass had been determined by weighting it on an analytical scale. We calculated through pre-established formulas the values of measures prostate as height, length, volume and weight. The weight and volume obtained from the formulas were compared with values obtained weight after weighing and the volume obtained after water column displacement. The values of length and height measurements obtained by the formulas were compared to values of sonographic linear measurements. We obtained the Residual Mean Square (RMS) and percentage to test the adherence of these formulas. After linear regression it was observed a bigger correlation in using the animal\'s measures as various explanation in formulas to calculate the values of length and height measures of the prostate. Measure prostatic length (CL) and height (AL) can be predicted using through formulas: CL = 1,59 + (0,06 * P) + (0,01 * CD) (0,01 * AA) (cm) and AL = 1,06 + (0,05 * P) + (0,003 * CD) + (0,04 * AA) (cm).
7

Correlações macroscópicas e ultrassonográficas das dimensões prostáticas no cão / Correlation of macroscopic and ultrasonographic prostate size in the dog

Manuela Martins Pinto 13 August 2010 (has links)
A proposta desse estudo foi verificar a acurácia das fórmulas, previamente estabelecidas em outros estudos, em determinar valores das dimensões prostáticas e sugerir uma nova fórmula que considere outras características do animal além do peso para fornecer uma análise quantitativa da próstata. Realizou-se a avaliação ultrassonográfica das próstatas de 63 cães hígidos, saudáveis com até 6 anos, em seguida obteve-se o peso, a altura e comprimento do dorso dos animais. Imediatamente após o óbito os animais foram submetidos à prostatectomia e determinou-se o volume glandular real por meio do deslocamento da coluna de àgua e a massa do órgão com a utilização de uma balança analítica. Calculou-se por meio de fórmulas previamente estabelecidas os valores de medidas prostáticas como a altura, comprimento, volume e peso. Os valores de peso e volume obtidos por meio das fórmulas foram comparados com os obtidos após pesagem e deslocamento da coluna de àgua respectivamente. Os valores das medidas de altura e comprimento obtidos por meio das fórmulas foram comparados aos obtidos ultrassonograficamente. Verificou-se o erro quadrático médio (EQM) e percentual ao testar a aderência dessas fórmulas. Após regressões lineares observou-se uma maior correlação ao se ultilizar medidas do animal como varíaveis explicativas em fórmulas para calcular os valores das medidas de comprimento e altura da próstata. Medidas de comprimento (CL) e altura (AL) da próstata podem ser estimadas por meio das fórmulas: CL = 1,59 + (0,06 * P) + (0,01 * CD) (0,01 * AA) (cm) e AL = 1,06 + (0,05 * P) + (0,003 * CD) + (0,04 * AA) (cm). / The purpose of this study was to verify the accuracy of the formulas previously established in other studies to determine values of prostate size and suggest a new formula that considers other characteristics of the animal besides the weight to provide a quantitative analysis of prostate. Prostatic ultrasonographic evaluation were performed in 63 non-castrated and healthy dogs of 6 years old in maximun. We obtained the animal\'s weight, height and length of the back. Immediately after death the animals underwent prostatectomy and the actual glandular volume was determined through water column displacement and its mass had been determined by weighting it on an analytical scale. We calculated through pre-established formulas the values of measures prostate as height, length, volume and weight. The weight and volume obtained from the formulas were compared with values obtained weight after weighing and the volume obtained after water column displacement. The values of length and height measurements obtained by the formulas were compared to values of sonographic linear measurements. We obtained the Residual Mean Square (RMS) and percentage to test the adherence of these formulas. After linear regression it was observed a bigger correlation in using the animal\'s measures as various explanation in formulas to calculate the values of length and height measures of the prostate. Measure prostatic length (CL) and height (AL) can be predicted using through formulas: CL = 1,59 + (0,06 * P) + (0,01 * CD) (0,01 * AA) (cm) and AL = 1,06 + (0,05 * P) + (0,003 * CD) + (0,04 * AA) (cm).
