title: Understanding STI AND HIV Testing Rates among Higher Risk University Students

contributor: Department of Community Health & Epidemiology

contributor: Dr. Donald Langille & Dr. Audrey Steenbeek

subject:
STI Testing
HIV Testing

abstract: Individuals of university age have the highest rates of diagnosed sexually transmitted infection (STI) and are at high risk of human immunodeficiency virus (HIV) acquisition. STI and HIV testing services are free and readily available to most university students in Canada, however, only some individuals choose to access them. Using data from a cross-sectional survey of eight Maritime Canadian universities, we determined that 62% of vaginally sexually active undergraduate students have never had an STI test and 85% have never been tested for HIV. Across groups stratified by biological sex and risk of STI acquisition, younger students with less sexual health knowledge were significantly less likely to be tested for STI and younger, heterosexual students were significantly less likely to be tested for HIV. Health promotion may be most effective at increasing overall lifetime STI and HIV testing when targeting younger students with campaigns designed to improve sexual health knowledge.


title: Seaweed Amendments for Reduction of Damping off Caused by Pythium ultimum

contributor:
Faculty of Agriculture
Master of Science
Dr. Stephen O'Leary
Dr. Dian Patterson
Dr. Kris Pruski
Dr. Nathan Boyd
Dr. Balakrishnan Prithiviraj
Not Applicable
Not Applicable
Not Applicable

abstract: Pythium ultimum is an oomycete which causes serious economic losses in greenhouses by causing damping off disease. Ascophyllum nodosum is known to act as a nutrient supplement and its application has shown to reduce diseases caused by microbial pathogens in plants. However, its byproduct, one that is left after the extraction, has not been tested for the same. In vitro antimicrobial assay showed that higher concentration of Ascophyllum nodosum byproduct (ABP) significantly increased Pythium ultimum growth. Its PGPR (Plant Growth Promoting Rhizobacteria - Bacillus subtilis, Pseudomonas putida and Penicillium) digested growth media amendment even at higher concentrations (3% w/w) showed significantly improved growth of cucumber seedlings as compared to the undigested ABP of same concentration, in in vivo experiments although not significantly different from control. Digested and undigested ABP did not show significant reduction in damping off caused by Pythium ultimum, and hence there was no significant increase in biochemical compounds and defence enzymes in cucumber leaf tissues as compared to the control. Further research is needed to determine the compounds present in the ABP, which can lead to a more targeted approach in utilizing it as an elicitor.


title: Thermodynamic Calculation of Multicomponent Phase Compositions

contributor: Department of Process Engineering and Applied Science

contributor: Dr. Gianfranco Mazzanti, Dr. Alejandro Marangoni

subject: Thermodynamic Tiracylglcerols Multicomponent

abstract:
Food industry scientists need to predict multicomponent solid fat compositions because
fat solid solutions define food texture and physical properties.
Experiments were conducted with two multicomponent fats of known composition to
determine solid fraction (via NMR), phase fraction, polymorphic form (via XRD) and
thermal melting profile (via DSC). A database including melting temperature and
enthalpy was digitized. Wesdorp’s methodology, implemented in MATLAB, was used to
estimate the equilibrium mole fractions of each phase. The program estimates melting
temperatures and enthalpies absent from the database, and estimates interaction
parameters for a 2-suffix Margules model. These parameters were used to find the
composition at equilibrium for each phase. The estimated overall melting enthalpy of the
mixtures was compared to the value obtained by DSC.
The predicted temperature values using Wesdorp’s coefficients were unsatisfactory;
hence an alternative approach was developed. The estimated overall melting enthalpies
agreed well with the experimental enthalpies.


title: Trelawny Maroon, the Colour of Freedom: Re-conceptualizing Subjecthood in the Eighteenth-Century British Atlantic

contributor:
Department of History
Master of Arts
Dr. Colin Mitchell
Dr. Justin Roberts
Dr. Krista Kesselring
Dr. Jerry Bannister
Dr. Justin Roberts
Not Applicable
Not Applicable
Not Applicable

subject:
Trelawny Maroons
Maroons
subjecthood
British Atlantic
kinship
loyalty
race

abstract: The Trelawny Maroons in Jamaica rebelled in 1795-96, and were temporarily removed to Halifax, Nova Scotia before being settled in Sierra Leone. This thesis starts by challenging current scholarly literature, which emphasizes rebellion against slavery as their motivation, by highlighting the Maroons’ role as slave captors, who benefited financially and socially by cooperating with, and not rebelling against, the British in Jamaica. An examination of how their kinship networks changed follows to underscore that, while they retained their cultural maroon identity, they increasingly adopted British social practices and customs to publicly confirm their loyalty and commitment as British subjects. Finally, by highlighting the close relationship that the Maroons had with the British, as well as the extent to which they were involved in colonial governance and took advantage of the British legal and political systems, themes of collaboration and acquiescence are emphasized as the keys to understanding the Maroons’ experiences.


