McGill University Thèses et mémoires par auteur commençant par B

Abstract: The rise and spread of antibiotic resistance in pathogens have led to ban on the use of antibiotic growth promoters (AGPs) in chickens. In the absence of AGPs, alternatives are needed to enhance chicken's ability against diseases and maintain efficacy of production. Given the interest in using probiotics, as a traditional means, and fecal microbiota transfer, as an emerging means of intervention, as alternatives to AGPs, we investigated the effects of two potential probiotics, Bacillus pumilus and Bacillus subtilis, and transfer of fecal microbiota from donor birds of different ages on the chicken’s production, gut microbiota and health parameters. …  Read more

Schedulers in optical switches are still electronic, the performance of these units has a significant impact on the performance of the network and could form a bottleneck in high speed networks, such as AAPN. Four time-slotted scheduling algorithms are investigated in this study, PIM, iSlip, PHM and Adapted-SRA. The study addresses the performance of AAPN for each of the algorithms, and evaluates the hardware complexity, estimating the running time of the algorithms. Performance measures were collected from an OPNET model, designed to emulate AAPN. Furthermore, hardware complexity and timing constraints were evaluated through hardware simulations, for iSlip, and through analysis …  Read more

An efficient and expedient synthetic method was developed for the preparation of chiral poly-substituted morpholine and oxazepine derivatives. The method was designed in the objective of applying the synthesis to the preparation of Cyclophilin A inhibitors. The stereo- and regioselective method involves the reaction of enantiopure beta-amino alcohols with alpha,beta-unsaturated aldehydes. The synthesis proceeds through three steps; i) Reductive amination, ii) N-alkylation/ N-tosylation and iii) intramolecular-haloetherification. Stereoselectivity of this last step was controlled by N-alkyl/ N-tosyl groups and substitution across the double bond, and was enhanced by the addition of Bronsted acids. Substitution across the double bond of the starting …  Read more

Stevens, M. (Supervisor)  Read more

The purpose of this study was to determine if age, gender, level of participation, onset of disability and sport classification have an impact on participation incentives (ego, fitness, social affective, social integration and task) in skiers with a disability. One hundred seventy-seven individuals between the ages of 4 and 66 years participated. The participants were described according to gender, time of onset of disability (congenital Vs acquired), level of sport involvement (recreation, local competition, provincial competition, national competition and international competition), and sport classification (LW1-LW9, LW10-LW12, blind, deaf and other [i.e. autistic, Down's Syndrome]). All the participants were active members …  Read more

Advanced laparoscopic procedures requiring technical skills, such as laparoscopic suturing (LS), are being done more frequently than in the past. Due to increasing concerns for patient safety, the current training paradigm focuses on learning outside of the clinical setting through simulation as an adjunct to learning in the operating room (OR). This allows trainees to gain certain skills and improves the learning curve for operative performance. In order to track skill gain and make sure that trainees are competent in performing LS, performance assessment in the OR and simulation settings plays a vital role. This thesis investigates the accuracy of …  Read more

Sniderman, Allan D. (Supervisor1)  Read more

The following thesis investigates local identities in Laconia between the Bronze Age to the Hellenistic period of ancient Greek history. These explorations are necessary contributions to the existing corpus of research on the region. The overwhelming historiographical focus on Sparta has overshadowed the local distinctiveness of smaller communities in the area. By focusing on three specific locations – the sanctuary of Artemis Limnatis in Messenia, political and religious affairs in Karyai, and the cults of Apollo Hyakinthos and of Alexandra-Agamemnon in Amyklai – the present research paper indeed shows that communities developed and performed specific strands of local identity. The …  Read more

This thesis presents a novel idea for object allocation, cache line reservation (CLR), whose goal is to reduce data cache misses. Certain objects are allocated from "reserved" cache lines, so that they do not evict other objects that will be needed later. We discuss what kinds of allocations can benefit from CLR, as well as sources of overhead. Prototypes using CLR were implemented in the IBM® J9 Java™ virtual machine (JVM) and its Testarossa just-in-time (JIT) compiler. A performance study of our prototypes was conducted using various benchmarks. CLR can offer a benefit in specialized microbenchmarks when allocating long-lived objects …  Read more

