Novel CO2 Regulated Proteins in Synechocystis PCC 6803

The large biodiversity of cyanobacteria together with the increasing genomics and proteomics metadata provide novel information for finding new commercially valuable metabolites. With the advent of global warming, there is growing interest in the processes that results in efficient CO2 capture through the use of photosynthetic microorganisms such as cyanobacteria. This requires a detailed knowledge of how cyanobacteria respond to the ambient CO2. My study was aimed at understanding the changes in the protein profile of the model organism, Synechocystis PCC 6803 towards the varying CO₂ level. In order to achieve this goal I have employed modern proteomics tools such as iTRAQ and DIGE, recombinant DNA techniques to construct different mutants in cyanobacteria and biophysical methods to study the photosynthetic properties. The proteomics study revealed several novel proteins, apart from the well characterized proteins involved in carbon concentrating mechanisms (CCMs), that were upregulated upon shift of the cells from high CO₂ concentration (3%) to that in air level (0.039%). The unknown proteins, Slr0006 and flavodiiron proteins (FDPs) Sll0217-Flv4 and Sll0219-Flv2, were selected for further characterization. Although slr0006 was substantially upregulated under C_i limiting conditions, inactivation of the gene did not result in any visual phenotype under various environmental conditions indicating that this protein is not essential for cell survival. However, quantitative proteomics showed the induction of novel plasmid and chromosome encoded proteins in deltaslr0006 under air level CO₂ conditions. The expression of the slr0006 gene was found to be strictly dependent on active photosynthetic electron transfer. Slr0006 contains conserved dsRNA binding domain that belongs to the Sua5/YrdC/YciO protein family. Structural modelling of Slr0006 showed an alpha/beta twisted open-sheet structure and a positively charged cavity, indicating a possible binding site for RNA. The 3D model and the co-localization of Slr0006 with ribosomal subunits suggest that it might play a role in translation or ribosome biogenesis. On the other hand, deletions in the sll0217-sll218- sll0219 operon resulted in enhanced photodamage of PSII and distorted energy transfer from phycobilisome (PBS) to PSII, suggesting a dynamic photoprotection role of the operon. Constructed homology models also suggest efficient electron transfer in heterodimeric Flv2/Flv4, apparently involved in PSII photoprotection. Both Slr0006 and FDPs exhibited several common features, including negative regulation by NdhR and ambiguous cellular localization when subjected to different concentrations of divalent ions. This strong association with the membranes remained undisturbed even in the presence of detergent or high salt. My finding brings ample information on three novel proteins and their functions towards carbon limitation. Nevertheless, many pathways and related proteins remain unexplored. The comprehensive understanding of the acclimation processes in cyanobacteria towards varying environmental CO₂ levels will help to uncover adaptive mechanisms in other organisms, including higher plants.

Concomitant infection of Neospora caninum and Bovine Herpesvirus type 5 in spontaneous bovine abortions

Bovine Herpesvirus type 5 (BoHV-5) has not been conclusively demonstrated to cause bovine abortion. Brain lesions produced by Neospora caninum and Bovine Herpesvirus type 1 (BoHV-1) exhibit common features. Therefore, careful microscopic evaluation and additional diagnostic procedures are required to achieve an accurate final etiological diagnosis. The aim of the present work was to investigate the occurrence of infections due to BoHV-1, BoHV-5 and N. caninum in 68 cases of spontaneous bovine abortions which showed microscopic lesions in the fetal central nervous system. This study allowed the identification of 4 (5.9%) fetuses with dual infection by BoHV-5 and N. caninum and 33 (48.5%) cases in which N. caninum was the sole pathogen identified. All cases were negative to BoHV-1. The results of this study provide evidence that dual infection by BoHV-5 and N. caninum occur during pregnancy in cattle; however, the role of BoHV-5 as a primary cause of bovine abortion needs further research. Molecular diagnosis of BoHV-5 and N. caninum confirmed the importance of applying complementary assays to improve the sensitivity of diagnosing bovine abortion.