title: Arrian's Events After Alexander in Photius

contributor:
Department of Classics
Master of Arts
Dr. Eli Diamond
Dr. Emily Varto
Dr. Peter O'Brien
Dr. Jack Mitchell
Not Applicable
Not Applicable
Not Applicable

subject: Hellenistic Historiography Greek Fragments Arrian Photius Bibliotheca Byzantine

abstract: This study seeks to examine Photius' 9th-century summary of Arrian's Events After Alexander. The original work, which no longer survives, records the early history of the successors to Alexander's empire. While Photius' summary preserves some important details of the history, the unique context in which the summary is found (part of a collection of 280 summaries written by Photius, known as the Bibliotheca) means that a unique approach must be used when attempting to reconstruct Arrian's original work, or when comparing it to other surviving accounts of the period following Alexander's death. By examining and comparing other historical summaries found in the Bibliotheca, it will be shown that Photius' summaries are often extremely accurate at some points, but that they do not preserve the form or development of the summarized work, and focus on a diplomatic view of history indicative of Photius' Byzantine tastes.


title: Exploring the Sensorimotor Network Using Functional Connectivity and Graph Theory

contributor: Dr. Shaun Boe and Dr. Timothy Bardouille

subject:
magnetoencephalography
functional connectivity
visuomotor
graph theory

abstract:
Background: Performing a motor task activates the sensorimotor network. Functional connectivity (FC) analysis can determine connections between distinct neural regions of a network. Graph theory can then be applied to quantify the network’s connections. Establishing the network in non-disabled participants can be used as a comparator in future neuroimaging research. Purpose: To determine the sensorimotor network in a group of non-disabled participants. Methods: Nineteen participants were scanned using magnetoencephalography while they performed a unilateral upper-limb visuomotor task. FC was compared between rest and task conditions to determine significant connections during task only. These connections were quantified using graph theory.
Results: FC significantly increased between 118 node pairs during the task state compared to rest. Graph theory quantitatively highlighted 40 nodes as important, including regions of the pre-established sensorimotor network (contralateral primary motor and somatosensory cortex among others).  This network can be used as a template for comparison in future studies.


title: USING TIME SERIES AND MULTIVARIATE TECHNIQUES TO ANALYZE CHANGES IN THE OCEAN NITROGEN CYCLE THROUGHOUT HISTORY

contributor: Department of Mathematics & Statistics - Statistics Division

abstract:
Nitrogen is a limiting resource in marine ecosystems that directly impacts the productivity
of marine life. Values of δ15N extracted from down core sediments are used
as a proxy measure of nitrogen in past marine environments. We analyzed historic
δ15N records from around the world, covering time periods that ranged 125,000 to
5000 years ago. The Kalman smoother was used to extract the true signal of δ15N
from the noisy observations. Applying multivariate techniques, we found both global
and regional signals of δ15N. From the principal components analysis we found global
signals characterized by sharp increases in δ15N values that began 60,000 and 20,000
years ago. Using k-means clustering, we identified cores with statistically similar
δ15N signals that were in close geographical proximity. These findings suggest that
there may be both global and regional forcing of the marine nitrogen cycle.


title: Supervised Non-negative Matrix Factorization for Analysis of Microbiome Data

subject:
Microbiome Data
NMF

abstract: Non-Negative Matrix Factorization (NMF) is a very useful tool to reduce dimension of data in machine learning and data mining. But it is an unsupervised learning method. To extract more discriminant information in the training data and improve the performance of classification, we developed a new supervised NMF method. We combine feature matrices from different classes as the feature matrix for the whole data and fit a non-negative Poisson regression to calculate the weight matrix. Our method is tested on the animal dataset and moving picture dataset. The experimental results show that our supervised NMF could greatly enhance the performance of NMF for classification.


title: ZEBRAFISH XENOTRANSPLANTATION AS A PRECLINICAL THERAPEUTIC PLATFORM FOR T-CELL ACUTE LYMPHOBLASTIC LEUKEMIA

contributor:
Department of Pathology
Master of Science
David Anderson
Wenda Greer
Paola Marcato
Conrad Fernandez
Graham Dellaire and Jason Berman
Received
Not Applicable
Not Applicable

subject:
Zebrafish
Leukemia
Pediatric cancer
Animal models of cancer
Acute lymphoblastic leukemia
Xenotransplantation
Drug screening

abstract: Pediatric T-cell Acute Lymphoblastic leukemia (T-ALL) is a high-risk disease. There is a need for targeted therapies for T-ALL, and techniques to rapidly screen drug candidates and personalize patient therapy. I developed a zebrafish xenotransplantation (XT) model to screen novel agents for efficacy and toxicity. I demonstrated that T-ALL cell lines recapitulate in vitro responses to targeted therapies in vivo. Importantly, patient-derived lymphoblasts engraft in zebrafish and specific drug responses can be quantitatively determined. I identified a mutation sensitive to γ-secretase inhibition in a xenograft from a child with T-cell acute lymphoblastic leukemia, confirmed by Sanger sequencing and validated as a gain-of-function NOTCH1 mutation. Furthermore, I employed the zebrafish XT assay to determine the efficacy of two novel compounds to protect against doxorubicin-induced cardiac damage. The zebrafish XT platform provides a novel cost-effective means of screening novel agents, and tailoring leukemia therapy in real-time to maximize efficacy and minimize toxicity.