8

Evaluation de l'excitabilité corticale par électroencéphalographie pour l'optimisation de la stimulation magnétique transcrânienne répétée chez les patients souffrant de troubles de l'humeur

Wozniak-kwasniewska, Agata 07 October 2013 (has links) (PDF)
La stimulation magnétique transcranienne (SMT) est une technique non invasive qui permet de stimuler le cerveau. Les SMT répétitives (SMTr), c'est-à-dire l'application de nombreuses impulsions magnétiques, sont capable d'induire des modifications de longue durée de l'excitabilité neuronale. La SMT s'est développée dans un but thérapeutique et scientifique. Les effets après la SMTr sur le cortex moteur sont bien documentés chez les individus sains, mais on en sait moins sur la stimulation du cortex préfrontal dorso-latéral (DLPFC).L'objectif de cette thèse était de comparer différents protocoles SMTr sur des sujets sains et de trouver des marqueurs électroencéphalograpiques (EEG) de la réponse ou pas à la thérapie SMTr dans la dépression majeure et bipolaire. La principale originalité de la méthode présentée est la comparaison intra-sujet d'effets entre-protocoles et le développement de techniques de localisation de sources.Nous avons étudié chez 20 sujets sains comment les oscillations corticales sont modulées suite à quatre protocoles SMTr actifs différents, et à un protocole sham utilisé comme contrôle, du DLPFC gauche et en comparant la puissance spectrale d'EEG avant et après SMTr de durée de 15 minutes. Le spectre EEG a été estimé grâce à la transformée de Fourier rapide (FFT) et partitionné en bandes de fréquence selon la classification commune.Nous avons trouvé pour chaque protocole actif une diminution significative de puissance delta et theta sur les électrodes préfrontales gauches, principalement localisées dans le DLPFC gauche. Dans des bandes de fréquences plus hautes, la diminution de puissance dans le DLPFC a été de plus observée dans le DLFPC controlatéral et dépend du protocole de stimulation. Parce que les activités delta et theta sont généralement associées à l'inhibition corticale, ces résultats suggérent que la SMTr du DLPFC diminue transitoirement l'inhibition corticale locale. Aussi, les oscillations d'EEG rapides sont associées à l'excitabilité corticale et on peut conclure que des diminutions observées non spécifiques dans l'activité rapide localisée dans le DLPFC suggérent également une réduction de l'excitabilité corticale.Dans la deuxième expérience, nous avons travaillé sur groupe de patients, souffrant de trouble dépressif majeur (MDD) et de trouble bipolaire (BP). Dans cette étude ouverte, nous avons cherché à déterminer s'il existe des différences d'EEG de repos dans l'activité cérébrale entre patients BP et MDD, et entre les répondeurs et non-répondeurs à la SMTr à 10 Hz en étudiant des biomarqueurs d'EEG. Le protocole SMTr à 10 Hz étaient le même entre patients MDD et BP. Les propriétés EEG dans les deux troubles dépressifs ont été étudiées, en comparant la puissance spectrale des enregistrements pré- et post-SMTr EEG au cours des sessions thérapeutiques chez les patients répondeurs et non-répondeurs.La conclusion est qu'il est possible de distinguer les répondeurs des non-répondeurs au traitement SMTr. Les répondeurs avaient une puissance en basse fréquence plus importante. Une augmentation de puissance alpha a aussi été observée au niveau du cortex cingulaire ventral dans les deux groupes. La comparaison des MDD et BP a révélé une activité significativement plus élevée dans la puissance des bandes thêta et bêta chez les patients BP, principalement localisée dans le cortex préfrontal.
