title: Rockslides in a Changing Climate: Establishing Relationships Between Meteorological Conditions and Rockslides in Southwestern Norway for the Purposes of Developing a Hazard Forecast System

contributor: Geological Sciences and Geological Engineering

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subject:
Geological Engineering
Natural Hazards

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2010-01-28 08:12:43.316

abstract:
The steep, mountainous terrain of southwestern Norway is prone to a high frequency of rockslides. It is known that many of these rockslides are triggered by meteorological conditions, yet there have been few studies dedicated to quantifying the link between rockslides and the runoff conditions and freeze/thaw processes that trigger failure. With recent climate research indicating that southwestern Norway will experience warmer temperatures and increased precipitation, it has become apparent that a better understanding of this link is required to help prepare for future events.

Rockslides in Norway lead to road closures, property damage and fatalities every year, and one of the biggest challenges for Norwegian authorities is to react to rockslides as they happen and to reopen roads as soon as possible. This is especially true when several rockslides occur on the same day in multiple locations. As a result, authorities wish to implement a hazard mapping system that uses a weather forecast to predict when and where geohazards are likely to occur. To this end, this thesis is aimed at providing a rockslide forecast map that changes every day based on the weather forecast.

By comparing a rockslide database to historic weather records, the work carried out for this thesis has indicated that extreme runoff during winter storms is responsible for triggering the majority of rockslides in the region. Using this knowledge as a basis, two potential hazard mapping systems are proposed, one based on trigger threshold exceedance and the other based on weights-of-evidence susceptibility mapping. Both of these methods operate by mapping areas experiencing extreme runoff conditions. Several runoff parameters were tested for possible inclusion, and it was found that 48-hr antecedent runoff, normalized by mean monthly precipitation had the best correlation with rockslide occurrence. Verification of these methods indicates that both approaches are successful in predicting days with extreme conditions, thereby alerting authorities that a high frequency of rockslides is likely.

Due to the complex nature of rockslide triggering, it is not fully understood how climate change will affect future rockslide activity; however, this thesis attempts to answer these questions and to provide a basis for future studies.

abstract: M.A.Sc.


title: Automatic Identification of Protein Characterization Articles in support of Database Curation

contributor:
Shatkay, Hagit
Computing

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rights: This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.

subject:
machine learning
database curation
bioinformatics
classification
biomedical text mining

abstract: Thesis (Master, Computing) -- Queen's University, 2010-01-28 18:45:17.249

abstract:
Experimentally determining the biological function of a protein is a process known as protein characterization.  Establishing the role a specific protein plays is a vital step toward fully understanding the biochemical processes that drive life in all its forms.  In order for researchers to efficiently locate and benefit from the results of protein characterization experiments, the relevant information is compiled into public databases.  To populate such databases, curators, who are experts in the biomedical domain, must search the literature to obtain the relevant information, as the experiment results are typically published in scientific journals.  The database curators identify relevant journal articles, read them, and then extract the required information into the database.  In recent years the rate of biomedical research has greatly increased, and database curators are unable to keep pace with the number of articles being published.  Consequently, maintaining an up-to-date database of characterized proteins, let alone populating a new database, has become a daunting task.
	In this thesis, we report our work to reduce the effort required from database curators in order to create and maintain a database of characterized proteins.  We describe a system we have designed for automatically identifying relevant articles that discuss the results of protein characterization experiments.  Classifiers are trained and tested using a large dataset of abstracts, which we collected from articles referenced in public databases, as well as small datasets of manually labeled abstracts.  We evaluate both a standard and a modified naïve Bayes classifier and examine several different feature sets for representing articles.  Our findings indicate that the resulting classifier performs well enough to be considered useful by the curators of a characterized protein database.

abstract: M.Sc.


title: Host-guest chemistry between cucurbit[7]uril and neutral and cationic guests

contributor:
Macartney, Donal H.
Chemistry

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subject:
Chemistry
Supramolecular Chemistry
Host-guest Chemistry
Organic Chemistry
Physical Chemistry
Cucurbiturils
Local Anaesthetics

abstract: Thesis (Ph.D, Chemistry) -- Queen's University, 2010-01-28 12:27:37.833

abstract: This thesis describes the host-guest chemistry between cucurbit[7]uril (CB[7]) and various series of guests, including neutral polar organic solvents, bis(pyridinium)alkane dications, local anaesthetics, acetylcholine analogues, as well as succinylcholine and decamethonium analogues, in aqueous solution. A focus of this thesis is the effects of varying the chemical structures within different series of guests upon the nature of the host-guest chemistry, such as the relative position and orientation of the guest relative to the CB[7] cavity, and the strengths of the binding affinities. The binding affinities of polar organic solvents with CB[7] depend upon the hydrophobic effect and dipole-quadrupole interactions. The polar guests align themselves so that their dipole moment is perpendicular to the quadrupole moment of CB[7]. The binding strengths of acetone and acetophenone to CB[7] decrease in the presence of alkali metals. Discrete 1:1 and 2:1 host-guest complexes are formed between CB[7] and a series of bis(pyridinium)alkane guests. In most cases the CB[7] initially occupies the aliphatic linker when the 1:1 complex is formed and migrates to the terminal regions as the second CB[7] is added. When bulky, hydrophobic tert-butyl substituents are present, however, the CB[7] occupies the terminal pyridinium region and not the central linker. Supramolecular complexes between CB[7] and a series of local anaesthetics have binding affinities 2-3 orders of magnitude greater than reported values with beta-cyclodextrin. The first pKa values of the guests increase by 0.5-1.9 units upon complexation. The binding positions of the guests within CB[7] differ in neutral and acidic media, with the systems thus behaving as pH-activated switches. With supramolecular complexes between CB[7] and various cationic cholines and their phosphonium analogues, the CB[7] cavity is occupied by the charge-diffuse cationic region. The binding affinities and positions vary depending on the nature of the onium group as well as the substituents within the guest molecule. Host-guest complexes between CB[7] and dicationic acetylcholinesterase inhibitors have very strong 1:1 binding affinities, with 2:1 binding being significantly weaker. These binding affinities are related to the nature of the cationic onium groups, and the length and hydrophobicity of the connecting linkers.

abstract: PhD


title: Identification and characterization of GmCaMK1: a novel calmodulin-binding receptor-like kinase from nodules of soybean (Glycine max)

contributor:
Snedden, Wayne A.
Biology

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subject:
Calmodulin
Receptor-Like Kinase
Calcium Signaling
Soybean
Nodules

abstract: Thesis (Master, Biology) -- Queen's University, 2010-01-28 16:00:48.69

abstract: Ca2+ functions as a second messenger in all eukaryotes.  Such Ca2+ signaling is used to coordinate plant responses to numerous stimuli, both developmental and environmental.  Ca2+ signals are often transduced via the action of the ubiquitous Ca2+ sensor calmodulin (CaM).  CaM-dependent protein phosphorylation forms an important component of such signal transduction pathways, including that regulating the initiation and development of symbiotic rhizobial nodules in legumes such as soybean (Glycine max).  To further understand the role of Ca2+/CaM during nodule organogenesis, a nodule cDNA expression library was screened using radiolabeled CaM as a probe to identify novel CaM-binding proteins (CaMBPs).  This screen resulted in the identification of a previously uncharacterized receptor-like kinase, termed GmCaMK1.  The CaM-binding domain (CaMBD) of GmCaMK1 is located in a 24 residue region of GmCaMK1, which overlaps with the subdomain XI of a conserved Ser/Thr kinase domain.  This CaMBD bound CaM in a Ca2+-dependent manner, and with high affinity (Kd = 1.4 nM).  Furthermore, two hydrophobic residues (V372 and L375) were identified as critical for GmCaMK1-CaM interaction.  Recombinant GmCaMK1 exhibited protein kinase activity in vitro, with autophosphorylation activity unaffected by the presence or absence of Ca2+/CaM.  GmCaMK1 expression is enriched in developing nodules and main roots, and highest expression level was observed in lateral roots.  While the function of CaM-binding to GmCaMK1 remains unclear, the affinity and Ca2+-dependence of the GmCaMK1-CaM interaction strongly suggests that GmCaMK1 is a physiologically relevant CaM target.  The Arabidopsis ortholog of GmCaMK1, AtCaMK1 also bound CaM when expressed as a recombinant protein.  GmCaMK1 is part of a multi-member family in soybean, as are putative homologs across taxa, suggesting that this is a novel, conserved family of CaMBPs.

abstract: M.Sc.


title: Straw Bale Construction: Assessing and Minimizing Embodied Energy

contributor:
MacDougall, Colin
Environmental Studies

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subject:
Straw Bale Construction
Embodied Energy

abstract: Thesis (Master, Environmental Studies) -- Queen's University, 2010-01-28 16:18:47.585

abstract:
As the effects of global warming and the exhaustion of natural resources become more and more evident, the importance of low-impact construction alternatives is becoming increasingly apparent. Conventional construction not only irreversibly drains natural resources; it is also responsible for the great amount of energy consumed in the production of building materials.   Natural renewable materials that offer low-impact, low-embodied energy construction alternatives have promising potential for the construction industry.
This thesis provides an insight into construction with natural materials, with particular emphasis on straw bale construction, by undertaking an embodied energy analysis. Firstly, the existing published sources were studied to obtain the embodied energy values of various construction materials relevant to conventional residential and straw bale construction. The embodied energy values for straw bales were found to have great variation from source to source. To obtain the value appropriate for the Canadian situation, the analysis completed in this thesis utilizes published material on straw and biomass. Secondly, a comparative analysis of embodied energy for various wall systems was completed. This analysis proves that straw bale construction is an effective low impact alternative to conventional residential construction styles. In particular, the embodied energy of the straw bale wall section is six times smaller than that of the most common conventional construction style - wood-frame with brick siding. Finally, the component of the straw bale wall that has the highest embodied energy – plaster – was examined to investigate further reduction of the embodied energy of the straw bale wall.  As a result of this investigation it was found that the plaster mix containing increased amounts of cementitious materials (for example, equal parts of cement and lime) has smaller embodied energy value.
The findings of this work can be utilized both in the conventional construction industry as a guide to making environmentally mindful decisions, as well as for natural building construction to further improve the performance of straw bale structures.