title: Non-Consensual Sex and Risk of Depression in Female Undergraduates at Universities in Maritime Canada

contributor: Dr. Don Langille and Dr. Audrey Steenbeek

subject:
Sexual Health
Mental Health
University
College
Sexual Victimization
Depression
Rape
Non-consensual sex

abstract: Sexual victimization and depression are common among female undergraduate students. There is little research on the prevalence of and relationship between victimization and depression in the context of Canadian undergraduate populations. The current study uses cross sectional data to determine the prevalence of being a victim of non-consensual sex and being at risk of depression among female undergraduate students attending Maritime Canadian universities, the factors associated with risk of depression and being victim of non-consensual sex, and the independent association between non-consensual sex and risk of depression. Results indicated that 36.7% of female students are at risk of depression and 6.8% have been sexually victimized while attending university. Factors associated with risk of depression and non-consensual sex included substance abuse and risky sexual behaviours. After adjusting for covariates, females that were victimized were 2.11 times more likely to be at risk of depression than females who were not victimized (p<.0001).


title: “Ohnmöglich können wir ihm hierin recht geben…” – DAS ANTIARISTOTELISCHE IN DER DRAMENTHEORIE VON J.M.R. LENZ. PROBLEMATIK DES DICHTUNGS-UND GESCHICHTSBEGRIFFS IN DEN  WERKEN VON ARISTOTELES UND LENZ.

contributor:
Department of German
Master of Arts
Prof. Dr. Hans- Günther Schwarz
Dr. Fritz Heuer
Prof. Dr. Gertrud Maria Rösch
Prof. Dr. Hans- Günther Schwarz
Not Applicable
Not Applicable
Not Applicable

subject: Aristoteles, Poetik, J.M.R. Lenz, Anmerkungen übers Theater, Der neue Menoza, Dramentheorie, Dichter, Geschichtsschreiber

abstract: Die Arbeit thematisiert, basierend auf den Texten Poetik von Aristoteles und An-merkungen übers Theaters von J.M.R. Lenz die Problematik des Historiker- und Dich-terbegriffs sowie das Anti-Aristotelische bei Lenz. Er benennt die Natur, die Wirklich-keit, als Inspirationsquelle für sein künstlerisches, literarisches Schaffen und leitet darauf aufbauend seine Forderungen nach freihandelnden Menschen ab. Dies steht im Gegen-satz zur griechischen Denkweise- so stellt sich Lenz gegen das französische Theater und folglich auch gegen jede Art der Reglementierung innerhalb seiner Werke. Lenz bedenkt in seinen Werken die gesellschaftlichen Umstände und macht sie sichtbar. Ausgehend davon entwickelt Lenz seine Dramenkonzeption- antithetisch zu Aristoteles- welche im neuen Menoza untersucht wird. Im Gegensatz zu Aristoteles wertet er die Aufgabe des Dichters gleichwohl als Darsteller der Wirklichkeit. So entwirft er eine poetische Wirk-lichkeit, in der sich zeitgenössische Ereignisse widerspiegeln- und die Aufgaben des Dichters und Geschichtsschreibers sind nicht mehr eindeutig zu trennen.

abstract: Based on Aristotle’s Poetics and J.M.R. Lenz‘ Anmerkungen übers Theater, this thesis deals with the problematic concept of historians and poets and Lenz’ anti-Aristotelian views. As sources of inspiration for his work, Lenz sites nature and reality from which he derives his demands for characters acting freely. This theory is in contrast to ancient Greek thought and Lenz is a strong opponent of French theater and subse-quently of any type of regulation in his works. In his works Lenz addresses the condition of society and attempts to visualize this. On this basis Lenz develops his theory of drama which is antithetical to Aristotle’s and is discussed in Der neue Menoza. For Lenz, the poet’s task is to depict reality, in contrast to the Aristotelian view. He designs a poetic reality combined with historic facts. As a result, the line between the historian and that of the poet is blurred.