Role of the extracellular matrix in variations of invasive pathways in lung cancers

Among the most common features of highly invasive tumors, such as lung adenocarcinomas (AD) and squamous cell carcinomas (SqCC), is the massive degradation of the extracellular matrix. The remarkable qualitative and quantitative modifications of hyaluronidases (HAases), hyaluronan synthases (HAS), E-cadherin adhesion molecules, and the transforming growth factor β (TGF-β) may favor invasion, cellular motility, and proliferation. We examined HAase proteins (Hyal), HAS, E-cadherin, and TGF-β profiles in lung AD subtypes and SqCC obtained from smokers and non-smokers. Fifty-six patients, median age 64 years, who underwent lobectomy for AD (N = 31) and SqCC (N = 25) were included in the study. HAS-1, -2 and -3, and Hyal-1 and -3 were significantly more expressed by tumor cells than normal and stroma cells (P < 0.01). When stratified according to histologic types, HAS-3 and Hyal-1 immunoreactivity was significantly increased in tumor cells of AD (P = 0.01) and stroma of SqCC (P = 0.002), respectively. Tobacco history in patients with AD was significantly associated with increased HAS-3 immunoreactivity in tumor cells (P < 0.01). Stroma cells of SqCC from non-smokers presented a significant association with HAS-3 (P < 0.01). Hyal, HAS, E-cadherin, and TGF-β modulate a different tumor-induced invasive pathway in lung AD subgroups and SqCC. HAases in resected AD and SqCC were strongly related to the prognosis. Therefore, our findings suggest that strategies aimed at preventing high HAS-3 and Hyal-1 synthesis, or local responses to low TGF-β and E-cadherin, may have a greater impact in lung cancer prognosis.

Effects of grape powder supplementation on inflammatory and antioxidant markers in hemodialysis patients: A randomized double-blind study

Introduction: Polyphenols contained in natural sources such as grapes, have been considered pharmacological agents to combat oxidative stress and inflammation, common features in Chronic Kidney Disease patients. Objective: To evaluate the effects of grape powder supplementation on inflammatory and antioxidant biomarkers in hemodialysis (HD) patients. Methods: The double-blind placebo-controlled randomized clinical trial evaluated non-diabetic HD patients that received grape powder (500 mg of polyphenols/day) (n = 16, 9 men, 53.0 ± 9.8 years of age, 111.6 ± 58.2 HD months) or placebo (n = 16, 9 men, 52.7 ± 13.7 years of age, 110.4 ± 93.1 HD months) for five weeks. The glutathione peroxidase (GSH-Px) activity and C-reactive protein (CRP) levels were evaluated by ELISA method. Results: After the intervention period, the patients receiving grape powder showed an increase in the GSH-Px activity (16.5 (41.0) to 42.0 (43.3) nmol/min/ml) (p < 0.05) and they did not have the CRP levels increased as seen in placebo group (2.6 (0.28) to 2.8 (0.23 mg/L) (p < 0.05). Conclusion: The use of grape powder as phenolic source could play an important role as an antioxidant and anti-inflammatory agent in non-diabetic HD patients.

The neo-liberal state and the crisis of public service broadcasting in the Anglo-American democracies /

