NCube/papyrus huggingface dataset:
Analyse fonctionnelle du gène BMP-2 lors de la régénération du membre chez l’axolotl

Urodele amphibians (e.g. the axolotls) have a remarkable ability to regenerate parts of their body. They will, among other things, fully regenerate an amputated limb by epimorphosis, a biphasic process comprising a preparation phase, specific to the regeneration, and a redevelopment phase, common to epimorphosis and embryonic development. During the preparation phase, the cells of the stump dedifferentiate into embryonic-like cells, proliferate and migrate distally from the level of amputation to form a regeneration blastema. Among vertebrates, the process of dedifferentiation is unique to urodeles. To better understand the molecular control of regeneration in urodeles, we chose to study BMP-2, a growth factor, because of its involvement in mammalian digit tip regeneration. The transcription factor MSX-1 has also been selected because of its ability to induce cellular dedifferentiation in vitro and its potential interaction with BMPs signaling. The results presented in this thesis show that BMP-2 and MSX-1 are expressed during phases of preparation and redevelopment of epimorphosis, and their spatio-temporal expression profiles are very similar at each stage of epimorphosis, suggesting an interaction of their signals during regeneration. In addition, in tetrapod amniotes, the expression of Shh is restricted to the posterior mesenchyme of developing limbs and overlaps with the expression of BMP-2. However, the expression of BMP-2 is not restricted to the posterior region but forms a posterior-anterior gradient. Shh is the main regulator of the anterior-posterior pattern formation of developing limbs. Given the overlapping expression domains of Shh and BMP-2, and the expression restriction of Shh in posterior, Shh is believed to iv regulate the pattern formation of developing limbs by the activation of BMP-2 expression. Interestingly, the axolotl also expresses Shh in the posterior region, but the limb develops from anterior to posterior rather than posterior to anterior as in other tetrapods, and this, during development and epimorphosis. We used this feature of the axolotl to demonstrate that Shh signaling does not regulate pattern formation through BMP-2. Indeed, the expression of BMP-2 is not regulated by the inhibition of hh signaling, and its expression is opposite to that of Shh during development and regeneration of the axolotl limb. It was observed, during limb development in mice that MSX-1 is regulated by Shh signaling. Our results suggest that in the axolotl, MSX-1 is not regulated by the inhibition of Shh signaling during limb regeneration. Furthermore, we demonstrated that unlike the expression of Shh, the expression of BMP-2 is correlated with the order of formation of the phalanges, is involved in cell condensation and apoptosis preceding chondrogenesis. Taken together, these results suggest a role for BMP-2 in the initiation of endochondral ossification. Finally, we demonstrated that BMP signaling is essential for the redevelopment phase of limb epimorphosis.

Keyphrases: Regeneration, Axolotl, Axolotl, BMP-2, BMP-2, MSX-1, MSX-1, blastema
Étude de la pharmacologie de ligands du récepteur EP4 de prostaglandine E2

Prostaglandin E2 (PGE2) is a lipid hormone mediator widely produced in the body, including in the kidney where it acts locally to regulate renal function. Classically, the PGE2 receptor EP4 has been classified as coupling to the Gαs subunit, leading to intracellular cAMP increases. However EP4 signaling has been revealed to be more complex and also involves coupling to PTX-sensitive Gαi proteins and ß-arrestin mediated effects. There are now many examples of selective activation of independent pathways by G-protein coupled receptor (GPCR) ligands, a concept referred to as functional selectivity that could be exploited for the development of more specific and efficacious drugs.  In a first study, the potencies and efficacies of a panel of EP4 ligands were systematically determined for the activation of Gαs, Gαi and ß-arrestin relative to the endogenous ligand PGE2. For this purpose, three bioluminescence resonance energy transfer (BRET) assays were adapted to evaluate the respective pathways in living cells. Our results suggest considerable functional selectivity among the tested, structurally related agonists and have implications for the use of PGE2 analogues in experimental and possibly clinical settings, as their activity spectra on EP4 differ from that of the native agonist. The BRET-based methodology used for this first systematic assessment of a set of EP4 agonists should be applicable for the study of other GPCRs. In a second study, peptides were derived from extracellular juxtamembranous regions of the EP4 receptor following the rationale that peptides that target regions of the receptor remote of the ligand-binding site might modulate a subset of the EP4-mediated activities. Acute renal failure is a serious medical complication characterized by an abrupt and sustained decline in renal function and for which there is currently no effective treatment. Our results show that the optimized EP4-derived peptidomimetic THG213.29 significantly improved renal functions and histological changes in acute renal failure induced by either cisplatin or renal artery occlusion in Sprague-Dawley rats. THG213.29 did not displace PGE2 binding to EP4, but modulated PGE2 binding dissociation kinetics, indicative of an allosteric binding mode. THG213.29 exhibited functional selectivity, as it partially inhibited EP4-mediated cAMP production but did not affect Gαi activation or ß-arrestin recruitment. Our results demonstrate that THG213.29 represents a novel class of diuretic agent with noncompetitive allosteric modulator effects on EP4 receptor function for improving renal function following acute renal failure.