title: PRIMARY HUMAN MAST CELL ANTIVIRAL AND PRO-INFLAMMATORY RESPONSES TO RESPIRATORY SYNCYTIAL VIRUS (RSV)

contributor:
Medical Sciences
Master of Science
Dr. Craig McCormick
Dr. Jason Berman
Dr. Robert Anderson
Dr. Scott Halperin
Dr. Thomas Issekutz
Dr. Jean Marshall
Received
Not Applicable
Not Applicable

subject:
RESPIRATORY SYNCYTIAL VIRUS
MAST CELL

abstract:
Respiratory syncytial virus (RSV) is a major cause of infant bronchiolitis and the leading cause of their hospitalization worldwide. It is also linked to airway hyper-responsiveness. Mast cells are essential in allergies and the immune response to pathogens, and can produce various mediators that influence vascularity, bronchoconstriction, and immune cell recruitment to sites of infection. Since mast cells are abundant in the airways at the site of RSV infection, we examined the human mast cell response to RSV in vitro and the role type I interferons, major antiviral cytokines, play in such a response.
Our data show that human mast cells responded to restricted RSV infection by producing pro-inflammatory chemokines and cytokines some of which were dependent on type I IFN response (CXCL10 and CCL4), while others were not (CCL5 and VEGF-A). Mast cell production of these mediators may enhance inflammation and effector cell recruitment during RSV disease.


title: WEED SEED PREDATION BY CARABID BEETLES AND CRICKETS FOR BIOLOGICAL CONTROL OF WEEDS IN WILD BLUEBERRY FIELDS

contributor:
Faculty of Agriculture
Master of Science
David McCorquodale
Dian Patterson
A. R. Olson
Vilis Nams
Chris Cutler
Not Applicable
Not Applicable
Not Applicable

subject:
Carabid Beetles
Weed  seed predation
Crickets
Biological control
Pesticides
Wild Blueberry

abstract: Weeds are a major pest problem of wild blueberry.  Granivorous insects may consume weed seeds, contributing to pest control.  In the laboratory, the ground beetle Harpalus rufipes and field cricket Gryllus pennsylvanicus consumed a significant number of seeds of sheep sorrel and hairy fescue, two important weeds of wild blueberry.  In a prey vs. seed preference experiment, H. rufipes preferred aphids over sheep sorrel seeds.  Field experiments also found considerable weed seed granivory by invertebrate herbivores.  There was generally no effect of distance from field edge and type of field (“crop” or “vegetative”) on the weed seed granivory.  In experiments with insecticides used in blueberry production, H. rufipes was highly susceptible to field rates of phosmet (Imidan) and acetamiprid (Assail) by topical exposure and ingestion of treated seeds, whereas no mortality was seen with spirotetramat (Movento).


title: Getting to the Core of the Matter: A historical materialist study of the apple industry in Nova Scotia, 1605-1980

subject:
Agricultural failure
Apple industry
Nova Scotia
Food regime theory
Historical materialism

abstract: The story of the apple in Nova Scotia between 1605 and 1980 shows how agriculture shapes our world, and our relationship to that world. This paper reviews the failure of the apple industry, and provides insights on how to go forward. Agricultural failure, defined as a large contraction in production, is as traumatic for a rural area as a major plant shutdown is for an urban area. Although agricultural failure may coincide with unexpected weather or environmental conditions, careful examination usually reveals broader structural problems at its root. This is certainly the case with the collapse of the Nova Scotia apple industry after World War II. Therefore, this paper asks the question: Why did the industry fail, despite significant geographic advantages and a promising early history? The apple was a formative and integral part of this province’s development. As such, when guided by a historical materialist methodology, the apple opens a broader discussion of historical developments, structures of power, and the human-nature relationship in Nova Scotia. This paper concludes with a discussion about positive options for the Nova Scotia apple industry based on a different set of values, a new approach to world markets, and a more sustainable relationship with nature.


title: Selecting and assessing quantitative early ultrasonic texture measures for their association with cerebral palsy.

subject: Engineering, Biomedical.

subject: Engineering, Electronics and Electrical.

subject: Health Sciences, Radiology.

abstract: Preterm infants are susceptible to white matter damage (WMD), which is associated with cerebral palsy (CP) and cognitive impairment. Ultrasound (US) is the preferred imaging modality to detect WMD but suffers from poor sensitivity and specificity in the early postnatal period. To improve on existing diagnostic rates, quantitative measures incorporating new information are needed. Ultrasound texture measures have been shown to reveal diagnostic information about human tissue. In this research, unique texture measures are extracted using adaptive preprocessing and high-resolution feature enhancement. The clinical diagnosis of CP presently is made at 12 to 18 months. As it is desirable to detect the disease in its early stage, clinical B-mode images taken within days of birth are used in this research.

abstract: In this study, the images are not standardized but use the patient as his or her own control. Speckle is not removed as speckle may contain information. To test the hypothesis that ultrasonic texture in these early images are associated with patient outcome, a model using only texture measures is created and evaluated. The "Random Forest" algorithm is used to form the model. The design of the texture measures and the selection of the variables are performed with a data set distinct from the set used for design and evaluation of the model. The resulting model has an accuracy of 72.5%. Random noise would provide a model with 50% accuracy, and designating all patients as having CP would result in 54% accuracy. This result suggests that early quantitative texture measures contain diagnostic information relevant to patient white matter health.

abstract: Thesis (Ph.D.)--Dalhousie University (Canada), 2006.


title: Middle Proterozoic evolution of the Parry Sound domain, southwestern Grenville Orogen, Ontario:  Structural, metamorphic, uranium/lead, and argon-40/argon-39 constraints.

