identifier: Maleki, Hoda  (2010) Structural and Fluid-Structure Interaction Analysis of Stenotic Aortic Valves: Application to Percutaneous Aortic Valve Replacement.  Masters thesis, Concordia University.

abstract: The main objective of this thesis is to study and investigate the mechanical behavior of the aortic valve with an emphasis on aortic stenosis. Moreover, this thesis aims to characterize the severity of AS in terms of material properties. The development of percutaneous heart valves allows valve replacement without open chest surgery. This is the most desirable option for patients with elevated surgical risks. To avoid the risk of failure in percutaneous valve implantation, determination of material properties of diseased leaflets before surgery is necessary. Therefore in this study, a series of numerical simulations, including both structural and fluid-structure interaction approach, and experimental studies were performed to achieve the objectives of this research. The results of the numerical simulations of the aortic stenosis are compared with in vitro results before testing the method using in vivo data. There is good agreement between the results of the numerical simulation and the in vitro experiments and the literature. An algorithm is suggested to estimate the material properties of the stenotic valve, considering the realistic material of the aortic valve with hyperelastic, nonlinear and anisotropic properties. The simulations using the structural modeling allow determination of the patient’s specific material property of a calcified aortic valve, knowing invasively measured aortic and ventricular pressure waveforms and the geometrical orifice area prior to percutaneous valve replacement. Also, fluidstructure interaction modeling helps to estimate a more realistic dynamic behavior of the aortic valve and also obtains the hemodynamic performance.


identifier: Sankaranarayanan, Ramesh  (2011) Role of Online Brand Communities in Making Strategic Marketing Decisions.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed


identifier: Haji-Bik, Husni  (2011) Anillin Interacts with Microtubules to Define the Division Plane.  Masters thesis, Concordia University.

abstract:
Cytokinesis is the process by which the cell divides into two daughter cells and is driven by the formation and ingression of an actin-myosin contractile ring, which is under the control of RhoA. The plane of division is dictated by the position of the mitotic spindle. In particular, central spindle-associated Ect2 (a GEF) generates active RhoA to form the contractile ring in the overlying cortex. We recently found that the conserved scaffold protein anillin interacts with Ect2 at the cortex, in addition to its many interactions with actin, myosin, septins and RhoA (and others). Anillin’s interaction with Ect2 may anchor central spindle microtubules at the cortex to activate RhoA in a discrete zone, in a feedback manner. Consistent with this, depletion of anillin or Ect2 results in the loss of cortically-localized central spindle microtubules. Furthermore, disrupting the central spindle by inhibiting Aurora B or by MKLP1 depletion results in the broad localization of contractile ring proteins. In addition, depletion of both MKLP1 and anillin prevents the establishment of an equatorial plane as contractile ring components spread around the entire cell.
These studies suggest that there is a strong relationship between anillin and microtubules, which may help define the division plane. We found that there is a strong negative relationship between astral microtubules and anillin’s cortical localization. Furthermore, we observed that anillin localization switches between the cortex and stable microtubules
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depending on the cell cycle stage or condition (i.e. drug treatment). In the absence of Rho signaling (Ect2 or RhoA RNAi), anillin localizes to central spindle microtubules. Anillin also strongly localizes to taxol-stabilized microtubules. This suggests that RhoA activation coupled with microtubule instability switches anillin from the microtubules to the cortex. Disrupting central spindle microtubules by inhibiting Aurora B or by MKLP1 depletion in taxol-stabilized cells causes anillin to re-locate to the cortex, and differs between discrete and broad depending on the treatment. Using deletion constructs, we mapped the possible microtubule-localizing region on anillin to the C-terminus. We hypothesize that there could be multiple sites where one could be Ect2-dependent to anchor cortical central spindle microtubules and the other could be Ect2-independent. We are still determining if the second interaction is direct. Recently, C. elegans ANI-1/anillin was shown to localize to astral microtubules where it removes myosin from the cortex and polarizes the early embryo. In addition, multiple Rho effectors, including mDia2, relocate to central spindle microtubules in the absence of Rho signalling in human cells. We propose that interacting with microtubules could be a conserved mechanism to keep Rho effectors off the cortex to help define cortical domains.


identifier: Hajizadeh Moghaddam, Azita  (2010) Development of a sustainable method for the disposal of chromated copper arsenate (CCA) treated wood.  PhD thesis, Concordia University.

abstract:
Preserved wood is commonly found in solid waste. Among the different types of
preserved wood, CCA wood has received much attention due to the scale of usage and its
significant role in soil and water contamination after disposal. As the ash of CCA wood is
hazardous, it cannot be burned, and the best available disposal method is thus landfilling.
Leaching of the metals from disposed CCA wood in landfills pollutes the environment.
To reduce the contamination of CCA, treatment before landfilling is required.
Nowadays, ethanol is seen as a promising source of energy. Lignocellulosic materials
such as wood are resources for ethanol production. This research focuses on the
possibility of producing ethanol from CCA wood. It suggests that production of ethanol
will not only be a solution to the disposal but will also generate a clean fuel.
The results showed the existence of copper, chromium and arsenic did not have a
negative effect on the fermentation, and producing ethanol from CCA wood is feasible.
The copper removed by sulfuric acid completely precipitated during the hydrolysis and
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neutralization. In addition about 50% of the chromium (VI) and also 60% of the arsenic
(V) were removed from the leachate by yeast during fermentation.
TCLP tests of the hydrolyzed wood leached less than 4 ppm of arsenic while minimal
amounts of chromium and copper remained in the hydrolyzed wood which makes
landfilling of hydrolyzed wood acceptable.
Baker's yeast behaves selectively by uptaking arsenic (V) and chromium (VI) but not
arsenic (III) and chromium (III). There is competition between copper and chromium
sorption by yeast. The kinetic model for removal of copper and chromium is a zero order
model while the appropriate model for uptaking arsenic by yeast is a first order model.
The kinetic models confirm that there are different mechanisms of uptaking metals by
yeast, a diffusion mechanism for removal arsenic and a surface adsorption mechanism for
copper and chromium.
As an overall conclusion of this study, using discarded CCA wood as the feed for ethanol
production is a sustainable method for disposal of CCA treated wood.


identifier: Balike, Krishna Prasad  (2010) Kineto-Dynamic Analyses of Vehicle Suspension for Optimal Synthesis.  PhD thesis, Concordia University.

abstract:
Design and synthesis of a vehicle suspension is a complex task due to constraints imposed by multiple widely conflicting kinematic and dynamic performance measures, which are further influenced by the suspension damper nonlinearity. In addition, synthesis of suspension for hybrid vehicles may involve additional design compromises among different measures in view of the limited lateral packaging space due to larger sub-frame requirements for placing the batteries. In this dissertation research, a coupled kineto-dynamic analysis method is proposed for synthesis of vehicle suspension system, including its geometry and joint coordinates, and asymmetric damping properties. Quarter-car and two-dimensional roll plane kineto-dynamic models of linkage suspensions are proposed for coupled kinematic and dynamic analyses, and optimal suspension geometry and damper syntheses.
The kinematic responses of quadra-link and double wishbone types of suspensions are evaluated using the single-wheel kinematic models. Laboratory measurements were performed and the data were applied to demonstrate validity of the 3- dimensional kinematic model. A sensitivity analysis method is proposed to study influences of various joint coordinates on kinematic responses and to identify a desirable synthesis. A kineto-dynamic quarter car model comprising linkage kinematics of a double wishbone type of suspension together with a linear, and single- and two-stage asymmetric damper is subsequently proposed for coupled kinematic and dynamic analyses. The coupling between the various kinematic and dynamic responses, and their significance are
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discussed for suspension synthesis. The effects of damping asymmetry on coupled responses are thoroughly evaluated under idealized bump/pothole and random road excitations, which revealed conflicting design requirements under different excitations. A constrained optimization problem is formulated and solved to seek design guidance for synthesis of a two-stage asymmetric damper that would yield an acceptable compromise among the kinematic and dynamic performance measures under selected excitations and range of forward speeds.
The coupled kinematic and dynamic responses in the roll plane are further analyzed through development and analysis of a kineto-dynamic roll-plane vehicle model comprising double wishbone type of suspensions, asymmetric damping and an antiroll bar. The results are discussed to illustrate conflicting kinematic responses such as bump/roll camber and wheel track variations, and an optimal geometry synthesis is derived considering the conflicting kinematic measures together with the lateral space constraint. A full-vehicle model comprising double wishbone type of suspensions is also developed in the ADAMS/car platform to study influences of faults in suspension bushings and linkages on the dynamic responses. The results of the study suggest that an optimal vehicle suspension synthesis necessitates considerations of the coupled kinematic and dynamic response analyses


identifier: Suchet, Myriam  (2010) Textes hétérolingues et textes traduits : de « la langue » aux figures de l’énonciation. Pour une littérature comparée différentielle.  PhD thesis, Concordia University - Lille 3 (France).

abstract:
Literature readily invents itself another tongue. Written simultaneously in
several languages, texts said to be “heterolingual” don’t invent another language ; they
imagine “language” otherwise. The particularly demanding reading pact they propose
entails a veritable experience of difference. Balanced at the intersection of idioms, the
subject of the heterolingual enunciation seems never to coincide with himself. When
approached from the perspective of the heterolingual imaginary, the translated text
reveals the presence of an instance of enunciation which is specific to itself. The
notion of ethos can be employed to characterise the one who is responsable for the
heterolingual text as the responsable for the translated text, by the manner in which
languages are placed into relation to one another. Between the respect for “the other
as other” and an ethnocentric attitude, it is necessary to envision a whole range of
relations to alterity. In the context of the debate on national identity and the claim to
cultural diversities, it seems imperative to recall the critical function of literature and
comparatist methodology. The future of comparative literature as a discipline is not all
that is at stake : there is the matter of ethical vigilance which far exceeds the framing
of Nation-States. The analysis is founded on four source texts and their French,
English, German and Spanish translations : The Voice by Gabriel Okara, Sozaboy by
Ken Saro-Wiwa, Juan sin Tierra by Juan Goytisolo and Die Niemandsrose by Paul Celan.