The NeO'liberal State and the Crisis ofPublic Service Broadcasting in the Anglo-American Democracies The purpose ofthis analysis ofthe present condition ofpublic service broadcasting in the Anglo- American democracies was to investigate whether such media can still be regarded as the primarypublic spherefor a dialogue between each nation 's civil society and the State. The motivationfor this thesis was based on a presumption that such fora for public discussion on the central issues of each society have become viewed as less relevant bypoliticians andpolicy-makers and thepublics they were intended to serve in the Anglo-American democracies over thepast two decades. It is speculated that this is the case because ofa beliefthat the post-war consensus between the respective States andpublics that led to the construction of the Keynesian Welfare State and the notion ofpublic service broadcasting has been displaced by an individualistic, neo-liberal, laissez-faire ideology. In other words, broadcasting as a consumer-oriented, commercial commodity has superseded concerns pertaining to the importance ofthe public interest. The methodology employed in this thesis is a comparative analysisfrom a criticalpolitical economy perspective. It was considered appropriate to focus on the United Kingdom, Australia, Canada and the\ United States because they comprise the four largest Anglo-American nations with democratic political systems andprimarily market economies. Justificationfor this particular sample is reinforced by thefact that case study countries also share a common socio-political and economic tradition. The evidence assembledfor this thesis consisted almost exclusively ofexisting literature on the subjects ofpublic service broadcasting, global economic andpolitical integration, and the ascendance ofthe 'free-market ' ethos in Western democracies since the late mid- to late-1970s. In essence, this thesis could be considered as a reinterpretation ofthe existing literature relevant to these issues. Several important common features werefound among the political, economic and broadcasting systems of the four case study nations. It is proposed that the prevalence of the neo-liberal world view throughout the political and policy environments of the four countries has undermined the stability and credibility of each nation 's national public service broadcasting organization, although with varying intensity and effect,. Deregulation ofeach nation 's broadcasting system and the supremacy ofthe notion of 'consumer sovereignty' have marginalized the view of broadcasting on any basis other than strictly economic criteria in thefour case study countries. This thesis concludes that,for a reconstruction ofa trulyparticipatory anddemocraticpublicsphere to be realized in the present as well as thefuture, a reassessment ofthe conventional concept ofthe 'public sphere ' is necessary. Therefore, it is recommended that thefocus ofpolicy-makers in each Anglo-American democracy be redirectedfrom that which conceived ofan all-encompassing, large, state-ownedand operated public broadcasting service toward a view which considers alternativeforms ofpublic communication, such as local community and ethnic broadcasting operations, that are likely to be more responsive to the needs of the increasingly diverse and heterogeneous populations that comprise the modem Anglo-American democracies. The traditional conception of public broadcasters must change in accordance with its contemporary environment if the fundamental principles of the public sphere and public service broadcasting are to be realized.