abstract: M.E.S.


title: Catch-22: Assessing Ontario's Proposed Formative Assessment Policy Within Ontario's Student Achievement Framework

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subject:
formative assessment
education policy

abstract: This paper examines the efficacy of Ontario’s proposed formative assessment policy in the context of Ontario’s student achievement framework which is founded upon large scale assessments for accountability. This paper comprises an extensive review of the literature on formative assessment policy, drawing heavily on the British experience, as well as an examination of the empirical evidence conducted on formative assessment in the ‘real’ classroom. This paper argues that the evidence clearly indicates that policies which are focused on measuring student achievement through large scale testing for accountability inhibit the practice of formative assessment in the classroom. It is also suggested that policies focused on increasing student scores on large scale assessments have not been as successful as anticipated  thereby increasing the visibility and promotion of formative assessment in recent policy texts. Highlighting the similarities between student achievement frameworks found in Britain and that of Ontario this paper suggests that Ontario’s student achievement framework does not fully address the complexity of formative assessment thereby preventing discussion on current education policies that may inhibit the successful implementation of the proposed formative assessment policy. Formative assessment and accountability is addressed throughout the paper.


title: Numerical Study and Load and Resistance Factor Design (LRFD) Calibration for Reinforced Soil Retaining Walls

contributor:
Bathurst, Richard J.
Civil Engineering

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subject:
Reinforced Soil Retaining Walls
Load and Resistance Factor Design
Limit States Design
Calibration
Numerical Modelling
AASHTO

abstract: Thesis (Ph.D, Civil Engineering) -- Queen's University, 2010-01-28 18:07:22.284

abstract:
Load and resistance factor design (LRFD) (often called limit states design (LSD)) has been mandated in the AASHTO Bridge Design Specifications and will be adopted in future editions of Canadian Highway Bridge Design Code for all transportation-related structures including reinforced soil retaining walls. The ultimate objective of this thesis work was to carry out reliability-based analysis for load and resistance factor design calibration for rupture and pullout limit states for steel and geosynthetic reinforced soil walls under self-weight and permanent surcharge loading conditions. In order to meet this objective it was necessary to generate large databases of measured load and resistance data from many sources and in some cases to propose new design models that improve the accuracy of underlying deterministic load and resistance models. Numerical models were also developed to model reinforced soil wall performance. These models were used to investigate load prediction accuracy of current analytical reinforcement load models. An important feature of the calibration method adopted in this study is the use of bias statistics to account for prediction accuracy of the underlying deterministic models for load and resistance calculations, random variability in input parameter values, spatial variation and quality of data. In this thesis, bias is defined as the ratio of measured to predicted value. The most important end product of the work described in this thesis is tabulated resistance factors for rupture and pullout limit states for the internal stability of steel and geosynthetic reinforced soil walls. These factors are developed for geosynthetic reinforced soil wall design using the current AASHTO Simplified Method, a new modified Simplified Method, and the recently proposed K-Stiffness Method. Useful quantitative comparisons are made between these three methods by introducing the concept of computed operational factors of safety. This allows designers to quantify the actual margin of safety using different design approaches.

The thesis format is paper-based. Ten of the chapters are comprised of journal papers that have been published (2), are in press (2), in review (3) and the remaining (3) to be submitted once the earlier background papers are accepted.

abstract: PhD


title: Towards the Fabrication and Characterization of a Nanomechanical Electron Shuttle

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subject:
physics
electromigration
electron shuttle
nanofabrication

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2010-01-28 23:01:15.735

abstract:
First proposed in the late 1990's, a nanomechanical electron shuttle is a device where an electrically isolated island moves a definite number of electrons between two leads, producing a current that is directly related to the number of electrons moved in a cycle and to the vibration frequency of the island. Since nanomechanical structures can have very well defined vibration frequencies, a device of this type is useful as, among other things, a current standard for metrology. The experimental shuttle implementations to date have had large island-lead spacings, which has limited their performance. The work presented here takes the first steps towards the fabrication of a nanomechanical electron shuttle using the process of electromigration to define very small lead-island gaps with conductivity on the order of the conductance quantum G_0=2e^2/h. These small gaps, coupled with the high vibration frequencies achievable with nanostructures, will allow investigation deeper into the realm of quantum effects.

In this work, the fabrication steps for the creation of these devices were developed. Electromigration of a single junction was successfully achieved to the 10--100\,k\ohm range. The simultaneous and symmetric electromigration of two junctions, as required for the shuttle, has not yet been achieved. The development of a fast electromigration cut-off circuit, however, gives hope that double-breaking success will be achieved soon.

abstract: M.A.Sc.


title: Geotechnical Characterization of the Bearpaw Shale

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subject:
Clay
Consolidation
Preconsolidation Pressure
Strain Rate Effects
Disturbance
Swelling Soils
Deuterium
Diffusion

abstract: Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2010-01-29 01:34:14.071

abstract:
This research takes a multidisciplinary approach to comprehensively investigate the material and mechanical properties as well as pore water chemistry of the Bearpaw shale. This made it possible to characterize how these properties relate to the mechanical strength of this material. The results of this research challenge our ideas of the hydrogeology and of the geological history of the region. Core samples of the Bearpaw Formation and the overlying glacial till were collected from a field site in southern Saskatchewan, Canada. A combination of laboratory tests including multi-staged oedometer tests, constant rate of strain oedometer tests, specialized triaxial swell tests, along with pore water chemistry and finite element modelling were used to meet the following objectives: (1) To investigate the material properties and compression behaviour of the Bearpaw in addition to assessing disturbance due to specimen size; (2) Examine the time dependent behaviour of the Bearpaw and the transferability of time rate models developed for soft soils to stiff soils; (3) Examine the swelling potential and behaviour of the Bearpaw Formation and the influence of boundary conditions on this behaviour, while assessing the applicability of the swell concepts developed for compacted materials to a naturally swelling clay material; and (4) Constrain the depositional age of the till overlying the Bearpaw Shale.
Contrary to what is seen in soft soils, smaller sized specimens were found to reduce disturbance, and produce more accurate and consistent results. Creep was found to follow the same laws as it does in soft soils, calling into question whether the use of preconsolidation pressure to predict geological history in stiff clays is appropriate. There was significant variation in the observed swell pressures of samples of the same size and depth. Finally, the glacial till at site was found to belong uniquely to the Battleford Formation and ranges in age from 22,500 to 27,500 years which is much younger (over 100,000 years younger) than previously believed.

abstract: PhD


title: The Effect of the Invasive Macroinvertebrate, Bythotrephes Longimanus, on the Growth of Cisco (Coregonus Artedii) in Ontario Shield Lakes

contributor:
Arnott, Shelley E.
Casselman, John M.
Biology

subject:
Invasive species
Fish Growth
Bythotrephes longimanus
Energy Flow
Cisco (Coregonus artedii)
Trophic Interactions
Ontario Shield Lakes

abstract: Thesis (Master, Biology) -- Queen's University, 2010-04-28 22:46:07.756

abstract: Bythotrephes longimanus is an invasive, macroinvertebrate from Eurasia that was introduced into the Great Lakes region in the mid 1980s. Bythotrephes introductions into lake ecosystems have resulted in substantial changes in zooplankton communities, including declines in species richness, abundance, biomass and production. Changes in zooplankton communities may alter the quantity and quality of prey to other predators such as cisco (Coregonus artedii), a pelagic forage fish. Here, I conduct a current day comparison of cisco populations to determine if prey consumption by cisco differs in the presence of Bythotrephes, and whether changes in diet result in energetic consequences (changes in growth and condition) for cisco. Effects of Bythotrephes on native zooplankton communities have resulted in substantial changes in the variety and proportion biomass of zooplankton and macroinvertebrate prey types in cisco stomachs, which have in turn modified growth of cisco. Cisco taken from invaded lakes achieve greater total lengths but changes in condition were not detected. This effect may be driven by improved growth in the second and subsequent growing seasons, suggesting that growth consequences for young fish (that do not feed on Bythotrephes) are different than for older individuals. Length-at-structure age data indicate that by the end of the first growing season (age 1) cisco achieve comparable total body lengths in invaded and reference lakes, suggesting that food consumption by young cisco remains unchanged by Bythotrephes. Alternatively, young cisco forage may be reduced in the presence of Bythotrephes, resulting in decreased survival and similar growth among individuals that survive to age 1. In contrast, despite changes in the zooplankton community; growth of older fish (≥ age 2) was enhanced in lakes that have Bythotrephes. Improved growth among older cisco (≥ age 2) in invaded lakes may be related to the presence of a newly attainable,  high energy prey source (Bythotrephes). Alternatively, enhanced growth may be explained by lower competition due to reduced recruitment of young cisco (≤ age 1) in invaded lakes. Increased knowledge regarding the effects of Bythotrephes on growth of cisco is important in furthering our understanding of its impact on lake ecosystems.

abstract: M.Sc.


title: Community Programs For At-Risk Children and Youth in the KFL&A Health Region: A Scoping Review

contributor:
King-VanVlack, Cheryl
Rehabilitation Science

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subject:
Occupation
Well-Being
Youth Development
At-Risk

abstract: Thesis (Master, Rehabilitation Science) -- Queen's University, 2010-01-29 12:19:33.014

abstract: A scoping review was used to identify community-based out-of-school programs which employed occupation as a means of intervention to support positive youth development for at-risk children and youth.  The purpose of the review was to explore how programs, via their structure and philosophy, may facilitate well-being and positive youth development.  Organizations that ran programs which were accessible to children and youth in the boundaries of KFL&A Public Health Unit were located through internet search, word of mouth, and printed resources in the community.  Nine programs (Boys and Girls Club, Big Brothers Big Sisters, Camp Outlook, Outward Bound, Tim Horton’s Children’s Foundation Camp, Children’s Aid Society, Youth Diversion, Girls Inc, and Katarokwi Native Friendship Centre) were identified and the associated documents were analyzed.  A search of scholarly journals was completed to locate peer-reviewed publications which evaluated the above programs.  Six publications were located which evaluated the effectiveness of the Boys and Girls Club (n=3) and Big Brothers Big Sisters (n=3).  These evaluations indicated that the programs produce positive effects for youth behaviours and reduce negative attitudes and risk behaviours.   Four common goals were identified through the analysis of the program documents: developing confidence/worth, safe supportive environment/relationships, skill development, and positive future outlook/place in the world.  From the program documents, key phrases were identified that related to one or more of the components of well-being, namely; physical health (healthy lifestyle and participation), self-esteem (view of self and succeed at new things/skill development), belonging (safe supportive environment, citizenship, relationships/safe adult relationship), security (personal and economic), and self determination (skill development, positive future outlook, choices, self-reliance).  Multiple links were observed between the goals and the components of well-being.  The component of Belonging appeared to have the greatest emphasis, with all program documents containing at least one statement related to this component.  This review provides insight into the role that youth programs which utilize occupation as the means of “intervention” can play in fostering a state of well-being and positive youth development among participants.

