title: Arsenic biotransformations in terrestrial organisms: A study of the transport and transformation of arsenic in plants, fungi, fur and feathers, using conventional speciation analysis and X-ray absorption spectroscopy

contributor:
Reimer, Ken J.
Ko, Kenton
Biology

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subject: Arsenic XAS Plants Fur Feathers Fungi Biotransformations

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2007-05-30 11:55:40.157

abstract:
Arsenic taken up by plants and fungi from contaminated soils can subsequently be introduced into food chains. Given the toxic properties of some arsenic compounds, this may be a cause for concern. Much remains to be learned about how these compounds are transformed and distributed in terrestrial organisms. Radishes, white button mushrooms, fur, and feather samples were thus investigated to gain a better understanding of arsenic biotransformations in terrestrial organisms.
   	In this study, we utilized two analytical techniques for the detection and identification of arsenic compounds (“arsenic speciation analysis”).  High performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) provided a highly sensitive method for detecting low levels (ng•g-1) of methanol:water extractable arsenic compounds.  X-ray absorption spectroscopy (XAS) techniques provided direct arsenic speciation analysis of tissues, resulting in a more representative arsenic profile of the original organisms, without the need to extract arsenic first. Overall, the results for speciation analysis underline the complementary nature of the HPLC-ICP-MS and XAS techniques.
	Mushrooms contained organic arsenic compounds which were not identified in the radish. In particular arsenobetaine (AB), which is usually found as a minor constituent of terrestrial organisms, was a predominant arsenic compound found in mushroom extracts. How AB is synthesized in the environment remains unclear; however, results presented here suggest it was a product of fungal biotransformation and we speculate it may play a role in osmoregulation. In radish, fur and feather samples, direct analysis identified arsenic(III)-sulphur compounds not observed using HPLC-ICP-MS. In plants, these compounds are likely to be metal/metalloid binding phytochelatin proteins the formation of which has yet to be confirmed in planta. In radish plant vasculature, XAS imaging revealed segregation of pentavalent and trivalent arsenic compounds, suggesting differences in arsenic transport. In hair and feathers the formation of arsenic(III)-sulphur compounds may be evidence of arsenic binding to keratin proteins which has been hypothesized to occur, and may contribute to the observed reduction of exogenous arsenic contamination.

abstract: PhD


title: A low feedback robust opportunistic scheduler and beamformer for MISO wireless systems

contributor:
Gazor, Saeed
Electrical and Computer Engineering

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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:
opportunistic beamforming
opportunistic scheduling

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-06-30 07:00:20.468

abstract:
Opportunistic Beamforming is a promising scheme with potential usage in a variety of applications
ranging from cellular audio/video communications to wireless mesh-networks. However, some
aspects in this scheme are open to further improvements, such as effective quality of service (QoS)
provisioning, and efficient handling of sparse/realistic networks.
We focus on the downlink channel of a multi-rate time-division multiplexing MISO (multiple
input single output) point-to-multi-point wireless communication system, and design a cross-layer
scheme. We employ a two-stage opportunistic scheduler. The scheduler receives channel state information
in the form of SNR (signal to noise ratio) measurements from each terminal, and schedules
one terminal in each time-slot. At the first stage in a time-slot a terminal is chosen, and our gradient
descent channel estimator finds an estimation of its channel vector. Then the beamformer produces
a beamforming vector in an adjacent pilot channel, or in the first part of the time-slot in the data
channel. Our beamforming is based on the estimation of the channel, as opposed to the random
beamformer used in the opportunistic beamforming. Each terminal measures its perceived SNR
even when the channel is assigned to another terminal, and sends this information back to the basestation
subject to a feedback-reduction policy. The scheduler uses the new channel state information
for its second stage and assigns a terminal for the succeeding time-slot. The channel estimation procedure
uses the reported SNRs for each terminal, which is a significantly lower feedback rate than
the amount required for coherent beamforming. Our approach efficiently handles sparse/realistic
networks, and also provides a better QoS than the opportunistic beamforming scheme.

abstract: M.Sc.


title: Ringdown spectroscopy in optical waveguides

contributor:
Loock, Hans-Peter
Chemistry

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subject:
absorption spectroscopy
optical waveguides

abstract: Thesis (Master, Chemistry) -- Queen's University, 2007-07-04 16:23:53.173

abstract:
Ringdown spectroscopy (RDS) is an absorption spectroscopic and detection
technique that makes use of an optical cavity to realize a long effective pathlength
through a sample and to render the measurement independent of intensity. These two
features give RDS an advantage over traditional absorption techniques and allows its
application in measuring concentrations of strongly absorbing analytes present in trace
amounts, or in measuring weak absorptions for analytes in higher concentrations. The
resonant optical cavities used here are created from optical fibre. This permits the easy
construction of an inexpensive apparatus for RDS. The performance of various cavity
geometries (linear, circular) in three ranges of the visible and near infrared spectrum (405,
800, and 1550 nm) was examined. Concurrent multiexponential decays arising from core
modes, cladding modes, and amplified spontaneous emission were analyzed in the
framework of an exponential decay model transformed into the frequency domain.
The small mode field diameter of light within a fibre is well suited to probing very
small liquid volumes on the order of pico- or femtolitres. This uniquely positions optical
waveguide-based RDS for application in absorption detection for separation techniques
such as capillary electrophoresis (CE) and high performance liquid chromatography
(HPLC) where high time resolution detection is required across narrow separation
channels. The experimental and theoretical work presented here was preformed with an
eye towards this purpose.

abstract: M.Sc.


title: Essays on the financial system and the transmission of monetary policy

contributor:
Head, Allen
Milne, Frank
Economics

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subject:
Financial crisis
Monetary policy
Banking system
Inside money

abstract: Thesis (Ph.D, Economics) -- Queen's University, 2007-07-06 11:55:49.942

abstract:
This thesis studies  the role of the banking system in several aspects of the macroeconomy, including the likelihood of financial
crises, volatility of asset prices and the transmission of monetary policy.

In chapter 2, I analyze the accumulation of international reserves by central banks as insurance against financial crises. In the
model, private banks borrow from foreign creditors to invest in domestic projects. By lending to banks in response to liquidity
shocks, the central bank can reduce the liquidation of bank assets and lower the probability of bank runs. I show that the
central bank will hold more reserves when  private banks hold lower reserves. I also find that if the central bank can borrow
additional loans  from external sources, then domestic banks will hold fewer reserves by themselves. If the borrowing cost of
external loan is very high, then the central bank may actually want to accumulate more reserves in order to avoid borrowing from
external sources at high costs.

In chapter 3, I show that the ability of banks to supply liquidity through money creation is important for financial stability.
By supplying liquidity, banks can smooth the sale of assets and stabilize asset prices. I find that without elastic money, the
attempt of non-bank mutual funds to raise cash by selling assets will only add more volatility into the market. Elastic money
provided by  banks can help mutual funds better smooth the consumption of their shareholders.

In chapter 4, we consider the role of elastic money in an different environment where liquidity shocks affect agents
asymmetrically. We show how money growth and interest rate policy can be used to adjust the consumption level of households. We
find that the optimal policy is affected by the sensitivity of the supply price to the interest rate. When the supply price is
more sensitive to the interest rate, it would be better to adopt a higher inflation rate, and to make the zero-bound of nominal
interest rate less likely to be binding.

abstract: PhD


title: An evaluation of the efficiency of lymphocytic choriomeningitis virus - nucleoprotein cross priming in vivo

contributor:
Basta, Sameh
Microbiology and Immunology

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subject:
LCMV
Cross priming
Antigen Presentation
Cytotoxic T cells

abstract: Thesis (Master, Microbiology & Immunology) -- Queen's University, 2007-07-10 14:33:18.115

abstract:
During viral infections, CD8+ T cells only respond to a select few epitopes derived from the respective foreign pathogen. These epitopes can be organized into a hierarchy, based on their ability to induce T cell priming. Such phenomenon is known as immunodominance. Cytotoxic T cells can be primed through the direct pathway, or the cross-priming pathway. The latter involves exogenously derived viral epitope presentation by uninfected professional antigen presenting cells.
      It has been previously reported that Lymphocytic Choriomeningitis nucleoprotein expressed in HEK cells (HEK-NP) could be cross presented to CD8+ T cells. In these studies we have used this same HEK-NP model to study the effects of LCMV-NP cross priming on the LCMV immunodominance hierarchy following viral challenge. Our results provide strong evidence that cross priming is an efficient route with which to induce cell-mediated immunity. We also highlight a regulatory role for cross priming in immunodominance by showing that a single dose of HEK-NP can completely shift the immunodominance hierarchy of a typical LCMV infection. Furthermore, we see that the induction of LCMV-NP cross priming boosts anti-viral immunity to subsequent LCMV infections.
      This work provides strong support for the physiological role that cross priming plays in normal cell-mediated immune responses. It may also provide relevant information to the realm of immunotherapy.

abstract: M.Sc.


title: Identification and characterization of N-glycosylation and structural genes involved in flagellation of methanogenic archaea from the genus Methanococcus

contributor:
Jarrell, Ken F.
Microbiology and Immunology

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subject: Archaea Glycosylation Flagellation

abstract: Thesis (Ph.D, Microbiology & Immunology) -- Queen's University, 2007-07-11 16:50:37.119

abstract:
The archaeal flagellum is a unique motility structure. Although functionally similar to the bacterial flagellum, the archaeal flagellum shares more similarities to the bacterial type IV pilus. Using the methanogenic archaea Methanococcus voltae and Methanococcus maripaludis as model organisms, the structural and post-translational requirements for flagellation have been investigated.
Known to contain glycosylated flagellin proteins, the N-glycosylation pathway was studied in M. voltae. A number of possible glycosylation component genes, including glycosyl transferases, flippases and an oligosaccharyl transferase were inactivated or deleted in M. voltae and their resulting phenotypes were characterized. Four glycosyl transferases were identified as involved in the assembly of the M. voltae glycan structure, with three of these enzymes, AglA, AglC1 and AglC2, experimentally verified. As well, the oligosaccharyl transferase, AglB, has also been experimentally confirmed and was found to be the homolog of the bacterial and eukaryotic equivalents, PglB and Stt3p, respectively. Disruption of glycan synthesis or attachment resulted in very poorly or non-flagellated cells, implicating for the first time that the glycan structure on archaeal flagellins is necessary for proper flagella assembly and/or stability. These findings also represent the first proven N-glycosylation genes within the domain Archaea.
New markerless, in-frame deletion methodology has allowed for advanced studies of a demonstrated and putative set of flagella-related genes in M. maripaludis. This collection of 11 co-transcribed genes, consisting of three flagellin genes (flaB1-flaB3), six genes of unknown function (flaC-flaH) and two genes implicated in flagellin subunit export (flaI and flaJ), make up the fla operon in this organism. Each gene from flaB1-flaI was systematically targeted for deletion and complementation to determine its necessity for flagellation. The analysis showed that both major flagellins, FlaB1 and FlaB2 are required for flagellation, while the minor flagellin, FlaB3, was required for the hook-like region of the flagella filament. FlaC, FlaF, FlaG and FlaH were shown for the first time to be essential for flagellation, while a naturally-occurring, truncated version of FlaD was found not to be required. These results continue to develop our understanding of the archaeal flagellum and the components necessary for its assembly and/or structure.