Shifting demographics and economic factors have recently necessitated the export of prefabricated homes. With respect to trade in the global market, home manufacturers can greatly benefit by using E-commerce and digital networks to communicate with their foreign clients. The author proposes a software application to assist Canadian home prefabricators and manufacturers of building components to display their services and products in an interactive and electronic format. This tool would help these companies by increasing the size of their potential client base and the speed of their business interactions. The study concludes that specialised software to facilitate the export of prefabricated …  Read more

Understanding bonding at metallic interfaces is crucial for optimizing cold-sprayed materials. This study investigates the influence of substrate roughness and hardness on the adhesion strength and energy of cold-sprayed copper (Cu) splats deposited onto steel, pure Cu, and Cu alloy substrates. Commercially pure Cu particles, with a size range of 38 – 53 μm, were cold-sprayed onto substrates featuring varying surface roughness levels, including fine polished surfaces (Ra ~ 20 nm) and as-received conditions (Ra ~ 300 nm). A micromechanical splat adhesion test was employed to quantify adhesion strength, while adhesion energy was also determined. The focus on single Cu …  Read more

Despite advances in understanding the pathogenesis of epilepsy, it remains a significant therapeutic challenge. Studies of the novel antiepileptic drugs (AEDs) gabapentin, lamotrigine and topiramate suggest that they will aid in managing seizures refractory to more established agents. However, a consensus has not been reached on their respective cellular and molecular mechanisms of action. Moreover, only a limited number of studies have examined the effects of these drugs in infants and children, a patient population with a particular propensity for seizure generation. Therefore, the objective of this investigation was to assess the effects of these new AEDs on the synchronous …  Read more

The degradation of type II collagen, the major collagen of articular cartilage, is thought to be initiated by a specific cleavage within its triple helical domain by one or more of MMP-1 (collagenase-1), MMP-8 (collagenase-2), and MMP-13 (collagenase-3). We demonstrate the direct involvement of increased collagenase activity in type II collagen cleavage, in osteoarthritic (OA) human femoral condylar cartilage, and in IL-1 stimulated mature bovine nasal and articular cartilages, by developing and using antibodies reactive to carboxy-terminal (COL-3/4Cshort) and amino-terminal (COL2-1/4N1) neoepitopes generated by cleavage of native type II collagen by these collagenases. A secondary cleavage followed the initial cleavage …  Read more

Le but de cette thèse est de démontrer, au moyen de trois études de cas, de quelle manière Actes construit un portrait public de Paul qui est conforme aux normes représentatives qui circulaient pendant le règne de l'empereur romain Trajan (98-117 ap. J.-C.). La première étude de cas démontre que le mode discursif du livre, caractérisé par son format narratif continu dramatique, par l'usage intensif de réalisme, et par le style encomiastique, est en corrélation avec les évolutions contemporaines de l'art Roman, parfaitement illustrés sur la colonne Trajane. La deuxième étude de cas utilise les dossiers épigraphiques de l'Asie Mineure …  Read more

Not many years after Hopkins had first prophesied that advance in the study of nutritional problems would concern itself largely with certain unknown dietary factors, (now calledvitamins), his prediction was fulfilled. In 1912, McCollum discovered and named the "fat-soluble vitamin", designating it "A" almost simultaneously with the similar discovery of Osborne and Mendel. {56,57). This dietary factor, found to be abundant in butter and cod liver oil, is essential for the growth of young animals, and for the maintenance of normal nutrition and health in all animals. [...]  Read more