Husserl's approach to transcendental intersubjectivity

It is our intention in the course of the development of this thesis to give an account of how intersubjectivity is "eidetically" constituted by means of the application of the phenomenological reduction to our experience in the context of the thought of Edmund Husserl; contrasted with various representative thinkers in what H. Spiegelberg refers to as "the wider scene" of phenomenology. That is to say, we intend to show those structures of both consciousness and the relation which man has to the world which present themselves as the generic conditions for the possibility of overcoming our "radical sol itude" in order that we may gain access to the mental 1 ife of an Other as other human subject. It is clear that in order for us to give expression to these accounts in a coherent manner, along with their relative merits, it will be necessary to develop the common features of any phenomenological theory of consdousness whatever. Therefore, our preliminary inquiry, subordinate to the larger theme, shall be into some of the epistemological results of the application of the phenomenological method used to develop a transcendental theory of consciousness. Inherent in this will be the deliniation of the exigency for making this an lIintentional ll theory. We will then be able to see how itis possible to overcome transcendentally the Other as an object merely given among other merely given objects, and further, how this other is constituted specifically as other ego. The problem of transcendental intersubjectivity and its constitution in experience can be viewed as one of the most compelling, if not the most polemical of issues in phenomenology. To be sure, right from the beginning we are forced to ask a number of questions regarding Husserl's responses to the problem within the context of the methodological genesis of the Cartesian Meditations, and The Crisis of European Sciences and Transcendental Phenomenology. This we do in order to set the stage for amplification. First, we ask, has Husserl lived up to his goal, in this connexion, of an apodictic result? We recall that in his Logos article of 1911 he adminished that previous philosophy does not have at its disposal a merely incomplete and, in particular instances, imperfect doctrinal system; it simply has none whatever. Each and every question is herein controverted, each position is a matter of individual conviction, of the interpretation given byaschool, of a "point of view". 1. Moreover in the same article he writes that his goal is a philosophical system of doctrine that, after the gigantic preparatory work. of generations, really be- . gins from the ground up with a foundation free from doubt and rises up like any skilful construction, wherein stone is set upon store, each as solid as the other, in accord with directive insights. 2. Reflecting upon the fact that he foresaw "preparatory work of generations", we perhaps should not expect that he would claim that his was the last word on the matter of intersubjectivity. Indeed, with 2. 'Edmund Husserl, lIPhilosophy as a Rigorous Science" in Phenomenology and theCrisis6fPhilosophy, trans". with an introduction by Quentin Lauer (New York.: Harper & Row, 1965) pp. 74 .. 5. 2Ibid . pp. 75 .. 6. 3. the relatively small amount of published material by Husserl on the subject we can assume that he himself was not entirely satisfied with his solution. The second question we have is that if the transcendental reduction is to yield the generic and apodictic structures of the relationship of consciousness to its various possible objects, how far can we extend this particular constitutive synthetic function to intersubjectivity where the objects must of necessity always remain delitescent? To be sure, the type of 'object' here to be considered is unlike any other which might appear in the perceptual field. What kind of indubitable evidence will convince us that the characteristic which we label "alter-ego" and which we attribute to an object which appears to resemble another body which we have never, and can never see the whole of (namely, our own bodies), is nothing more than a cleverly contrived automaton? What;s the nature of this peculiar intentional function which enables us to say "you think just as I do"? If phenomenology is to take such great pains to reduce the takenfor- granted, lived, everyday world to an immanent world of pure presentation, we must ask the mode of presentation for transcendent sub .. jectivities. And in the end, we must ask if Husserl's argument is not reducible to a case (however special) of reasoning by analogy, and if so, tf this type of reasoning is not so removed from that from whtch the analogy is made that it would render all transcendental intersubjective understandtng impos'sible? 2. HistoticalandEidetic Priority: The Necessity of Abstraction 4. The problem is not a simple one. What is being sought are the conditions for the poss ibili:ty of experi encing other subjects. More precisely, the question of the possibility of intersubjectivity is the question of the essence of intersubjectivity. What we are seeking is the absolute route from one solitude to another. Inherent in this programme is the ultimate discovery of the meaning of community. That this route needs be lIabstract" requires some explanation. It requires little explanation that we agree with Husserl in the aim of fixing the goal of philosophy on apodictic, unquestionable results. This means that we seek a philosophical approach which is, though, not necessarily free from assumptions, one which examines and makes explicit all assumptions in a thorough manner. It would be helpful at this point to distinguish between lIeidetic ll priority, and JlhistoricallJpriority in order to shed some light on the value, in this context, of an abstraction.3 It is true that intersubjectivity is mundanely an accomplished fact, there havi.ng been so many mi.llions of years for humans to beIt eve in the exi s tence of one another I s abili ty to think as they do. But what we seek is not to study how this proceeded historically, but 3Cf• Maurice Natanson;·TheJburne in 'Self, a Stud in Philoso h and Social Role (Santa Cruz, U. of California Press, 1970 . rather the logical, nay, "psychological" conditions under which this is possible at all. It is therefore irrelevant to the exigesis of this monograph whether or not anyone should shrug his shoulders and mumble IIwhy worry about it, it is always already engaged". By way of an explanation of the value of logical priority, we can find an analogy in the case of language. Certainly the language 5. in a spoken or written form predates the formulation of the appropriate grammar. However, this grammar has a logical priority insofar as it lays out the conditions from which that language exhibits coherence. The act of formulating the grammar is a case of abstraction. The abstraction towards the discovery of the conditions for the poss; bi 1 ity of any experiencing whatever, for which intersubjective experience is a definite case, manifests itself as a sort of "grammar". This "grammar" is like the basic grammar of a language in the sense that these "rulesil are the ~ priori conditions for the possibility of that experience. There is, we shall say, an "eidetic priority", or a generic condition which is the logical antecedent to the taken-forgranted object of experience. In the case of intersubjectivity we readily grant that one may mundanely be aware of fellow-men as fellowmen, but in order to discover how that awareness is possible it is necessary to abstract from the mundane, believed-in experience. This process of abstraction is the paramount issue; the first step, in the search for an apodictic basis for social relations. How then is this abstraction to be accomplished? What is the nature of an abstraction which would permit us an Archimedean point, absolutely grounded, from which we may proceed? The answer can be discovered in an examination of Descartes in the light of Husserl's criticism. 