abstract: PhD


title: Design and development of an intelligent neuro-fuzzy system for automated visual inspection

contributor:
Surgenor, Brian W.
Mechefske,Chris K.
Mechanical and Materials Engineering

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subject:
Mechanical
Engineering
Machine vision
Automotive
Fuzzy logic
Neural networks

abstract: Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2007-07-12 10:24:43.367

abstract: This thesis presents work on the use of intelligent algorithms to solve a real-world machine vision problem in the automotive industry. Compared to commercial systems, the algorithm developed is both more robust to changes in the inspection environment and more intuitive for the user to configure.

abstract: M.A.Sc.


title: Trait self-esteem moderates the effect of initiator status on emotional and cognitive responses to romantic relationship dissolution

contributor:
MacDonald, Tara K.
Psychology

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subject:
Self-esteem
Break-up
Rejection
Initiator status

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2007-07-12 12:36:26.478

abstract:
Romantic relationship dissolution has been implicated in the onset of mood disorders (Monroe et al.,1999; Overbeek et al., 2003). It is therefore imperative that researchers and mental health professionals have an understanding of the factors that contribute to dysfunctional responses so as to assist vulnerable individuals with developing healthy strategies for coping with relationship dissolution. Prior research on the relationship between initiator status (i.e., who ended the relationship) and subsequent emotional distress has been mixed, with multiple researchers finding that a person's level of distress was unrelated to whether he or she ended the relationship. I hypothesized that the effect of initiator status on post-break-up distress would vary as a function of trait self-esteem such that individuals with low self-esteem would experience more distress after being rejected by their partners, whereas individuals with high self-esteem would be no more distressed after a rejection than after acting as the rejecter.

I tested this hypothesis using two designs. First, I used a prospective, naturalistic design in which university students were assessed for emotional responses following the dissolution of their romantic relationships. Those who had self-reported lower trait self esteem at the outset of the study experienced higher levels of break-up-specific distress. On the other hand, those who had reported higher trait self-esteem did not exhibit differing distress levels as a function of who ended the relationship. This pattern was replicated in a laboratory design in which university students imagined breaking up with their partners. Participants with low trait self-esteem experienced more negative mood, reported lower state self-esteem, and evaluated themselves more negatively after a scenario in which they were rejected as compared to a scenario in which they rejected their partners. Participants with high self-esteem did not differ on any of these variables as a function of rejection condition. Results are discussed in terms of the theoretical implications for understanding self-esteem processes and the effects of romantic rejection. Implications for interventions for individuals with low self-esteem who are coping with romantic rejection are also explored.

abstract: PhD


title: Study of pre-evaporation and matrix effects on multi-elemental analysis by ICP-TOFMS

contributor:
Beauchemin, Diane
Chemistry

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subject:
ICP-MS
Matrix effect
Pre-evaporation

abstract: Thesis (Ph.D, Chemistry) -- Queen's University, 2007-07-12 13:51:55.115

abstract:
The ultimate goal of this project was to improve the sensitivity and detection limits of inductively coupled plasma time-of-flight mass spectrometry (ICP-TOFMS) and then apply it to the speciation analysis of As. To this end, two approaches were taken: the use of organic modifiers and that of a pre-evaporation interface between the spray chamber and the plasma torch.

The radial profiles of some background ions and analytes in three different matrices (1% HNO3, 1% HNO3 with 2% v/v methanol, 1% HNO3 with 0.2% m/v sodium dodecylsulfate (SDS)) were investigated in ICP-TOFMS. Although these concentrations of methanol and SDS induced the same increase (37%) in sample introduction efficiency, the change in analyte signal as a function of m/z followed opposite trends in these two matrices. The results show that matrix effects arising from different organic modifiers affected the distribution of ions in the plasma differently as a result of changes induced in the predominant ionisation mechanisms in the plasma.

The effect of a pre-evaporation interface on the distribution of ions in ICP-TOFMS was also investigated by spatial profiling, which showed that the optimal axial position of all elements shifted closer to the load coil. Furthermore, the radial profiles became significantly narrower and Gaussian. The decrease of droplet size thus improved the sensitivity and detection limits for multi-elemental analysis.

A further investigation of the effect of the pre-evaporation interface revealed that, for cationic analytes, the signal enhancement had an inverse dependency on analyte mass upon heating the interface. In the case of As, a signal enhancement upon heating the interface only resulted when concomitant ionic analytes were present or with a 0.01 M NaOH matrix.  All these observations could be rationalised by changes in the number of Coulomb fission events occurring during pre-evaporation, which depend on the size and charge of droplets, as well as the identity and concentration of the matrix.

Finally, the baseline separation of four As species by ion exchange liquid chromatography with detection by ICP-TOFMS and application of the pre-evaporation interface tube to As speciation were achieved using a mobile phase of NH4NO3, following an investigation of its matrix effects.

abstract: PhD


title: Effect of computer decision support system on antibiotic utilization in a complex continuing care and rehabilitation hospital

contributor:
O'Callaghan, Chris
Zoutman, Dick
Community Health and Epidemiology

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subject:
Community health and epidemiology
Antibiotic utilization
Computer order entry
Decision support system

abstract: Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2007-07-13 10:47:38.035

abstract:
Background: Considerable amount of inappropriate antibiotic utilization has been observed in both acute and non-acute care hospitals. Literature has shown that strategies such as an order entry (OE) and computer decision support system (DSS) have improved prescribing practices in acute care settings. However, there is limited research on the effect of OE on antibiotic utilization in non-acute care settings.
Objective: To determine the relationship between OE with DSS and antibiotic utilization in a complex continuing care and rehabilitation hospital.
Methods: A retrospective analysis of OE and Pharmacy dispensing data, prospectively collected between July 1, 1999 and December 31, 2005, was conducted. Dispensing events for oral and intravenous antibiotics were merged with corresponding OE’s (when present) to form a final database of 4,739 dispensing events with 2,397 OE’s. The presence of OE and the proportion of OE to dispensing events formed the exposure variable while antibiotic utilization in defined daily dose (DDD) was calculated using dose and number of doses of an antibiotic. Antibiotic utilization was examined at the hospital and individual service in-patient unit levels (complex continuing care/CCC and rehabilitation medicine/REH). Statistical analysis consisting of multiple regression modeling was conducted to determine the association between use of OE and antibiotic utilization.
Results: A best-fit model using multiple regression analysis at hospital level indicated a significant positive relationship between the presence of OE and antibiotic utilization when service, patient age, gender and antibiotic classes were accounted for. This model explained 11% of the variation in antibiotic utilization. No significant associations were found in the CCC in-patient unit while in the REH in-patient unit a significant positive relationship between the presence of OE and antibiotic utilization was observed. Similarly, antibiotic utilization increased significantly with increase in the proportion of OE to dispensing events at the hospital and REH in-patient unit levels but not in the CCC in-patient unit.
Conclusion: The results of this study demonstrate that antibiotic utilization increased over the years following the inception of the OE system with DSS at the study hospital. Further research is required to examine the effect of OE with a rudimentary DSS on antibiotic utilization management in non-acute care.

abstract: M.Sc.


title: Nonlinear finite element study of deteriorated rigid sewers including the influence of erosion voids

contributor:
Moore, Ian D.
Civil Engineering

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subject:
Deteriorated rigid pipes
Erosion voids

abstract: Thesis (Master, Civil Engineering) -- Queen's University, 2007-09-24 20:33:29.689

abstract:
The service life of rigid sewer pipes is often controlled by joint integrity. Leaking joints can cause ingress of water and develop voids where surrounding soil has eroded. The influence of soil voids on the stability of buried rigid pipes is investigated, considering the effects of void size, void location and void shape.

A series of simplified void geometries are defined, and their influence on bending moments in the rigid sewer is studied through finite element analysis. Elastic analysis indicates that the bending moments from expanding voids at the springline will increase slowly, accelerating once the void spans a 45 degree arc, approximately doubling at 90 degrees, and tripling if the loosened backfill is modeled for shear failure. This preliminary study suggests that the growth of erosion voids should be stopped before they reach 45 degrees, but validation through physical testing is necessary.