identifier: Bashmal, Salem  (2010) Analytical and Experimental Studies on In-plane Vibrations and Noise of Rolling Disks Subject to Non-homogeneous Constraints.  PhD thesis, Concordia University.


identifier: Cheng, Jialin  (2010) Condition Based Maintenance Optimization for Multi-Component Systems Based on Neural Network Health Prediction.  Masters thesis, Concordia University.

abstract:
Condition-based maintenance (CBM) is an effective maintenance approach to prioritize and optimize maintenance resources based on condition monitoring information. A well established and effective CBM program can eliminate unnecessary maintenance actions, lower maintenance costs, reduce system downtime and minimize unexpected catastrophic failures. Most existing work reported in the literature only focuses on determining the optimal CBM policy for single units. Replacement and other maintenance decisions are made independently for each component, based on the component’s age, condition monitoring data and the CBM policy.
In this thesis, a CBM optimization method is proposed for multi-component systems, where economic dependency exists among the components subject to condition monitoring. The proposed multi-component systems CBM policy is based on a method using artificial neural network (ANN) for remaining useful life (RUL) prediction which is proposed by Tian et al. (2009). Deterioration of a multi-component system is represented by a conditional failure probability value, which is calculated based on the predicted failure time distributions of components. The proposed CBM policy is defined by a two-level failure probability threshold. A simulation method is developed to obtain the optimal threshold values in order to minimize the long-term maintenance cost.
We conduct a case study using real-world vibration monitoring data to validate the proposed CBM approach. These data are collected from bearings on a group of Gould pumps at a Canadian Kraft pulp mill company and help to demonstrate the effectiveness of the proposed CBM approach for multi-component systems. The proposed CBM approach is also demonstrated using simulated degradation data for
multi-component systems. The proposed maintenance policy can fulfill the requirements of a real plant environment where multiple components are under condition monitoring. By using the proposed CBM policy, maintenance managers can easily and quickly adjust the maintenance schedule according to the working condition of the system.


identifier: Du, Xiaojun  (2011) Image Segmentation and Its Applications Based on the Mumford-Shah Model.  PhD thesis, Concordia University.

abstract:
Image segmentation is an important topic in computer vision and image processing. As a region-based (global) approach, the Mumford and Shah (MS) model is a powerful and robust segmentation technique as compared to edge-based (local) methods. In this thesis we apply the MS model to two interesting problems: image inpainting and text line detection. We further extend it by proposing a new image segmentation model to overcome some of the difficulties of the original model. As a demonstration of the new model, we apply it to
the segmentation of retinal images. The results are better than the
state-of-the-art approaches.

In image inpainting, the MS model is used to detect and estimate the object boundaries inside the inpainting areas. These boundaries are preserved in the inpainting results. We present a hierarchical segmentation method to detect boundaries of both the main structure and the details. The inpainting result can preserve detailed edges.

In text line detection, we use a combination of Gaussian blurring, the MS model, and morphing method. Different from other general text image detection approaches, our method segments text documents without any knowledge of the written texts, so it can detect handwriting text lines of different languages. It can also handle different gaps and overlaps among the text lines.

Although the MS model has been used successfully in many applications, its implementation has always been based on some forms of approximation. These approximations are either inefficient computationally or applicable only to some special cases. Our new model consists of only one variable, the segmentation curve, therefore the computation is very efficient. Furthermore, no approximation is required, hence the method can segment objects with complicated intensity distribution. The new model can detect both step and roof edges, and can use different filters to detect objects of different levels of intensity. To show the advantages of the new model, we use a combination of the new model and Gabor filter to detect blood vessels in retinal images. This new model can detect objects with complicated image intensity distribution, and can handle non-uniform illumination cases effectively.


identifier: Quiros, Veronica  (2010) Exploring the role of the H4-S4 loop and of the N-terminal His-tag in stabilizing quaternary structure of enolase from Streptococcus pyogenes.  Masters thesis, Concordia University.

abstract:
Yeast (Saccharomyces cerevisiae) enolase is known to be a dimer of identical monomers while Streptococcus pneumoniae enolase is a tetramer of dimers.  Dimeric enolase is a well-studied ubiquitous protein; however, not much is known about the octameric protein.  Therefore, understanding the amino acids that determine quaternary structure could provide important information regarding its role.  Based on the crystal structure of both enolases, it was hypothesized that the loop connecting helix 4 (H4) and strand 4 (S4) could be responsible for preventing formation of octamers in yeast enolase (Ehinger et al., 2004).  In the octameric enolase this loop contributes to the dimer-dimer interface; however, in yeast enolase this loop is shorter due to the presence of an extra turn at the end of H4.  The goal of my project is to understand if the extra turn at the end of H4 will destroy the dimer-dimer interface and prevent the formation of octameric enolase.
In order to study the effects of the extra turn in the octameric enolase, site-directed mutagenesis was performed on the H4-S4 loop.   Residues 135-138 were changed from GGFN to ADLS, which corresponds to the amino acid sequence of yeast enolase.  The same amino acids were also changed to AAAA, since alanine is known as a helix-forming amino acid. Characterization of the quaternary structure by analytical ultracentrifugation (AUC) showed that the variant enolase proteins are formed by a mixture of octamers, monomers, dimers and possibly other intermediates. Consistent with this observation, the specific activity of the variant proteins decreased considerably compared to the wild-type, due to a lower percentage of octamers.  These results suggest that those amino acids in the extra turn play an important role in quaternary structure.
The second goal of this project is to determine if the polyhistidine tag (His-tag) affects the stability of octameric enolase.  This protein is expressed with an N-terminal polyhistidine tag (His-tag) to facilitate the purification processes.  The enolase gene also was inserted into a vector which carries a C-terminal His-tag with a thrombin recognition site, permitting removal of the tag.  In order to study stabilization, sodium perchlorate, a weak chaotrope, was used to dissociate the octameric enolase (Karbassi et al., 2010).  This dissociation was monitored by sedimentation velocity using AUC.  Although, His-tagged proteins are commonly used to facilitate purification, we have observed that the His-tag at the N-terminus stabilizes the octameric structure.


identifier: Spry, Mike  (2011) Working Up the Bottle.  Masters thesis, Concordia University.

title: Working Up the Bottle

abstract:
ABSTRACT
Working Up the Bottle
Mike Spry
Working Up the Bottle is the story of three friends from youth who decide to rob a restaurant.  Hunter, a chef with suicidal tendencies yet cursed with drunken immortality; Riley, a waitress (who Hunter loves) trapped in a dead-end job and an abusive relationship; and Jack, a successful entrepreneur who amuses himself by toying with his old friends’ existence.  The novel finds Hunter and Riley trying to achieve some measure of salvation in escaping the world of the service industry; a forgotten community of addicts, miscreants, misfits, and savages.  Set against the backdrop of an unnamed Canadian metropolis, Working Up the Bottle is a darkly humorous tragedy that discusses the sad reality of the educated working poor, characters whose aspirations have long since dissolved into the bottom of their drinks and their desperate attempt to climb back to the top.


identifier: Mihailovic, Katarina  (2011) Visions of 1968: Radical Aesthetics in Porcile, WR and Tout va bien.  Masters thesis, Concordia University.

abstract: In my thesis, I examine the responses of four politically radical filmmakers—Jean-Luc Godard and Jean-Pierre Gorin, Dušan Makavejev, and Pier Paolo Pasolini—to their cultural, ideological and theoretical contexts. I am particularly interested in the filmmakers’ respective conceptions of the politically radical work of art and their understanding of the role of the politically committed intellectual in the aftermath of the 1968 movement. I undertake an analysis of Godard's and Gorin’s Tout va bien (All’s Well, 1972), Makavejev's WR:Misterije organizma (WR: Mysteries of the Organism, 1968-71), and Pasolini's Porcile (Pigsty, 1969), in light of the filmmakers’ political modernist projects. The first chapter establishes the cultural and political contexts in which the filmmakers worked. I pay close attention to the intellectual debates in France, Yugoslavia and Italy that shaped the directors’ understanding of the role of the committed intellectual and the social and political function of art. The second chapter discusses their respective "returns" to the avant-garde aesthetics of Sergei Eisenstein and Bertolt Brecht. I examine Godard-Gorin’s, Makavejev’s and Pasolini’s use of the montage and collage techniques. The third chapter examines understanding of revolution and revolt, highlighting the directors’ different ideological and political positions.


identifier: Chen, Wei  (2010) Synthesis of Optical Nanodevices with Application in Biosensing.  Masters thesis, Concordia University.


identifier: Mathew, Sacha  (2011) Indian Religion and Western Yoga Practice.  Masters thesis, Concordia University.

abstract:
Yoga has become a very recognizable feature of Western culture. Almost every person who has taken a yoga class can tell you that yoga originated in India. However, contemporary North American yoga – focused on postures and physical practice – departs considerably from “classical” yoga in India. The various yoga styles and yoga studios in North America differ with respect to their relationship to the history and tradition of yoga. My thesis seeks to understand the different ways that Indian religion – “Indian-ness” and religiosity – are expressed in yoga classes and among yoga practitioners. This thesis is a case study conducted in Montreal carried out at three studios representing three styles that one could find in almost every major North American city: Sattva Yoga Shala (Ashtanga-Vinyasa Yoga), Moksha Yoga Montreal (hot yoga) and Centre de Yoga Iyengar de Montréal (Iyengar Yoga).
	At each studio I interviewed teachers and students to discover their experiences with yoga, their beliefs about benefits from practicing yoga, as well as their knowledge and relation to the tradition of yoga. Indian religious elements are present to varying degrees in North American yoga classes but both teachers and students appreciate these aspects as pleasant exoticisms that are basically inessential to their yoga practice. At the same time, students and teachers may be prone to projecting non-Indian spiritual ideas onto their yoga practice, which enhances its significance for them.


identifier: Blakney, Andrew  (2011) Tangible User Interfaces and Metaphors for 3D Navigation.  Masters thesis, Concordia University.

abstract:
The most fundamental and common 3D interaction is the control of the virtual camera or viewpoint, commonly referred to as navigation. The navigational requirements of controlling multiple degrees of freedom and maintaining adequate spatial awareness are big challenges to many users. Many tasks additionally demand large portions of cognitive effort from the user for non-navigational aspects. Therefore, new solutions that are simple and naturally efficient are in high demand. These major challenges to 3D navigation have yet to be satisfactorily addressed, and as a result, there has yet to be a declaration of a suitable unified 3D interaction technique or metaphor.