Keyphrases: PGE2, BRET, Prostaglandin, EP4, G protein-coupled receptor, functional selectivity, allosteric, acute renal failure, peptidomimetic, signaling, GPCR
Analyse cinétique des rétinaldéhydes déshydrogénases recombinantes de type 3 et 4 de souris

SUMMARY         Retinal dehydrogenases (RALDHs) catalyze the dehydrogenation of retinal into retinoic acids (RA) that are required for embryogenesis and tissue differentiation. This study sought to determine the detailed kinetic properties of 2 mouse RALDHs, namely RALDH3 and 4, for retinal isomer substrates, to better define their specificities in RA isomer synthesis.          RALDH3 and 4 were expressed as His-tagged proteins and affinity-purified. RALDH3 oxidized all-trans retinal with high catalytic efficiency but did not show activity for either 9-cis or 13-cis retinal substrates. RALDH4 was inactive for all-trans retinal substrate, exhibited high activity for 9-cis retinal oxidation, and oxidized 13-cis retinal with lower catalytic efficiency.          β-ionone, a potent inhibitor of RALDH4 activity, suppressed 9-cis and 13-cis retinal oxidation competitively, but had no effect on RALDH3 activity. The p-HMB inhibited the activity for both RALDH3 and RALDH4. The divalent cation MgCl2 activated 13-cis retinal oxidation by RALDH4 by 3-fold, slightly decreased 9-cis retinal oxidation, and did not significantly influence RALDH3 activity.         These data extend the kinetic characterization of RALDH3 and 4, providing their specificities for retinal isomer substrates, which should help in determining their functions in the synthesis of RAs in specific tissues.

Keyphrases: Retinoic acids, Aldehyde dehydrogenases, Retinal isomers, Retinal dehydrogenases, β-Ionone, β-Ionone
De l'ethnicité dans les langages musicaux contemporains : au-delà de l'exotisme : processus de composition de quatre oeuvres : Deux tempêtes et une langueur, Sept gestes ludiques, Azabache, Landocinogena

This Memory of Master Degree presents the analyses of the four works composed during the program (from Autumn 2007 to Autumn 2008): Two Storms and a Languor (cello and piano), Seven Playful Gestures (violin, horn and piano), Azabache (music for contemporary dance, six musicians) and Landocinógena (orchestra).  Those projects have different compositional concepts.  Nevertheless, the sources of oral musical traditions are the common link between the most of them.  This view has conducted my interest to develop a co-direction in the field of Compositions and Ethnomusicology. These analyses will be preceded by a contextual Introduction and will close with some reflexives conclusions.

Keyphrases: Research-creation, Contemporary, Oral tradition, Amérique latine, Latin America, Subsaharan Africa, Perception, Perception
Trois compositions, trois genres musicaux et une démarche programmatique : Le chat noir, La nébuleuse de la tour, Le livre de Thot

This thesis presents the results of my research project which consisted in elaborating and testing my compositional approach in three musical forms, namely, electroacoustic, instrumental, and mix. My aim was to systematize my approach—which belongs essentially with romantic aesthetics—and to make it uniform by combining program music, graphic partitions, and other modern compositional techniques. The first chapter is devoted to the detailed and commented description of the three stages of my creation process : program, analysis, as well as form and structure. To test my approach, I have composed three pieces, 1- Le chat noir, a mixed piece for gamelan, recording and real-time processing  inspired by a novel by Edgar Allan Poes, 2- La nébuleuse de la tour, an electroacoustic  piece based on a graphic partition and performed on guitar and trombone, and 3- Le livre de Thot, for string trio and piano and performed in four movements inspired by four tarot cards. These three pieces are described and analyzed in chapters two, three, and four respectively.