Elastic-plastic finite element analysis is used to calculate the deformation of rigid fractured pipe with different thicknesses, considering both bonded and full-slip interface conditions. The analysis confirms that bonded idealized flexible pipe theory is very effective for calculation of increases in horizontal diameter of the fractured pipe. Furthermore, decreases in vertical diameter can be simply related to increase in horizontal diameter using (1-2t/OD) obtained from fractured pipe kinematics.
Both elastic and elastic-plastic finite element analyses used to study the deformations of fractured rigid pipe reveal that contact angle appears to be the dominant factor affecting fractured pipe deformations. Deformation of the damaged rigid pipe increases dramatically with void growth and accelerates when erosion void contacts with the outer surface of the pipe over an arc greater than 45 degrees. Computational analyses examine the behavior of centrifuge model tests which examine soil load transfer to flexible sewer liners after fracture and erosion voids form nearby. The magnitude of deformation changes for finite element models is found to be comparable to observations when voids are formed at springline. However the development patterns are dramatically different as voids located under the invert, and it appears that the laboratory test featured physical characteristics that are not modeled in the analysis.

abstract: M.Sc.


title: Transimpedance amplifier design using 0.18 um CMOS technology

contributor:
Frank, Brian M.
Cartledge, John C.
Electrical and Computer Engineering

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subject:
Transimpedance Amplifier
CMOS Technology
Optical Receiver
Fiber to the Home
Integrated Circuit

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-07-16 13:34:41.46

abstract:
This thesis examines the design of high speed transimpedance amplifiers (TIAs) in low cost complimentary metal oxide semiconductor (CMOS) technology. Due to aggressive scaling, CMOS has become an attractive technology for high speed analog circuits. Besides the cost advantage, CMOS offers the potential for higher levels of integration since the analog circuits can be integrated with digital electronics on the same substrate.

A 2.5 Gbps transimpedance amplifier fabricated using 0.18 um CMOS technology is presented. The TIA uses a shunt-shunt feedback topology with a cascode gain stage. Measurements of the transimpedance gain, group delay, and common mode rejection ratio are presented for the TIA and show a good match to simulated results. The noise of the TIA was characterized by measuring the noise parameters of the TIA. The noise parameters are then used to determine the input referred noise current spectral density.

A 10 Gbps transimpedance amplifier fabricated using 0.18 um CMOS technology is also presented. This TIA uses a shunt-shunt feedback topology with a common source gain stage. In order to achieve the required bandwidth, the TIA uses a bandwidth extension technique called shunt-series inductive peaking. A discussion of the different methods of bandwidth extension using inductive peaking is included, and the optimal configurations for maximally
flat responses are shown for shunt inductive peaking,series inductive peaking, and shunt-series inductive peaking. The TIA circuit topology is optimized using a novel noise analysis that uses a high frequency noise model for the transistor. The optimum transistor size and bias current are determined to minimize the amplifier noise. Unfortunately differential measured results are not available due to a stability problem in the amplifier. The cause of this instability is further explored and modifications to solve the problem are discussed. Single-ended results are presented and show reasonable agreement with simulated results. Differences in the results are attributed to poor modelling of the on-chip spiral inductors.

abstract: M.Sc.


title: Fitness, fertility and femininity: Making meaning in the tying of tubes: A feminist discourse analysis of women's sterilization

contributor:
Burfoot, Annette J.
Sociology

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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:
Qualitative sociology
Gender
Discourse analysis
Femininity
Reproductive health technology
Sterilization

abstract: Thesis (Master, Sociology) -- Queen's University, 2007-07-17 17:09:15.595

abstract: As a contraceptive technology, women’s sterilization is a medical event that is uniquely situated in relation to the dominant discursive link between women and reproduction. Intended as a contraceptive option that permanently ends a woman’s potential ability to sexually reproduce, women’s sterilization presents a significant point for exploring the discursive formation of femininity, and how the concepts thereof relate to broader questions of access, control, and regulation of sterilization and the female sterilization patient. This study uses a Foucauldian feminist theory of discourse to explore such questions in a qualitative discourse analysis of women’s sterilization, from both a historical perspective and from within contemporary medical texts. Sterilization has had a particularly tumultuous history in the provision of reproductive healthcare for women; situated within public health and welfare discourse that differentiates the “unfit” from the “fit” reproducers, women have been forcibly sterilized under classist and racist eugenic programs, while subtle yet coercive forms of sterilization abuse continue to occur as inequality of reproductive healthcare access is an ongoing issue for immigrant women, poor women, and women of colour. In light of this historical analysis, as well as the impact of feminist and bioethics discourse upon contemporary medical practice, an analysis of medical texts further explores the association of women with reproduction in the discursive form of the sterilization patient. This study argues that the sterilization patient is situated within a discourse of ideal femininity, associated with normalized forms of mothering, sexuality, and family structure. Given the historical link between the discursive “fit” reproducer, these concepts have continued implications for women’s experience of accessing sterilization as a contraceptive option.

abstract: M.A.


title: Prolonged dietary iron restriction alters total tissue iron but not heme iron: lack of impact on blood pressure and salt sensitivity

contributor:
Adams, Michael A.
Nakatsu, Kanji
Pharmacology and Toxicology

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subject:
Iron deficiency
Tissue iron
Salt sensitivity
Blood pressure

abstract: Thesis (Master, Pharmacology & Toxicology) -- Queen's University, 2007-07-18 12:00:09.853

abstract:
The World Health Organization (WHO) states that iron deficiency (ID) is the preeminent global micronutrient deficiency. Maternal ID is linked to cardiovascular disease and hypertension in offspring, and yet the impact of ID on the kidney is not known.  We characterized the impact of ID on circulating and tissue levels of iron and renal function.

Seven and ten week old male and female Wistar rats were fed either control (270ppm) or low iron (3ppm) diet for ten weeks.  Total, non-heme and heme iron levels in liver, kidney cortex and kidney medulla were measured following the dietary period.  Hematocrit decreased most in males regardless of age (Male 7-17wk: 47%→ 31%; 10-20wk: 47%→ 33.5%; Female 7-17wk: 47%→ 34%; 10-20wk: 47%→ 39%). Dietary ID markedly decreased liver and kidney cortex non-heme iron in both males and females (Female: liver-178±25 to 21±7 ppm; kidney cortex-51±9 ppm to 10±1 ppm;  Male: liver-102±18 ppm to 11±1 ppm; kidney cortex 36±14 to 15±8 ppm).  In contrast, non-heme iron in the kidney medulla was not significantly decreased

Secondly, in order to determine the impact of ID on renal function, blood pressure was monitored using radio-telemetry starting at six weeks of age (~175g body weight). Dietary salt challenge (5 days Low5 days HighNormal) was administered to all animals (n=16) starting at eight weeks of age.  At ten weeks rats were assigned to either control (225pm) or low (3ppm) iron diet.  Dietary salt challenge was repeated at 13 and 18 weeks of age respectively. Despite significant lowering of hematocrit (Control 45%  Low iron 38.6%) hemodynamic changes were minimal, in that, although blood pressure was lowered following ten weeks of dietary iron restriction, blood pressure did not change in response to dietary salt (Control MAP:105.0 ± 2.5mmHg; ID MAP:100.6 ± 3.2mmHg ).

 Collectively the tissue and functional analyses demonstrate that the body adapts to lowering of tissue iron supply with ID. The relative sparing of non-heme iron in the kidney medulla suggests that iron in this region of the kidney may be spared because of its importance in the systems responsible for regulating fluid and sodium balance.

abstract: M.Sc.


title: The complex classrooms of three award-winning Ontario high school physics teachers

contributor:
Klinger, Don A.
Education

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subject:
Physics
Complexity
Curriculum
Self-organization
Emergence
Science
High school
Secondary
Ontario
Canada

abstract: Thesis (Master, Education) -- Queen's University, 2007-07-18 13:48:42.481

abstract:
Complexity theory investigates complex systems and how parts of a system give rise to collective behaviours. My thesis focuses upon the nature of the complex systems emerging within the classrooms of three award-winning high school physics teachers in Ontario.
Using vignettes for each teacher and their classroom system, I have highlighted themes related to the emergence of collective behaviours. My interpretations found the first classroom collective agreeing to work towards academic excellence with the intention of achieving success in university. The second classroom collective was invested in relationship-building and used the resulting emphasis on teamwork and group-oriented learning to further physics understanding. The final classroom system was in the process of learning to grapple with discovering physics through following and contending with the results of their instincts. From a complex systems perspective, differences amongst teachers and students and different sets of interactions result in unique systems. Therefore, a single prescription for the emergence of certain collective behaviours is unlikely.
The journal/commentary format traces my changing understandings of complexity thinking in education and how those understandings made an impact on the way I approached and reflected upon the observations of the study. As such, the thesis also documents shifts in perspectives highlighting the tensions felt between reductionist and complexivist thinking. Ultimately, complexity thinking illuminated how important it was to consider the teacher as part of the system instead of separated from it. Further issues relating to complex emergence and physics education that lead to greater pedagogical awareness are discussed.

abstract: M.Ed.


title: Optimal design in regression and spline smoothing

contributor:
Levit, Boris
Mathematics and Statistics

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subject:
Non-parametric regression
Optimal design

abstract: Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2007-07-18 16:06:06.767

abstract:
This thesis represents an attempt to generalize the classical Theory of Optimal Design to  popular regression models, based on Rational and Spline approximations. The problem of finding optimal designs for such models can be reduced to solving certain minimax problems. Explicit solutions to such
problems can be obtained only in a few selected models, such as polynomial regression.

Even when an optimal design can be found, it has, from the point of view of modern nonparametric regression, certain drawbacks. For example, in the polynomial regression case, the optimal design crucially depends  on the degree m of approximating polynomial.
Hence, it can be used only when such degree is given/known in advance.

We present a partial, but practical, solution to this problem. Namely, the so-called Super Chebyshev Design has been found, which  does not depend on the degree m of the underlying
polynomial regression in a large range of m, and at the same time is asymptotically more than 90% efficient. Similar results are obtained in the case of rational regression, even though the exact form of optimal design in this case remains unknown.