A series of studies have been made in both rats and guinea pigs with respect to their oxygen consumption, and the results are reported. The controlvalues of the metabolic rates observed in 360 normal guinea pigs and 136 normal rats were treated statistically. For guinea pigs, the mean was153.98 1 0*274, with a standard deviation of 18.97. For rats, the values were 175.06 * 0.577; S. D. 19.08. Female rats were found to have lower andsteadier rates than males, but in guinea pigs there was no significant difference. A small rythimic seasonal variation of less than = 5$ wasobserved in …  Read more

Mackay, H. (Supervisors)  Read more

In-flight ice accretion poses a serious and ongoing risk to the safety of air travel as it may cause performance degradation and loss of control. It is reported as being the major cause of many incidents and accidents. Most of the supercooled droplets encountered during flight conditions are small in nature and, as such, adhere quickly to the surface where they impinge. When large droplets impinge on a surface, they may stick, fragment and splash, or bounce back into the airstream surrounding the surface. These rebounded droplets may impinge at an unprotected location on an aircraft.A purely Eulerian numerical approach …  Read more

Marco, Fossati, (Supervisor2)  Read more

In 1811, Nicolas Vauquelin reported the presence of potassium in brain (408). Ana1yzing the ash residues of muscle, Liebig found more potassium than sodium (cited by Kaunitz,211). He suggested that potassium occupies an intracellular position and sodium, an extracellular position, in muscle tissues (see Tower,392). Since that timea long series of analytical studies have shown that an analogous distribution of the two elements exist almost universa1ly in bacterial, plant and animal cells (see Reinberg,J27). Fenn has defined this phenomenon, writing: "As is well known, potassium is of the soi1 and not the sea; it is of the cell but not …  Read more

In this study, a modified model based on the classical nucleation theory (CNT) was applied to a hydrous peraluminous pegmatite composition and tested against crystallization experiments performed in order to further constrain the quantification of nucleation delay in felsic melts. Crystallization experiments were performed in a piston cylinder apparatus at 630 MPa and temperatures between 750 and 1000 °C for durations ranging from 0.3 to 211 hours. Experimental run products were investigated by scanning electron microscopy (SEM) paired with energy dispersive spectroscopy (EDS) analyses of both crystalline and quenched liquid phases, the results of which were compared to a theoretical …  Read more

Alors que les secteurs public et privé poursuivent leur expansion rapide dans le domaine de l’espace extra-atmosphérique, les gouvernements et la société civile constatent leur dépendance à l’égard des technologies et biens spatiaux dans tous les aspects de leur vie quotidienne. Bien que les discussions sur la protection de ces biens contre les attaques soient nombreuses, elles se concentrent plutôt sur les menaces cinétiques telles que les armes antisatellites et les technologies à double usage. Cette approche a détourné l’attention d’une menace beaucoup plus réaliste et réalisable – celle d’une cyberattaque menée contre des biens situés dans l’espace. Non seulement …  Read more

When electrons are constrained to one dimension, interparticle interactions should become a determining feature for the underlying quantum ground state. In essence, the effectively non-interacting Fermi liquid description ubiquitous in higher dimensions is expected to fail. In its stead, the strongly-interacting Luttinger liquid theory has been proposed, and is remarkable in that it is a mathematically exact theory. Discerning the genuine interaction-induced Luttinger liquid physics from the surrounding Fermi liquid environment has shown difficult in experiments. A promising approach is to probe not a single one-dimensional wire, but a set of coupled wires. In this case, signals will necessarily be …  Read more

Le phénomène de l'éthique en recherche, selon la perspective de jeunes résidant dans les camps de réfugiés a été très peu étudiée. Cette dissertation en trois manuscrits explore le sens qu'on donné des jeunes vivant à Kakuma, camp de réfugiés au Kenya, à leur participation à des initiatives de recherche. En examinant les constructions théoriques de l'éthique avec ces jeunes réfugiés, cette dissertation enquête sur les manières dont d'anciens sujets perçoivent l'impact et les effets de leur participation en recherche. Usant de techniques méthodologiques d'ethnographie critique, incluant l'entrevue qualitative, 31 jeunes réfugiés ont explorés les fondements de la recherche éthique. …  Read more