subject: Geology

abstract: The Parry Sound domain (PSD) is an allochthon of quite different character to adjacent rocks in the Central Gneiss Belt, southwestern Grenville orogen, Ontario. Three distinct tectonostratigraphic units are recognized in the domain: the Parry Island and Twelve Mile Bay thrust sheets are dominated by upper amphibolite facies supracrustal rocks with subordinate plutonic rocks, whereas the overlying Parry Sound thrust sheet comprises mostly granulite facies plutonic rocks with lesser supracrustal rocks. The pre-Grenvillian history of the Parry Island and Twelve Mile Bay thrust sheets involved deposition of sedimentary detritus after ca. 1385 Ma, anorthositic to granitic magmatism between ca. 1350 and 1290 Ma, and granodiorite-tonalite magmatism in the period ca. 1312-1288 Ma. Sedimentation in the overlying Parry Sound thrust sheet predated intrusion of ca. 1294-1279 Ma tonalitic plutons.

abstract: The Grenvillian history of the PSD was primarily marked by several distinct episodes of deformation and metamorphism. The earliest episode involved high-PT granulite facies metamorphism of Parry Sound thrust sheet rocks which shortly predated northwestward thrusting at ca. 1159-1157 Ma. In turn, ca. 1163-1151 Ma anorthosite and mafic dyke emplacement, intermediate-PT granulite facies metamorphism, and orogen-parallel extension in the Parry Island thrust sheet occurred penecontemporaneously with early thrusting. Rocks from the bottom part of the Parry Island thrust sheet record a second northwestward thrusting event at ca. 1120 Ma which may have closely coincided with high-PT metamorphism. Large-scale erosion, as recorded by detrital zircon ages from post-ca. 1120-1140 Ma synorogenic sediments, may have led to thrusting and rapid exhumation of PSD rocks. At ca. 1080-1075 Ma, PSD rocks were reheated, possibly in response to major reactivation of the structurally higher Central Metasedimentary Belt boundary thrust zone. Finally, the deepest structural level rocks of the PSD were exhumed in the footwall of a shear zone developed within a ca. 1020-970 Ma episode of late extension.

abstract: The pre- and early Grenvillian history (between ca. 1400 and 1120 Ma) of the PSD is strikingly similar to that described from the Central Metasedimentary Belt, suggesting that the latter represents the source region of the Parry Sound allochthon.

abstract: Thesis (Ph.D.)--Dalhousie University (Canada), 1994.


title: Controls on Westphalian peat accumulation: The Springhill Coalfield, Nova Scotia.

subject: Geology. Paleoecology.

abstract: During the early Westphalian (Early to Middle Pennsylvanian), tropical peatlands (mires) flourished along the southern margin of the intermontane Cumberland Basin in the area of the present day Springhill coalfield. The resulting bituminous coal seams and associated sideritic mudrocks and multistorey channel sandstone bodies (Springhill Mines Formation) lie basinward of, and progressively onlap, alluvial fan conglomerates (Polly Brook Formation) derived from the adjacent Cobequid Highlands. Within the basin-fill sequence, coals occur in association with grey mudrock and multistorey sandstones (cyclothems, 20-30 m thick). These strata are constrained within a 600 m-thick "coal window" within the fining and reddening upward basin-fill sequence (2-5 km thick). The Springhill coals, up to 4.3 m thick and spanning a transverse distance of 5 to 8 km, exhibit a distance areal zonation. The piedmont zone is marked by ill sorted partings attributed to distal alluvial fan sheetfloods. The inner mire zone contains few inorganic partings and is lowest in ash and sulphur. The riverine zone is characterized by splits which locally entomb sandstone bodies of basin-axis rivers.

abstract: The precursors to the Springhill coals were rheotrophic (flow fed) peatlands, fed by nutrient-rich groundwater emanating from the fans. Evidence includes the consistent relation between coals and basin-margin conglomerates, the incursion into the mires of distal fan sheetfloods, trends in lithotype and maceral composition of the coals, especially gelification of vitrinite macerals, and the domination of mire flora by arboreous lycopsids suited to areas of nutrient-rich groundwater influx. The rheotrophic mires, and their reliance on fan discharge, indirectly suggest a sub-humid tropical paleoclimate.

abstract: A number of controls interacted to influence the development of the peat-forming ecosystems. Tectonism exerted a major control at the basin-fill sequence level (10$\sp6$ yr.) through both extremely rapid subsidence and orogenesis. The resulting alluvial fans discharged nutrient-rich groundwater supply which in modern sub-humid settings is crucial to the maintenance of wetlands in drier periods. The degree to which tectonism influenced mire development through groundwater discharge was therefore linked inextricably to the prevailing climate. Progressive denudation of the Cobequid Highlands probably resulted in a decreased catchment area, orographic rainshadow and fan size and may have contributed to the progressive decline in peat accumulation. The coal window within the basin-fill sequence is inferred to reflect a coincidence of optimal groundwater supply and net subsidence. Cyclothems indicate that conditions favouring peat accumulation recurred with a cyclicity in the order of 10$\sp4$yr. The similar timeframe of Milankovitch cycles of obliquity and precession suggest that climatic or related (eustasy, geoid) change was influential in cyclothem and mire development.