Optimal Designs in the case of Spline Interpolation are also currently unknown. This problem, however, has a simple solution in the case of Cardinal Spline Interpolation. Until recently, this model has been practically unknown in modern nonparametric
regression. We demonstrate the usefulness of Cardinal Kernel Spline Estimates in nonparametric regression, by proving their
asymptotic optimality, in certain classes of smooth functions. In this way, we have found, for the first time, a theoretical justification of a well known empirical observation, by which cubic splines suffice, in most practical applications.

abstract: PhD


title: The direct and moderating effect of bullying on adolescent health

contributor:
Craig, Wendy M.
Psychology

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subject:
Bully
Victim
Adolescence
Health psychology
Aggression
Sexual activity
Dating violence
Physical activity

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2007-07-18 21:11:08.184

abstract: In the last two decades, research has established a negative association between involvement in bullying and emotional health difficulties.  Few studies, in comparison, explore the relationship between bullying and victimization and physical health.  Moreover, studies are lacking on the influence of bullying on health in adolescence.  Three studies were conducted to explore the association between bullying and adolescent positive and negative health behaviours.  Using an ecological model, we examined the influence of bullying and victimization on physical activity and health status, risky sexual behaviours and sexual coercion, and dating violence perpetration and victimization.  Each study explored how bullying influenced the relationship between environmental factors and adolescent health.  Results suggest that both bullying and victimization can have a negative influence on risky health behaviours.  As well, the findings suggest that relationships with adults may protect youth involved in bullying from negative health experiences.  These results support a model of co-occurring health behaviours in youth, including involvement in bullying.  Hence, we propose that teen health promotion programs target overall lifestyle choices rather than solely focusing on individual health behaviours.  As well, we recommend that bullying prevention programs need to address engagement in unhealthy habits during adolescence, while being sensitive to the complex relationship between environmental and bullying factors that can influence physical health in adolescence.

abstract: PhD


title: Data-driven estimation for Aalen's additive risk model

contributor:
Tu, Dongsheng
Takahara, Glen
Mathematics and Statistics

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subject:
Aalen's additive model
Bandwidth selection
Data-driven estimation
Event history analysis
Generalized cross-validation
l-curve
Ridge regression
Weighted least squares

abstract: Thesis (Master, Mathematics & Statistics) -- Queen's University, 2007-07-18 22:13:13.243

abstract: The proportional hazards model developed by Cox (1972) is by far the most widely used method for regression analysis of censored survival data. Application of the Cox model to more general event history data has become possible through extensions using counting process theory (e.g., Andersen and Borgan (1985), Therneau and Grambsch (2000)). With its development based entirely on counting processes, Aalen’s additive risk model offers a flexible, nonparametric alternative. Ordinary least squares, weighted least squares and ridge regression have been proposed in the literature as estimation schemes for Aalen’s model (Aalen (1989), Huffer and McKeague (1991), Aalen et al. (2004)). This thesis develops data-driven parameter selection criteria for the weighted least squares and ridge estimators. Using simulated survival data, these new methods are evaluated against existing approaches. A survey of the literature on the additive risk model and a demonstration of its application to real data sets are also provided.

abstract: M.Sc.


title: Responses of zooplankton community structure and ecosystem function to the invasion of an invertebrate predator, Bythotrephes longimanus

contributor:
Arnott, Shelley E.
Biology

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subject:
Zooplankton communities
Invasive species
Bythotrephes longimanus
Dispersal
Historic acidification
Ecosystem function
Freshwater lakes
Boreal shield

abstract: Thesis (Ph.D, Biology) -- Queen's University, 2007-07-19 14:56:57.102

abstract: Freshwater ecosystems face unprecedented levels of human-induced stresses and it is expected that the invasion of non-indigenous species will cause the greatest loss of biodiversity in lakes and rivers worldwide.  Bythotrephes longimanus is a predatory invertebrate that invaded North America in the early 1980s, first being detected in the Great Lakes, and then moving to a number of inland lakes in Ontario and the northern United States.  Using experimental and survey-based approaches, I tested several hypotheses concerning the effects of Bythotrephes on native zooplankton community structure and function.  My results indicate that Bythotrephes reduces total abundance, biomass, and richness of zooplankton, especially cladoceran taxa, throughout the ice-free season.  As a result of high predation pressure by the invader, total seasonal and epilimnetic zooplankton production was also substantially reduced in invaded lakes, which may have important consequences for the transfer of energy to fish and other taxa that feed on zooplankton.  Interestingly, there was some evidence that zooplankton shifted their reproduction in time and space to avoid Bythotrephes, which may buffer the effects of the invader on food web functioning.  Other measures of ecosystem function were relatively unaffected by the invasion of Bythotrephes.  In addition, Bythotrephes may interact in unexpected ways with other anthropogenic stressors, and act to slow down the process of recovery by preying on species that maintain community abundance during acidification, but also affecting species attempting to recolonize historically acidified lakes.  Although dispersal of zooplankton may maintain some of the ecosystem functions provided by zooplankton communities, loss of biodiversity may be a permanent result of invasion.  The effects of the continued spread of invasive species across the landscape may be profound, as the invader Bythotrephes has demonstrably altered zooplankton communities and may reduce the ability of freshwater ecosystems to respond to future environmental change and maintain ecosystem functioning.

abstract: PhD


title: Geodesic reduction via frame bundle geometry

contributor:
Lewis, Andrew D.
Mathematics and Statistics

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subject:
Frame bundle geometry
Affine connections
Reduction

abstract: Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2007-07-24 01:00:05.635

abstract:
Reduction theory for systems with symmetry deals with the problem of understanding dynamics on a manifold with an action of a Lie group.  In geometric mechanics, this problem can be formulated in the Lagrangian, Hamiltonian or affine connection frameworks. While the  Lagrangian and Hamiltonian formulations have been well developed, the results obtained in these setups are based on variational principles and symplectic geometry.  These methods cannot be used directly in the affine connection formulation unless additional structure is available.

In this thesis, a manifold with an arbitrary affine connection is considered, and the geodesic spray associated with the connection is studied in the presence of a Lie group action. In particular, results are obtained that provide insight into the structure of the reduced dynamics associated with the given invariant affine connection. The geometry of the frame bundle of the given manifold is used to provide an intrinsic description of the geodesic spray. A fundamental relationship between the geodesic spray, the tangent lift and the vertical lift of the symmetric product is obtained, which provides a key to understanding reduction in this formulation.

abstract: PhD


title: Nonparametric statistical procedures for therapeutic clinical trials with survival endpoints

contributor:
Tu, Dongsheng
Mathematics and Statistics

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subject:
Nonparametric statistics
Equivalence clinical trial
Time to event endpoint

abstract: Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2007-08-01 10:43:32.345

abstract:
This thesis proposed two nonparametric statistical tests, based on the Kolmogorov-Smirnov distance and L2 mallows disatnce.
To implement the proposed tests, nonparametric bootstrap method is employed to approximate the distributions of the test statistics to construct the corresponding bootstrap confidence interval procedures. Monte-Carlo simulations are performed to investigate the actual type I error of the proposed bootstrap procedures. It is found that the type I error of the bootstrap BC confidence interval procedure is close to the nominal level when censoring is not heavy and the boosttrap percentile confidence interval procedure works well when Kolmogorov-Smirnov distance is used to characterize the equivalence. When the data is heavily censored, the procedures based on the Kolmogorov-Smirnov distance have very conservative type I errors, while the procedures based on the Mallows distance are very liberal.

abstract: PhD


title: A numerical study of galaxy mass density profiles

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subject:
Astrophysics
Disk galaxies
Numerical simulations

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2007-07-30 14:46:24.568

abstract:
An understanding of the shape and nature of galaxy density profiles remains a major challenge to galaxy structure studies.  The physical mechanisms thought to control these profiles include star formation rates and dynamical interactions, but we focus in this thesis on the contribution of dynamical parameters associated with the dark and baryonic matter.  We follow the evolution of mass density profiles, and investigate the development of a truncation radius.  Using GADGET-2, an N-body/SPH code with a prescription for star formation and feedback, and the SHARCNET computational facilities, we have generated over 200 galaxy models covering a full range of structural parameters.  The galaxy models have a minimum of 1.4 million particles and most are evolved over a period of 10 Gyr.

We find that the evolution of the galaxy mass density profile is controlled by the ratio of the disk mass fraction, $m_{d}$, to the halo spin parameter, $\lambda$.  The strength of the two-component structure in disk profiles and speed at which this structure develops, is directly proportional to $m_{d}/\lambda$.  While the development of a two-component profile is coupled to bar formation, not all barred galaxies develop a two-component profile.

We also show that the slope of the outer profile is in close agreement with that of the initial profile and remains stable over time, whereas the inner profile slope evolves considerably.  This result will greatly improve comparisons of observed with predicted measures of galaxy density profiles.

Our galaxy database is the largest of its kind and a valuable resource for many potential galaxy structural studies.  We conclude with a list of future investigations based on our study and new database.

abstract: M.Sc.


title: Influence of Membrane-Damaging Agents and the Sigma Factor AlgU on the Induction of the MexCD-OprJ Efflux System of Pseudomonas Aeruginosa

contributor:
Poole, R. Keith
Microbiology and Immunology

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subject:
Efflux
Antibiotic Resistance
Pseudomonas Aeruginosa

abstract: Thesis (Master, Microbiology & Immunology) -- Queen's University, 2007-07-31 12:03:52.535

abstract: The MexCD-OprJ multidrug efflux pump of Pseudomonas aeruginosa confers resistance to a range of antimicrobials.  Although not expressed under normal laboratory conditions, exposure to the membrane-active biocides, chlorhexidine or benzalkonium chloride, results in mexCD-oprJ expression.  This suggests that membrane disruption provides the inducing signal.  Consistent with this, increased mexCD-oprJ expression was demonstrated in the presence of additional membrane-damaging agents including polymyxin B, ethanol, SDS, EDTA, the organic solvents n-hexane and p-xylene, and the antimicrobial peptides melittin, V8 and V681.  MexCD-OprJ expression was initially verified through increased resistance to known MexCD-OprJ antimicrobial substrates and subsequently using a mexC-lacZ transcriptional fusion and RT-PCR.  Since the P. aeruginosa sigma factor AlgU is responsive to envelope stress, it was of interest to ascertain whether AlgU is capable of mediating this increased mexCD-oprJ expression.  Thus, the impact of AlgU loss on mexCD-oprJ expression in response to membrane-damaging agents was assessed in a algU strain.  In contrast with above, little or no mexCD-oprJ expression (assessed using resistance to MexCD-OprJ antimicrobial substrates, the mexC-lacZ transcriptional fusion and RT-PCR) occurred in response to membrane-damaging agents in the algU strain, consistent with AlgU playing a role in the envelope stress inducibility of mexCD-oprJ.  Overall, envelope stress, and the ability to react to this stress through AlgU, appears to play an important role in mexCD-oprJ induction.  This suggests an important role for MexCD-OprJ in alleviating envelope stress, independent of its ability to export and provide resistance to antimicrobials.  A gene, PA4596, whose product shows substantial homology to the NfxB repressor of mexCD-oprJ expression, occurs downstream of mexCD-oprJ and shows AlgU-dependence and chlorhexidine inducibility, suggesting a role in the chlorhexidine-induced, AlgU-mediated expression of mexCD-oprJ.  Thus, the impact of PA4596 loss on mexCD-oprJ expression was assessed.  Paradoxically, the loss of PA4596 increases mexCD-oprJ expression in wild-type cells in response to chlorhexidine treatment (as assessed through RT-PCR), while its loss compromises mexCD-oprJ expression in an nfxB mutant.  Nonetheless, this suggests that PA4596 is involved in the induction of mexCD-oprJ and that its ability to induce mexCD-oprJ differs depending on the state of nfxB.