Keyphrases: compositional approach, program music, instrumental music, mixed music, electroacoustic, gamelan, string trio with piano
Entre nationalisme et modernité : le répertoire pour le piano de la péninsule ibérique des années 1886-1927

This essay targets the musical language of the art music piano repertoire of the Iberian Peninsula, covering the years 1886 to 1927, pianistic composition having known an unprecedented effervescence in Iberian music history between the end of the XIXth and the beginning of the XXth Century. One finds in the ensemble of works hereby studied a will for national expression and a concern for the research of a modern musical style. In these works, national expression materializes mainly through the borrowing of Iberian folk and popular musical material, as well as by the evocation of peninsular life. On the other hand, the quest for musical modernity draws its inspiration from aesthetic and stylistic elements of French, Russian and Central-European modernism. The works studied are those of three Portuguese composers: Luiz Costa (1879-1960), Francisco de Lacerda (1869-1934) and Fernando Lopes-Graça (1906-1994) and four Spanish composers: Isaac Albéniz (1860-1909), Enrique Granados (1867-1916), Manuel de Falla (1876-1946) and Federico Mompou (1893-1987). The musical language of these works is mainly analyzed in terms of form, harmony and texture, whereas historical and biographical information brings context to this analysis. Each chapter attempts to address a particular issue or phenomenon proper to the studied work (or group of works) and offers some elements of reflection concerning the interrogations raised by musical analysis.

Keyphrases: Portugal, Spain, Modernism, Music, Analysis
« Tomorrow Belongs To Me » : représentations de la femme dans une ballade suprémaciste blanche

This Master’s thesis examines the intertextuality processes related to female gender representation in the folk and soft rock music culture and examines the mechanisms by which those are hijacked by tenants of white supremacism. The research focuses solely on the analysis of a folk ballad for voice and piano: Tomorrow Belongs To Me, as recorded by Swedish racist songstress Saga. This arrangement of an excerpt from the movie soundtrack Cabaret raises the issue of the emergence of women on the racist musical scene, as well as the issue of the reception of their music by male militants. The thesis shows that Saga’s esthetic allows her to conform herself to the codes of a male-dominated milieu, as well as to defy them simultaneously, thus allowing her to assimilate a fascist ideology to the expression and experience of womanhood.In its first section, the paper is based upon the semiological analysis of the musical components of the piece, supported by musicological and sociological literature about folk and mass music, as well as by interviews aiming at collecting inter-objective comparison material from the participants, according to Tagg’s model. The analysis is then grounded ona holistic approach, which integrates a text analysis, providing the setting as context in addition to the understanding of that piece as propaganda, with the aim to understand the new forms of rhetoric employed in racist music.

Keyphrases: Popular music, Far-right, Genre, Gender, Semiology
Étude de la relation entre l’engagement organisationnel et la détresse psychologique chez les travailleurs et les travailleuses

The multi-dimensional concept of organizational commitment is a key criterion of the quality of mental health in the work life. Moreover, many researchers clearly showed that organizational commitment is associated with mental health. However, many studies, up to today, contradict themselves to determine the direction of the relationship between organizational commitment and mental health problems, including psychological distress.  The aim of the study is to determine (a) the direction of the relationship between the multidimensional construct of organizational commitment and psychological distress among men and women workers, and (b) whether the gender status acts as a moderator of the relationship between organizational commitment and psychological distress. The results were obtained from a population of two hundred and sixty-one workers from a Canadian insurance company.  The study found that organizational commitment is a four component construct (affective, normative, continuance, resigned). The multiple regression analysis revealed that affective and continuance commitment influence negatively psychological distress. More specifically, an employee displaying a strong affective or continuance commitment, is less likely to experience psychological distress at work. Moreover, the results of our study suggest that “resigned” commitment influences positively psychological distress. Therefore, workers showing signs of resignation at work, are more likely to experience psychological distress. However, results indicate that normative commitment is not associated with psychological distress. Finally, the gender status only acts as a moderator of the relationship between affective commitment and psychological distress. The implications of these results are discussed.