abstract: M.Sc.


title: The Role of Enjoyment, Motivational Climate, and Coach Training in Promoting the Positive Development of Young Athletes

contributor:
Côté, Jean
Deakin, Janice
Kinesiology and Health Studies

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subject:
Sport Psychology
Youth Development

abstract: Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2010-01-29 13:19:00.872

abstract:
Structured sports are the most common activity in which youth participate.  Research links sport participation to positive and negatives outcomes; however few studies have investigated the processes that affect positive and negative experiences.  Considering that enjoyment, motivational climate, and coach behaviors are factors that are known to affect participation, it is of interest to determine if these factors can contribute to increased positive experiences for youth sport participants.
	Study 1 investigated the psychometric properties of the Youth Experience Survey 2.0 with a group of athletes.  This instrument was originally designed to investigate experiences across a range of structured activities; however its psychometric properties had yet to be reported.  Results of confirmatory factor analyses did not show strong psychometric support for the instrument.  Follow-up exploratory analyses resulted in the instrument being modified and renamed the Youth Experience Survey for Sport.  The revised scaled showed improved psychometric properties compared to the original instrument which makes it a preferred tool for investigation of personal development of youth sport participants.
Study 2 explored the role of enjoyment and motivational climate on the personal development of team sport athletes.  Stepwise multiple regression analyses were used to examine the relationships.  Results demonstrated that positive experiences in sport were most strongly predicted by affiliation with peers, self-referenced competency, effort expenditure, and a task climate.  Negative experiences were most strongly predicted by an ego climate and other-referenced competency.
Study 3 examined differences on personal development and motivational climate for athletes in programs where coaches received positive youth development training and athletes in programs that did not provide training to coaches.  Results showed that personal and social skills were higher for athletes of trained coaches.  Cognitive skills and task climate did not reach significance but can be considered as marginal effects.
Results from these studies provide researchers with an instrument to measure positive youth development in sport.  In addition, results demonstrate that enjoyment, motivational climate, and coach training are important factors in promoting personal development.  Youth sport program administrators that wish to incorporate positive development in their programs should consider these findings.

abstract: PhD


title: Antifreeze Proteins: Activity Comparisons and De Novo Design of an Ice-Binding Protein

contributor:
Davies, Peter L.
Biochemistry

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subject:
Antifreeze Protein
Thermal Hysteresis
Ice Recrystallization Inhibition
Ice-Binding Protein

abstract: Thesis (Master, Biochemistry) -- Queen's University, 2010-01-29 17:37:24.322

abstract:
Antifreeze proteins (AFPs) help cold-adapted organisms survive below 0 ◦C by binding to and inhibiting the growth of ice crystals.  In this way, AFPs depress the freezing point of aqueous fluids below the melting point of ice (thermal hysteresis; TH).   They also have the ability to inhibit ice recrystallization in the frozen state (ice recrystallization inhibition; IRI).  Some AFPs show an order of magnitude higher TH activity than others, and are termed ‘hyperactive’.  One of the objectives of this thesis was to see if IRI activities of the hyperactive AFPs are also an order of magnitude higher than the moderately active AFPs.  Using a capillary-based assay for IRI, the activities of three hyperactive and three moderately active AFPs were determined.  There was no apparent correlation between hyperactivity in TH and high IRI activity.  However, mutations of residues on the ice-binding face (IBF) of both types of AFP reduced IRI and TH activities to a similar extent.  In this way, the use of IBF mutant AFPs showed that the IBF responsible for an AFP’s TH activity is also responsible for its IRI activity.
Analysis of the diverse AFP structures solved to date indicate that their IBFs are relatively flat, occupy a significant proportion of the protein’s surface area and are more hydrophobic than other surfaces of the protein.  The IBFs also often have repeating sequence motifs and tend to be rich in alanine and/or, threonine.  The de novo design of an ice-binding protein was undertaken using these features to verify the underlying physicochemical requirements necessary for a protein’s interaction with ice.  Using site-directed mutagenesis, a total of sixteen threonine substitutions were made on one of the four faces of a cyanobacterial protein with no endogenous TH activity.  The inclusion of eight paired threonines on one face of this quadrilateral helix gave the engineered protein low levels of TH activity, but at the cost of destabilizing the structure to some extent.  The results of this study have validated some of the properties needed for the ice-binding activity of AFPs.

abstract: M.Sc.


title: Friction and External Surface Roughness in Single Point Incremental Forming: a study of surface friction, contact area and the ‘orange peel’ effect

contributor:
Jeswiet, Jack
Mechanical and Materials Engineering

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subject:
Incremental Forming
Contact Area
Friction
Orange Peel Effect
SPIF

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-02-01 16:47:17.249

abstract:
This work studied the effects of step size, angle, spindle speed, and feed rate on the external surface roughening, orange peel effect, observed in single point incremental forming (SPIF).  Experimental results were used to estimate models to categorize the extent of orange peel roughening based on visual inspection and on surface roughness measurements.  Tests were performed at very high rotational speeds and feed rates and showed various influences on surface roughness, thickness distribution, and grain size.
Friction at the tool-sheet interface was also studied with a completely instrumented tool that measured and recorded torsion and forming forces through deformation strains.  Coefficients of friction for each part were determined and through statistical analysis, the influence of each of the following forming parameters was established: material thickness, formed shape, tool size, step size, forming speeds (feed rate and rotational speed), and forming angle.  Multidimensional response surfaces were generated to show when and under what condition friction was minimized.
A new contact zone representation for SPIF was also established.  This formulation used common forming parameters and geometric considerations to determine the contacting zone between the sheet and the tool.  Area models were proposed for both the tangential and torsional component of friction in SPIF.

abstract: M.A.Sc.


title: Adjustable Wheelchair Obstacle Simulator and Instrumentation for Assessing Wheelchair Suspension

contributor:
Bryant, J. Tim
Wyss, Urs P.
Mechanical and Materials Engineering

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subject:
Wheelchair
Suspension
Vibration
Obstacle Simulator

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-01-30 12:17:57.181

abstract:
Wheelchair users are exposed to whole-body vibrations, particularly when traversing rugged terrain such as in less resourced areas. Suspension systems have been added to wheelchair systems to protect occupants from secondary injuries associated with whole-body vibration.  Current suspension systems need to be further developed in order to optimize the protection against these secondary injuries. Until further research finds conclusive evidence for comfort
level, and the onset of injury due to vibrations, it has been recommended to reduce whole-body vibration exposure to the lowest possible level. A versatile testing apparatus and method were designed and built to detect the acceleration and frequencies a wheelchair occupant would be exposed to while riding on simulated rough terrain. A novel dummy was instrumented with accelerometers to measure the accelerations and frequencies experienced by the wheelchair user.  The apparatus and method was able to detect peak acceleration magnitudes, and was able to detect resonant frequencies and their intensities with either a PSD or FFT analysis. The minimum
observable effect of change between two test conditions ranged from 6.0% for peak acceleration analysis when using six tests and a light dummy; to 41.0% for PSD analysis when using three tests and a heavy dummy. This adjustable testing apparatus and method can be used to tune a wheelchair system suspension design because it can elucidate whether or not a design is able to reduce accelerations and attenuate resonant frequencies experienced by a wheelchair occupant.

abstract: M.A.Sc.


title: New Technologies to Improve the Transient Response of Buck Converters

contributor:
Liu, Yan-Fei
Electrical and Computer Engineering

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subject:
Power Electronics
DC/DC Conversion
Non-Linear Control
Digital Control

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2010-01-31 23:01:24.606

abstract:
As the speed and power demands on Buck converters continue to increase, it has become time to replace the linearly-controlled conventional Buck converter. Digital circuits, such as microprocessors, are requiring higher dynamic currents, at lower voltages, than ever before.

Traditionally, such Buck converters have been controlled by linear voltage-mode or current-mode control methods. While these controllers offer such advantages as fixed switching frequencies and zero steady-state error, their reaction speed is inherently limited by their bandwidth which is a fraction of the converter switching frequency. Therefore, to improve the transient response of a Buck converter in a practical manner, four novel ideas are presented in this thesis.

The first contribution is an analog “charge balance controller”. The control method utilizes the concept of capacitor charge balance to achieve a near-optimal transient response for Buck converters undergoing a rapid load change. Unlike previous work, the proposed controller does not require expensive and/or slow analog multipliers/dividers. In addition, the nominal inductance value is not required by the proposed controller. Simulation and experimental results demonstrate a significant improvement in transient performance over that of a linear voltage-mode controller.

For low duty cycle applications, the unloading transient performance of a Buck converter tends to be poor when compared to the corresponding loading transient performance. Therefore, the second contribution is an auxiliary circuit and an analog auxiliary controller which drastically improves the performance of a Buck converter undergoing an unloading transient. Significant overshoot reduction was observed over that of a linearly-controlled conventional Buck converter.

The third contribution is a digital implementation of the aforementioned “charge balance control” concept. Through digital implementation the control law is extended to include load-line regulation. Unlike previous work, large lookup tables are not required to perform complex mathematical functions, thus the number of required gates is significantly reduced.