We present a new domain and task independent 3D navigation metaphor, Navigational Puppetry, which we intend to be a candidate for the navigational portion of a unifying 3D interaction metaphor. The major components of the metaphor - the puppet, puppeteer, stage, and puppet-view - enable a new meta-navigational perspective and provide the user with a graspable navigational avatar, within a multiple-view perspective, that allows them to ‘reach’ within the virtual world and manipulate the viewpoint directly. We position this metaphor as a distinct articulation of the front wave of a puppetry related trend in recent 3D navigation solutions. The metaphor was implemented into a tangible user interface prototype called the Navi-Teer. Two usability studies and a unique spatial audio experiment were completed to observe and demonstrate, respectively, the metaphor’s benefits of tactile intimacy, spatial orientation, easy capture of complex input and support for collaboration.


identifier: Saldarriaga, Lina Maria  (2010) The moderating effects of prosocial behaviour, friendship quality and social problem solving in the relationship between risk factors and peer victimization in Colombian early adolescents.  PhD thesis, Concordia University.

abstract: The current series of three studies was designed to use the “buffering hypothesis” model to assess the relative buffering effectiveness of positive peer experiences and personal characteristics in the association between risk factors and peer victimization in a sample of 623 Colombian early adolescents. These longitudinal studies assessed the extent to which changes in victimization varied as a function of the interaction between risk factors and positive peer and personal experiences. Using structural equation modeling techniques, the results provide evidence that reveals the specificities of the protective effects of each of the moderators. Results from Study 1 supported previous findings by revealing a significant change on children’s victimization scores across the school year. More specifically, it was found that students experienced a decline on their victimization scores over the school year, and that this decline was especially strong for the students who had the highest levels of victimization at the beginning of the year. Similarly, results from Study 1 showed that both aggression and avoidance were predictive of initial scores on peer victimization, however, only avoidance was found to predict the ways in which children change over the school year. The buffering effectiveness of prosocial behaviour was also tested in this study. It was found that prosociality acts as a buffer only for highly relationally aggressive children at the beginning of the school year, and for highly avoidant children across the school year. Study 2 examined the moderating effect of positive provisions of friendship in the association between aggression, avoidance and peer victimization over time. Contrary to our expectations, results showed that for relationally aggressive students, having a high quality friendship predicted an increase on their victimization scores over time. In contrast, for highly avoidant children friendships were protective against risk of peer victimization. Finally, Study 3 examined how social problem solving skills impacted the relationship between risk factors and peer victimization over time. Only a main effect of this variable was found at the beginning of the year; no moderating effects emerged in the analyses. Results from all studies supported the buffering hypothesis model by providing evidence that the protective effect of positive peer experiences and personal characteristics is especially effective for children who are considered to be at-risk.


identifier: Masson, Marie  (2011) Withdrawn and (Not) Reissued U.S. and Canadian IPOs and SEOs.  Masters thesis, Concordia University.

abstract:
Between 1993 and 2009, 14.69% and 12.34% of all public equity offerings announced in the U.S. and Canada were eventually withdrawn, respectively. Less than 10% of all cancelled IPOs are eventually completed versus over 20% of all withdrawn SEOs. We measure the impact of issuer riskiness, issuer characteristics and timing of the offerings on the likelihoods of IPO and SEO cancelations and subsequent return of these offerings. We find that the dotcom and subprime crises have a greater positive influence on the probability of withdrawal in the United Stated than in Canada. Our results suggest that greater post-announcement changes in market and economic conditions tend to increase the probability of withdrawal and that good general market conditions subsequent to announcement and to withdrawal are positively related to the completion and reissue of offerings, respectively. Overall, cancelation of initial and seasoned equity offerings is driven by different firm- and issue-specific factors and the effect of these variables varies across countries.

An analysis of stock price performance of successfully returning offerings on the three days centered on their announcements suggests that second-time successful SEOs underperform a sample of contemporaneous offerings by 2.09% and 5.76% in the U.S. and Canada, respectively. Overall, underpricing on the day of issue is not affected by prior offering cancellation. However, over the long-term, we find that U.S. equity offerings underperform their profitability-matched sample of contemporaneous offerings.


identifier: Pakarian, Paknoosh  (2010) Identification of novel regulators of cytokinesis.  Masters thesis, Concordia University.


identifier: Ma, Ling  (2011) Development of Fault Detection and Diagnosis Techniques with Applications to Fixed-wing and Rotary-wing UAVs.  Masters thesis, Concordia University.

abstract:
ABSTRACT
Development of Fault Detection and Diagnosis Techniques with Applications to Fixed-wing and Rotary-wing UAVs
Ling Ma
Fault Detection and Diagnosis (FDD), as the central part of a Fault Tolerant Control System (FTCS), detects and diagnoses the source and the magnitude of a fault when a fault/failure occurs either in an actuator, sensor or in the system itself. This thesis work develops an applicable procedure for a FDD scheme to both fixed-wing and rotary-wing UAVs (Unmanned Aerial Vehicles) in the discrete-time stochastic domain based on the Kalman filter techniques. In particular, the proposed techniques are developed in highly nonlinear and 6 degree-of-freedom equations of Matlab/Simulink simulation environment for a quad-rotor helicopter UAV, a Boeing 747, and a NASA Generic Transport Model (GTM) fixed-wing UAV. A key development in this thesis is that an Adaptive Two-Stage Extended Kalman Filter (ATSEKF) algorithm and a Dual Unscented Kalman Filter (DUKF) algorithm are applied for simultaneous states and fault parameters estimation of these UAVs. The statistical decision-making techniques for fault detection and diagnosis are also discussed in the presence of partial faults in the UAVs. The measured system outputs and control signals are used as inputs of the ATSEKF and DUKF, and the estimated states and parameters are used for comparison and analysis in the fault detection and diagnosis. The simulation results show that the effectiveness and performance of ATSEKF and DUKF for the purpose of fault detection and diagnosis of both fixed- and rotary-wing UAVs are satisfactory.


identifier: Kinuma, Emile  (2011) Institutional Environments and Mode of Entry.  Masters thesis, Concordia University.

abstract: Mode of entry studies the international behavior of multinational firms and the factors that impact their international behavior. This study examines the impact the macro level institutions of a host country on the entry strategy of a foreign multinational enterprise (MNE). The framework developed in the study focuses on two sets of institutions, formal institutions which comprise the political and judicial rules and informal institutions which are comprised of cultural and business practices that are not formally codified. The results of the study provide further empirical evidence that the institutional environment influences MNE behavior. In particular this study found that, for a constant level of informality, the increased degree of formality of an institutional environment encourages multinational firms to choose acquisitions over joint ventures. Meanwhile the increased degree of formality and informality makes MNEs more likely to choose joint ventures over acquisitions and strategic alliances as modes of entry.


identifier: Zhu, Boming  (2010) Microfluidic Fuel Cells -- Modeling and Simulation.  Masters thesis, Concordia University.


identifier: Milly, Sonya  (2010) The eLiterate Revolution: From Orality to New Media – Literacy as Communication Technology.  Masters thesis, Concordia University.

abstract: This thesis explores the potential theoretical contribution from the history of communications to literacy research in the field of educational studies. The relation between literacy and new media is examined from a history of communications perspective that treats literacy as communication technology. This thesis shows that current debates about literacy practices in the context of new media (eLiteracies) are grounded in, and continue to reflect, older debates concerning technology, literacy, culture, and society.  Current research focuses predominately on the cultural, social, and ideological aspects of literacy (print or digital). This thesis asserts that prevailing theoretical models of literacy, notably the ideological model – one of the most influential theoretical frameworks in contemporary literacy research – are insufficient to effectively investigate relationships between literacy and new media technologies because they neglect technological dimensions that shape communication and literacy practices. The guiding research question this thesis addresses is: In what ways might the understanding of earlier shifts in communication technologies inform that of the transition from print literacy to eLiteracies?


identifier: Barsky, Georgy  (2011) Lower Bounds on Broadcast Function for n = 23; 24 and 25.  Masters thesis, Concordia University.


identifier: Deng, Li  (2010) Simulatable Auditing in Micro-Databases.  Masters thesis, Concordia University.

title: Simulatable Auditing in Micro-Databases

abstract: How to protect individuals’ privacy while releasing microdata tables for analysis pur- poses has attracted significant attention. We study the case where different microdata tables generalized over the same underlying secret table may be released upon users’ queries. To satisfy privacy constraints, an auditing system must determine whether the next query can be safely answered based on the history of answered queries. However, when answering a new query is not safe, denying it may not be, either, since a denial itself may still convey some sensitive information to the user. We first model this issue in the context of releasing microdata tables. Inspired by the Simulatable Auditing technique in statistical databases, we propose a safe strategy for auditing queries that ask for microdata tables generalized over secret tables. The strategy can provide provably safe answers and good data utility. We also study how to efficiently maintain the history of answered queries for the auditing purpose. To the best of our knowledge, this is the first study on the simulatable auditing issue of microdata queries.