Keyphrases: Organizational commitment, Psychological distress, Gender, Mental health
Die Wahrnehmung des Fremden im Caoba-Zyklus von B. Traven

The fictitious retelling of the events of the Mexican Revolution in the six novels of the Caoba cycle shows the consequences of colonialism. It also shows the social and economic injustices under which Mexican indigenous peoples suffered. The distinctive character of the native is well shown in the context of the cultural conflict between the colonizer and the colonized. The examination of the portrayal of the native section of the population is the major aim of the following thesis, which combines a narratological and postcolonial approach. The examination of selected text extracts shows, how and to what extent the German-speaking author is detached from a colonial discourse and if he can be seen as a forerunner of postcolonial discourses. The following central questions guide the analysis: To what extend does the representation of indigenous characters correspond to the one of the "noble savage"? How are the different groups of society portrayed (as individuals, type or allegory)? Which methods does the author employ in order to give the European or Western reader an understanding of the foreign culture? Traven's narrative technique of showing the various societies from different perspectives plays an important role in this respect. In his desire to show societal situations as oppression and exploitation, Traven writes from the perspective of the colonized; but he narrates from the perspective of the colonizer with the intention to understand the dictatorial system. This approach corresponds to the "contrapuntal" method described by Edward E. Said in his work Orientalism. I want to show to which extent the author utilises the "contrapuntal" method in his postcolonial criticism and to which extent it is a real postcolonial criticism. Furthermore, the thesis draws on Homi K. Bhabhas theory of the hybrid contact zones to assess the importance Traven gives to transcultural, viz. reciprocal influences?

Keyphrases: Mexican Revolution, Indigenous peoples, Postcolonialisme, Postcolonialism, Adventure novel
Un análisis del discurso político en el Perú contemporáneo : el caso de Alan García y la cortesía positiva

Peruvian President Alan Garcia is one of the most controversial politicians in Peruvian history. His successful career as a presidential candidate is opposed to the catastrophic results of his first presidential government. Garcia’s discursive skills and the high contrast between his political success and his poor performance as a president have become a myth in Peruvian popular culture.. In this work we will present a pragmatic-linguistic analysis of the discursive strategies used by Garcia in his second administration (2006-2011). The analysis will be focused on the relationship established by Steven Pinker (2007) between Positive Politeness and Communal Sharing. The works of Brown and Levinson (1978, 1987) and Alan Fiske (1991) will be our theoretical groundwork.  Social exclusion in Peruvian electoral population, as explained by Vergara (2007), is the key factor to understand the success of Garcia’s discursive strategy. In his work, Vergara presents a diachronic multi-variable analysis of the Peruvian political situation that explains the rationality behind Peruvian elector’s decisions. Once established the referential political framework, we will proceed with the lexicometric analysis that will help us to identify the discursive strategies used in a previously selected sample of Garcia’s public discourses. In order to match Pinker’s scheme, we will classify these findings according to the positive politeness categorization of Brown and Levinson. Finally, we will associate these results to the Communal Sharing model of social relationship, as defined by Fiske. Our goal is to demonstrate that Garcia’s discursive style is rationally structured to reduce the social gap between the Politician and the Elector.