abstract: M.Sc.


title: Structural analysis of brittle deformation features along Grenvillian shear zones in southeastern Ontario

contributor: Geological Sciences and Geological Engineering

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subject: Neotectonics

abstract: Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2007-07-30 15:14:44.542

abstract: Brittle features along two prominent shear zones in the Grenville Province of southeastern Ontario, the Central Metasedimentary Belt boundary thrust zone (CMBbtz) and Robertson Lake mylonite zone (RLmz), are investigated to understand the brittle deformation history of this intraplate region. Evolution of brittle deformation is interpreted from detailed mapping and characterization of joint, fault and vein patterns in Proterozoic basement rocks, Paleozoic cover rocks and Pleistocene sediments. Relationships among joint and fault orientations and maximum-horizontal stress directions associated with major tectonic events suggest a history of repeated stages of deformation along the CMBbtz and RLmz. Neoproterozoic-Cambrian opening of the Iapetus Ocean is interpreted to have produced NNE-striking Proterozoic structural highs in Paleozoic cover above the RLmz. Normal faults striking NW to WNW and ESE-striking dextral strike-slip faults in the RLmz and Paleozoic cover above both shear zones are compatible with Ordovician-Devonian Taconic and Acadian stresses. Prominent NNE- and NW-striking subvertical joint sets along the RLmz, CMBbtz and Paleozoic cover above the CMBbtz are compatible with Late Carboniferous to Permian Alleghanian stresses. Brittle features attributed to Mesozoic opening of the Atlantic Ocean are numerous and include: NNE-, ENE-, NW- and WNW-striking subvertical joint sets, WNW-striking normal faults, and NNE-striking normal faults in Paleozoic cover above the RLmz; NNW-striking dextral strike-slip faults and NW-striking normal faults in the RLmz; N- and NW-striking normal faults in Paleozoic cover above the CMBbtz; and, E- and SSW-striking normal faults in the CMBbtz. Joint sets in Pleistocene sediments above the CMBbtz and RLmz (oriented NNE, NW, NE, NNW and ENE) are compatible with both Pleistocene post-glacial flexural stress and the current in-situ stress. Strike-slip faults oriented SSW and W in the CMBbtz and a NNW-striking reverse fault in the RLmz are compatible with the current regional stress field. Further understanding of this neotectonic deformation is relevant to assess the seismic risk in the intraplate region of southern Ontario.

abstract: M.A.Sc.


title: Synthesis and photoluminescent properties of linear and starburst compounds based on benzimidazole, 2-(2'-pyridyl)benzimidazole and 2,2'-dipyridylamine

contributor:
Wang, Suning
Chemistry

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subject:
Inorganic Chemistry
Organic Light Emitting Diodes

abstract: Thesis (Master, Chemistry) -- Queen's University, 2007-07-31 12:17:06.011

abstract:
The objective of this thesis was to explore the chemistry of series of linear and star shaped compounds based on benzimidazolyl, 2-(2’-pyridyl)benzimidazolyl, and 2,2’-dipyridylamino functional groups.  These groups all possess Lewis base sites suitable for metal coordination, and are all known fluorophores.
	The first compounds to be presented are the homo-substituted benzimidazolyl derivatives.  Compounds 2.1-2.5 have been fully characterized and are all luminescent with emission energies in the UV region.  While coordination complexes with these ligands have not been isolated, the effect of metal ion complexation on ligand luminescence has been explored via metal ion titration experiments.  Furthermore, these compounds all have electron affinities greater than -3.0 eV and large optical bandgaps that range between 3.55 and 3.95 eV.  These compounds also have high thermal and morphological stability.  In light of this, compound 2.3 was selected as a representative example, and further characterized as an electron transport/hole blocking material for OLED applications.  It has demonstrated a performance comparable to that of the well known electron transport material Alq3 (q = 8-hydroxyquinolinate).
	The second class of compounds, 3.2 and 3.3, represent a pair of hetero-substituted ligands with two different binding sites available for coordination chemistry.  A copper (I) complex of 3.3 has been isolated and exhibits orange phosphorescence at room temperature and at 77 K.  Furthermore, a series of metal titration experiments have been performed on 3.3 and 3.4, and have demonstrated the preference of different metal ions for either the 2,2’-dipyridylamino site, or the 2-(2’-pyridyl)benzimidazolyl binding site.  The details of these explorations will be presented in the subsequent chapters.

abstract: M.Sc.


title: The dimensionality and construct valid measurement of life meaning

contributor:
Holden, Ronald R.
Psychology

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subject:
Life meaning
Meaning in life
Scale construction
Measurement
Personality
Assessment
Positive psychology

abstract: Thesis (Ph.D, Psychology) -- Queen's University, 2007-08-14 13:59:44.903

abstract: This research sought to clarify the construct of life meaning by creating a new, multidimensional measure of life meaning. In an initial study, 392 university undergraduates (317 women, 75 men) completed several existing life meaning measures. Exploratory factor analytic procedures undertaken on the item responses supported the extraction of 10 factors: Achievement, Framework/Purpose, Religion, Death Acceptance, Interpersonal Satisfaction, Fulfillment/Excitement, Giving to the World, Existential Vacuum, Intimacy, and Control. Of the original 170 items, the 64 items with the highest factor loadings were retained, and together comprise the Multidimensional Life Meaning Scale (MLMS). Higher-order exploratory factor analyses yielded three factors: Personal Efficacy, Self-Transcendence, and Fulfillment. A second study, conducted with an independent sample of undergraduate students (N = 262; 200 women, 62 men), provided mixed support for the factor structure of the MLMS at the item level, but replicated the higher-order factor structure revealed in the initial study. The criterion-related (concurrent and discriminant) validity was also examined in the second study, by factor analyzing the MLMS factors along with criterion subscales thought to be related to life meaning, and support was found for 7 of the 10 first-order factors. In a final study, support was found for the existence of group differences that were hypothesized on the basis of rational links to interpreted higher-order dimensions of life meaning. In accordance with predictions, Theology students (n = 28) reported higher levels of Self-Transcendence and depressed students (n = 31) indicated lower levels of Fulfillment compared to a baseline group of undergraduate students (n = 262). Contrary to expectations, Law/Business students (n =35) were not significantly different from the baseline group on  Personal Efficacy. Based on the results of these three studies, it is concluded that the life meaning construct is multidimensional. The Multidimensional Life Meaning Scale is a promising measure of the construct, and the inclusion of both lower-order and higher-order factors is a new way of conceptualizing life meaning.

abstract: PhD


title: The effectiveness of the recovery workbook as a psychoeducation intervention for facilitating recovery in persons with serious mental illness

contributor:
Krupa, Terry
Rehabilitation Science

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subject:
Recovery
Mental health

abstract: Thesis (Master, Rehabilitation Science) -- Queen's University, 2007-08-01 11:55:02.924

abstract: Objective: In this study, the effectiveness of the modified Recovery Workbook as a psychoeducational tool for facilitating recovery in persons with serious mental illness was examined. Methods: The study was a multi-center, prospective, single-blinded, randomized controlled trial. A total of 33 people receiving Assertive Community Treatment (ACT) services participated in the study. For 12 weeks, a control group continued receiving their usual treatment as determined by the ACT team, and an intervention group received the Recovery Workbook training in addition to the normal standard of care from the ACT team. Groups were compared using t-tests for continuous measures and chi-squared analyses with correction for continuity of dichotomous measures, as appropriate. The overall effects of the Recovery Workbook Training on individuals’ perceived level of hope, empowerment, knowledge, and quality of life were measured using a repeated measures analysis of variance (ANOVA). Team (PCCC-MHS/Frontenac) and group (experimental/control) were the between-subject factors, and time of testing (initial, final) was the within subject factor.  Results: Participation in the Recovery Workbook was associated with significant change in participants’ perceived sense of hope, empowerment, and goal and success orientation. These associations remained significant when commensurate demographic variables were controlled for. Conclusions:  This study is the first randomized controlled trial of a recovery-based psychoeducational intervention in persons with serious mental illness, and opens a new chapter of evidence-based practice for implementing recovery in mental health service delivery.

abstract: M.Sc.


title: Fabrication and DC characterization of single electron transistors at low temperature

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subject:
Single electron transistor
Low temperature

abstract: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2007-08-01 14:07:55.427

abstract:
The metallic single electron transistor (SET) has been shown to provide charge sensitivity on the order of 10-6 e/(Hz)1/2, when operated as a charge amplifier. This makes it an ideal candidate for low-noise measurement schemes, such as monitoring nano-mechanical oscillations, or reading out the charge state of a quantum bit. The SET operates by exploiting quantum tunneling across an ‘island’ between two insulating tunnel junctions, and can be modulated by a capacitively coupled gate electrode.
A metallic SET has been fabricated and characterized at low frequencies. The device was fabricated on a silicon substrate coated with a bi-layer resist, using electron beam lithography. The Al-AlOx¬-Al tunnel junctions were created using double angle evaporation. Samples were tested near 300 mK in a custom helium-3 cryostat system. Results which characterize the SET parameters and conductance behaviour were obtained, in both the superconducting and normal states.
This thesis contains a discussion of the fabrication procedures and dc measurement techniques required to produce and test a single electron transistor. Relevant background theory relating to SET operation and cryogenic laboratory techniques is presented. A brief discussion of proposed future experiments using a dual gate radio frequency SET as a more sensitive amplifier is introduced.