3. The Impulse for Scientific Philosophy. The Method to which it Gives Rise. 6. Foremost in our inquiry is the discovery of a method appropriate to the discovery of our grounding point. For the purposes of our investigations, i.e., that of attempting to give a phenomenological view of the problem of intersubjectivity, it would appear to be of cardinal importance to trace the attempt of philosophy predating Husserl, particularly in the philosophy of Descartes, at founding a truly IIscientific ll philosophy. Paramount in this connexion would be the impulse in the Modern period, as the result of more or less recent discoveries in the natural sciences, to found philosophy upon scientific and mathematical principles. This impulse was intended to culminate in an all-encompassing knowledge which might extend to every realm of possible thought, viz., the universal science ot IIMathexis Universalis ll •4 This was a central issue for Descartes, whose conception of a universal science would include all the possible sciences of man. This inclination towards a science upon which all other sciences might be based waS not to be belittled by Husserl, who would appropriate 4This term, according to Jacab Klein, was first used by Barocius, the translator of Proclus into Latin, to designate the highest mathematical discipline. . 7. it himself in hopes of establishing, for the very first time, philosophy as a "rigorous science". It bears emphasizing that this in fact was the drive for the hardening of the foundations of philosophy, the link between the philosophical projects of Husserl and those of the philosophers of the modern period. Indeed, Husserl owes Descartes quite a debt for indicating the starting place from which to attempt a radical, presupositionless, and therefore scientific philosophy, in order not to begin philosophy anew, but rather for the first time.5 The aim of philosophy for Husserl is the search for apodictic, radical certitude. However while he attempted to locate in experience the type of necessity which is found in mathematics, he wished this necessity to be a function of our life in the world, as opposed to the definition and postulation of an axiomatic method as might be found in the unexpurgated attempts to found philosophy in Descartes. Beyond the necessity which is involved in experiencing the world, Husserl was searching for the certainty of roots, of the conditi'ons which underl ie experience and render it pOssible. Descartes believed that hi~ MeditatiOns had uncovered an absolute ground for knowledge, one founded upon the ineluctable givenness of thinking which is present even when one doubts thinking. Husserl, in acknowledging this procedure is certainly Cartesian, but moves, despite this debt to Descartes, far beyond Cartesian philosophy i.n his phenomenology (and in many respects, closer to home). 5Cf. Husserl, Philosophy as a Rigorous Science, pp. 74ff. 8 But wherein lies this Cartesian jumping off point by which we may vivify our theme? Descartes, through inner reflection, saw that all of his convictions and beliefs about the world were coloured in one way or another by prejudice: ... at the end I feel constrained to reply that there is nothing in a all that I formerly believed to be true, of which I cannot in some measure doubt, and that not merely through want of thought or through levity, but for reasons which are very powerful and maturely considered; so that henceforth I ought not the less carefully to refrain from giving credence to these opinions than to that which is manifestly false, if I desire to arrive at any certainty (in the sciences). 6 Doubts arise regardless of the nature of belief - one can never completely believe what one believes. Therefore, in order to establish absolutely grounded knowledge, which may serve as the basis fora "universal Science", one must use a method by which one may purge oneself of all doubts and thereby gain some radically indubitable insight into knowledge. Such a method, gescartes found, was that, as indicated above by hi,s own words, of II radical doubt" which "forbids in advance any judgemental use of (previous convictions and) which forbids taking any position with regard to their val idi'ty. ,,7 This is the method of the "sceptical epoche ll , the method of doubting all which had heretofor 6Descartes,Meditations on First Philosophy, first Med., (Libera 1 Arts Press, New York, 1954) trans. by L. LaFl eur. pp. 10. 7Husserl ,CrisiS of Eliroeari SCiences and Trariscendental Phenomenology, (Northwestern U. Press, Evanston, 1 7 ,p. 76. 9. been considered as belonging to the world, including the world itself. What then is left over? Via the process of a thorough and all-inclusive doubting, Descartes discovers that the ego which performs the epoche, or "reduction", is excluded from these things which can be doubted, and, in principle provides something which is beyond doubt. Consequently this ego provides an absolute and apodictic starting point for founding scientific philosophy. By way of this abstention. of bel ief, Desca'rtes managed to reduce the worl d of everyday 1 ife as bel ieved in, to mere 'phenomena', components of the rescogitans:. Thus:, having discovered his Archimedean point, the existence of the ego without question, he proceeds to deduce the 'rest' of the world with the aid of innate ideas and the veracity of God. In both Husserl and Descartes the compelling problem is that of establ ishing a scientific, apodictic phi'losophy based upon presuppos itionless groundwork .. Husserl, in thi.s regard, levels the charge at Descartes that the engagement of his method was not complete, such that hi.S: starting place was not indeed presupositionless, and that the validity of both causality and deductive methods were not called into question i.'n the performance of theepoche. In this way it is easy for an absolute evidence to make sure of the ego as: a first, "absolute, indubitablyexisting tag~end of the worldll , and it is then only a matter of inferring the absolute subs.tance and the other substances which belon.g to the world, along with my own mental substance, using a logically val i d deductive procedure. 8 8Husserl, E.;' Cartesian 'Meditation;, trans. Dorion Cairns (Martinus Nijhoff, The Hague, 1970), p. 24 ff.