abstract: Thesis (Ph.D.)--Dalhousie University (Canada), 1991.


title: FREE-RANGING MARINE MAMMALS: THE NEXT ACOUSTIC SHIPS OF OPPORTUNITY?

contributor:
Department of Biology
Master of Science
Dr. Hal Whitehead
Prof. Mike Dowd
Dr. Joanna Mills Flemming
Dr. Sara Iverson
Received
Yes
Yes

subject:
Grey Seal
Biotelemetry
Acoustics
Animal Movement
Ships of Opportunity
Telemetry

abstract: Understanding the nature of species interactions in the ocean is challenging because direct observation is usually impossible. The deployment of dual transmitting and receiving acoustic transceivers and satellite-linked GPS tags on mobile marine predators provides a unique opportunity to resolve species associations in space and time. However, an approach for how best to analyze and draw biological inferences from these data is lacking. I evaluated the detection efficiency of acoustic transceivers deployed on grey seals (Halichoerus grypus) in 2010 off Sable Island in response to changing field conditions using generalized linear models (GLM) applied to post-processed detection data and summarized raw transceiver data. Distance between seals, wind stress, and depth were the most important predictors of detection efficiency. Access to the raw acoustic transceiver data greatly improved our ability to identify legitimate periods of silence when the receiver recorded no part of an acoustic transmission. I demonstrated how the non-parametric Lagrangian method, T-LoCoH, may be applied to GPS location data to characterize pat- terns in the individual and collective movement of instrumented grey seals and account for uneven sampling effort. Consistent patterns in collective area-use emerged that may relate to seasonal energy requirements and prey distribution. At the individual-level, T-LoCoH can be used to identify behavioural patterns and to calculate the transmission reception per unit sampling effort (TPUE) using time and space-use metrics. This thesis represents a first step towards analyzing acoustic data collected by mobile marine animals. My findings highlight the importance of understanding the factors influencing tag performance and the biological processes driving animal movement in order to draw accurate biological inferences. In addition, these findings demonstrate effective approaches that may be used to quantify and account for changes in detection efficiency and uneven sampling effort.


title: INTERACTIVE TERM SUPERVISED TEXT DOCUMENT CLUSTERING

contributor:
Faculty of Computer Science
Doctor of Philosophy
Dr. Carlotta Domeniconi
Dr. Evangelos Milios
Dr. Stan Matwin
Dr. Vlado Keselj
Dr. Evangelos Milios
Dr. Dirk Arnold
Not Applicable
Not Applicable
Not Applicable

subject:
Text clustering
Wikipedia
Double clustering
Ensemble clustering
User-supervised clustering

abstract:
Text document clustering has broad applications in practice. For instance, a conference
chair should place accepted papers into meaningful sessions. Students writing a thesis,
or professors writing a proposal or planning a reading course need to organize their
reference papers. Organizing documents into folders on a personal computer, or
grouping emails into multiple inboxes are other instances of document clustering.
Unsupervised document clustering algorithms require no user effort, but the obtained
partitionings may be far from what the user intended to generate. User-supervised
clustering algorithms involve the user in the clustering process and let her decide
on the numb er and topics of document clusters. Generating useful clusters with
minimum user effort is the main challenge in this mode. To address this challenge,
we propose a user-supervised clustering algorithm, designed in three stages. First,
we design a novel unsupervised clustering algorithm that can b e easily extended into
a user-supervised algorithm, thanks to its double clustering approach. We evaluate
its performance against state-of-the-art clustering algorithms in unsupervised mode.
We also extend this algorithm into an ensemble algorithm to incorporate Wikipedia
concepts in document representation. We demonstrate that the integration can improve
the quality of document clusters even though representing documents by Wikipedia
concepts solely, may result in inferior clusterings to bag of words representation.
Second, we propose three user-supervised versions for our clusterer based on term
supervision (in the form of term labeling), document supervision, and dual supervision.
We then demonstrate that with a comparable amount of simulated user effort, our
proposed term labeling is more effective than a baseline term selection method. Third,
we propose a graphical interface to support our term-supervised clusterer in interaction
with human users. We then conduct a user study to evaluate the interface and its
underlying clusterer. Analyzing the participants’ opinions and comments reveals the
usefulness of the proposed term-supervised clustering algorithm.