The final contribution is a digital implementation of the “charge balance controller” capable of operating with the previously-mentioned auxiliary circuit. This complete solution is capable of improving the voltage deviation caused by loading and unloading transients. In addition, the combined auxiliary circuit and control law is extended to load-line regulation applications.

abstract: PhD


title: Latent Amine Cures of Brominated Poly(isobutylene-co-isoprene)

contributor:
Parent, J. Scott
Whitney, Ralph A.
Chemical Engineering

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subject:
Bromobutyl Rubber
Latent Curatives
Delayed-Onset
Imine
Cure Acceleration

abstract: Thesis (Master, Chemical Engineering) -- Queen's University, 2010-02-01 15:18:16.004

abstract:
The allylic bromide functionality within brominated poly(isobutylene-co-isoprene), or BIIR, alkylates primary amines repeatedly to generate thermoset products at reaction rates that are too fast to support commercial rubber processing operations.  The objective of this work was to assess the utility of latent N-nucleophiles as curatives and modification reagents for BIIR.  Ideally, BIIR formulations containing these latent amines would not cure at standard compound mixing temperatures, but support high crosslinking rates and yields upon heating to conventional vulcanization temperatures.

Carbon dioxide-derived salts of ammonia, including (NH4)2CO3, (NH4)HCO3 and (NH4)H2NCO2, can be mixed with BIIR without incurring crosslinking at temperatures below 100oC, but they generate adequate crosslink yields upon heating to 160oC.  The corresponding CO2-derived salts of primary amines decompose below 100oC and, therefore, do not provide adequate scorch protection when mixed with BIIR. Latency was conferred on primary amines using imine derivatives, in particular N-alkylbenzaldimine and its substituted analogues. These latent curatives are activated by hydrolysis, thereby providing a means of controlling active nucleophile concentrations, and minimizing crosslinking activity at 100oC without impacting negatively on cure rates at 160oC.

The scorch problems generated by primary amines extend to BIIR cure formulations employing conventional sulfur and ZnO curatives.  In contrast, imine analogues are shown to provide low temperature scorch stability without impacting negatively on high temperature cure rates and extents.

abstract: M.A.Sc.


title: Computational Studies of Lipid Autoxidation and Solvent-Mediated Antioxidant Activity and a Kinetic Study of a Halogenase in the Pyrrolnitrin Biosynthetic Pathway

contributor:
Pratt, Derek A.
Chemistry

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subject:
Lipid Autoxidation
Propagation
Beta-Fragmentation
Computational
PCET
Oxygen Dependent Halogenase
Pyrrolnitrin
PrnC
Kinetic
E,coli

abstract: Thesis (Master, Chemistry) -- Queen's University, 2010-02-03 15:42:39.67

abstract:
Chapter 1
Hydrocarbon autoxidation, a free radical chain reaction, is believed to play a key role in the onset and developments of most degenerative diseases and disorders. The two propagating steps: 1) H-atom abstraction from the hydrocarbon by a hydrocarbon-derived peroxyl radical, and 2) addition of oxygen to the resultant alkyl radical to form a new peroxyl, play a role in determining the rate of hydrocarbon autoxidation, as well as the regio- and stereochemistry of the product hydroperoxides. In the current study, we carried out a set of calculations to provide a detailed framework for understanding the mechanism of the first two steps of autoxidation.

Chapter 2
Radical-trapping chain-breaking antioxidants inhibit hydrocarbon autoxidation. Phenols are the prototypical radical-trapping antioxidants and are employed in nature, as well as in industry, to inhibit the autoxidation of hydrocarbons. The mechanism of inhibiting radical chain propagation has recently been suggested to be a PCET on the basis of theoretical calculations. It has been demonstrated that the antioxidant activitiy of phenols is increased in the presence of either protic acids or alcohols, but the basis of this acceleration is not well understood. In the current study, we used computational methods to investigate the effects of acids and alcohols on the PCET pathway for the reaction of phenol with a peroxyl radical.

Chapter 3
The antibiotic pyrrolnitrin [3-chloro-4-(2’-nitro-3’-chlorophenyl) pyrrole] (PRN) is biosynthesized from L-tryptophan in four steps, catalyzed by the enzymes PrnA, B, C and D encoded by the prn operon. Two of the four gene products, PrnA and PrnC, are flavin-dependent halogenases, a recently discovered and highly interesting class of enzymatic halogenation catalysts. Their activities have never been unequivocally demonstrated by reconstitution of the activity from a recombinant protein. Herein, we report the results of our efforts to clone the genes encoding PrnA and PrnC, and overexpress, isolate and purify the proteins from E. coli. We were able to successfully reconsistute halogenation activity of both and have obtained the first kinetic data for PrnC, which shows kinetics similar to other flavin-dependent halogenases, along with substrate inhibition.

abstract: M.Sc.


title: Impulsivity and Reward Sensitivity: Attentional and Emotional Factors Underlying Stimulus-Reward Learning

contributor:
Olmstead, Mary C.
Psychology

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subject:
Impulsivity
Reward Sensitivity
Associative Learning
Contingency Awareness

abstract: Thesis (Master, Psychology) -- Queen's University, 2010-02-05 13:33:27.076

abstract: Increased impulsivity and alterations in reward sensitivity co-occur in many psychiatric disorders.  Moreover, individuals reporting more impulsive traits are less efficient in learning stimulus-reward associations.  This suggests that impulsivity and reward sensitivity may be linked, consistent with evidence that the orbital frontal cortex (OFC) is implicated in both processes.  This study examined the relationship between impulsive traits, assessed by the Barratt Impulsiveness Scale (BIS) and the Eysenck (EIQ), and performance on three behavioral tasks that measure impulsivity and reward sensitivity.  The tasks included a Conditioned Pattern Preference (CPP) task, which measures the preference for abstract visual cues as an index of implicit emotional learning, a Probabilistic Reversal Learning (PRL) task that assessed the ability to alter behaviour when reward contingencies change and an Emotional Stroop task which assessed attentional control in response to emotionally salient stimuli.  This study provided novel information on the relationship between processes that mediate impulsivity and reward sensitivity. In brief, subjects that were considered to have some explicit knowledge of experimental conditions showed a higher preference formation for the pattern paired with the reward on 90% of the conditioning trials. Although there was no overall effect of impulsivity, the medium impulsive group displayed the strongest preference formation (highest score for the 90% pattern and lowest score for the 10% pattern) compared to the low and high groups. Furthermore, there was an overall effect of Word Category in that participants made more errors for the emotional words (positive and negative) than the neutral words. There was no overall effect of Impulsivity on Stroop performance in this sample. Finally, for the PRL task more participants in the high impulsive group did not meet criterion for the Acquisition stage while more low impulsive subjects did not meet reversal criterion. Furthermore, high impulsive subjects made more overall errors in the Acquisition stage but not Reversal stage. In brief, low and high impulsive subjects performed sub-optimally on the CPP and PRL tasks but not on the Stroop task.  This pattern reflects an inverted-U shaped relationship of the effects of impulsivity on associative learning.

abstract: M.Sc.


title: Early Postnatal Cardiac Development in Atrial Natriuretic Peptide Gene-Disrupted Mice

contributor:
Pang, Stephen C.
Anatomy and Cell Biology

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subject:
Postnatal Cardiac Development
Natriuretic Peptide System

abstract: Thesis (Master, Anatomy & Cell Biology) -- Queen's University, 2010-02-05 14:15:33.982

abstract: The natriuretic peptide system (NPS) is a hormonal system critical to mammalian cardiovascular homeostasis. The purpose of the present study was to investigate the role of ANP during early postnatal cardiac development by i) monitoring the development of cardiac hypertrophy during early postnatal development of the ANP-/- mice, and ii) comparing morphologic, morphometric and molecular differences in ANP+/+ mice compared to ANP-/- mice during this developmental period. Age matched male ANP+/+ and ANP-/- mice, aged day 1 and weeks 1 to 5, were evaluated. Body weight, organ weights and hematocrit were recorded. RNA was isolated and quantitative real-time RT-PCR was used to monitor cardiac gene expression. An additional cohort of animals was used for morphologic and morphometric analysis. Heart weight to body weight ratio (HW/BW) was dramatically higher in ANP-/- animals at all time points, indicating cardiac hypertrophy is established before the advent of adult blood pressure. Molecular analysis of gene expression revealed a compensatory response of the NPS in the ANP-/- mice. Specifically an up-regulation of BNP expression in ANP-/- mice was noted throughout postnatal development. Similarly, NPR-A and NPR-C demonstrated compensatory action for the lack of ANP, as expressional levels also varied throughout development. Morphological analysis of cardiac vasculature revealed striking structural differences between ANP+/+ and ANP-/- mice. Quantitative stereological analysis of LM images indicated a greater vessel volume in ANP-/- compared to ANP+/+ mice. This study demonstrates that alterations in early molecular events, such as changes in NPS expression, may be responsible for the maintenance and progression of cardiac hypertrophy during early postnatal development in the ANP-/- mice. The absence of ANP during this critical period of development has a profound impact on final cardiac structure leading to future pathological states.

abstract: M.Sc.


title: Test of an Innovative Stochastic Design System on an Open Pit

contributor:
Archibald, James F.
Mining Engineering

format:
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subject:
Open pit mine planning
Stochastic metal price

abstract: Thesis (Master, Mining Engineering) -- Queen's University, 2010-02-08 22:07:52.331

abstract:
Commodity markets are fundamentally cyclical, exposing mining companies to large swings in profitability during periods of economic boom and bust. Although this is well documented, companies continue to produce mine plans based on present market conditions that fail to acknowledge long-term metal price variability. The purpose of this thesis is to adapt McIsaac’s (2008) mathematical model for determining the most robust underground mining plan under conditions of metal price uncertainty for application in an open pit environment.

An overview of conventional open pit algorithms is given to demonstrate that a circular analysis precludes the determination of an optimal solution when metal prices are uncertain. Under the proposed methodology, the optimal solution is achieved by selecting the cutoff grade and production rate under stochastic metal prices such that the net present value and probability of a positive net present value are maximized.

The mathematical model was formulated with costs represented as a function of the level of production, rate of production or both. Revenues are achieved from either a mill, heap leach or stockpile process dependent on the level of production and metal price in the year of consideration. Metal prices are generated annually according to a stochastic model that balances short-term volatility with long-term trends. The compiled cash flow model determines the optimal net present value for a given production profile under input metal prices.