Keyphrases: Lexicometric analysis, Peru, Alan Garcia, Alan Garcia, Positive politeness, Social exclusion
Mécanismes de recuit dans le silicium implanté par faisceau d’ion caractérisés par nanocalorimétrie

We present the fabrication process, characterization and numerical model allowing the optimization of a new device that allows us to perform nanocalorimetry measurements on a silicon single crystals. The thermal properties of this device allows us to perform measurements at temperature higher than 900 C with a resolution better than 16 C. The device is used to study the ion implantation induced defect dynamic in monocrystalline silicon. Two different behaviours regarding the nucleation of the amorphous phase are observed at 10 and 80 keV. These results are confronted to Monte Carlo simulations based on the interstitial vacancy pair model. The comparison between simulations and measurements show that the model is incomplete as it reproduces only qualitatively some features of the experimental observations. Measurements performed from -110 C in monocrystalline and amorphized silicon implanted with light ions revealed clear differences between structural relaxation in amorphous silicon and defect annealing in monocrystalline silicon. Two processes with activation energies of 0.48 and 0.6 eV are observed after implantation performed in monocrystalline silicon while a uniform heat release associated with a continuous spectrum in terms of activation energy is observed in amorphous silicon.

Keyphrases: relaxation structurelle, surface science, defect, structural relaxation, amorphous silicon
Régulation de l'activité transcriptionnelle du récepteur nucléaire FXR par la ghréline et les modifications post-traductionnelles

The farnesoid X receptor (FXR) is a ligand-activated transcription factor within the nuclear receptor superfamily. FXR is activated by bile acids and plays a crucial role in the regulation of glucose and lipid metabolism and in bile acid homeostasis. Our group has recently identified the contribution of the ghrelin receptor in the regulation of the nuclear receptor PPARγ. Indeed, ghrelin triggers transcriptional activation of PPARγ through a concerted signaling cascade involving Erk1/2 and Akt kinases. These results support the peripheral actions of ghrelin in diseases associated with the metabolic syndrome. It is recognized that there is interplay between PPARγ metabolic cascade and FXR. Here, we demonstrate that ghrelin promotes FXR transcriptional activity in a dose-dependent manner and also promotes its phosphorylation on serine residues. By using truncated ABC and CDEF constructs of FXR, we found that ghrelin induces FXR activity through the AF-1 and AF-2 activation domains. The ghrelin-induced FXR activity is additive to the induction by the selective agonist GW4064. Also, we demonstrate that FXR is the target of sumoylation, another post-translational modification. In particular, FXR is modified by SUMO-1 and SUMO-3 in a ligand-independent manner. SUMO-1 and SUMO-3 promote dose-dependent transcriptional activity of FXR. Our results show that lysine 122 is the prevalent site of sumoylation by SUMO-1, though a compensation mechanism seems to exist between the various sumoylation sites of FXR. With its emerging role in several metabolic cascades, identification of FXR modulators represents a promising approach for the treatment of the metabolic syndrome and type 2 diabetes.

Keyphrases: Bile acids, FXR, Ghrelin, GHS-R1a, Phosphorylation, Nuclear receptors, Sumoylation, Metabolic syndrome, Transcription
Relevé polarimétrique d'étoiles candidates pour des disques de débris

The DEBRIS survey, being performed by the space telescope Herschel, is an unbiased sampling of the debris disks candidates in the solar neighbourhood. In the first part of this thesis, a ground-based polarimetric survey of 108 DEBRIS candidate stars is presented. Using the polarimeter, “La Belle et la Bete,” at the Mont-Megantic Observatory, observations were carried out in order to detect polarization induced by the presence of a debris disk. Due to a low rate of detection, a statistical analysis was performed to compare the polarization between stars owning a debris disk with stars without one. Using Mie scattering theory, a basic model was constructed to estimate the level of polarization produced by dust grains in a debris disk. The results of this model are consistent with our observations. The second part of the thesis presents the optical tests of the polarimeter POL-2, built at Université de Montréal. The James Clerk-Maxwell-Telescope imager SCUBA has been upgraded to SCUBA-2, which is more than one hundred times faster than its predecessor with 500 times more pixels. Likewise, the polarimeter follows the improvement as a new polarimeter, POL-2, was installed on SCUBA-2 in July 2010. In order to verify the optical performance of POL-2, tests were completed at the submillimeter laboratories at the University of Western Ontario in June 2009, and the University of Lethbridge in September 2009. These tests and their implications for future observations are discussed.

Keyphrases: Instrumentation, Circumstellar matter, Instrumentation: polarimeters, Scattering, Stars: individual (HR 8799, HD 115404), Surveys, Polarization