HG 303.85-303.95

This is a dark grey, coarse grained sediment with inclusions of fine grained sand. Lineations and grains stacking are the most common features seen, along with grain crushing (mainly edge-to-edge). A few minor rotation structures can also be observed with comet structures.

Wage Policy of Firms: an Empirical Investigation.

This paper analyzes the dynamics of wages and workers' mobility within firms with a hierarchical structure of job levels. The theoretical model proposed by Gibbons and Waldman (1999), that combines the notions of human capital accumulation, job rank assignments based on comparative advantage and learning about workers' abilities, is implemented empirically to measure the importance of these elements in explaining the wage policy of firms. Survey data from the GSOEP (German Socio-Economic Panel) are used to draw conclusions on the common features characterizing the wage policy of firms from a large sample of firms. The GSOEP survey also provides information on the worker's rank within his firm which is usually not available in other surveys. The results are consistent with non-random selection of workers onto the rungs of a job ladder. There is no direct evidence of learning about workers' unobserved abilities but the analysis reveals that unmeasured ability is an important factor driving wage dynamics. Finally, job rank effects remain significant even after controlling for measured and unmeasured characteristics.

The FCLT with Dependent Errors: an Helicopter Tour of the Quality of the Approximation

This note investigates the adequacy of the finite-sample approximation provided by the Functional Central Limit Theorem (FCLT) when the errors are allowed to be dependent. We compare the distribution of the scaled partial sums of some data with the distribution of the Wiener process to which it converges. Our setup is purposely very simple in that it considers data generated from an ARMA(1,1) process. Yet, this is sufficient to bring out interesting conclusions about the particular elements which cause the approximations to be inadequate in even quite large sample sizes.

Finite-Sample Diagnostics for Multivariate Regressions with Applications to Linear Asset Pricing Models

In this paper, we propose several finite-sample specification tests for multivariate linear regressions (MLR) with applications to asset pricing models. We focus on departures from the assumption of i.i.d. errors assumption, at univariate and multivariate levels, with Gaussian and non-Gaussian (including Student t) errors. The univariate tests studied extend existing exact procedures by allowing for unspecified parameters in the error distributions (e.g., the degrees of freedom in the case of the Student t distribution). The multivariate tests are based on properly standardized multivariate residuals to ensure invariance to MLR coefficients and error covariances. We consider tests for serial correlation, tests for multivariate GARCH and sign-type tests against general dependencies and asymmetries. The procedures proposed provide exact versions of those applied in Shanken (1990) which consist in combining univariate specification tests. Specifically, we combine tests across equations using the MC test procedure to avoid Bonferroni-type bounds. Since non-Gaussian based tests are not pivotal, we apply the “maximized MC” (MMC) test method [Dufour (2002)], where the MC p-value for the tested hypothesis (which depends on nuisance parameters) is maximized (with respect to these nuisance parameters) to control the test’s significance level. The tests proposed are applied to an asset pricing model with observable risk-free rates, using monthly returns on New York Stock Exchange (NYSE) portfolios over five-year subperiods from 1926-1995. Our empirical results reveal the following. Whereas univariate exact tests indicate significant serial correlation, asymmetries and GARCH in some equations, such effects are much less prevalent once error cross-equation covariances are accounted for. In addition, significant departures from the i.i.d. hypothesis are less evident once we allow for non-Gaussian errors.