The feasible area of production is established based on mine life, resource and financing constraints. Net present values are generated for a broad search grid, which converges towards a unimodal solution according to a golden search algorithm. The process is then repeated many times in order to identify the production profile at which the optimal solution is repeatedly reached. As a visual representation, the solutions are plotted on a bubble graph where the size of the bubble corresponds to the frequency of the solution; the largest bubble is associated with the optimal solution. The methodology is tested on two massive copper porphyry deposits, contained within a single claim, for which a Preliminary Economic Assessment has been completed.

abstract: M.A.Sc.


title: Fight for Your Right to Party: An Exploratory Study of Queen’s Homecoming Weekend and the Phenomenon of Student Celebratory Riots

contributor:
Sacco, Vincent F.
Sociology

subject:
Queen's University
homecoming weekend
riots

abstract: Thesis (Master, Sociology) -- Queen's University, 2010-02-23 08:18:16.333

abstract:
While college and university students have long been associated with newfound
independence, alcohol and unrest, the phenomenon of celebratory rioting, which combines these key elements of student culture, is relatively new. While incidents have occurred since 1985,
their recent escalation in size, frequency, and property damages continues to raise public concern
in many college and university towns across North America. Research indicates that celebratory riots result from large non-protest related assemblies of mostly students where alcohol is consumed freely, participants spontaneously engage in unruly behaviour, and police intervention
invites resistant and aggressive responses from crowd members. However, such outbursts are often difficult to predict since they may emerge from a myriad of possible trigger events. In order to further interpret celebratory rioting, this thesis examines a number of individual-centred and event-centred crowd theories to determine what is known about crowd behaviour. This study
concludes that the analysis of a celebratory riot event requires a process-rooted approach, such as the Value-Added model, to account for the situational factors which shape the event’s precursors, transactions and aftermath.
This thesis focuses analytical attention on the annual Queen’s Homecoming Aberdeen
street party in Kingston, Ontario which became riotous in 2005. This case study comprised an extensive media content analysis, Queen’s archival research, and direct observation at a number of student focus groups, committee meetings and student gatherings. This study, which concludes with an analysis of the non-riotous Homecoming celebrations of 2006, revealed that the riot of 2005 was hardly unique; instead, it followed decades of intermittent student
disturbances in the Queen’s student neighbourhood. Furthermore, the 2005 Aberdeen Street riot ultimately parallels the story of so many celebratory riots which have recently occurred and continue to emerge in a number of college and university towns across North America.

abstract: M.A.


title: Structure-Function Studies on the Novel Alpha-Kinase Family

contributor:
Côté, Graham P.
Biochemistry

subject:
Alpha-Kinases
MHCK A
TRPM7

abstract: Thesis (Master, Biochemistry) -- Queen's University, 2010-02-11 11:23:04.195

abstract: Dictyostelium myosin heavy chain kinase A (MHCK A) and mammalian transient receptor potential melastatin-related 7 (TRPM7) are two divergent members of a family of atypical protein kinases called the alpha kinases.  The crystal structures of the alpha-kinase domains of MHCK A (A-CAT, residues 552-841) and mouse TRPM7 (TRPM7-CAT, residues 1548-1862) are very similar.  In both cases a C-terminal tail (C-tail) sequence (A-CAT, residues 806-841 and TRPM7-CAT, residues 1819-1862) is missing from the crystal structure.  Here I show that the unstructured C-tail is required for the catalytic activity of A-CAT and TRPM7-CAT.  Truncation of the C-tail of A-CAT to residue 823 decreased kinase activity by ~98% and ATPase activity by ~97%. Truncation of the C-tail of TRPM7-CAT to residue 1827 decreased kinase activity by ~97% and ATPase activity by ~58%. Ligation of the C-tail sequence of MHCK B (residues 326-354) to A-CAT-802 (residues 552-802), fully rescued kinase activity. Alignment of the C-tail sequences of MHCK A-D revealed a conserved Gly-Thr-hydrophobic motif. Previous work has shown that in A-CAT, the conserved threonine (T825) is a site of autophosphorylation. Mutation of the T825 to alanine reduced A-CAT kinase and ATPase activities by 97%, whereas mutation to serine decreased kinase and ATPase rates by 85% and 60%, respectively.  This result is consistent with the finding that A-CAT strongly prefers to phosphorylate threonine residues. Surprisingly, mutation of T825 to glutamic acid reduced kinase activity by ~93% and ATPase activity by ~96%.  This result suggests that glutamic acid does not properly mimic phosphothreonine in this situation, or that the free hydroxyl group of T825 is required for the catalytic activity of A-CAT. Mutation of T825 to alanine or glutamic acid in full-length MHCK A reduced kinase activity by ~90% and ATPase activity by ~40%.  Further studies are required to determine if the C-tail of TRPM7-CAT also contains an essential threonine residue.

abstract: M.Sc.


title: In Vitro Characterization of the Function of ABCA1: Effects of Naturally Occurring Mutations

contributor:
Deeley, Roger G.
Pathology and Molecular Medicine

format:
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subject:
ATP-binding cassette transporter
Tangier Disease
Atherosclerosis
Heart disease
25-hydroxycholesterol
Cholesterol
Phospholipid
Apolipoprotein
HDL
Lipid efflux

abstract: Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2010-02-12 11:14:11.381

abstract:
The ATP-binding cassette (ABC) transporter, ABCA1, plays a pivotal role in reverse cholesterol transport, which is the elimination of excess sterols from peripheral cells and their transport to the liver for elimination.  Early studies failed to detect significant ATPase activity, prompting the suggestion that ABCA1 was an ATP-regulated receptor, rather than an active transporter.  We have provided evidence that ABCA1 can bind ATP and trap its hydrolysis product, ADP, in the presence of either ortho-vanadate or beryllium fluoride and Mg2+ or Mn2+.  We have also shown that both nucleotide-binding domains (NBDs) trap nucleotide comparably, suggesting that ABCA1 is a functional ATPase.  In addition, we have shown that ABCA1 can directly transport 25-hydroxycholesterol (25-OHC) in an ATP-dependent manner using a membrane vesicle uptake assay, and can do so when the physiological substrate acceptor apoA-I is replaced with BSA as a non-specific binding protein.
Although more than 50 naturally occurring missense mutations and polymorphisms in ABCA1 have been identified in individuals with HDL-C levels within the lowest 5th percentile of the general population, the extent to which many of these mutations affect ABCA1 function is not known and cannot be predicted.  Naturally occurring extracellular loop (ECL) mutations W590S and C1477R have both been shown to effectively eliminate the ability to mediate lipid efflux, despite the fact that the W590S mutant protein retains the ability to bind apoA-I.  We show that neither mutant can transport nor efflux 25-OHC, whether in the presence of apoA-I or BSA, despite apparently full retention of the ability to bind and trap nucleotide.  This suggests that these two ECL mutations inhibit transport by a mechanism that is independent of their effect on apoA-I binding.  By introduction of naturally occurring mutations in the NBDs, we show that although some mutations associated with Tangier Disease, such as N935S, essentially eliminate nucleotide trapping and substrate translocation, other polymorphisms such as L1026P and T2073A associated with low HDL-C, appear to be fully functional.  Lastly, we observed differences in the behaviour of both wild-type and mutant forms of ABCA1-GFP depending on whether they were expressed in insect or mammalian cell lines.

abstract: PhD


title: Stable Free Radical Polymerization Conducted In Emulsion Polymerization Systems

contributor:
Cunningham, Michael F.
Chemical Engineering

subject:
Stable Free Radical
Emulsion Polymerization

abstract: Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2010-02-18 09:49:52.336

abstract:
Free radical polymerization is the most common polymerization technique that is used for the manufacturing of polymers, due to the ease of the polymerization initiation, wide latitude of the material design for a large variety of monomers, and the excellent process robustness for commercial production.  In the 1990’s, research activities for the precise control of radical polymerization process resulted in the discovery of ‘Living Radical Polymerization’.  The discoveries opened the door for the next generation of radical polymerizations. Extensive research has been conducted to understand the mechanisms and kinetics for numerous practical applications, particularly for polymerization in bulk and solution systems. However, despite the interest of industry, the mechanistic understanding in aqueous dispersed systems such as emulsion and miniemulsion polymerization is far behind the aforementioned two systems. There are still major challenges from the production viewpoint. One reason for the poor understanding is the complexity of the heterogeneous system, which includes multiple　reaction phases that are accompanied by the segregation and transfer of the reaction species among different phases.
The purpose of this research was to investigate living radical polymerization or “Stable Free Radical Polymerization” (SFRP) in aqueous dispersed systems to obtain better mechanistic understanding of how the heterogeneous nature of the system interacts with the novel living radical chemistry. The theoretical and experimental feasibility of the SFRP emulsion process were studied in this research, in particular, focusing on the compartmentalization effect. Particle size influence on the polymerization kinetics and the polymer livingness was experimentally confirmed, and compared to bulk polymerization.  In addition, a comprehensive mathematical model including all major chemical and physical events was developed to further our mechanistic understanding. Based on the results from the experimental and modeling studies, it was shown that rate reduction in the smaller particles is the primary cause of difficulty in implementing a conventional emulsion process (i.e. ab initio emulsion polymerization). Finally, for overcoming this difficulty, a new approach using a combination of TEMPO with highly hydrophobic 4-stearoyl TEMPO was proposed for a coagulum free ab initio emulsion process.