identifier: Emani, Vijaya Kumar  (2010) Curvelet Transform-Based Techniques For Biometric Person Identification.  Masters thesis, Concordia University.

abstract:
Biometric person identification refers to the recognition of a person based on the physical or behavioral traits. Palm print based biometric identification system is one of the low cost biometric systems, since the palm image can be obtained using low cost sensors, such as desktop scanners and web cameras.  Because of ease of image acquisition of palm prints and identification accuracy, palm images are used in both uni- modal and multimodal biometric systems. A multi-scale and multi-directional representation is desirable to represent thick and scattered thin lines of a palm image. Multi-scale and multi-directional representation can also be used in image fusion, where two images of two different biometric traits can be fused to a single image to improve the identification accuracy. Face and palm images can be fused to keep the desired high pass information of the palm images and the low pass information of the face images. The Curvelet transform is a multi-scale and multi-directional geometric transform that provides a better representation of the objects with edges and requires a small number of curvelet coefficients to represent the curves.
In this thesis, two methods using the very desirable characteristics of the curvelet transform are proposed for both the uni-modal and bi-modal biometric systems. A palm curvelet code (PCC) for palm print based uni-modal biometric systems and a pixel-level fusion method for face and palm based bi-modal biometric systems are developed. A simple binary coding technique that represents the structural information in curvelet directional sub-bands is used to obtain the PCC. Performance of the PCC is evaluated for both identification and verification modes of a palm print based biometric system, and then, the use of PCC in hierarchical identification is investigated. In the pixel-level fusion scheme for a bi-modal system, face and palm images are fused in the curvelet transform domain using mean-mean fusion rule. Extensive experimentations are carried out on three publicly available palm databases and one face database to evaluate the performance in terms of the commonly used metrics, and it is shown that the proposed methods provide a better performance compared to other existing methods.


identifier: Curry, Nathan  (2010) Modeling and Design of a Food Waste to Energy System for an Urban Building.  Masters thesis, Concordia University.

abstract:
Urban sustainability is a subject of recent focus in North America, and Canada specifically. As our urban areas continue to grow and consume large quantities of energy and produce massive amounts of waste, we are faced with the challenge of how to manage this situation in a way which is both responsible and sustainable. One feasible urban waste-to-energy technology is anaerobic digestion. Anaerobic digestion (AD) has been a usable energy source for over 100 years and is currently being employed in countries around the world in rural settings to generate electricity and heat, but it has yet to make a large migration to the urban environment though it is a viable and mature process.
Applied to the organic waste produced in urban environments, anaerobic digestion could provide a critical solution to growing garbage problems while simultaneously reducing external energy requirements. The cost of transporting waste outside of cities to landfills will continue to rise and if a substantial portion of this waste could be retained, digested, reduced, and converted into useable energy in the urban environment, then this is something to be seriously considered. The goal of this thesis is to investigate the feasibility of power and energy generation through the use of anaerobic digestion of food waste in the urban environment, suggest a novel modeling technique using the International Water Association’s Anaerobic Digestion Model #1, and provide a case study from the downtown campus of Concordia University in Montreal, Canada.


identifier: Chowdhury, Mazharul Huq  (2010) Electrical Properties of Grain Boundaries in Low Doped Polycrystalline Materials with Applications to Detectors.  Masters thesis, Concordia University.

abstract: Polycrystalline materials are widely used in large area electronic devices such as flat panel x-ray image detectors, and solar cells due to their suitability to deposit over large area at low cost. The performance of polycrystalline-based flat panel detectors are showing encouraging results (good sensitivity, good resolution and acceptable dark current) and give possibility to replace existing x-ray film/screen cassette. Therefore large area polycrystalline based flat panel detectors have opened new clinical possibilities and the polycrystalline solar cells give the opportunity of manufacturing low cost photovoltaic cells. Consequently, active research has been carried out to find out suitable polycrystalline materials (e.g. HgI2, CdTe, CdZnTe, PbI2, PbO etc) for various large area applications.  However a polycrystalline material is composed of micro crystallites joined together by grain boundaries (complex structure, consisting of a few atomic layers of disordered atoms) which posses trap centers for charge carriers. Therefore, grain boundaries can trap a large amount of charges during detector operation. A potential barrier for drifting carriers may exist at the grain boundary, which controls the carrier mobility. Moreover, the performance of these polycrystalline detectors are affected due to the polarization phenomena (any change in the performance of the detector after the detector biasing) under applied bias. Therefore, in this research work, an analytical model is developed to study the electrical properties (electric field and potential distributions, potential barrier height, and polarization phenomenon) of polycrystalline materials at different doping levels for detector and solar cell applications by considering an arbitrary amount of grain boundary charge and a finite width of grain boundary region. The general grain boundary model is also applicable to highly doped polycrystalline materials. The electric field and potential distributions are obtained by solving the Poisson’s equation in both depleted grains and grain boundary regions. The electric field and potential distributions across the detector are analyzed under various doping, trapping and applied biases. The electric field collapses, i.e., a nearly zero average electric field region exists in some part of the biased detector at high trapped charge densities at the grain boundaries. The model explains the conditions of existence of a zero average field region, i.e., it explains the polarization mechanisms in polycrystalline materials. The potential barrier at the grain boundary exists if the electric field changes its sign at the opposite side of the grain boundary. The potential barrier does not exist in all grain boundaries in the low doped polycrystalline detector and it never exists in intrinsic polycrystalline detectors under applied bias condition provided there is no charge trapping in the grain.


identifier: Niang, Papa O  (2010) Solving the Eternity II Puzzle using Evolutionary Computing Techniques.  Masters thesis, Concordia University.


identifier: Routy, Mathilde  (2010) L'étranger, le penseur, le fou et l'obèse : quatre figures de l'Autre dans la littérature québécoise actuelle.  Masters thesis, Concordia University.

abstract: Dans la littérature québécoise actuelle, la question de la migrance ne se pense plus uniquement comme le déplacement d’un territoire à un autre, mais aussi comme un déplacement métaphorique. En nous appuyant sur les travaux de Pierre Ouellet (L’Esprit migrateur, 2003), nous proposons d’actualiser et de repenser le phénomène de l’écriture migrante. Dépassant l’esthétique ou le courant littéraire, l’esthésie migrante formulée par Pierre Ouellet est davantage une forme de vie, une expérience du monde ou une épreuve intérieure. Le théoricien distingue quatre grandes classes de personnages dans cette esthésie ou sensibilité migratoire, à savoir l’étranger, l’artiste, le fou et l’exclu. Afin de mieux saisir ces figures, nous nous appuierons sur quatre romans québécois contemporains : l’étrangère dans Hadassa (2006) de Myriam Beaudoin, le penseur dans Le Cri des oiseaux fous (2000) de Dany Laferrière, le fou dans Le Fou d’Omar (2005) d’Abla Farhoud, et pour finir, l’obèse dans La Danse juive (1999) de Lise Tremblay. Dans une conjoncture particulière, chacun de ces protagonistes incarne la figure de l’Autre au sein d’un groupe. Ils font l’expérience, certes de façon différente, de la migrance. Ainsi nous tenterons de cerner les particularités qui caractérisent ces exils intérieurs, mais également leurs points de convergence et leurs ressemblances. Ce qui, par le biais de la littérature, nous permettra de mieux appréhender l’essence de ce malêtre face au monde.


identifier: Mostofi Darbani, Reza  (2010) Development of a Procedure to Measure the Effectiveness of Electret N-95 Respirator Filter Media for Capturing Nano-Particles.  Masters thesis, Concordia University.

abstract:
The phenomenal growth of the nano-technological products and their impacts on our society led government organizations and scientists to consider the risks related to human exposure to nano-particles (NPs). As a precautionary approach, respiratory protection is suggested for workers to reduce their exposure to NPs. Thus, it is important to characterize the performance of these respirators to capture NPs.
In this study, the performance of one model of N95 respirators was characterized against poly and mono-disperse NPs. With poly-disperse NPs, a methodology was developed to measure the performance of the N95 respirators against NaCl aerosols in the size range of 15 to 200 nm in three scenarios. The N95 respirator performance was also characterized at 85 liters/min against twelve mono-size aerosols with size ranging from 20 to 200 nm.
Using poly-disperse aerosols test (PAT) method; the results demonstrated that the initial penetration was significantly enhanced with the increased airflows and a shift toward small particle size was observed for the most penetrating particle size (MPPS). For particles below 100 nm, the penetration decreased with further loading. The MPPS was also found to shift toward the large sized particles. In addition, the penetration augmented slightly as the (RH) increased.
Using mono-disperse aerosol test (MAT) method; the results revealed the initial particle penetration is less than 5% NIOSH certification criterion. However, it was found that the initial value, measured with (MAT) method, is not related with the initial penetration measured with (PAT) method at each corresponding particle size at 85 liters/min.


identifier: Harding-Jones, Celyn M.  (2010) Souvenirs of a Forgotten Highway.  Masters thesis, Concordia University.

title: Souvenirs of a Forgotten Highway

abstract:
Souvenirs of a Forgotten Highway contributes to the tradition of Western literature by depicting contemporary people struggling to find balance in the extreme desert landscape; they are beset by the consequences of the rise, fall and sustenance of the Cowboy myth. The novella is inspired from personal experiences living in the Sonoran desert, and encouraged by Jack Spicer’s Billy the Kid and B.P. Nichol’s The True Eventual Story of Billy the Kid. Just as William Faulkner’s The Sound and the Fury is haunted by the Old South, my characters are tormented by whispers of Owen Wister’s The Virginian and Theodore Roosevelt’s Frontier myth. Cormac McCarthy’s modern take on the West’s violent past in Blood Meridian cannot be escaped. Provoked by Michael Ondaatje’s fragmented form in The Collected Works of Billy the Kid, my thesis collects various storytelling techniques such as rumours, TV guide schedules, real crimes, and Native American tales mirroring the historical influence the West has had on literature, and the effect literature had on creating the Cowboy myth.