title: OCCUPATIONAL WELL-BEING AND BURNOUT IN PERSONAL SUPPORT WORKERS WORKING LONG TERM CARE FACILITIES

contributor:
School of Occupational Therapy
Master of Science
Dr. Ruth Martin Misener
Dr. Robin Stadnyk
Dr. Robin Stadnyk
Dr. Grace Warner
Received
Not Applicable
Not Applicable

subject:
Occupational well-being
Burnout
Personal Support Workers
Long Term Care Facilities

abstract: Personal Support Workers (PSWs) who work in nursing homes may be at risk of developing burnout; however, those PSWs who meet their occupational needs may have a decreased risk. This study was designed to examine the relation between burnout and occupational well-being in a sample of PSWs working in nursing homes. PSWs working in two nursing homes were recruited to complete the Maslach Burnout Inventory (MBI) and the Occupational Well-Being Questionnaire (OWBQ) (N=20). The MBI generates three subscale scores, that is, Emotional Exhaustion (EE), Depersonalization (DP), and Personal Accomplishment (PA). Persons with higher levels of burnout are expected to score higher on the EE and DP subscales and lower on the PA subscale. Rasch analysis was used to convert participant ordinal responses to the OWBQ into equal interval linear occupational well-being measures (in logits). A moderate inverse association was found between participants’ OWB measures and their MBI EE subscale scores (r=-0.41, p=0.07) whereas only a low inverse association (r=-0.37, p=0.11) and a low positive association (r=0.25, p=0.30) was found between participants’ OWB measures and their MBI DP and PA subscales respectively. Participants’ years of work experience were also moderately related to their MBI EE subscale scores (r=0.48, p=0.04). The findings of this study provide some evidence that there may be an association between the degree to which individuals are able to meet their occupational needs and the experience of burnout at work; however, further studies with larger samples using mixed methods are needed.


title: DEVELOPMENT OF A RAPID ATP ANALYSIS METHOD: BIOMASS GROWTH ATP METHOD FOR UV DISINFECTION MONITORING IN WASTEWATER TREATMENT

contributor:
Department of Environmental Engineering
Master of Applied Science
Hany El Naggar
Margaret Walsh
Lisbeth Truelstrup Hansen
Graham Gagnon
Not Applicable
Not Applicable
Not Applicable

abstract:
Adenosine triphosphate (ATP) analysis is gaining popularity as a robust method to quantify microbial content in water supplies and wastewater treatment processes. ATP testing provides cost effective microbial analysis results in a matter of minutes in the laboratory or the field. A challenge with ATP monitoring is that an Ultraviolet (UV) dose sufficient to cause a significant reduction in culturability yields little to no reduction in ATP. To date, few studies have been conducted to investigate the possible techniques that enable the application of ATP assays in assessing the effectiveness of UV disinfection.

The objective of this study was to develop a pre-treatment technique prior to ATP assay that can detect differences in cellular ATP (cATP) between pre and post UV treated wastewater in a single shift (<8hrs) to improve compliance monitoring and disinfection performance. The research approach involved incubating both untreated and irradiated samples in a suitable growth environment to accelerate bacterial growth prior to ATP analysis. The treatment efficacy was determined by the disparity in increase of cATP growth.

A robust Biomass Growth ATP Method (optimum chemical reagent, optimum incubation temperature, 4 hours) has been developed to test UV disinfection efficacy in municipal wastewater treatment. The response of the method indicated a significant direct correlation to the microbial population reduction observed in HPC method (R2A agar, 28℃, 7days) for both pure E. coli culture and secondary effluent. The Biomass Growth ATP Method was then tested in field samples from three wastewater treatment plants (WWTPs) to validate its practicality. The result that Biomass Growth ATP Method could detect a 1-2-order of magnitude of microbial inactivation implied a prospective application of this new method in WWTPs with high microbial loading rates to evaluate UV disinfection performance.


title: MITIGATING IMPACTS OF NEW FOREST ACCESS ROADS ON WATER LEVELS IN FORESTED WETLANDS: ARE CROSS-DRAINS ENOUGH?

contributor: School of Resource & Environmental Studies

subject:
Road
Forested Wetland
Best Management Practice
Culvert

abstract: New forest access roads are routinely constructed across sections of forested wetland in Canada’s maritime provinces. Seven such roads in southwestern Nova Scotia and central New Brunswick were examined. Treatments of 20 m and 40 m culvert spacing were used to determine which spacing would best maintain natural wetland hydrology under the road after construction. Water table depths on both sides of each road were measured, with shallow wells, before and after the road was constructed. In six of seven sites, the part of the wetland upslope from the road had a significantly higher water table than the adjacent wetland downslope, after right-of-way clearing (before road construction). This condition continued after road construction regardless of treatment. These results suggest that natural wetland hydrology had been altered during right-of-way clearing and that alternative approaches to right-of-way clearing seem warranted to maintain natural wetland hydrology. In addition, further testing of culvert installation or other methods to maintain natural hydrology under roads through wetlands is needed.