abstract: PhD


title: Novel mechanisms of Stat3 activation

contributor:
Raptis, Leda
Pathology and Molecular Medicine

subject: Stat3

subject: Rho GTPases

subject: Cadherins

subject: Cell-cell adhesion

subject: IL6

subject: gp130

abstract: Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2010-02-18 10:38:29.549

abstract:
Stat3 (signal transducer and activator of transcription-3) is activated by a number of receptor and non-receptor tyrosine kinases, while a constitutively active form of Stat3 alone is sufficient to induce neoplastic transformation.  Results presented in this thesis reveal that Stat3 can also be activated through homophilic interactions by the epithelial (E)-cadherin and cadherin-11, two members of the classical type I and II cadherin family of surface receptors, responsible for the formation of cell to cell junctions.  Indeed, by plating cells onto surfaces coated with fragments encompassing the two outermost domains of these cadherins, we definitively demonstrate that cadherin engagement can activate Stat3, even in the absence of direct cell to cell contact.  At the same time, levels of the extracellular signal regulated kinase (Erk)1/2, which is often coordinately activated by growth factor receptors and oncogenes, remain unchanged upon cadherin ligation.  Most importantly, we report, for the first time, an unexpected surge in total Rac1 and Cdc42 protein levels, triggered by cadherin engagement, and an increase in Rac1 and Cdc42 activity, which is responsible for the Stat3 stimulation observed.  Inhibition of cadherin interactions reduced Rac/Cdc42 and Stat3 levels and induced apoptosis, pointing to a significant role of this pathway in cell survival signalling, a finding which could also have important therapeutic implications.
To better understand the role of Rac/Cdc42 in the cadherin-mediated Stat3 activation, we compared Stat3 activity in mouse HC11 cells before and after expression of the mutationally activated, RacV12.  We demonstrate a dramatic increase in protein levels and activity of both the endogenous Rac and RacV12 with cell density, which was due to inhibition of proteasomal degradation.  Moreover, we clearly show that RacV12 expression can activate Stat3 through an increase in expression of members of the IL6 family of cytokines, known potent Stat3 activators.  In fact, knockdown experiments indicate that gp130 receptor function, and Stat3 activation, are essential for the migration and proliferation of RacV12-expressing cells, thereby demonstrating that the gp130/Stat3 axis represents an essential target of activated Rac in the regulation of both of these fundamental cellular functions.

abstract: PhD


title: Site Specific Practices and City Renewal: The Geo-Politics of Hotel Installations in Urban Spaces

contributor:
McKittrick, Katherine
Helland, Janice
Art History

subject:
Installation Art
Hotel Buildings
Site Specific Art
Gentrification
City Renewal
Urban Geography
Critical Aesthetics

abstract: Thesis (Ph.D, Art History) -- Queen's University, 2010-02-18 11:46:10.712

abstract: This dissertation examines site specific works produced in hotel buildings by exploring the multiple and contending narratives which gave meaning to city spaces where divergent communities lived, worked and socialized. I analyze the ways in which artists altered urban sites on a visual, sensorial and perceptual levels by focusing on installations produced in three hotels from 1980 to the present: the Embassy Hotel in London, Ontario, and the Cameron House and the Gladstone Hotel in Toronto, Ontario. By facilitating critical interventions in these architectural spaces, artists responded to the conflicting agendas of varying constituencies—from city planners and artists to hotel owners and residents. These commercial establishments, which combined bars, cafés, performance venues, galleries and room rentals, demonstrate the ways in which art and cultural production reflect broader social patterns and urban life: economic shifts, questions of diversity, activist struggles, consumerism, unemployment, and community. In addition to providing spaces for creative practices and art installations, the hotels each went through a series of renovations, transforming the once derelict buildings where low income tenants formerly resided into gentrified buildings, thus changing the social, symbolic and historical significance of the architectural sites.                  Working across these complex socio-spatial patterns creative communities re-envisioned urban geographies through contemporary art practices which impacted how and why people perceived, conceived and experienced the surrounding environment. By producing and exhibiting works in city spaces artists participated in urban regeneration in the local neighborhoods of London and Toronto; yet this was necessarily coupled with gentrification, and the displacement of local residents (including creative communities and people living in poverty) who could not afford rental increases. I evaluate the critical aesthetics shaping site specific installations by drawing attention to the contradictions and tensions underlying city revitalization which concurrently enabled and disenabled community formations. I argue that artists contended with the geo-politics of identification, dis-identification, belonging and unbelonging by negotiating differing subject positions through which tenants and workers made claims to property rights and ownership. They produced what Michel Foucault referred to as “heteropias” by representing, contesting and inverting the hotel sites, thus creatively and critically engaging with – rather then simply supporting or opposing – the paradoxical possibilities of urban regeneration (Foucault, "Of Other Spaces", 24).

abstract: PhD


title: CYP26B1 limits inappropriate activation of RARgamma by retinoic acid during murine embryogenesis

contributor:
Petkovich, Martin
Pathology and Molecular Medicine

subject:
retinoic acid signalling
mouse
morphogenesis
limb development
eyelid closure
defects of the axial skeleton
Cyp26b1
RARgamma

abstract: Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2010-04-01 15:38:52.05

abstract: Proper embryonic patterning requires precise spatio-temporal regulation of retinoic acid (RA) activity. Morphogenesis can be regulated at the level of RA distribution, mainly via its synthesis and catabolism by the RALDH and CYP26 enzymes respectively, and at the level of RA-mediated transcription through activation of its cognate nuclear receptor, the retinoic acid receptors (RARs) α, β, and γ. Loss of Cyp26b1 leads to increased local levels of RA in tissues such as the limb and craniofacial structures, and results in neonatal lethality. Visible gross phenotypic defects in neonates include phocomelia (shortening of the limbs), adactyly (missing digits), micrognathia (shortened lower jaw), and open eyes at birth. In addition, these embryos exhibit cleft palate and have a paucity of vibrissal (whisker) and pelage (hair) follicles. We have previously shown that ablating the gene encoding RARγ in a Cyp26a1-null background was able to rescue the caudal abnormalities associated with improper RA exposure in these embryos by limiting aberrant RA signalling, and thus rescuing expression domains of target genes involved in caudal development. I show here that ablating Rarg in a Cyp26b1-null background is able to partially rescue the defects associated with loss of CYP26B1. These include a reduction in the severity of limb defects, rescued vibrissae, fused eyelids, and recovered aspects of axial skeletal development. This compound-null murine model illustrates that RARγ plays a specific role in transducing the RA signal within tissues that are affected by the loss of CYP26B1. Further molecular analysis of the pathways responsible for directing limb bud outgrowth and eyelid fusion provided insight into pathways regulated by RARγ in these rescued tissues.

abstract: Chapters 4 and 6 of this thesis are being prepared for publication and we would like to prohibit competing labs from seeing these results before they are in press.

abstract: PhD


title: Post-Weaning Social Isolation and Subchronic NMDA Glutamate Receptor Blockade: Effects on Locomotor Activity and GABA Signalling in the Rat

contributor:
Reynolds, James
Beninger, Richard J.
Neuroscience Studies

subject:
Schizophrenia
Animal models
GABA

abstract: Thesis (Master, Neuroscience Studies) -- Queen's University, 2010-09-01 15:21:58.474

abstract: The etiology and pathophysiology of schizophrenia are poorly understood, although increasing evidence suggests an important role for altered GABA neurotransmission. Animal models of schizophrenic symptoms include administration of noncompetitive N-methyl-D-aspartate (NMDA) glutamate receptor antagonists, such as dizocilpine (MK-801), and post-weaning social isolation.  The present study tested the hypothesis that a “double-hit” model, in which subchronic MK-801 administration and post-weaning social isolation are combined, produces greater behavioural and neurochemical effects than either insult alone. As a secondary objective, the present study also assessed whether the timing of the subchronic MK-801 injections (early adolescence vs. early adulthood) influences these measures. Male Sprague-Dawley rats (N = 74) were obtained at weaning (P21) and were either socially isolated (n = 42) or group housed (n = 32) for the duration of the experiment. Subgroups received subchronic treatment with MK-801 (0.5 mg/kg ip) or saline injections (1.0 ml/kg ip) twice daily for seven days either during early adolescence (P25-P32) or early adulthood (P56-63). At P70, all groups were tested for locomotor activity and subsequently sacrificed to assess the function of the GABA membrane transport protein, GAT-1, and GABAA receptor expression in the frontal cortex and hippocampus. For animals treated in early adulthood, post-weaning social isolation, in comparison to group housing, resulted in an increase in (1) locomotor activity (2) GAT-1 activity in frontal cortex and hippocampus and (3) GABAA receptor expression in the frontal cortex. MK-801 treatment in early adulthood increased GABAA receptor expression in the hippocampus, whereas post-weaning social isolation had no effect on GABAA receptor expression in the hippocampus. Previous studies have demonstrated that increased GAT-1 activity is associated with suppression of GABA-mediated inhibitory synaptic transmission.  Furthermore, increased GABAA receptor expression may be a compensatory response to decreased availability of GABA. These data indicated that combined post-weaning social isolation and subchronic MK-801 treatment do not produce additive or synergistic effects on locomotor behaviour or GABA signalling, but rather induced differential effects on GABAA receptor binding.

abstract: M.Sc.


title: Automatic Urban Modelling using Mobile Urban LIDAR Data

contributor:
Greenspan, Michael A.
Harrap, Robin
Computing

subject:
Computer Vision
Computer Science
LIDAR
LADAR
Object Recognition
Segmentation
Point Cloud
Range Data
Interest Operator
Scale Theory

abstract: Thesis (Master, Computing) -- Queen's University, 2010-03-01 12:26:34.698

abstract:
Recent advances in Light Detection and Ranging (LIDAR) technology and integration
have resulted in vehicle-borne platforms for urban LIDAR scanning, such as Terrapoint Inc.'s TITAN system. Such technology has lead to an explosion in ground LIDAR data. The large size of such mobile urban LIDAR data sets, and the ease at which they may now be collected, has shifted the bottleneck of creating abstract urban models for Geographical Information Systems (GIS) from data collection to data processing. While turning such data into useful models has traditionally relied on human analysis, this is no longer practical.
This thesis outlines a methodology for automatically recovering the necessary
information to create abstract urban models from mobile urban LIDAR data using
computer vision methods. As an integral part of the methodology, a novel scale-based interest operator is introduced (Di erence of Normals) that is e cient enough to process large datasets, while accurately isolating objects of interest in the scene according to real-world parameters.
Finally a novel localized object recognition algorithm is introduced (Local Potential Well Space Embedding), derived from a proven global method for object recognition (Potential Well Space Embedding). The object recognition phase of our methodology is discussed with these two algorithms as a focus.

abstract: M.Sc.