Set in a hamlet in rural Arizona, nine year-old Christina is trapped in wide-open spaces, and attempts a dangerous escape. Maria, her mother, is isolated, sun-beaten, and holed-up her trailer. Sam is perpetually overwhelmed with the long list of lives he must “fix”. Lucy faces bringing a baby into a dysfunctional world. Jerome finds that he has run out of space to hide in, tormented by his urge to run and a troubled past. Even the rain is rejected by the desert, creating disaster for those who live in it.


identifier: Ganjidoost, Amin  (2011) Toward Sustainability: An Optimization Framework for Life Cycle Assessment and Life Cycle Costing of Office Buildings.  Masters thesis, Concordia University.

abstract:
This thesis presents an optimization model to minimize total life cycle cost of sustainable office building, subject to a set of environmental impact constraints with emphasis on relationship between reducing environmental impacts and minimizing total life cycle cost of office buildings due to sustainable building design strategies.

The concepts of green design, sustainability, life cycle assessment and life cycle costing have been reviewed and presented in this thesis. Three green assessment tools which are used for buildings are also described. The role of life cycle costing and life cycle assessment in previous studies on office buildings, and related previous studies on optimization of environmental performance of buildings are also reviewed in this study.

The methodology of this research was tested through a case study of an eight-story office building to demonstrate the capability of the proposed optimization model. Two of the structural components (walls and floors) and one of the envelope component (windows) were compared on the basis of six environmental indicators. The indicators used were primary energy, solid waste generated, water pollution index, air pollution index, global warming potential and weighted raw resource use. Also, the life cycle costing of each alternative was compared. The results of LCC and LCA have been used in the optimization model to find the optimum solution.

The result of the case study has shown that the optimum alternative of tilt-up building was the most cost effective and with lower environmental impacts. In a conclusion, the proposed optimization model can be used as a decision support tool in the preliminary stages of building design.


identifier: Xu, Di  (2010) The range time for jump diffusion with two-sided exponential jumps.  Masters thesis, Concordia University.


identifier: Araki, Marci M  (2011) SLeducating: An exploration of the evolution of educators in Second Life.  Masters thesis, Concordia University.


identifier: Desai, Chirag  (2010) Design and Optimization of Hybrid Electric Vehicle Drivetrain and Control Strategy Parameters Using Evolutionary Algorithms.  Masters thesis, Concordia University.

abstract: Advanced propulsion technologies such as hybrid electric vehicles (HEVs) have demonstrated improved fuel economy with lower emissions compared to conventional vehicles. Superior HEV performance in terms of higher fuel economy and lower emissions, with satisfaction of driving performance, necessitates a careful balance of drivetrain component design as well as control strategy parameter monitoring and tuning. In this thesis, an evolutionary global optimization-based derivative-free, multi-objective genetic algorithm (MOGA) is proposed, to optimize the component sizing of a NOVA® parallel hybrid electric transit bus drivetrain. In addition, the proposed technique has been extended to the design of an optimal supervisory control strategy for effective on-board energy management. The proposed technique helps find practical trade off-solutions for the objectives. Simulation test results depict the tremendous potential of the proposed optimization technique in terms of improved fuel economy and lower emissions (nitrous-oxide, NOx, carbon monoxide, CO, and hydrocarbons, HC). The tests were conducted under varying drive cycles and control strategies


identifier: Hotz, Natascha  (2010) Active Site Studies of a Thermophilic Dehydrogenase.  Masters thesis, Concordia University.

abstract: Prephenate dehydrogenase (PD) is one enzyme within the family of TyrA proteins dedicated to the biosynthesis of L-tyrosine (L-Tyr). It catalyzes the NAD+-dependent oxidative decarboxylation of prephenate to hydroxyphenylpyruvate (HPP), which then undergoes transamination to L-Tyr, a feedback inhibitor of the enzyme. Guided by the recent crystal structures of a monofunctional PD from the hyperthermophilic bacterium Aquifex aeolicus in complex with active site ligands (63), residues were targeted for mutagenesis and the variant proteins were characterized by kinetic, biophysical and computational methods as an attempt to provide insight into how these residues participate in the catalytic mechanism and mode of regulation of A. aeolicus PD. We identified H205, a highly conserved residue, as an important catalytic group which likely maintains H147 in a catalytically competent conformation via a hydrogen bonding network, whereas electrostatic interactions afforded by D206 appear critical for the overall stability of the enzyme. We demonstrated that S254 is critical for feedback inhibition by L-Tyr, likely mediated by a hydrogen bonding network involving S254, T152, H217 and water. Moreover, R250 and K246 act in an additive fashion to facilitate the binding of prephenate to the enzyme. The combination of substrates and L-Tyr with the enzyme was further probed using fluorescence emission quenching, equilibrium dialysis and isothermal titration microcalorimetry. The latter technique revealed that L-Tyr binds with very high affinity to the native enzyme and that the combination is enthalpy driven. Perturbations in the binding of L-Tyr are further highlighted for selected variant proteins.


identifier: Paspaliaris, Pantelis  (2010) The Strategic Role of Training and Development at a North American Airline.  Masters thesis, Concordia University.

abstract: Training and development (T&D) (also known as Human Resource Development – HRD) and its strategic role are currently debated at the national, organizational and individual levels. General literature regarding its impact is undecided. In the airline industry, training literature and studies have been confined to either “great carriers” such as Southwest and Singapore Airlines or to technical areas of expertise such as engineering, maintenance and navigation of aircraft. Very little work has been done at the broader levels of a typical network airline carrier, particularly its frontline branches. Therefore, the current qualitative study will focus on if and how training and development is strategic at the organizational, departmental and individual levels of an international North American airline. Here, a collective case study approach is used whereby three frontline departments from three distinct branches (Airports, Call Centers, and In-Flight) have been assessed.  Semi-structured interviews have been conducted with a Training Manager, Curriculum Developer/Instructor and Frontline employee from each branch making a total of nine interviewees. This study will show if and how each department deems T&D as strategic in its own way. It also shows how the three different T&D departments have different requirements to become more strategic due to the very different nature of their work.


identifier: Najafi Nejad Nasser, Azita  (2011) An Experimental Investigation of Flow Energy Losses in Open-Channel Expansions.  Masters thesis, Concordia University.

abstract:
Channel expansions are common in both natural and engineered open channels. They connect a relatively narrow upstream section of channel with a large downstream section of channel. Due to increasing cross-sectional dimensions in an expansion, the flow decelerates. Under steady flow conditions flow deceleration results in an increase in water pressure and hence an adverse pressure gradient. This often triggers flow separation and turbulent eddy motion, and causes energy losses in the flow. When conservation of flow energy is required, the issue of energy losses becomes important, a consideration which has motivated this study. The focus of this study is on subcritical flow, a typical flow seen under a wide range of flow conditions. This study aims to quantify the energy losses in a lateral expansion and to further investigate how effective a hump fitted on the channel-bed of the expansion is at reducing energy losses.
This study adopted the experimental approach. Using a recirculating laboratory flume, experiments of flow in expansions with or without a hump were performed to measure flow depth, pressure, and cross-sectional mean velocities. These measurements were analysed using the energy concept for direct estimates of the energy loss coefficient. Without the hump, measured water pressures showed adverse gradient in the expansion, opposing the approaching flow. Estimates of the energy loss coefficients ranged from 0.46 to 0.62. These results would be useful for the design of channel expansions, and for calibrating and validating numerical hydrodynamics models. The presence of the hump has been shown to accelerate the flow, convert adverse to favourable pressure gradient, and lower the energy loss coefficients by more than 50% when compared with the corresponding values without the hump.
So far no satisfactory theory has been established for determining the energy loss coefficient for a given expansion. In this study, the momentum concept is combined with the energy concept in order to derive a theoretical expression for the energy loss coefficient. When applying the momentum concept to flow in an expansion, the pressure forces may be evaluated using the hydrostatic approximation, as supported by experimental evidence from this study. The theoretical expression involves extra parameters whose values are obtained based on the experimental data. It has been shown that the theoretical and experimental values for the energy loss coefficient are in good agreement. This theoretical expression can easily be extended to study channel expansions of different configurations.


identifier: Hacib, Mounia  (2010) Récit multiple est diversité romanesque dans L’Amour la fantasia d’Assia Djebar.  Masters thesis, Concordia University.

abstract:
Notre recherche a eu pour sujet d’étude le fonctionnement des récits multiples et la diversité romanesque dans L’Amour, la fantasia d’Assia Djebar. Notre objectif était de faire ressortir l’originalité d’une femme écrivaine et de pallier la négligence de la critique pour les innovations textuelles et narratives des écrivaines femmes.
Le mémoire s’intéresse à l’hétérogénéité de la structure du roman et étudie le système d’écriture qui l’organise en privilégiant plusieurs approches théoriques. Ces lectures entrecroisées ont pour but de rendre justice à la richesse de l’écriture djebarienne.
 Pour mieux appréhender les trois récits combinés, il était nécessaire d’analyser l’écriture plurivoque du roman comme aboutissement du parcours multidisciplinaire de l’auteure et son tiraillement entre son propre imaginaire, son attachement patriotique et son statut de femme algérienne francophone.
Le premier chapitre étudie les techniques d’écriture ainsi que les dispositions formelles comme vecteurs de sens. Le deuxième chapitre propose une étude stylistique en retenant l’allégorie comme figure de rapprochement entre le récit autobiographique et le récit historique. Le troisième chapitre analyse le jeu narratif et l’alternance des instances du discours pour mettre en avant l’éclatement du « je » autobiographique. Le quatrième chapitre examine surtout la polyphonie du roman en lien avec la posture langagière de l’auteure. Le cinquième chapitre traite de la résonance médiatique de l’œuvre et fait ressortir l’effet de cette interaction sur le style et la forme de l’écriture.