L'esprit de corps à l'oeuvre dans les équipes de football universitaire

Sur la base d’une étude des équipes de football universitaire, le présent mémoire de maîtrise cherche à mettre en évidence les éléments de l’« esprit de corps » — c’est-à-dire l’adhésion pas forcément consciente « des individus aux valeurs et à la valeur d’un groupe qui, en tant que corps intégré, dispose des espèces d’échanges propres à renforcer l’intégration et la solidarité entre ses membres » (Bourdieu, 1989, p. 258) — qui peuvent être applicables à ce groupe donné tout en analysant de quelle façon cette notion vient influencer les performances des équipes. En s’appuyant sur des notes de terrain recueillies lors d’une observation exploratoire et sur des entretiens semi-dirigés réalisés auprès de joueurs de football qui jouent ou qui ont joué au niveau universitaire, ce mémoire a pour objectif de mieux saisir en quoi un esprit de corps présent à l’intérieur d’une équipe de football vient influencer les performances de celle-ci. Sur la base des données recueillies, une équipe présentant un fort esprit de corps en ses rangs voit ses performances la mener au succès. Lorsque les composantes de l’esprit de corps sont présentes, partagées par tous les joueurs et suivies à la lettre, les équipes sont appelées à mieux performer dans la ligue de football universitaire, contrairement à d’autres formations où certains éléments caractérisant l’esprit de corps ont une importance moindre.

Étude de l'impact de combinaisons d'acides gras et de l'insuline sur la fonctionnalité des cellules musculaires lisses vasculaires

L’athérosclérose est étroitement liée au diabète de type 2. De fortes concentrations plasmatiques en acides gras libres (AGL) et en insuline sont des caractéristiques retrouvées chez les patients souffrant de ces deux pathologies. Les AGL, présents dans notre alimentation, font partie de l’environnement auquel les cellules sont exposées. Leurs effets dépendent de leur nature, les acides gras saturés (AGS) étant néfastes et les acides gras monoinsaturés (AGMI) plus protecteurs. Ils ont donc des effets variés sur les cellules musculaires lisses vasculaires (CMLV) impliquées dans la pathogénèse de l’athérosclérose. Ainsi, l’objectif principal de ce projet de maîtrise était d’évaluer l’impact de deux combinaisons d’AGL sur la viabilité des CMLV, en condition hyperinsulinémique ou non. Les deux combinaisons renfermaient les mêmes AGL mais en proportions différentes, l’une étant plus riche en AGS et l’autre en AGMI. Nos résultats ont montré que les combinaisons d’AGL ont un effet pro-apoptotique principalement dû aux AGS. L’acide oléique présent dans les combinaisons atténue cependant cet effet. Il diminue même plus fortement l’apoptose des CMLV lorsqu’associé à un AGS que lorsqu’utilisé seul. Cet impact est significatif uniquement dans certaines proportions de ces AGL et est plus efficace en présence d’insuline. Ces résultats mettent en lumière la présence d’une compétition entre mécanismes anti- et pro-apoptotiques en fonction des proportions d’AGS versus AGMI et de l’insulinémie chez les CMLV. Ils soulignent également l’importance de la présence des AGMI dans les diètes riches en AGS et pourraient être utiles pour l’élaboration de nouvelles diètes adaptées aux patients athérosclérotiques et diabétiques.

Rôle du facteur de transcription PITX1 dans la pathogenèse de l'arthrose.