title: Progress Towards the Quantum Limit: High and Low Frequency Measurements of Nanoscale Structures

subject:
Physics
Low temperature
Quantum Hall effect
Quantum limit

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2010-03-01 22:55:56.427

abstract:
In this thesis, I present the work performed towards a proposal to couple a piezoelectric, nanomechanical beam to a radio frequency single electron transistor (RF-SET). Lumped element RF circuit theory is applied to 50 kOhm single electron transistors acting as the resistor in an RLC circuit. It is shown that for the expected inductances and stray capacitances, at an operating frequency of 1.25 GHz, the RF-SET is expected to have a usable half-bandwidth of 175-200 MHz and a charge sensitivity on
the order of 10^(−5) e/√Hz. A fabricated RF-SET device is cryogenically cooled and used to find experimental values of the stray capacitance. A heterostructure made of gallium arsenide and aluminum gallium arsenide from which piezoelectric beams can be made is designed to contain a 2-dimensional electron gas (2DEG). Quantum Hall effect samples are fabricated from the wafer, and magnetoresistance measurements for each sample are presented. It is shown that the 2DEG has a high electron concentration of about 8 × 10^11 cm−2 but a low mobility of about 3.5 × 10^4 cm^2/(V·s) for this type of heterostructure.

abstract: M.Sc.


title: Conceptualizing Community Development from an Occupational Therapy Perspective

contributor:
Paterson, Margo
Krupa, Terry
Rehabilitation Science

subject:
Community Development
Occupational Therapy
Multiple Case Study
Constructivist Grounded Theory
Health Promotion
Community-Based Rehabilitation

abstract: Thesis (Ph.D, Rehabilitation Science) -- Queen's University, 2010-03-04 13:35:42.337

abstract: Despite our theoretical commitment to community development (CD) approaches in occupational therapy, current practice models focus on individual interventions, rather than identifying how occupational therapists (OTs) can contribute at a community level. Consequently, OTs attempting to work with communities may not have clear guidance on methods of community engagement or strategies for addressing community level issues. This research examined three cases of OTs working in CD in different regions of Canada in order to 1) generate in-depth interpretive case descriptions of CD practice; and 2) conceptualize CD from the perspective and practices of occupational therapy. Data collection in each case occurred over three weeks and included approximately 30 hours of observations, document reviews and 14 interviews with health professionals and program participants. Constructivist grounded theory informed data analysis. The conceptual framework generated from the cross-case analysis describes the context of CD in which the OTs bridged the health and community sectors. The OTs were in community-focused positions located within regional health authorities. The OTs strategically used both professional and personal self to enable more equitable power sharing between health services, community agencies and consumers, creating opportunities for meaningful engagement with and in communities. Four main CD strategies contributed to this power shift: 1) building consumer and community capacity, 2) nurturing community partnerships, 3) influencing the health care system, and 4) linking sectors and resources. These OTs focused on a set of core values while drawing on their professional experiences. Individual, organizational and community-level changes resulted from these CD initiatives. The conceptualizations developed in this study can inform the practice of OTs by identifying potential CD strategies for enabling occupations with communities and sensitizing OTs to historical contextual tensions and power inequities. From this, the applicability of current occupational therapy models to communities can be extended, enhancing reflexive CD practice.

abstract: PhD


title: Size, Dynamics and Consequences of Large-Scale Horizontal Coherent Structures in Open-Channel Flows: an Experimental Study

contributor:
da Silva, Ana Maria Ferreira
Civil Engineering

subject:
Turbulence Coherent Structures
Alternate Bars
Shallow Flows
River Morphology
Quadrant Analysis
Energy Spectrum

abstract: Thesis (Ph.D, Civil Engineering) -- Queen's University, 2010-03-09 10:20:53.596

abstract:
This thesis concerns the occurrence of the large-scale bed and plan forms known as alternate bars and meandering, and the internal structures of the flow associated with their formation. The work is to be viewed as an extension of previous work by da Silva (1991), Yalin (1992), and Yalin and da Silva (2001).
As a first step in this work, the criteria for occurrence of alternate bars and meandering of Yalin and da Silva (2001) is re-considered in view of additional field and laboratory data from the recent literature and data resulting from two series of experimental runs carried out in two sediment transport flumes. This leads to a number of modifications of the boundary-lines in the related existence-region diagram of Yalin and da Silva.
The size of the largest horizontal coherent structures (HCS’s) of an alternate bar inducing flow was then investigated experimentally on the basis of three series of flow velocity measurements. These were carried out in a 21m-long, 1m-wide straight channel, conveying a 4cm-deep flow. The bed consisted of a silica sand having a grain size of 2mm; its surface was flat. The measurements were carried out using a Sontek 2D Micro ADV. The horizontal burst length was found to be between five and seven times the flow width. The effect of the HCS’s on the mean flow was also investigated. A slight internal meandering of the flow caused by the superimposition of burst-sequences on the mean flow was clearly detectable.
Finally, with the aid of three new series of measurements in the same channel, an attempt was made to penetrate the dynamics and life-cycle of the HCS’s. For this purpose, quadrant analysis was used; the cross-sectional distribution of relevant statistical turbulence-related parameters was investigated; and cross-correlations of flow velocity along the flow depth and across the channel were performed. The analysis indicates that the HCS’s originate near the channel banks, with the location of ejections and sweeps being anti-symmetrically arranged with regard to the channel centreline, and then evolve so as to occupy the entire depth of the water and the entire width of the channel.

abstract: PhD


title: A Magnetic Flux Leakage NDE System for CANDU Feeder Pipes

subject:
Non-destructive Evaluation
Magnetic

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2010-03-11 15:59:23.978

abstract:
This work examines the application of different magnetic flux leakage (MFL) inspection concepts to the non destructive evaluation (NDE) of residual (elastic) stresses in CANDU reactor feeder pipes. The stress sensitivity of three MFL inspection techniques was examined with flat plate samples, with stress-induced magnetic anisotropy (SMA) demonstrating the greatest stress sensitivity. A prototype SMA testing system was developed to apply magnetic NDE to feeders. The system consists of a flux
controller that incorporates feedback from a wire coil and a Hall sensor (FCV2), and
a magnetic anisotropy prototype (MAP) probe. The combination of FCV2 and the MAP probe was shown to provide SMA measurements on feeder pipe samples and predict stresses from SMA measurements with a mean accuracy of ±38MPa.

abstract: M.A.Sc.


title: Basketball With(out) Borders: Interrogating the Intersections of Sport, Development, and Capitalism

contributor:
King, Samantha J.
Kinesiology and Health Studies

subject:
Sport for Development and Peace
Development
Corporate Capitalism
Corporate Philanthropy
National Basketball Association

abstract: Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2010-03-17 14:51:15.919

abstract: The purpose of this thesis is to explore the intersection of sport for development and peace (SDP) and global corporate philanthropy through a case study of the National Basketball Association’s (NBA) “Basketball Without Borders” (BWB).  The NBA promotes BWB as a means to social and economic development in the global South by wedding basketball with education on social issues and the development of sport-related infrastructure.  However, the NBA’s participation in SDP is emblematic of broader issues in neoliberal globalization, and, as such, an historical and discursive analysis is undertaken to interrogate the seemingly divergent pursuits of capitalism and international development.  I argue that the consequences of transnational corporations like the NBA entering developing nations for the purposes of promoting development through sport results in the prioritization of commercialism over development, and the (re)production of hegemonic and neocolonial ideologies and practices.

abstract: M.A.


title: Applications of Quantum Cryptography

contributor:
Akl, Selim
Computing

subject:
Quantum Cryptography
Sensor Networks
One-Time Pads
Databases
Authentication

abstract: Thesis (Ph.D, Computing) -- Queen's University, 2010-03-12 11:38:07.086

abstract:
This thesis extends the applicability of quantum cryptography.

First, we prove that quantum cryptography at least equals classical cryptography in an important area, namely authentication. The quantum key distribution protocols presented here show that, contrary to previous belief, authentication can be done with quantum methods only.

In addition, we have designed quantum security systems in unconventional settings. The security of sensor networks poses specific challenges, as the sensor nodes in particular can be physically picked up by the intruder. Our scheme protects both the integrity of the communication messages and it also protects the identity of the nodes, such that a reading intrusion of a node is detectable.

The problem of access control in a hierarchy refers to a large number of users, organized in a hierarchy, having selective access rights to a database. Our quantum solution introduces quantum keys to the effect that the cryptographic scheme is dynamically adaptable to changes in the user structure, and it exhibits increased security levels.

To the best of our knowledge, this thesis is the first to introduce quantum keys, that is secret keys defined by an array of qubits. We show that quantum keys make it possible for two parties to communicate with one-time pads without having to meet in advance. Also, opposite to previous cryptographic ``common sense", the security level of a quantum cryptosystem with quantum keys and quantum messages increases while being used, meaning the security increases over time.

abstract: PhD


title: North Atlantic Quadrangle: The Importance of France in Canadian Strategic Culture, 1760-1949

contributor:
Haglund, David G.
Political Studies

subject:
Canadian Foreign Policy
France

abstract: Thesis (Ph.D, Political Studies) -- Queen's University, 2010-03-22 12:52:20.99

abstract: The objective of this dissertation is to answer the puzzle raised by political scientist John Kirton: Why has Canada, for the last century, gone to war for and beside France? In other words, I assess France’s relative importance in Canadian strategic culture. The hypothesis defended is that the emergence of France in Canadian strategic culture stems from the social construction of Canada's internal state identity as a bicultural (English and French) country, with its corollary external identity as an Atlanticist country, emerging in 1940, and whose associated principles (allied unity, status and functional representation) explain the legitimacy to use force outside Canada's borders as well as the magnitude of Canada's military contribution. This gives France a double influence on Canada’s strategic culture, that is to say, in the constitution of what is considered a “just” cause: the legitimacy of quadrilateral multilateralism, as well as the "Christian democratic" values and ethnocultural heritage shared between Canada and France, which I call "francosphère.” The demonstration that France is an essential geonormative pillar in Canada’s international security policy – justifying an extension of the geometric metaphor of the North Atlantic triangle - is established in three stages. First, I reject the realist hypotheses explaining the peculiarity of Franco-Canadian relations (anti-American and anti-Soviet balancing, collective defence, relative power, and the Gaullist assault on Canada’s territorial integrity) because of their inconsistency and/or their lack of empirical support. Then, I develop a constructivist analytical framework of foreign policy. Finally, the empirical and historical study that follows, examining Franco-Canadian relations from 1760 to 1949, confirms my hypothesis, namely that the importance of France in Canadian strategic culture is determined by the emergence of bicultural and Atlanticist identities, both institutionalized after the trauma of June 1940.