identifier: Glasgow, Stephen  (2011) Cholinergic modulation of the superficial layers of the parasubiculum.  PhD thesis, Concordia University.

abstract:
ABSTRACT

Cholinergic modulation of the superficial layers of the parasubiculum

Stephen D. Glasgow, Ph.D.
Concordia University, 2011

Recent evidence suggests that the parahippocampal area, including the entorhinal cortex and parasubiculum, may play a crucial role in spatial processing and memory formation.  However, little is known about the basic cellular and network properties of the parasubiculum, an isocortical brain region that receives input from the hippocampus and other subcortical regions associated with spatial navigation, and projects exclusively to the superficial layers of the entorhinal cortex.  Neurons in layer II of the parasubiculum demonstrate theta-frequency membrane potential oscillations at near-threshold voltages that are generated via an interplay between a persistent Na+ current and the hyperpolarization-activated cationic current Ih, and these rhythmic fluctuations in membrane potential may contribute to the generation of oscillatory local field potentials.  Further, the parasubiculum receives strong cholinergic projections from the medial septum.  Acetylcholine has been linked to theta-frequency oscillations via regulation of cellular and network dynamics through membrane depolarization, while concurrently suppressing excitatory synaptic transmission, and it is likely that cholinergic receptor activation has similar effects in the parasubiculum.  I found that  activation of cholinergic receptors depolarizes layer II cells of the parasubiculum by exerting numerous effects on K+ channels, including IM and IKir, however also suppresses incoming excitatory synaptic transmission from the CA1.  These results indicate that increases in cholinergic tone during network-level theta-frequency oscillations in the parasubiculum may increase neuronal excitability by exerting strong effects on postsynaptic conductances, but may also regulate network dynamics by reducing the strength of incoming afferents.


identifier: Mayer, Esther R.  (2011) Yosse ben Yosse: The Social Function of Liturgical Poetry in 5th Century Palestine.  Masters thesis, Concordia University.

abstract:
The literary genre of Piyyut reflects the time and place in which it was composed, and may therefore be considered an appropriate means for research concerning the sociological religious culture of 5th century Palestinian Jewish life, given the paucity of original source materials from this post-destruction formative period in Judaism. Piyyutic literature was an engine for engendering national identity, fostering kinship and cohesiveness, and displacing revenge or assimilation in favour of Torah observance, which was deemed by the Sages to be essential for the maintenance of the vitality and continuity of Judaic life until its prophesied messianic regeneration.

	Yosse ben Yosse composed his Piyyutim in Hebrew, labouring in the Galilee under Byzantine rule. His poems are analyzed as vehicles for transmitting religious, political, social, and didactic messages that were incorporated into the worship lives of Jews. This paper examines the ontological aspects of identity construction, 5th century Jewish historiographic understanding of the nature of time, and elements of messianism that pervade the prayerful Piyyutim. Through tenacious adherence to Hebrew as a repository of culture and destiny, Yosse ben Yosse drew biblical and midrashic allusions, and articulated the rabbinic ethos and concerns with his unique literary style and cadence which mark him as the first in a line of many Paytanim who left their mark on Jewish liturgy.

Seven of his known Piyyutim are presented and translated into English, as a means of fostering further scholarly investigation of Yosse ben Yosse’s contribution to the Piyyutic genre.


identifier: SHE, Ying Ying  (2011) Goal-oriented Behaviour for Intelligent Game Agents.  PhD thesis, Concordia University.

abstract:
This thesis concerns our innovation in game AI techniques, mainly game agents' modeling, planning and learning. The research topic involves the development of a game design software --- Gameme. Our work mainly focus on the development of the core AI module.

In this thesis, after discussing the system design of Gameme, we explain our contributions in two parts: off-line design and real-time processing. In off-line design, we present goal-oriented behaviour design and related modeling methodology for game agents. The goal-oriented design provides not only an intuitive behaviour design methodology for non-professional game designers but also efficient support for real-time behaviour control. In particular, the goal-oriented design can be used in modeling agents in different games.

The real-time processing component includes planning and learning mechanisms for game agents. These mechanisms are placed in a layered architecture. Basically, a procedural planning mechanism allows game agents to have the ability of fast reaction to their environment. Then, the creative transfer and adaptive learning mechanism trains game agents to learn from their experience and cooperate in teamwork. Furthermore, the unique emergent learning mechanism can allow game agents to have the ability to analyze different PCs' behaviour patterns and to find the suitable strategy to defeat PCs in real-time.

Most of the experiments in this thesis are performed in fighting scenarios. We connected the core AI module with a 3D graphics engine in order to have visual testing results. All test cases show that our goal-oriented behaviour design along with planning and learning mechanisms can provide fast, autonomous, collaborative and adaptive behaviour instructions for game agent in real-time game play.


identifier: Grenier, Jennifer Lys  (2010) Uncovering the political lives of children: Valuing the Social Agency and Contributions of Youth in Northeast Brazil.  Masters thesis, Concordia University.


identifier: Alzaidy, Rabeah  (2010) Criminal Network Mining and Analysis for Forensic Investigations.  Masters thesis, Concordia University.

abstract:
Criminal network analysis tools are widely used by law enforcement, mainly in cases of organized crime. The data required for a majority of these tools are police records and databases. In many cases, forensically collected data contains valuable information about the suspect’s social network. This information is normally obtained by manual inspection of the collected documents using forensic tools’ queries and other basic search features. The information is then manually entered in the police database. There are no known tools that provide methods to automatically extract social networks from raw documents on behalf of the investigator add them to a knowledge base and then analyze them. In this thesis, we propose a method that is capable of performing these tasks. In our proposed system, we claim three distinct contributions to cyber forensics investigations. The first is by constructing the social network of one or multiple suspects from documents in a file system. Secondly, we provide an analysis of the interactions and structures of these social networks and the communities comprising them. Thirdly, potential evidence and leads are identified by extracting conceptual links between members of the social network across the document set.
Finally, the proposed method is implemented and experimental results are obtained to demonstrate the feasibility of the approach.


identifier: Derghazarian, Sevag  (2011) Immobilization Of Arsenic In Mine Tailings Using Standard And Nanoscale Metal Oxides.  Masters thesis, Concordia University.


identifier: Qasem, Altayeb  (2011) Performance Assessment Model for Wastewater Treatment Plants.  PhD thesis, Concordia University.

abstract:
Management of wastewater treatment plants has become a major environmental and economic concern in North America because of the unprecedented deterioration of these facilities. This situation is aggravated by the lack of adequate funds for upgrading and maintenance. In 2008, Statistics Canada estimated that wastewater treatment assets have exceeded 63% of their useful life, the highest level among public infrastructure facilities. Similar studies in the United States found current wastewater treatment facilities with a near-failure average grade of D-. These facts show the urgent need for rehabilitation decision tools to keep these facilities running effectively. This dissertation aims to respond to such a pressing need by developing a performance assessment model (PAM) for the maintenance and rehabilitation of wastewater treatment plants (WWTPs) that depends on various treatment and infrastructure aspects.
The developed PAM is based on the evaluation of both treatment and infrastructure performance for the main treatment phases of a WWTP. The treatment performance of each phase is based on efficiency of treatment and robustness of its parameters as set by design standards. The infrastructure performance of each treatment phase is determined using infrastructure condition rating models developed by integrating the multi-attribute utility theory (MAUT) and the analytic hierarchy process (AHP).The required data for these models were collected via questionnaires from, site visits to, and interviews with experts in Canada and the United States. The results reveal that physical factors have the highest impact on deterioration of WWTP infrastructure and that pumps are the most vulnerable infrastructure unit. Deterioration curves for different infrastructure units in a WWTP are generated using sensitivity analysis, which shows the effect of age over their condition rating indexes. The treatment and infrastructure performance indexes are merged and presented in a combined condition rating index. Integer programming approach is used to optimize the rehabilitation interventions within available budget constraints with a minimum desired condition rating for each infrastructure unit.
The developed PAM is validated using data of three WWTPs from Canada and the United States. Managers of these WWTPs acknowledged the efficacy of the developed model outputs and deemed it systematic, straightforward, and valuable for clearly pinpointing the main problems in these WWTPs.


identifier: Nassiboullina, Lira  (2011) Comparative Analysis of the French, English, and Russian Versions of the Musical Notre-Dame de Paris.  Masters thesis, Concordia University.

abstract:
Abstract/Résumé

This thesis presents a detailed comparative analysis of the French, English, and Russian versions of the widely acclaimed musical Notre-Dame de Paris. For this study, I will examine three versions of Notre-Dame de Paris: that were presented in France, in the United States and Great Britain, and in Russia. Although its focus is on translation studies, much of my research is indebted to the contributions of scholars in the field of musical theatre, particularly in the translation of musicals.

I discuss the problems with the English and Russian translations as well as their deviations from the original French text. My methodology is rooted in the analysis of linguistic level such as syntactical figures and rhetorical devices. The results of this research demonstrate how the translator’s vision or interpretation of the reality he or she describes can modify the original message of the source text, as displayed by the translations of selected songs. The analysis shows that the English version reproduces the style and content of the source text as closely as possible, whereas the Russian version interprets the source text more freely. Furthermore, I analyze the relationship between the translation of a musical and the reception of the production by its target audience.

Cette thèse présente une analyse comparative approfondie des versions française, anglaise et russe de la comédie musicale largement acclamée Notre-Dame de Paris. Aux fins de cette étude, j'explore trois versions de Notre-Dame de Paris, celles qui sont présentées en France, aux États-Unis, en Grande-Bretagne et finalement, en Russie. Bien qu’appartenant au domaine des études de traduction, ma recherche est également basée sur les contributions faites par des chercheurs dans le domaine du théâtre musical, en particulier, des comédies musicales et de la traduction.