9

Aproveitamento do dorso mecanicamente separado da rã-touro (lithobates catesbeiana) na elaboração de surimi

Fragoso, Sinara Pereira 16 February 2017 (has links)
Submitted by Maike Costa (maiksebas@gmail.com) on 2017-09-05T12:44:35Z No. of bitstreams: 1 arquivototal.pdf: 1934445 bytes, checksum: df85a8fce8aac05573575236c659735e (MD5) / Made available in DSpace on 2017-09-05T12:44:35Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1934445 bytes, checksum: df85a8fce8aac05573575236c659735e (MD5) Previous issue date: 2017-02-16 / Bullfrog meat is a delicacy in many countries and its consumption has expanded in the last decades. The back is a byproduct that presents high nutritional value and its use is being exploited through mechanical deboning, obtaining mechanically separated meat, providing raw material for the elaboration of various food products, which add value to the back, among them surimi. The objective of this study was to study the feasibility of using mechanically separated meat from the back of bullfrogs in the elaboration of surimi gel, evaluating the influence of the number of washing cycles and of different concentrations of corn starch on the characteristics of nutritional quality, Physicochemical properties, sensorial acceptance, and to evaluate its lipid and protein oxidative stability during storage under refrigeration (± 4 ° C) for a period of 60 days. The characterization of the surimi gels was performed from the physicochemical properties of partial chemical evaluation, pH, Aw, CRA, color parameters (L *, a* and b *), texture profile, and nutritional quality through composition Of fatty acids and amino acid profile. The evaluation of oxidative stability was measured by the analysis of TBARS, for lipids, and NBVT, carbonyl compounds and free thiols, for proteins. Sensory acceptance (appearance, taste, color, odor and texture) were also determined. The results showed that the studied variables exerted significant effects on the characteristics of the gels. The washing number was the factor that affected the highest number of parameters studied. Increasing the wash cycles was positive when the lipid content decreased, the gel color improved, the whiteness increased, and the gel firmness improved. Gels have good amounts of polyunsaturated fatty acids (linoleic, linolenic and arachidonic), and it has all the essential amino acids. Changes in oxidative stability were observed during storage, especially after the 30th day. The increase in the number of washing cycles of surimi was an effective method to significantly reduce (p <0.05) the formation of oxidation-indicating compounds, since treatments with higher number of washes had the lowest oxidative values. In sensory evaluation, the preference of the consumers was for firmer and white gels, leading to the choice of treatments 4 and 5, but all the treatments presented means of acceptance index above 70%. It was possible to use DMS in the elaboration of surimi gel, since the processing improved the functional and sensorial properties of this byproduct, making possible the use of the same in food of this genus. / A carne de rã-touro é uma iguaria em muitos países e seu consumo tem se expandido nas últimas décadas. O dorso é um subproduto que apresenta alto valor nutricional e sua utilização está sendo explorada através da desossa mecânica, na obtenção de carne mecanicamente separada, disponibilizando matéria prima para elaboração de diversos produtos alimentares, que venham agregar valor ao dorso, dentre eles o surimi. Neste contexto objetivou-se estudar a viabilidade da utilização da carne mecanicamente separada do dorso de rãstouro na elaboração de gel de surimi, avaliando a influência do número de ciclos de lavagem e de diferentes concentrações de amido de milho sobre as características de qualidade nutricional, propriedades físico-químicas, aceitação sensorial, além de avaliar sua estabilidade oxidativa lipídica e proteica durante armazenamento sob refrigeração (±4 °C) por um período de 60 dias. A caracterização dos géis de surimi foi realizada a partir das propriedades físicoquímicas de avaliação química parcial, pH, Aa, CRA, parâmetros de cor (L*, a* e b*), perfil de textura, e a qualidade nutricional através da composição dos ácidos graxos e perfil aminoacídico. A avaliação da estabilidade oxidativa foi medida a partir da análise de TBARS, para lipídeos, e NBVT, compostos carbonílicos e tióis livres, para proteínas. A aceitação sensorial (aparência, sabor, cor, odor e textura) também foram determinados. Os resultados demonstraram que as variáveis estudadas exerceram efeitos significativo nas características dos géis. Sendo o número de lavagem o fator que afetou o maior número de parâmetros estudados. O aumento dos ciclos de lavagens foi positivo quando diminuiu o teor de lipídios, aperfeiçoou a cor do gel, aumentando o valor da brancura, e melhorou a firmeza do gel. Os géis possuem boas quantidades de ácidos graxos poliinsaturados (linoleico, linolênico e araquidônico), e apresenta todos os aminoácidos essenciais. Foi observado alterações na estabilidade oxidativa durante o armazenamento, sobretudo após o 30º dia. O aumento do número de ciclos de lavagem do surimi foi um método eficaz para reduzir significativamente (p <0,05) a formação dos compostos indicadores da oxidação, pois os tratamentos com maior número de lavagens apresentaram os menores valores oxidativos. Na avaliação sensorial, a preferência dos consumidores foi por géis mais firmes e brancos, conduzindo a escolha dos tratamentos 4 e 5, porém todos os tratamentos apresentaram médias do índice de aceitação acima de 70%. Foi viável a utilização do DMS na elaboração de gel de surimi, pois o processamento melhorou as propriedades funcionais e sensoriais desse subproduto, tornando possível a utilização do mesmo em alimentos desse gênero.