The lipopolysaccharide (LPS) translocation process was studied by a pulse-chase experimental procedure designed to follow the fate of newly synthesized LPS through the cell wall fractions of the marine bacterium Alteromonas haloplanktis, strain 214, variant 3 (ATCC 19855). It was determined that newly synthesized LPS I (the prominent LPS species under the conditions employed) initially enters an LPS fraction which can be released from the cell wall along with periplasmic material. This is followed by rapid entry of the newly synthesized LPS into a loosely bound LPS fraction (released from the cell wall by washing with NaCl) before final insertion …  Read more

Cette thèse soutient que les explications dans l’histoire, quand elles prétendent établir les causes qui produisent certains phénomènes ou les particularités de phénomènes, doivent, ainsi: .que celles dans les sciences plus exactes, être évaluées en tant que conclusions d’arguments déductifs dont les prémisses ont été confirmées. Nous examinons trois types principaux d'argument contre ce point de vue: (1) que la forme narrative de plusieurs compte rendus historiques indiquent au mode d’explication alternatif, propre à l'histoire; (2) que l'analyse des explications causales indique que les considérations d'ordre pragmatique devraient avoir la préséance sur le critère déductif dans l'évaluation de telles explications; …  Read more

Les lymphocytes T régulateurs (Treg), CD4+Foxp3+, sont des médiateurs fondamentaux de la tolérance périphérique face aux antigènes du soi et de l'environnement. Chez les humains, des mutations au niveau du gène FOXP3 affectent le développement des lymphocytes Treg et sont la cause du syndrome IPEX qui est caractérisé par une maladie auto-immune sévère le plus souvent mortelle. Grâce à une stratégie très sensible de clonage de cellules individuelles, de précédents travaux dans notre laboratoire ont révélés l'étendue de l'hétérogénéité fonctionnelle des lymphocytes T Foxp3+ chez l'homme; notamment le fait que 30% des cellules T Foxp3 positives d'un individu sain ne …  Read more

Netrin-1 contributes to the development of oligodendrocytes throughout their lineage, regulating oligodendrocyte precursor cell migration, process branching by immature oligodendrocytes, and elaboration of myelin membranes in vitro. Mature myelinating oligodendrocytes express netrin-1, but determining whether this is important for myelin formation and maintenance has been difficult due to the lethality of netrin-1 knockout mice at or before birth, prior to myelin formation. In the adult brain, netrin-1 protein localizes to paranodes, specialized regions along myelinated axons where myelin segments terminate and adhere to the axon. Previous in vitro studies have implicated netrin-1 function in paranode maintenance; however, it is not …  Read more

Partie I: La voie métabolique du mévalonate est un processus essentiel pour la biosynthèse des isoprenoïdes. Les métabolites de ce processus permettent une modification post-traductionnelle de petite protéines qui se lient au GTP et qui sont des précurseurs d’autres biomolécules comme le cholestérol et l’ubiquinone. Beaucoup d’études ont été menés sur la farnésyl-pyrophosphate synthase humaine (hFPPS) et la géranylgéranyl pyrophasphate synthase humaine (hGGPPS). Ces enzymes sont de potentiels cibles pour le traitement du myélome multiples, de la maladie d’Alzheimer et de plusieurs autres types de cancer. Dû à la limitation biopharmaceutique des médicaments bisphosphonates contenant de l’azote (N-BPs), plus d’attention …  Read more

Normal cellular proliferation is controlled by two major pathways, the pRB and the p53 pathways. It is believed that one or both of these two pathways is disrupted in all tumour cells. The functions of pRB are disrupted by viral oncoproteins, which displace important cellular components from a highly conserved region known as the "pocket". The first cellular "pocket"-binding protein identified is the retinoblastoma binding protein 1 (RBP1). RBP1 and the RBP1-like protein BCAA are inherent subunits of the chromatin modifying transcription repression complex mSIN3A/HDAC. By linking the pRB protein to this repression complex, RBP1 is believed to mediate repression …  Read more