Je discute des problèmes et des différences qu’on trouve dans les traductions anglaise et russe du texte original français. Ma méthode d'analyse repose sur les niveaux linguistiques qui comprennent les figures syntaxiques et rhétoriques. L’analyse démontrera la façon dont la vision ou l'interprétation de la réalité décrite par le traducteur peut modifier le message d'origine du texte source, ce qui peut être le cas dans la traduction de certaines chansons. L'analyse montre que la version anglaise reprend le style et le contenu du texte source d'aussi près que possible, alors que la version russe donne une idée de la libre interprétation du texte source. Dans cette étude, je présente également une analyse de la relation entre la traduction des comédies musicales et la réception de la production par le public cible.


identifier: Zamal, Hasna Hena  (2011) Monitoring Fatigue Damage Behavior of Glass/Epoxy Composites Using Carbon Nanotubes as Sensors.  Masters thesis, Concordia University.

abstract:
Abstract

       Monitoring Fatigue Damage Behavior of Glass/Epoxy
          Composites Using Carbon Nanotubes as Sensors

                     Hasna Hena Zamal

Carbon nanotubes have been used as sensors in glass fiber/epoxy laminates for monitoring damage under fatigue loading. Carbon nanotubes are embedded in epoxy resin. The modified resin is infused between glass fibers to make composites. Silver paste electrodes are deposited on the surface of the laminate. Changes in electrical resistance are measured along several in-plane and through-thickness positions of the laminate. The changes in resistance are compared with the strain changes measured by strain gages. It is found that the changes in electrical resistance are sensitive to the degradation in the composite laminate. The electrical resistance method is proved to be more reliable in detecting damage in CNT incorporated GFRP composites than strain measurements as it senses the initiation of damage earlier than strain measurement. Among the in-plane and through- thickness resistance response, the through-thickness response can represent the initiation of damages more sensitively and quickly. This technique may be used to provide effective in-situ monitoring of damages in composites.


identifier: Akhlaque-E-Rasul, Shaikh  (2010) Compressive Response of Tapered Curved Composite Plates.  PhD thesis, Concordia University.

abstract:
Tapered laminated structures have considerable potential for creating significant weight savings in engineering applications. In the present thesis, the ply failure and global buckling failure of internally-tapered curved laminates are considered. For the buckling analysis, four different analytical approaches are employed: (1) classical shell theories using Ritz method, (2) first-order shear deformation shell theories using Ritz method, (3) linear finite element analysis based on first-order shear deformation shell theories, and (4) non-linear finite element analysis. Due to the variety of tapered curved composite plates and the complexity of the analysis, no closed-form analytical solution is available at present regarding their response to compressive loading. Therefore, the Ritz method is used for the global buckling analysis considering uniaxial compressive load. Linear buckling analysis of the plates is carried out based on eight classical shell theories and six first-order shear deformation shell theories. To apply the first-order shear deformation shell theories, an appropriate set of shear correction factors has been determined. The buckling loads obtained using Ritz method are compared with the existing experimental and analytical results, and are also compared with the buckling loads obtained using finite element method. The strength characteristics and load carrying capability of the tapered curved plates are investigated considering the first-ply failure and delamination failure. The commercial software ANSYS® is used to analyze these failures. Based on the ply failure and buckling analyses, the critical sizes and parameters of the tapered curved plates that will not fail before global buckling are determined.

Linear buckling analysis is insufficient to take into account the effect of large deflections on the buckling loads. This effect can only be considered in the non-linear buckling analysis. However, very large number of load steps is required to determine the buckling load based on the non-linear analysis in which the stability limit load is calculated from the non-linear load-deflection curve. In the present thesis, a simplified methodology is developed to predict the stability limit load that requires the consideration of only two load steps. The stability limit loads calculated using the present simplified methodology are shown to have good agreement with that calculated from the conventional non-linear load-deflection curve.

Parametric studies are carried out using the above mentioned four different types of analytical methods. In these studies, the effects of boundary conditions, stacking sequence, taper configurations, radius, and geometric parameters of the plates are investigated.


identifier: Pelletier, Marie A.  (2011) Finding Meaning in Oral History Sources through Storytelling and Religion: Case Study of Three Cambodian Refugees.  Masters thesis, Concordia University.

abstract: : This research is based on three oral life stories narrative of Cambodian refugees living in Montreal. Careful observation of the narrative form and the religious framing of these interviews allowed for a better understanding of the meaning that is assigned to events by their narrators and the potential for the uses of narrative analysis in oral history research. Analysis of these life story interviews was done on three levels: isolated stories, life stories and cultural and historical context. At the level of isolated stories, interviewees transformed the events of their lives into narrative in order to give them meaning, a meaning often shaped by religious beliefs. In life stories as a whole, they created links between stories and between disparate events of their lives and thus reinforced a sense of coherent identity. In this task, religion provided a framework through which the meaning of life could be understood and conveyed. However, the experience of genocide often proved a challenge both for the creation of a coherent life narrative and for the religious framework through which these individuals perceived their lives. Furthermore, the narrative structure of the interviews reflected how these individuals related to their community – by speaking about the community, and to the community – and how they situated themselves in time.


identifier: Amans, Thomas E  (2010) L’amour, la haine et la dissolution : une mise en contexte des relations interpersonnelles dans les romans de Michel Houellebecq.  Masters thesis, Concordia University.

abstract:
Les romans de l’auteur français Michel Houellebecq ne cessent de susciter la polémique. Celle-ci découle notamment de la représentation problématique des relations entre les hommes et les femmes dans tous les romans de l’auteur. De fait, l’animosité entre certains personnages masculins et féminins, la représentation négative de nombreux personnages féminins ainsi que des commentaires apparemment anti-femmes de certains protagonistes masculins ont mené de nombreux critiques à traiter Houellebecq et ses romans de misogynes.
Or, plusieurs aspects des romans semblent réfuter ces accusations catégoriques de misogynie : la représentation négative de certaines femmes se juxtapose avec des représentations positives de certaines autres ; les commentaires désobligeants des protagonistes à l’égard de certains personnages féminins sont contrebalancés par des passages sentimentaux qui frôlent la révérence ; de même, les protagonistes n’épargnent pas non plus les personnages de sexe masculin de leurs commentaires calomnieux. À la lumière de ces éléments, ma propre analyse des romans de Houellebecq m’a mené à poser l’hypothèse que les relations interpersonnelles qui y sont représentées se décrivent plus précisément comme des manifestations d’un phénomène plus vaste d’effondrement social. Pour étudier ce phénomène, j’effectue une analyse des quatre romans de Houellebecq comme un même grand récit raconté selon différentes perspectives cognitives et temporelles. Cette perspective me permet d’analyser la société telle que représentée dans le texte plutôt que de voir dans les divers narrateurs un reflet des positions idéologiques de l’auteur lui-même.


identifier: Gagnon, Martine  (2010) Golden Age Spain Wearing English Clothes: James Mabbe, Renaissance Translator of Spanish Prose Literature.  Masters thesis, Concordia University.

abstract: James Mabbe (1572-1642?) was an English translator of works by Mateo Alemán, Fernando de Rojas, Miguel de Cervantes Saavedra, Fray Cristóbal de Fonseca and Fray Juan de Santa María. He worked during a time of religious, economic, and political rivalries between Spain and England, and produced a body of work that is significant in the field of Translation Studies because his technique and methods lie somewhere between “foreignizing” and “domestication”. Mabbe’s dual quality allows contemporary academia to understand the elements of Spanish prose and culture that were of interest to a seventeenth-century English readership and also to introduce another artist of literary merit from the same period as Shakespeare, Ben Jonson, and other great Jacobean dramatists. By examining the context of English literacy and translation during the period 1500 to 1640, Mabbe emerges as one of the first serious critics and translators of Spanish prose work in the English-speaking world.


identifier: Ly, Li Shang  (2011) A Multi-Method Exploration on Coffee Shop Atmospherics.  Masters thesis, Concordia University.


identifier: Kucera, Miroslav  (2010) Three Essays in Empirical Labour Economics.  PhD thesis, Concordia University.

abstract:
The following thesis consists of three essays, each one being a study of issues of accumulation of and returns to human capital using real-world individual-level data. The first study examines what underlies differences in educational attainment between the children of immigrants to Canada and the children of the Canadian-born parents. It concludes that the children of immigrants have done better in terms of schooling, and that individual and family variables as well as unobserved characteristics such as ability cannot fully account for this difference.
      The second study utilizes unique Canadian surveys to investigate the effects of overeducation on wages of post-secondary graduates. It confirms that jobs requiring a post-secondary degree pay substantially higher wages than jobs that do not require education beyond high-school, and also finds a large variation both in returns to required education as well as in overeducation premia across genders, degrees and fields of study.
      The last essay proposes and estimates a structural dynamic model of optimal schooling and wages to explain differences between American whites and ethnic minorities of Afro-Americans and Hispanics. The study finds, among other things, that differences in educational attainment between the three ethnics can largely be explained by differences in individual endowments, while behavioural differences seem to be more important in explaining wage differences.


identifier: Burton, Euan  (2010) Proteomic Analysis of Cellulose Metabolism in Clostridium thermocellum.  Masters thesis, Concordia University.