abstract: M.Sc.


title: Assessing the spatial and temporal patterns of total mercury δ 15N and δ13C in yellow perch and their prey items from a contaminated site, St. Lawrence River, Cornwall, ON

contributor:
Hodson, Peter
Campbell, Linda M.
Biology

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subject:
Yellow Perch
Prey Items
Mercury
St. Lawrence River
Stable Isotopes of Nitrogen
Stable Isotopes of Carbon

abstract: Thesis (Master, Biology) -- Queen's University, 2007-08-02 08:02:40.26

abstract: As a result of the legacy of industrial contamination over the last century, areas of sediment deposition in the St. Lawrence River at Cornwall, ON, contain high concentrations of mercury (Hg). The popular sport-fish species, yellow perch (Perca flavescens) and walleye (Sander vitreus) have been found to contain mercury concentrations exceeding Ontario Ministry of Environment consumption guidelines. Interestingly, a paradox exists between two contaminated sites – despite elevated sediment Hg concentrations at Zone 2, fish from Zone 1 contain higher Hg concentrations. Further research has indicated that these patterns of Hg were not attributed to growth rate, condition factor, diet composition, or trophic position of yellow perch. Rather, Hg concentrations in yellow perch may be described by the heterogeneity of prey contamination and fish bioenergetics. As a result of the paradox between total Hg (THg) concentrations in sediments and biota between two contaminated sites, it was necessary to examine the benthic invertebrate community and how it may transfer Hg from sediments to yellow perch. This apparent paradox now extends to all prey items, since prey items from the stomach contents of yellow perch caught in Zone 1 were significantly more contaminated than those of Zone 2. Use of δ15N and δ13C, measures of trophic position and energy source, respectively, indicated that prey selection, but not food chain length, may also be an important factor in explaining the variation in Hg burdens in yellow perch. Small-scale patterns of biomagnification, as shown by a comparison of δ15N and logTHg, indicated that the rates of biomagnification were similar among zones, but the amount of THg present at the base of the food web was twice as high at Zone 1 as at other contaminated sites. Overall, the relative importance of vertical and horizontal food web structure changed spatially and temporally, highly influencing THg concentrations of prey items and yellow perch.

abstract: M.Sc.


title: Phytoextraction of lead from contaminated soil by Panicum virgatum L. (switchgrass) and associated growth responses

contributor:
Wood, Susan
Newcomb, William
Biology

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subject: Phytoextractions Switchgrass

abstract: Thesis (Master, Biology) -- Queen's University, 2007-08-02 11:34:42.469

abstract: Growing interest in biomass crops for energy production has focused attention on Panicum virgatum L. (switchgrass) as a promising perennial feedstock native to much of North America. Switchgrass may be processed into products such as pulp and paper, ethanol, and fuel pellets. A robust C4 grass, switchgrass typically produces 10-12 dry tonnes/ha on agricultural soils in average growing conditions; this study shows that reduced but substantive yields are also possible on soils rendered unsuitable for food crop production by lead contamination over the acceptable level of 70 ppm. Switchgrass offers not only tolerance to lead in the soil environment, but also the potential for extraction of lead contaminants. Integrating the growth of switchgrass for biomass with phytoremediation could provide greater opportunity for biomass production, while eventually increasing the suitability of such lands for agricultural production. This study examines the potential for using switchgrass to remove lead from the soil and to translocate the contaminant to the leafy portions of the plant, where it could be removed from the site through biomass harvest. Roots of plants treated with 6000 and 10000 ppm lead solution from the time of seeding displayed some morphological changes and growth inhibition, yet, produced biomass comparable to expected yields and removed up to 0.1% of the applied lead solution. Established switchgrass displayed few morphological changes and no significant loss of biomass when treated with lead acetate solution while extracting lead into harvestable tissues. As the primary root is the organ through which water, solutes and heavy metals pass into the plant, the dense, fibrous root system of switchgrass may aid in the ability of this plant to extract contaminants from soil without significantly hindering above ground biomass production. Switchgrass grown on brownfield soil, with contamination levels of up to 23600 ppm translocated lead into harvestable tissues without significant changes in biomass production or growth characteristics. However, symptoms of phytotoxicity were observed in switchgrass grown on soil containing 36100 ppm lead. Atomic absorption spectrometry and inductively coupled plasma analyses indicate that lead accumulation in harvestable tissues of switchgrass occurs at rates comparable to those in previous studies. The presence of dark staining deposits, detected by light microscopy in the root and shoot tissue of switchgrass treated with high concentrations of applied lead (13800, 10000), suggests an adaptive response within the plant. Successful integration of phytoremediation with growth of biomass crops such as switchgrass may provide effective reclamation of contaminated soils, while contributing to a sustainable energy economy.

abstract: M.Sc.


title: The impact of information processing goals and capacity restrictions on attitude-memory

contributor:
Fabrigar, Leandre R.
Psychology

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subject: Attitude-memory

abstract: Thesis (Master, Psychology) -- Queen's University, 2007-08-02 17:42:47.148

abstract: Researchers have long presumed that attitudes play a role in information processing, affecting memory in an attitude-consistent manner. This is known as congeniality.  This presumption was largely dismissed as a result of a large scale, comprehensive meta-analysis (Eagly et al., 1999).  The current project proposed that the conditions under which congeniality was tested in the past were not conducive for eliciting these effects.  The present research tests cognitive capacity restrictions and salient information processing goals as moderators of the effects of attitude on memory in a 3 (Information Processing Goal: Attitude Expressive vs. Alternative Perspective Taking vs. No Goal) X 2 (Time Restriction: Restricted vs. Unrestricted) X 3 (Issue: Eating Red Meat vs. Marijuana Use vs. Playing Contact Sports) design. Participants were given a specific processing goal and were presented with issue-relevant information at either a restricted or unrestricted time interval.  After a delay, they were presented with recall and recognition tasks.  Results indicated that goals moderated the effects of attitudes on the favorability of correct recall such that memory tended to be biased in the same direction as the goal.  Experiment 2 expanded this research by including a second session 48 hours later which served as a second testing phase for memory.  Again, during the first session, information processing goals were found to moderate the effects of attitude on the favorability of correct recall. Interestingly, the second session failed to find these effects, but instead found weak evidence of global congeniality regardless of goal condition.  The implications of these findings are discussed.

abstract: M.Sc.


title: A new generic maximum-likelihood metric expression for space-time block codes with applications to decoding

contributor:
Yousefi, Shahram
Electrical and Computer Engineering

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subject:
Electrical engineering
Communications

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-08-13 11:13:01.504

abstract: Space-time block coding is a technique used to exploit diversity in a multiple-input multiple-output (MIMO) environment. Orthogonal space-time block codes (OSTBCs) are desirable because they can achieve full transmit diversity while maintaining a simple low-complexity maximum-likelihood (ML) decoding algorithm. However, OSTBCs are limited in their error performance. This has led to the development of more general linear space-time block codes, such as quasi-orthogonal space-time block codes (QOSTBCs). QOSTBCs offer better error performance, but their decoding complexity is a concern since it is no longer a linear function of the number of transmitted symbols. In this thesis, a new vectorization for linear STBCs is proposed that explicitly maintains the redundancy in the STBC transmission matrix. By expressing the ML metric using the new vectorization, a new generic representation of the ML metric expression for a linear STBC is derived. One immediate application of this new metric expression is the convenient partial decoupling and simplification of the detection metric for linear STBCs. The new metric expression can also be used as a design tool to help in the construction of new STBCs with low decoding complexity. As an example, a new QOSTBC is constructed that has lower decoding complexity than one previously proposed in the literature of equal rate and diversity. A comparison is conducted to answer the following question: for the family of QOSTBCs, when is it best to perform an exhaustive search using a metric expression that is simplified and decoupled as much as possible, and when should an efficient implementation of the sphere decoding algorithm be applied? Determining this boundary is an important and practical issue not yet directly addressed in the literature. The new metric expression can also be used as the framework for a new family of sub-optimal decoding algorithms for STBCs that trade-off error performance for a reduction in decoding complexity. A practical example of such an algorithm is given as an example.

abstract: M.Sc.


title: Directed ortho metalation-boronation Suzuki-Miyaura cross coupling leading to synthesis of azafluorenol core liquid crystals

contributor:
Snieckus, Victor A.
Lemieux, Robert P.
Chemistry

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subject:
Azafluorenol synthesis
Chemistry

abstract: Thesis (Master, Chemistry) -- Queen's University, 2007-08-03 21:35:28.017

abstract:
The synthesis of chiral fluorenol crystal materials employing directed ortho metalation (DoM) combined with directed remote metalation (DreM) and Suzuki-Miyauara Coupling was previously reported by McCubbin, Snieckus and Lemieux.ref?  This study reported that certain fluorenol derivatives form a chiral smectic C phase (SmC*) with a spontaneous polarization (Ps) that is amplified by intermolecular hydrogen bonding. Dilution and deuterium exchange experiments suggest that antiparallel hydrogen bonded dimer formation increases the rotational bias about the director that is thought to induce the Ps.needs definition The research reported in this thesis is concernded with an investigation on the effects of hydrogen bonds on the Ps of the liquid crystal by the variation of core structure, particularly the substitution of one aryl ring to pyridinyl ring.
An efficient synthesis of liquid crystals (LC) 1.14 and 2.22 by Directed ortho Metalation-boronation, Suzuki-Miyaura Cross Coupling reaction accompanied with Directed remote metalation was achieved. Compound 1.14 was found to be not useful as a LC material because it was unstable in the air and underwent rapid oxidation to give 2.22 upon heating. Thus, this project was focused on the preliminary study on mesophase characterization of 1.14 and 2.22. The results (Table 2.3) show both 1.14 and 2.22 formed SmC phases, but only 1.14 showed smectic A (SmA) mesophase and only 2.22 showed nematic (N) mesophase cooling from isotropic liquid phase. The increase in temperature range of smectic phases for the azafluorenol 1.14 is expected because intermolecular hydrogen bonding between the hydroxyl group and aza group as shown by Figure 1.21 may play a role to stabilize the formation of smectic (Sm) phase.

abstract: M.Sc.