L'arthrose ou ostéoarthrite (OA) est la plus commune des maladies chroniques associées au vieillissement. La multiplicité des loci et des polymorphismes associés à l'OA suggère l'implication de nombreuses voies de signalisation. La plupart des voies empruntées partagent des points en commun avec le processus d'ossification endochondrale. Dans l'arthrose, la réinitiation de ce processus pourrait être responsable de la dégradation du cartilage et de la présence d'ostéophytes. Un des gènes ayant fait surface autant dans l'OA que dans le développement musculosquelettique est PITX1. Contrairement à ce que son nom l'indique, PITX1 n'est pas seulement exprimé dans la glande pituitaire mais également dans l'os, le cartilage, les muscles et les fibroblastes. Pitx1 joue un rôle clé dans l'identité des membres inférieurs et son inactivation complète chez la souris mène à un phénotype ressemblant aux membres supérieurs. Moins sévère, son inactivation partielle provoque des symptômes apparentés à l'arthrose précoce chez la souris vieillissante. Chez l'humain, une perte d'expression de PITX1 est observée dans le cartilage OA de concert avec une augmentation des protéines EXTL3, REG1 et PARP1. Ces dernières pourraient favoriser la phase initiale de régénération associée à l'arthrose. Pour induire la prolifération des chondrocytes, de bas niveaux de PITX1 sont nécessaires. À l'inverse, de hauts niveaux de PITX1 pourraient prévenir la prolifération et être responsables du statut différencié des chondrocytes articulaires normaux. L'étude des mécanismes de régulation du gène PITX1 a mené à l'identification d'un co-répresseur, nommé prohibitine (PHB1), lié sur une région promotrice distale. PHB1 est normalement retrouvé au niveau des mitochondries mais son accumulation nucléaire semble corréler avec la perte de PITX1 et l'initiation de l'OA. Cette découverte pourrait avoir un impact sur le diagnostic et d'éventuels traitements visant à prévenir l'apparition de l'arthrose.

«Comment je suis devenu toxicomane» : le point de vue d’hommes ayant une dépendance aux drogues

La toxicomanie est un problème bien réel dans la société québécoise. Cette problématique touche autant les hommes que les femmes, de tous les âges et de toutes les sphères de la société. Toutefois, les hommes adultes étant plus nombreux à utiliser les services en réadaptation des toxicomanies, le but de ce mémoire est de donner une voix à ces hommes, afin de connaitre leurs visions sur les trajectoires qui les ont menées vers cette problématique. Les témoignages de six hommes adultes ayant une dépendance à l’alcool ou aux drogues ont donc été recueillis à l’aide d’entrevues de type récit de vie. Les résultats qui se dégagent de ces histoires de vie viennent, d’un côté, corroborer certaines données de la littérature, mais mettent aussi en lumière de nouveaux éléments. En effet, les facteurs de risque de la littérature tel que l’influence des pairs, des parents consommateurs et un début précoce de la consommation font partie intégrante de la trajectoire des répondants de cette recherche. Par contre, certains éléments dont l’impulsivité qui est fortement ressortie comme facteurs de risque de la toxicomanie dans la recension des écrits n’a pas été soulevée comme notion principale par ces hommes. Les similitudes de certains éléments entre chacun des récits de vie des participants lèvent toutefois le voile sur de nouveaux facteurs de risque. Les liens pauvres avec la figure paternelle doivent être pris en considération comme facteurs puisqu’ils font partie de la majorité des histoires de vie des répondants. De plus, le revenu est aussi un élément qui a grandement été relaté par les participants puisqu’il influence la quantité ainsi que la substance consommée. Cette recherche permet de prendre davantage conscience de la réalité des hommes toxicomanes ainsi que des particularités de leur trajectoire de vie.

L’influence réciproque qu’exerce la pratique conjointe de la composition de musique à l’image et de la composition de musique de concert sur le développement de mon langage musical

La version intégrale de ce mémoire est disponible uniquement pour consultation individuelle à la Bibliothèque de musique de l’Université de Montréal (www.bib.umontreal.ca/MU).