abstract: The cytoplasmic and membrane proteomes of the cellulolytic bacterium Clostridium thermocellum grown on either cellulose or cellobiose were quantitatively compared using a metabolic 15N isotope labelling method in conjunction with nanoLC-ESI-MS/MS. In total 1255 proteins were identified in the study and 95 of those were able to have their relative abundance per cell compared in at least one cellular compartment in response to the substrates provided. Three cellulosome anchoring proteins, OlpB, Orf2P, and SdbA, were all found to be more abundant in cellulose grown cells. Cellodextrin transport complex B, appearing to be the major cellodextrin transporter in the organism, did not demonstrate any difference in abundance on either substrate. Cellodextrin transport complex A, putatively a strict cellotriose transporter, demonstrated increased abundance in cellobiose grown cells. This study reveals that cells grown on cellulose increase their abundance of phospoenolpyruvate carboxykinase while decreasing the abundance of pyruvate kinase, suggesting that the organism diverts carbon flow into a transhydrogenase malate cycle that can increase the production of the biosynthetic intermediates NADPH and GTP. Glutamate dehydrogenase and copper amine oxidase proteins were also found to have increased abundance in cellulose grown cells, suggesting that the assimilation of ammonia is up-regulated during growth on the substrate. The up-regulation of enzymes leading to increased production of biosynthetic intermediates and the assimilation of ammonia reveal how the organism produces the substrates necessary to increase the production of cellulosomes required for the hydrolysis of crystalline cellulose.


identifier: Khan, Maqsood Ahmed  (2010) Piecewise Arc-Length Parameterized NURBS Tool Paths Generation for 3-Axis CNC Machining of Accurate, Smooth Sculptured Surfaces.  PhD thesis, Concordia University.

abstract:
In current industrial applications many engineering parts having complex shapes are designed using sculptured surfaces in CAD system. Due to the lack of smooth motions and accurate machining of these surfaces using standard linear and circular motions in conventional CNC machines, new commercial CNC systems are equipped with parametric curve interpolation function. However, in some applications these surfaces can be very complex that are susceptible to gouging and due to the approximation of; CL-path in CAM system and path parameter in real –time, high machining accuracy, smooth kinematic and feed-rate profiles, are difficult to achieve. This dissertation focuses on developing algorithms that generate tool paths in NURBS form for smooth, high speed and accurate sculptured surface machining. The first part of the research identifies and eliminates gouge cutter location (CL) point from the tool path. The proposed algorithm uses global optimization technique (Particle Swarm Optimization) to check all the CC-points along a tool-path with high accuracy, and only gouging free CC-points are used to generate the set of valid CL-points. Mathematical models have been developed and implemented to cover most of the cutter shapes, used in the industry.
In the second phase of the research, all valid CL-points along the tool-path are used to generate CL-path in B-spline form. The main contribution of this part is to formulate an error function of the offset approximation and to represent it in NURBS form to globally bound the approximation errors.  Based on this error function, an algorithm is proposed to generate tool-paths in B-spline from with; globally controlled accuracy, fewer control points and low function degree, compared to its contemporaries. The proposed approach thus presents an error-bounded method for B-spline curve approximation to the ideal CL-path within the accuracy. This part of research has two components, one is for 2½- axis (pocket) and the other one is for 3-axis (surface) CNC machining.
The third part deals with the problem of CL-path parameter estimation during machining in real time. Once the gouging free CL-path in NURBS form with globally controlled accuracy is produced, it is re-parameterized with approximate arc-length in the off-line stage. The main features of this work are; (1) sampling points and calculating their approximate arc-lengths within error bound by decomposing the input path into Bezier curve segments, (2) fitting the NURBS curve with approximate arc-length parameter to the sample points until the path and parameterization errors are within the tolerance, and (3) segment the curve into pieces with different feed rates if during machining the cutter trajectory errors are beyond the tolerance at highly curved regions in the NURBS tool path.


identifier: Chen, Jianjun  (2010) Development of the Change Management Method for Small and Medium Construction Projects.  Masters thesis, Concordia University.

abstract:
Changes often happen during the process of the construction project.  Main changes could be absence of workers, breakdown of machines, and adverse weather.  These changes can impact the project at all kinds of levels.  Meanwhile, the project manager needs to make appropriate decisions to minimize the impact of changes.  Typical decisions would be re-allocation of resources and re-arrangement of the tasks.  However, how to make appropriate decisions for change management is not easy to answer.

In this context, we propose the Decision-based Change Management (DCM) approach as a change management tool to deal with the change scenarios in construction engineering.  The DCM approach is intended to help the project managers (especially new project management practitioners) to assess the level of change impacts and select an appropriate change option for project revision.  The DCM approach in this thesis is applied to the cases of sub-project of pipeline installation in the Wastewater Treatment Plant Project, which addresses how to find an appropriate change option to deal with the change scenarios concerning absence of the workers for a period of time.  In specific, three change options are categorized for the DCM approach based on two types of schedule revision activities (Patch Actions & Repair Actions).  When a change scenario occurs, three key change impact factors are used to estimate the level of change impact for this change scenario during the implement procedure of the DCM approach.  Then, a proper change option can be chosen to revise the schedule based on the estimated level of change impact.

At last, we propose evaluating two criteria (project delay and re-organization efforts) to examine the quality of the revised schedules.  Experimental results of the cases indicate validity of the DCM approach to tackle most of the change scenarios concerning absence of the workers in the construction project.


identifier: Khalil, Sofia  (2011) Studies of the Protein Interaction Network Required for Enterobactin Biosynthesis in Escherichia coli.  PhD thesis, Concordia University.

abstract:
Abstract
Studies of the Protein Interaction Network Required for Enterobactin Biosynthesis in Escherichia coli

Sofia Khalil, Ph.D.
Concordia University, 2010

Siderophores are small-molecule iron chelators that many bacteria synthesize and secrete in order to survive in iron-depleted environments. In Escherichia coli, biosynthesis of the siderophore molecule enterobactin requires the activities of six enzymes, EntA-EntF. These enzymes function sequentially to produce enterobactin molecule in the cytoplasm. The enterobactin biosynthesis pathway is divided into two modules. The first module involves the conversion of chorismate to 2,3-dihydroxybenzoic acid (2,3-DHB), and requires the activities of EntC, EntB (N-terminal domain) and EntA. The second module involves non-ribosomal peptide synthesis (NRPS) such that three molecules of 2,3-DHB are condensed with three molecules of L-serine to form the siderophore. The NRPS module requires the activities of EntE, EntB (C-terminal domain), EntD and EntF.
The overall goal of my research project is characterization of the enterobactin biosynthetic enzyme EntE. EntE catalyzes the activation of 2,3-DHB via adenylation producing DHB-AMP. I am interested in addressing the following questions: (i) How does EntE bind its 2,3-DHB substrate? (ii) How does it interact with its upstream and downstream partner proteins: EntA, which produces 2,3-DHB, and EntB, which uses the EntE product (DHB-AMP) as a substrate, respectively? My thesis is divided into three research-related chapters:
The first research chapter focused on the interaction of EntE with its substrate, 2,3-DHB, as well as the characterization of EntE-EntB interaction in the presence and absence of 2,3-DHB. A significant change in EntB conformation was observed upon the interaction with EntE when in the presence of 2,3-DHB. In the pull-down assay, EntB as bait protein pulled down more EntE in the presence of exogenous 2,3-DHB. We conclude from this chapter that the ligand-loaded state of the protein was necessary for efficient protein-protein interaction.
 The second research chapter involves the characterization of a novel interaction between EntE and its upstream partner protein EntA. A significant increase in EntE activity was observed upon adding EntA. Furthermore, EntA reduces the FRET signal of EntE-bound 2,3-DHB in a saturable manner with increasing EntA concentrations. Using this fluorescence binding assay at 20 °C revealed a positive cooperativity in EntA-EntE interaction with Hill coefficient greater than one. The AUC experiments showed that EntA conformation is highly dependent on its concentration. In conclusion, the results of this chapter suggest that EntA-EntE interaction likely induces remodeling of EntE active site, resulting in the observed increase in EntE catalysis.
In the third research chapter, the EntA-EntE interaction interface was characterized using phage display. Based on the interaction interface predicted by phage display data, EntA variants containing single-site and double-site mutations were created (Q64A, A68Q, and Q64A/A68Q). Our in vitro biophysical techniques and growth phenotype experiments revealed that EntA (Q64A) and EntA (Q64A/A68Q) mutations have a more pronounced effect than EntA (A68Q) mutation on disruption of the EntA-EntE interaction interface.


identifier: Goring, Mark  (2011) Characterization of temperature-sensitivity and its intragenic suppression in Saccharomyces cerevisiae tRNA nucleotidyltransferase mutants.  Masters thesis, Concordia University.

abstract: ATP:CTP-specific tRNA nucleotidyltransferase enzymes catalyze the stepwise addition of one CMP, a second CMP, and finally an AMP as needed to generate the functional 3’ termini of tRNA molecules. The following work concerns the structural and functional characterization of a temperature-sensitive variant E189F of tRNA nucleotidyltransferase from Saccharomyces cerevisiae, and two suppressor variants; R64WE189F and R64WE189K of this phenotype. Previous work has shown that E189K, E189F, and other variants of tRNA nucleotidyltransferase with substitution mutations at E189 are temperature-sensitive, and can exhibit enzymatic activity levels as low as 4% relative to that of native enzyme (Aebi et al., 1990, Shan et al., 2008). Moreover, E189F and E189K display almost identical levels of compromised thermal stability as compared to the native enzyme. Here, tRNA nucleotidyltransferase from recently isolated intragenic suppressor mutants of the temperature-sensitive phenotype are characterized in an effort to understand the development of the temperature-sensitive phenotype and its suppression. The suppressor strains R64WE189F and R64WE189K show a level of thermal stability that is comparable to E189F, or intermediate to E189F and E189 respectively. However, both suppressors display native-like levels of activity. It is evident that severely reduced activity is the major determining factor of the temperature-sensitive phenotype, not compromised thermal stability, and that a marked increase in specifc activity is responsible for its suppression. Consequently, these data also suggest that the temperature-sensitive phenotype may be caused by an inability of temperature-sensitive variants to meet the demand for mature tRNA at the restrictive temperature.


identifier: Deeba, Farah  (2010) Assessment of SHM Data Integrity by Statistical Pattern Recognition Techniques.  Masters thesis, Concordia University.