abstract: PhD


title: Geotechnical Applications of LiDAR Pertaining to Geomechanical Evaluation and Hazard Identification

contributor: Geological Sciences and Geological Engineering

subject:
Geomechanics
Remote Sensing
LiDAR
Engineering Geology
Structural Geology
Geotechnical

abstract: Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2010-03-26 11:25:15.741

abstract:
Natural hazards related to ground movement that directly affect the safety of motorists and highway infrastructure include, but are not limited to, rockfalls, rockslides, debris flows, and landslides. This thesis specifically deals with the evaluation of rockfall hazards through the evaluation of LiDAR data.
Light Detection And Ranging (LiDAR) is an imaging technology that can be used to delineate and evaluate geomechanically-controlled hazards. LiDAR has been adopted to conduct hazard evaluations pertaining to rockfall, rock-avalanches, debris flows, and landslides. Characteristics of LiDAR surveying, such as rapid data acquisition rates, mobile data collection, and high data densities, pose problems to traditional CAD or GIS-based mapping methods. New analyses methods, including tools specifically oriented to geomechanical analyses, are needed.
The research completed in this thesis supports development of new methods, including improved survey techniques, innovative software workflows, and  processing algorithms to aid in the detection and evaluation of geomechanically controlled rockfall hazards.
The scientific research conducted between the years of 2006-2010, as presented in this thesis, are divided into five chapters, each of which has been published by or is under review by an international journal. The five research foci are: i) geomechanical feature extraction and analysis using LiDAR data in active mining environments; ii) engineered monitoring of rockfall hazards along transportation corridors: using mobile terrestrial LiDAR; iii) optimization of LiDAR scanning and processing for automated structural evaluation of discontinuities in rockmasses; iv) location orientation bias when using static LiDAR data for geomechanical analysis; and v) evaluating roadside rockmasses for rockfall hazards from LiDAR data: optimizing data collection and processing protocols.
ii
The research conducted pertaining to this thesis has direct and significant implications with respect to numerous engineering projects that are affected by geomechanical stability issues.
The ability to efficiently and accurately map discontinuities, detect changes, and standardize roadside geomechanical stability analyses from remote locations will fundamentally change the state-of-practice of geotechnical investigation workflows and repeatable monitoring. This, in turn, will lead to earlier detection and definition of potential zones of instability, will allow for progressive monitoring and risk analysis, and will indicate the need for pro-active slope improvement and stabilization.

abstract: PhD


title: Cationic and Anionic Carbon Dioxide Responsive Switchable Surfactants

contributor:
Jessop, Philip G.
Chemistry

subject:
switchable surfactant
heavy crude oil
emulsion polymerization
transport emulsion
carbon dioxide
revesible latex

abstract: Thesis (Master, Chemistry) -- Queen's University, 2010-04-03 12:28:07.115

abstract:
Tail modified amidine type cationic switchable surfactants were synthesized. The modified structures included ethylene oxide units in the tail to increase water solubility. Surfactants with different hydrophile-lipophilic balance were available by virtue of the commercial availability of the alcohol precursors.
Low viscosity emulsions of heavy crude oil were generated by activating indigenous crude oil surfactants with a water-soluble base. The emulsions containing approximately 70 wt% heavy crude oil were visually stable under ambient conditions for two weeks. Immediate phase separation was found to occur with the addition of carbon dioxide gas. Free water was easily separated from high viscosity crude oil. Improvements in the quality of phase separation were possible with water-soluble organic bases. Amidine surfactants with appropriate structure were also capable of stabilizing heavy crude oil emulsions.
Anionic switchable surfactants were developed. The surfactants reacted with carbon dioxide to cause changes to interfacial properties. Carbon dioxide in aqueous solution was able to neutralize the anionic form of the surfactant. Examples include carboxylic acids and phenols. Heating and removal of carbon dioxide was, in most cases, sufficient to cause the surfactant to become anionic again. Interfacial properties such as surface tension and emulsion stability were controlled using the anionic switchable surfactant system. Otherwise stable emulsions were triggered to separate by addition of carbon dioxide.
Polystyrene particles of 30 nm to 40 nm in diameter were made by emulsion polymerization using anionic switchable surfactants. The latex was stabilized by electrostatic charges with measured zeta potential below –30 mV. Treating the latex with carbon dioxide was found to cause aggregation of polymer particles. The aggregates were much larger with diameter of approximately 100 μm and readily separated by flotation and dried into a fine free flowing powder. Re-dispersion of the aggregates was possible after heating and mixing the slurry in water. The re-dispersed latex was found to be stabilized by electrostatic charges with measured zeta potential below –30 mV.

abstract: M.Sc.


title: Novel Aspects to the Role of Rad9A During the DNA Damage Response

contributor:
Davey, Scott
Biochemistry

subject:
Checkpoint
DNA Repair

abstract: Thesis (Ph.D, Biochemistry) -- Queen's University, 2010-03-26 12:02:41.304

abstract: The human Rad9A checkpoint protein is required for genomic stability and proper execution of the DNA damage checkpoint.  Previous work has shown Rad9A to be the key member of a heterotrimeric toroidal structure known as the 911 complex, along with Hus1A and Rad1, which is similar in structure to PCNA.  Recent literature suggests Rad9A is a novel oncogene, found to be upregulated in a number of cancers and high mRNA levels are thought to have a protective effect on tumour growth.  This thesis describes two novel functions for the Rad9A protein.  The first is as a facilitator for the nuclear translocation of the Claspin adaptor protein, required for successful Chk1-mediated checkpoint activation.  The second is as part of a novel nuclear structure containing important members of the homologous recombination DNA repair pathway.  Work described herein also confirms the existence of a Rad9A paralogue, Rad9B, that partially rescues defects associated with Rad9A-deficiency and is expressed in both tumour and undifferentiated embryonic stem cell lines.  This work discusses these findings in the context of current literature and provides future experiments to continue investigations into the function of this vital checkpoint protein.

abstract: Some of the work described within the thesis have been submitted for publication and we are currently awaiting a decision.

abstract: PhD


title: Contributions to the Theory, Design and Optimization of Microwave Bandpass Filters

contributor:
Amari, Smain
Freundorfer, Alois P.
Electrical and Computer Engineering

subject:
Microwave Filters
Dual-Mode Filters
Dual-Band Filters
Space Mapping Optimization
Representation Theory
Eigen-Modes
Synthesis
Coupling Matrix
Maxwell's Equations
Boundary Conditions
Resonators
Resonant Modes

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2010-03-31 01:33:36.818

abstract:
Bandpass microwave filters are often modeled as a set of coupled discrete and localized resonators. This model is adequate in the narrow-band case. It, however, fails to describe accurately compact structures where stray couplings can be strong.
 	To address this problem, a new view is proposed in this thesis. Instead of basing the model on localized discrete resonances, we start by constructing a model that is based on the global resonances of the structure. These are the resonances that the ports see and emerge when the entire structure is treated as a single unit. The resulting circuit, the transversal circuit, is universal. It is valid for any coupled resonator filter. The circuit is used in optimization of compact and ultra wideband suspended stripline filters and excellent results were obtained.
   	In order to relate the global-eigen modes model to the conventional model, the issue of
representation of microwave filters is investigated in detail. It is shown that a microwave filter can be represented by an infinite number of similar coupling matrices by using different modes as basis. According to this new view, a similarity transformation in microwave coupled resonator filters is interpreted as a change of basis. Two circuits that are related by a similarity transformation represent the same filter structure by using different sets of modes as basis.
  	These conclusions were exploited in establishing a design theory for filters with dual-mode cavities. The new theory leads to direct and accurate design techniques that need no, or minimal, optimization. No tuning is used in the CAD steps. Tuning may only be required to account for manufacturing tolerances. A new tuning configuration is described and validated by computer simulation.
  	A novel dual-mode filter with improved quality factor and reduced sensitivity is developed and designed within the same approach. The filter is fabricated and measured and excellent results are achieved. The same design methodology was used to introduce a new class of dual-mode dual-band microwave filters with improved sensitivity. It is also shown that canonical dual-mode filters can be designed within the same view with minimal local optimization of the input cavity.

abstract: PhD


title: The Physical and Spectroscopic Study of a Series of Poly(3-hexyl thiophene) Homopolymers and Poly(3-hexyl thiophene)-block-Poly(2-hydroxyethyl methacrylate) Diblock Copolymers

contributor:
Liu, Guojun
Chemistry

subject:
poly(3-hexyl thiophene)
diblock copolymer

abstract: Thesis (Master, Chemistry) -- Queen's University, 2010-03-31 11:30:44.539

abstract:
In block-selective solvent, the rod-coil block copolymers can form various micellar structures.  With block copolymers that contain a conjugated polymer block, the conformation of the conjugated polymer can be reflected by spectral changes in the solution.  Therefore, it is of interest to study the relationship between the spectral changes and the nature of the conjugated polymer.
The fundamental physical properties of poly(3-hexyl thiophene) (P3HT) were studied.  Five P3HT samples with different molecular weights were used.  We have determined the relationship between physical and spectral properties of this polymer and its molecular weight.  In particular, we have found that the refractive index increments, the maximum absorbance wavelength, extinction coefficients, and the emission wavelengths, increase with molecular weight.
Diblock copolymers of poly(3-hexyl thiophene)-block-poly(2-hydroxyethyl methacrylate) (P3HT-b-PHEMA) were also studied.  The morphological and spectral changes of these block copolymers were studied at various stages of micelle formation in block selective solvents.  The relationship between the volume fraction of the P3HT block and their physical and spectral properties were also discussed.

abstract: M.Sc.