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Caractérisation et généralisation de l’implication de la voie NOTCH cytoplasmique au cours des processus de transition épithélio-mésenchymateuse chez l’embryon de poulet / Enforcement of cytoplasmic Notch pathway implication in epithelio-mesenchymal transition and cell differentiation in chicken embryos

Lebrun, Diane 08 June 2018 (has links)
La transition épithélio-mésenchymateuse (EMT) est un processus incontournable dans de nombreux contextes normaux et pathologiques, tels que gastrulation, organogenèse, fibroses et cancers. Cette transformation de cellule épithéliale en cellule mésenchymateuse est indissociable de l'acquisition de propriétés migratoires et est généralement associée à un changement de destin cellulaire. Différentes voies moléculaires sont impliquées selon le contexte de l'EMT concernée. Récemment, notre laboratoire a mis en évidence que la voie Notch cytoplasmique contrôle l'EMT des cellules de la lèvre dorso-médiale du somite (DML). Les crêtes neurales exprimant DLL1 activent « en passant » le récepteur NOTCH, liberant ainsi le domaine intra-cytoplasmique de NOTCH (NICD). Dans le cytoplasme, NICD inhibe la kinase GSK3ß, conduisant à la stabilisation de SNAIL, un gène maître de la transition épithélio-mésenchymateuse. Il en résulte une libération de la βcaténine des jonctions adhérentes qui, après translocation dans le noyau, active la transcription des gènes de la myogénèse (Myf5). Ainsi, l'activation de la voie Notch cytoplasmique permet une induction concomitante de l'EMT et de la myogénèse. La fonction cytoplasmique de Notch reste controversée et le mécanisme par lequel NICD inhibe GSK3ß reste obscur. Au cours de ma thèse j'ai cherché à élucider le mécanisme par lequel NICD inhibe l'activité kinase de GSK3ß. J'ai confirmé l'interaction de GSK3ß et de NICD en démontrant leur interaction via CoIP. Après avoir démontré l'implication de la sérine-thréonie kinase AKT dans la myogenèse des cellules de la DML, j'ai mis en évidence, via CoIP et électroporation, que l'inhibition GSK3ß par NICD est très certainement médiée par AKT, connue pour être impliquée dans l'EMT et inhiber GSK3ß par phosphorylation. En comparant le NICD1 de poulet et les 4 NICD de souris, j'ai montré que l'expression exogène de ces 5 molécules induit l'EMT et la différenciation myogénique de manière similaire. J'ai aussi montré que parmi des différents domaines de NICD, le domaine RAM, connu pour se lier à l'ADN (via RBPJ), est nécessaire et suffisant à l'inhibition de GSK3ß. Un second axe de ma thèse a été de tester l'implication de la voie Notch cytoplasmique dans d'autres contextes d'EMT. Pour ce faire, j'ai mis en évidence que cette voie est impliquée dans les autres lèvres du dermomyotome mais aussi dans les crêtes neurales qui délaminent du toit du tube neural. J'ai en particulier mis en évidence une co-activation des voies Wnt et Notch, une inhibition de la kinase GSK3ß par NICD cytoplasmique ainsi qu'une inhibition de la différenciation en présence d'une ß-caténine mutée, retenue à la membrane, ou en présence d'une molécule SNAIL2 dominant-négative. Le dernier axe de ma thèse a consisté à élucider le mécanisme de régulation de l'induction de l'EMT et de la myogenèse via l'activation de NICD. Il a été mis en évidence que toutes les cellules de la DML peuvent être activées via DLL1 et que la surexpression massive de NICD dans la DML provoque une différenciation massive et une déplétion du groupe de cellules progénitrices. Afin de déterminer si la régulation de cette initiation se fait avant ou après induction de NICD, j'ai créé un plasmide permettant de répondre à cette question et afin de visualiser son expression in vivo, j'ai initié une collaboration avec une équipe de l'ILM afin de créer un microscope vertical SPIM biphoton permettant l'observation d'embryon de poulets vivants [etc...] / The epithelio-mesenchymal transition (EMT) is a well-known mechanism by which epithelial cells lose their adherent connections and gain migratory properties, associated with a gain of a mesenchymal phenotype. This EMT is required in numerous processes as gastrulation, organogenesis, fibrosis and cancers. Various molecular pathways orchestrate the EMT depending on the EMT biological context. Recently, our laboratory highlighted the implication of the cytoplasmic Notch pathway in the dorso-medial lip (DML) EMT. In the DML tissue, theEMT is synchronized with differentiation pathways, to generate cells forming the primary myotome. Our laboratory showed that neural crests cells expressing DLL1 activate NOTCH receptor of the DML cells, via a “kiss and run” model. This leads to NOTCH cleavage, releasing an activated intra-cytoplasmic NOTCH domain (NICD). In the cytoplasm, NICD inhibits the GSK3ß kinase, leading to the stabilization of SNAIL and the free cytoplasmic ßcatenin. These molecules translocate into the nucleus and lead to the activation of MRF as Myf5 (ß-catenin) and to the repression of adherent genes (SNAIL). Therefore, Notch cytoplasmic pathway allows a synergized induction of both, the EMT and myogenic programs. This pathway remains controversial and the precise mechanism how NICD inhibits GSK3ß needs to be elucidated. Therefore, the aim of my thesis project was to clarify how NICD inhibits GSK3ß activity. First, I confirmed that NICD and GSK3ß physically interact by CoIP. Moreover, I demonstrated that the serin-threonin kinase AKT, known to inhibit GSK3ß by phosphorylation and also to mediate EMT in cancer, can physically interact with NICD in the cytoplasm. I have also shown that AKT mediates the induction of the myogenic program through the inhibitory phosphorylation of GSK3ß and that SNAIL is downstream of AKT. Together, these experiments indicate that AKT mediates, through phosphorylation, the cytoplasmic NICD inhibition of GSK3ß leading to myogenesis. A comparison of the chicken NICD1 and the 4 isoforms of mouse NICD highlighted that these 5 proteins induce EMT and myogenesis similarly. The dissection of the different conserved domains in the 5 different NICD proteins demonstrated that the RAM domain, known to activate transcription by binding to RBPJ, is necessary and sufficient for GSK3ß inhibition. A second axis of the thesis has been to test the involvment of the cytoplasmic Notch pathway in other EMT contexts. First, I highlighted that this pathway induces myogenesis, showing that NICD inhibits GSK3ß activity in the ventro-lateral lip. I further demonstrated that the cytoplasmic Notch pathway is implicated in the EMT and differentiation of the neural crests cells delaminating from the dorsal neural tube. Particularly, I have shown a co-activation of the Wnt and Notch pathway in premigratory and migratory neural crests. Moreover, I demonstrated a cytoplasmic inhibition of the kinase activity of GSK3ß by NICD, as well as the induction of the differentiation by cytoplasmic ß-catenin or SNAIL2. In a third axis of my thesis, I tried to clarify the regulatory mechanism involved in Notch activation. Previously it has been demonstrated that in all the DML cells Notch can be activated by an overexpression of DLL1 and that an ectopic expression of NICD in the DML cells induce a massive differentiation and depletion of the progenitor pool. To determine if the regulation of this initiation of the myogenic program occurs before or after Notch activation, I designed a plasmid to visualize Notch activation in vivo. In order to be able to follow the DLM cells and Notch activation in vivo, I initiated a collaboration with an ILM team to create a vertical SPIM biphoton microscope. In the future, this microscope will allow us to follow cells in living chicken embryos [etc...]

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