title: Climate and environmental change inferred from diatom communities in Lake Challa (Kenya-Tanzania)

contributor:
Cumming, Brian F.
Biology

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subject:
Lake Challa
Paleoclimatology

abstract: Thesis (Master, Biology) -- Queen's University, 2007-08-06 18:22:25.157

abstract:
Lake Challa is a 5 km2, 97m deep freshwater crater lake located at 880m elevation on the southeast slope of Mount Kilimanjaro (Kenya-Tanzania). Information gained from a preliminary limnological survey of Lake Challa, presented here, will give insight into tropical limnological processes as well as aid in the paleoclimatological interpretation of a 25,000-yr diatom record. The survey, which included depth profiles of temperature, oxygen, pH and specific conductance, as well as epilithic and surface sediment diatom samples, revealed that Lake Challa is a meromictic lake which presently has at least 30 diatom species.
A 22m sediment core, recovered in 2005, has well-preserved diatoms throughout its length. Diatom species assemblages were dominated by Nitzschia sp. 1 and Gomphocymbella sp. 1, for which the taxonomy is uncertain, and therefore general ecological characteristics were used in the data interpretation. An increase in Gomphocymbella sp. 1 may reflect an increase in the amount of benthic habitat and therefore lower lake levels. Diatom productivity may increase during periods of high precipitation and runoff which increases the total nutrient concentration, and high Nitzschia sp. 1 concentrations occur when input water has high Si:P ratios (warm, wet climate).
Analysis of the diatom record suggests that Lake Challa experienced fluctuating intermediate lake levels from 25-21 thousand years before present (ka BP), low lake levels from 21-14.5 ka BP, sustained high lake levels from 14.5-11 ka BP, and high-intermediate lake levels from 11-5 ka BP but with short-term recessions at 10.6-11, 8.5 and 6.6 ka BP. After 5 ka BP, levels remained fairly stable, with a gradual decrease in lake level beginning at ~4 ka BP culminating at ~1.8 ka BP. Inferred climate changes from Lake Challa generally agree with other records in the area.
Continuous sedimentary records from lakes in equatorial regions on which to base paleoclimatic reconstructions are rare. In conjunction with other biological and geochemical paleoproxy indicators, this high-resolution diatom record will help us better understand climate-driven environmental change in the vicinity of Mount Kilimanjaro, site of the only African ice-core record.

abstract: M.Sc.


title: Cucurbit[n]uril host-guest complexes: the effects of inclusion on the chemical reactivity and spectroscopic properties of aromatic guest molecules

contributor:
Macartney, Donal H.
Chemistry

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Cucurbit[n]uril
Host-guest self-assembly

abstract: Thesis (Ph.D, Chemistry) -- Queen's University, 2007-08-07 09:21:06.553

abstract:
This thesis deals primarily with supramolecular chemistry based on cucurbit[n]uril (CB[n], n = 7 and 8) host molecules.  The research has been focused on the synthesis and characterization of host-guest complexes CB[n] with aromatic guest molecules, and the study of the effects of the host-guest complexation on the chemical reactivity and spectroscopic properties of the included guests, such as their photoreactivity and their UV-visible absorption and emission properties, in aqueous solution.
The [4+4] photodimerization of protonated 2-aminopyridine (APH+) occurs stereoselectively to give the anti-trans product as the result of a preferred orientation of two APH+ guests in the cavity of CB[7].  The CB[7] host inhibits photohydration in the course of the photoisomerizations of protonated trans-1,2-bis(4-pyridyl)ethylene and trans-1,2-bis(1-methyl-4-pyridinium)ethylene by including the (4-pyridyl)ethylene portion of the guest, while this is not observed with trans-1,2-bis(1-hexyl-4-pyridinium)ethylene, as preferential inclusion of the hexyl groups leaves the vinyl group vulnerable to photohydration.  Very strong CB[7] complexation of (E)-1-ferrocenyl-2-(1-methyl-4-pyridinium)ethylene completely inhibits the (E)→(Z) photoisomerization process.
The H/D exchange rates and acidities of the C(2)-proton of cationic imidazolium and thiazolium (including thiamine and thiamine phosphates) carbon acids are decreased upon their complexation with CB[7].  Inclusion of protonated aromatic amines (and aromatic alcohols) in the cavity CB[7] significantly decreases their ground and excited state acidities, such that the emission is switched from the neutral amine to the protonated amine excited state, resulting in changes in the color of fluorescence.  The fluorescence of acridizinium cations can be switched off by the formation of 2:1 complexes with CB[8] and then switched back on again by the addition of CB[7] or a competing guest molecule.
The stabilization of the deep blue color of the 4,4’-bis(dimethylamino)diphenyl carbonium ion, upon complexation of the corresponding carbinol with CB[7], results from a complexation-induced shift in the carbinol/carbonium ion equilibrium.  A dramatic purple to blue color change in pinacyanol chloride upon addition of CB[7] is due to a partial breakup of dye aggregates, upon the interactions of the dye with the host molecule.  The CB[n] complexation-induced emission and/or absorption color switch have the potential to be employed in molecular switches and in chemical sensing.

abstract: PhD


title: SQL Query Disassembler: An Approach to Managing the Execution of Large SQL Queries

contributor:
Martin, Patrick
Computing

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subject:
DB2
Database Performance
Database Workload Management

abstract: Thesis (Master, Computing) -- Queen's University, 2007-09-17 22:05:05.304

abstract:
In this thesis, we present an approach to managing the execution of large queries
that involves the decomposition of large queries into an equivalent set of smaller queries and then scheduling the smaller queries so that the work is accomplished with less impact on other queries. We describe a prototype implementation of our approach for IBM DB2™ and present a set of experiments to evaluate the effectiveness of the approach.

abstract: M.Sc.


title: The strength of a knitted home: retrieving histories through Janet Morton's wool installations

contributor:
Jessup, Lynda
Lord, Susan
Art History

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subject:
Art
Craft
Social history
Women
Feminism
Artists
Knitting
Architecture
Homeless
Urban cultural geography
Space
Gender

abstract: Thesis (Master, Art History) -- Queen's University, 2007-08-07 15:32:00.667

abstract: This thesis focuses on the ways in which Janet Morton’s installations explore geographic and architectural spatial arrangements, and the ways in which these arrangements reproduce hierarchies of gender, race, and class.  As cultural geographers and architectural historians have argued, and as I argue in the context of Morton’s work, architecture and geography exist in a reciprocal relationship with the social context in which they exist. Consequently, social histories that amass in politicized spaces referred to as “home,” such as gendered suburban houses, urban shelters, segregated neighbourhoods, are often marginalized.  By discussing the way Morton’s work alludes to marginalized social and spatial histories within home environments, I demonstrate the ways that mainstream understanding of the subordination of marginalized groups is informed by sociospatial histories.

abstract: M.A.


title: Delivery of hydrophobic substrates to degrading organisms in two-phase partitioning bioreactors

contributor:
Daugulis, Andrew J.
Chemical Engineering

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subject:
Biodegradation
Polychlorinated biphenyls
PCBs
Bioavailability
Two-phase partitioning bioreactor
Ex-situ bioremediation
Burkholderia xenovorans LB400
Biochemical engineering
Solid-liquid TPPB
Polymers
Microbial consortia
Microbial kinetics
Hydrophobic compounds
Microbial kinetics

abstract: Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2007-08-07 16:11:00.494

abstract:
This thesis examined the use of two-phase partitioning bioreactors (TPPBs) for the biodegradation of poorly water-soluble compounds. TPPBs are stirred tank bioreactors composed of a biocatalyst-containing aqueous phase and an immiscible second phase containing large amounts of poorly water-soluble or toxic substrates. Degradation of the bioavailable substrate in the aqueous phase will result in equilibrium-driven partitioning of additional substrate from the immiscible phase into the aqueous phase, theoretically allowing for complete substrate degradation.
 Fundamental work was undertaken with the PCB-degrading organisms Burkholderia xenovorans LB400 in liquid-liquid and solid-liquid TPPBs. Initially biphenyl was used as the sole carbon source due to its hydrophobic nature and structural similarity to the environmentally relevant PCBs. The critical LogKO/W (octanol/water partitioning coefficient) of the organism was determined to be 5.5 and its growth kinetics on biphenyl were determined in a liquid-liquid TPPB. A polymer selection strategy for solid-liquid TPPBs was developed in the next chapter, and it was shown in the following chapter that biphenyl degradation in solid-liquid TPPBs was mass transfer limited, as described mathematically utilising the previously estimated microbial kinetics.
The fundamental knowledge gained in the early chapters was then applied to the degradation of PCBs by the same organism. It was shown that the aqueous phase availability of PCBs is the rate-limiting step in biphasic bioreactors, and not the mass transfer rate. The low specific microbial degradation rates, resulting from substrate-limited growth were addressed with increased biomass concentrations; however, it was also found that an additional carbon source was required to maintain microbial activity over an extended period of time. Pyruvic acid was selected as a carbon source which, once added to actively PCB-degrading cells, maintained the cells’ activity towards PCBs and up to 85 % of 100 mg l-1 was degraded in 15 h.
It was shown as the final contribution in this thesis that TPPBs can be combined with a PCB soil extraction step as a potential remediation scheme for PCB contaminated soil. PCBs were extracted from soil with polymer beads (up to 75 % removal), followed by biodegradation of the PCBs in a solid-liquid TPPB in which PCBs were delivered to the degrading organism from the same polymer.

abstract: PhD


title: Visual and olfactory sensory systems employed by monarch butterflies (Danaus plexippus) to locate their milkweed host plants

contributor:
Frost, Barrie J.
Neuroscience Studies

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subject:
Monarch Butterfly
Vision
Olfaction
Flight choice apparatus

abstract: Thesis (Master, Neuroscience Studies) -- Queen's University, 2007-08-09 12:22:17.691

abstract: Monarch butterflies (Danaus plexippus) are well known to depend almost exclusively on milkweed (genus Asclepias) host plants for oviposition sites, as their larvae need to ingest compounds critical for adult butterfly chemical defense against predators.  Many phytophagous insects make fast and accurate decisions on the quality of host plants, and whether or not to accept them as oviposition sites.  We were interested in the cues that attract monarchs (males and females) to milkweed, while in flight, before contact stimulation can occur.  We developed a novel flight apparatus to test monarch attraction behaviour, under a number of different experimental protocols, to both milkweed and control stimuli in order to identify the cues necessary or sufficient for monarch attraction to milkweed.  Monarchs were found to be attracted to milkweed stimuli when the visual image alone of milkweed was available or when olfactory cues alone were available.  Attraction behaviour was maximized when both cues were available.  It was also discovered that attraction to milkweed was significantly diminished when ultraviolet reflection from milkweed leaves was prevented from being detected by monarchs in flight.