In Germany, the role of shareholders in the structure of corporate governance has recently been the object of extensive discussion. Shareholder value has become a fashionable concept in the last few years, and some voices have demanded a stronger orientation of German corporations towards the consideration of shareholder value. Also, factual changes in the environment of the German corporate system have taken place. Germany faces major changes of the social security system that could encourage the emergence of private pension funds and modify the structure of share ownership. The capital market is gaining importance. A comparison of the historical development …  Read more

Grad, Roland (Supervisor2)  Read more

Au fur et à mesure que la technologie LPBF progresse, le développement de protocoles pour l’impression réduite et/ou sans support de surfaces en porte-à-faux orientées vers le bas devient de plus en plus essentiel pour améliorer l’efficacité économique et environnementale du processus. Par conséquent, cette thèse pose un contexte fondamental de la procédure, des paramètres, des propriétés résultantes et de sa performance économique globale. Avec un manque de connaissances dans la littérature disponible, cette recherche cherche à apporter de nouvelles idées et de nouveaux résultats pour développer et explorer davantage ladite technologie. La présente étude examine le décalage possible dans …  Read more

During the 35 years from 1926 to the end of 1959, residential construction comprised from 3.23 to 6.71 per cent of gross national income, from 24.9 to 35.8 per cent of total construction activity, and from 14.7 to 21.1 per cent of total public and private investment in Canada. Despite the size of the residential construction sector, Canadian economists have not given it the attention it deserves. [...]  Read more

One of the central problems concerning research with children is the delineation of appropriate levels of risk exposure. In the U.S. Code of Federal Regulations, the "minimal risk" concept serves as an anchoring measure for allowable risk. While the regulations sought to promote a balance between scientific advances and the protection of children's vulnerable status, ambiguities in the language of the regulations and the regulatory definition of "minimal risk" have given rise to a great deal of confusion. Research ethics boards and the medical community espouse a multitude of varying opinions regarding the interpretation and application of the federal regulations …  Read more

Levy, Barry (Supervisor)  Read more

Any treatment of the theme of education for appreciation should be welcome to the growing company of thinking people who are casting about for means of restoring some measure of harmony and dignity to a world gone awry. For some time a crust of sanity has held the social structure more or less intact; but the gathering pressure underneath is now breaking loose into tremors and disruptions that leave us aghast at the possibilities of an overwhelming catastrophe to our civilization. There can be little doubt, however, that knowledge of society's present position, well seasoned by contemplative awareness to all …  Read more

Ecomorphology is founded on the premise that ecological interactions are reflected in adaptive morphological change across individuals, populations, and communities. Specialization in feeding structures is often used to describe and classify species and is believed to be an important mechanism driving speciation in a number of taxa including Darwin's finches, Caribbean labrid fishes, and African cichlid fishes. However, morphology and ecology are not always tightly linked, and a number of studies have shown species with specialized morphologies consuming primarily generalist diets, a phenomenon known as Liem's Paradox. In this thesis, I use both spatial (interdemic) and seasonal studies to explore …  Read more

Berk, Dimitrios (Internal/Cosupervisor2)  Read more

Prolactin (PRL) is an anterior pituitary hormone that plays a key role in mammary gland development and lactation through the activation of the JAK2/STAT5 pathway. While the role of PRL in breast carcinogenesis is debatable, recent findings have uncovered its potential anti-tumorigenic effects. Breast cancer is a major cause of death in females. Therefore, characterizing the mechanisms contributing to breast tumorigenesis is crucial for the discovery of novel targets for breast cancer prognosis and therapy. Previously, we identified cleavage and polyadenylation specific factor 6 (CPSF6) as a novel PRL downregulated gene in mammary epithelial cells. Nevertheless, the exact role of …  Read more

Prakash, Satya (Supervisor2)  Read more