abstract: M.Sc.


title: The effect of nurse-coordinated telecare intervention on depressed mood and diabetes-related stress among community-dwelling older adults with type 2 diabetes mellitus in Southeastern Ontario

contributor:
Buchanan, Diane
Nursing

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subject:
Nurse telecare
Depression
Diabetes-related stress

abstract: Thesis (Master, Nursing) -- Queen's University, 2007-08-08 14:30:24.945

abstract: The purpose of the study was to examine the effects of nurse-coordinated telephone monitoring among community-dwelling older adults with type 2 diabetes. In a randomized controlled trial 28 participants (aged 65-84yrs) with type 2 diabetes living in Southeastern Ontario were randomly assigned to an intervention group (15) and control group (13). The intervention group received weekly nurse-coordinated telephone monitoring and the control group received usual care from their family doctor.  The main outcome measures were depression and diabetes-related stress as measured by measured by the Geriatric Depression Scale (GDS) and the Problem Areas In Diabetes (PAID) questionnaire at baseline and 12-weeks. All participants completed the study. At 12 weeks, mean scores for the intervention group were significantly lower for the GDS (p = .00) and the PAID (p = .03). Participants were receptive to the intervention. Nurse telephone monitoring may decrease depressive symptoms and diabetes-related stress among community-dwelling older adults.

abstract: MNSc.


title: Neural networks for transmission over nonlinear MIMO channels

contributor:
Ibnkahla, Mohamed
Electrical and Computer Engineering

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subject:
Neural networks
Nonlinear MIMO channels

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-08-08 14:55:50.489

abstract:
Multiple-Input Multiple-Output (MIMO) systems have gained an enormous amount of attention as one of the most promising research areas in wireless communications. However, while MIMO systems have been extensively explored over the past decade, few schemes acknowledge the nonlinearity caused by the use of high power amplifiers (HPAs) in the communication chain. When HPAs operate near their saturation points, nonlinear distortions are introduced in the transmitted signals, and the resulting MIMO channel will be nonlinear. The nonlinear distortion is further exacerbated by the fading caused by the propagation channel.
The goal of this thesis is: 1) to use neural networks (NNs) to model and identify nonlinear MIMO channels; and 2) to employ the proposed NN model in designing efficient detection techniques for these types of MIMO channels.
In the first part of the thesis, we follow a previous work on modeling and identification of nonlinear MIMO channels, where it has been shown that a proposed block-oriented NN scheme allows not only good identification of the overall MIMO input-output transfer function but also good characterization of each component of the system. The proposed scheme employs an ordinary gradient descent based algorithm to update the NN weights during the learning process and it assumes only real-valued inputs. In this thesis, natural gradient (NG) descent is used for training the NN. Moreover, we derive an improved variation of the previously proposed NN scheme to avoid the input type restriction and allow for complex modulated inputs as well. We also investigate the scheme tracking capabilities of time-varying nonlinear MIMO channels. Simulation results show that NG descent learning significantly outperforms the ordinary gradient descent in terms of convergence speed, mean squared error (MSE) performance, and nonlinearity approximation. Moreover, the NG descent based NN provides better tracking capabilities than the previously proposed NN.
The second part of the thesis focuses on signal detection. We propose a receiver that employs the neural network channel estimator (NNCE) proposed in part one, and uses the Zero-Forcing Vertical Bell Laboratories Layered Space-Time (ZF V-BLAST) detection algorithm to retrieve the transmitted signals. Computer simulations show that in slow time-varying environments the performance of our receiver is close to the ideal V-BLAST receiver in which the channel is perfectly known. We also present a NN based linearization technique for HPAs, which takes advantage of the channel information provided by the NNCE. Such linearization technique can be used for adaptive data predistortion at the transmitter side or adaptive nonlinear equalization at the receiver side. Simulation results show that, when higher modulation schemes (>16-QAM) are used, the nonlinear distortion caused by the use of HPAs is greatly minimized by our proposed NN predistorter and the performance of the communication system is significantly improved.

abstract: M.Sc.


title: Modeling and evaluation of multi-core multithreading processor architectures in SystemC

contributor:
Sudharsanan, Subramania
Manjikian, Naraig
Electrical and Computer Engineering

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subject: SystemC CMT Processors

abstract: Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-08-09 11:45:46.749

abstract:
Processor design has evolved over the years to take advantage of new
technology and innovative concepts in order to improve performance.
Diminishing returns for improvements based on current techniques
such as exploiting instruction-level parallelism have caused
designers to shift their focus. Rather then focusing on
single-threaded architectures, designers have increasingly sought to
improve system performance and increase overall throughput by
exploiting thread-level parallelism through multithreaded multi-core
architectures.

Software modeling and simulation are common techniques used to aid
hardware design. Through simulation, different architectures can be
explored and verified before hardware is actually built. An
appropriate choice for the level of abstraction can reduce the
complexity and the time required to create and simulate software
models.

The first contribution of this thesis is a transaction-level
simulation model of a multithreaded multi-core processor.  The
transaction level is a high level of abstraction that hides
computational details from the designer allowing key architectural
elements to be quickly explored. The processor model that has been
implemented for this thesis is flexible and can be used to explore
various designs by simulating different processor and cache
configurations. The processor model is written in SystemC, which is
a standard design and verification language that is built on C++ and
that can be used to model hardware systems.

The second contribution of this thesis is the development of an
application model that seeks to characterize the behavior of
instruction execution and data accesses in a program. An
application's instruction trace can be profiled to produce a model
that can be used to generate a synthetic trace with similar
characteristics. The synthetic trace can then be used in place of
large trace files to drive the SystemC-based processor model. The
application model can also produce various workload scenarios for
multiprocessor simulation.

From experimentation, various processor configurations and different
workload scenarios were simulated to explore the potential benefits
of a multi-core multithreaded processor architecture. Performance
increased with diminishing returns with additional multi-core
multithreading support. However, these improvement were limited by
the utilization of the shared bus.

abstract: M.Sc.


title: I'm still learning: the lived experience of disengagement from school of five young aboriginal women

contributor:
Lewis, Magda Gere
Education

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subject:
Aboriginal
Education
Engagement
Secondary schooling
Drop outs
Identity
Academic self-image
School reform

abstract: Thesis (Master, Education) -- Queen's University, 2007-08-09 15:48:56.987

abstract:
This study sought to understand the lived experience of disengagement from formal schooling of five young Aboriginal women in a mid-Northern community.
	Using the qualitative methodology of narrative inquiry, and through a series of guided open-ended interviews, this research explored each participant’s experiences as a learner; informally and in school.
	Analysis of the personal histories of learning shared by the participants enabled the identification of attributes of best-remembered learning experiences and also elements that contributed to marginalization and dis-continuing of school.
	Key elements for each learner clustered around relationship and connectedness. Contexts of optimal learning as revealed in the narratives can be characterized as authentic, situated, experiential, guided, and often culturally-relevant. Marginalization and dis-continuing of school were related to: a sense of emotional insecurity in the school, the need for community and a sense of belonging, disrespectful treatment and relational bullying by teachers and/or peers, administrative policy related to placement and psycho-social needs, and restrictive curricular decisions. The participants’ desire to learn and continuing pursuit of learning goals, although out of school, is expressed in the title of this thesis by Participant A as she speaks for all in saying, “I’m still learning” (PA#1, p. 3).
	Recommendations for formal schooling are made based on the needs and preferences expressed by the participants and by the institutional circumstances revealed in the narratives that affected engagement and dis-engagement.

abstract: M.Ed.


title: All-optical 3R regeneration for agile all-photonic networks

contributor:
Cartledge, John C.
Electrical and Computer Engineering

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subject: Fiber-optics Regeneration

abstract: Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2007-08-09 16:31:25.462

abstract:
Transmission impairments degrade the quality of optical signals, ultimately limiting the achievable transmission distance. Optical 3R regenerators provide an effective means of coping with transmission impairments by restoring the quality of optical signals through reamplification, reshaping, and retiming (3Rs), thereby enabling reliable transmission over long distances.  Beyond the 3Rs, however, regenerators must also be able to operate within the practical constraints of the network. The specific network of interest in this thesis is referred to as an agile all-photonic network (AAPN).

In AAPNs, traffic consists of optical packets that are routed through the core of the network without undergoing optical-to-electrical conversion for signal processing (e.g., 3R regeneration). As a result, 3R regeneration must be performed all-optically, otherwise known as all-optical 3R regeneration (AO-3R). Although a variety of AO-3R techniques have been demonstrated, none have been specifically designed to operate within the practical constraints of AAPNs.

In this thesis, a 10 Gb/s all-optical 3R regeneration (AO-3R) technique is proposed, specifically designed to operate within the practical constraints of AAPNs.  The technique performs AO-3R in a novel 2-stage design. In the first stage, all-optical retiming is achieved using a self-pulsating distributed feedback laser (SP-DFBL) for all-optical clock recovery and cross-phase modulation (XPM) in highly nonlinear fiber (HNLF) with offset spectral slicing for the retiming. In the second stage, all-optical reshaping (and reamplification) is achieved using self-phase modulation (SPM) in HNLF with offset spectral slicing.

Experimental assessment of the AO-3R system performance yields excellent results. In particular, AO-3R is shown to improve the performance of input signals degraded by transmission impairments, such as amplified spontaneous emission (ASE) noise, while providing low sensitivity to input signal properties, such as the state-of-polarization. Furthermore, AO-3R is shown to successfully achieve its ultimate goal for AAPNs – the regeneration of optical packets.

abstract: PhD