title: Prenatal exposure to environmental contaminants and newborn immune system biomarkers

contributor:
Interdisciplinary PhD Programme
Interdisciplinary PhD
Dr. Paul Villeneuve
Dr. William Barker
Dr. Tye Arbuckle
Dr. Robert Platt
Dr. Jean Marshall
Dr. Adrian Levy
Dr. Linda Dodds
Received
Yes
No

subject: epidemiology immunology

abstract: Allergic disease are among the most common chronic childhood disease and a leading cause of hospitalization.  Exposure to certain environmental contaminants has been hypothesized to be a risk factor for childhood allergies and asthma.  Scientific understanding regarding the effect of prenatal contaminant exposure on fetal immune system development and subsequent susceptibility to allergic diseases is limited.  Elevated levels of immunoglobulin E (IgE) are a hallmark sign of an allergic response.  Elevated levels of interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP) are implicated in inflammatory responses and early life manifestations of allergic disease but have not been measured in neonates.  The objectives of this research were to 1) assess the levels of, correlation among and predictors of IgE, IL-33 and TSLP in umbilical cord blood and 2) determine the association between prenatal exposure to environmental contaminants and elevated levels of IgE, TSLP and IL-33.  Concentrations of metals, phthalates, bisphenol A, pesticides, and polychlorinated biphenyls were measured in maternal urine, blood or plasma.  IgE, IL-33 and TSLP were measured in umbilical cord blood samples.  Data were obtained from the Maternal-Infant Research on Environmental Chemicals (MIREC) study, a Canadian cohort study of 2,001 women recruited from 10 sites between 2008 and 2011.  TSLP and IL-33 were highly correlated with each other but neither was strongly correlated with IgE.  Elevated levels of TSLP and IL-33 were significantly associated with maternal characteristics indicative of inflammatory responses.  None of the environmental contaminants were associated with elevated immune system biomarker levels.  These findings support the mechanistic hypothesis that IL-33 and TSLP are both operational in early life inflammatory pathways.  Determination of whether the observed absence of environmental exposure-induced immunotoxicity persists into childhood requires follow-up in a cohort of children.


title: 10 Days of Darkness Does Not Restore Neural or Visual Plasticity in Adult Cats

contributor:
Department of Medical Neuroscience
Master of Science
Ian Weaver
Kazue Semba
Kazue Semba
Donald Mitchell
Kevin Duffy
William Baldridge
Received
Not Applicable
Not Applicable

subject:
Neuroscience
Plasticity
Development
Neurofilament
Amblyopia
Lateral Geniculate Nucleus
Cat
Critical Periods
Vision

abstract: Recently it was demonstrated that 10-days of darkness could restore visual plasticity and promote fast and complete recovery from amblyopia in juvenile kittens (Duffy and Mitchell, 2013). To test whether 10-days of darkness could restore plasticity and promote recovery from amblyopia in adult cats (≥1year), two sets of studies were conducted. First, the effect of darkness on promoting recovery from monocular deprivation was tested behaviourally by examining the visual acuity of amblyopic adult cats placed in darkness, and examined histologically by measurement of soma size and neurofilament-H (NF-H) label density in the dorsal lateral geniculate nucleus (dLGN). Second, the capacity of darkness to induce plasticity in normal adult cats was tested through examining the effect of a subsequent period of monocular deprivation on visual acuity and on soma size and NF-H label density in the dLGN. In all conditions examined, darkness was wholly unable to promote visual or anatomical plasticity.


title: Farmer perceptions of wetland ecosystem goods and services

subject:
social perceptions
agriculture
wetlands

abstract: Wetlands provide services to humans through ecological functions including water filtration, flood prevention, freshwater provision etc. Farmers risk losing these essential services as a result of wetland drainage. Wetlands have been established as valuable ecosystems through the economic study of ecosystem goods and services (EGS). However, in comparison to monetary valuation studies, which dominate research, few studies have examined non-monetary values such as human perceptions. In situ, unstructured interviews taking place near wetlands were used to examine farmers’ perceptions of wetland EGS on farms in the Annapolis Valley, NS. Three wetland types were used and each farmer was interviewed twice to test whether perceptions varied by wetland type and season. Analysis suggests that different wetland types elicit discussion about different EGS. The results of the qualitative analysis do not closely align with monetary valuations and could be used to inform more efficient extension programs towards better wetland conservation on farms.


title: Anti-inflammatory properties of potato protein hydrolysates in cellular and animal models

contributor:
Faculty of Agriculture
Master of Science
Dr. Apollinaire Tsopmo
Dr.Dian Patterson
Dr. Gefu Wang-Pruski
Dr. Kirsti Rouvinen-Watt
Dr.Chibuike Udenigwe
Not Applicable
Not Applicable
Not Applicable

subject:
Inflammation
Potato protein hydrolysates
TNF-α
Antioxidant activity
ADAM17

abstract: Inflammation is a series of non-specific immune responses and irregular inflammation can lead to injury and chronic diseases such as cardiovascular diseases. TNF-α is one of the primary pro-inflammatory cytokines mediating inflammatory responses including release of reactive oxygen species (ROS). In this study, potato protein hydrolysates produced with 8 proteases were evaluated for anti-inflammatory activities using mice ANA-1 and C57BL/6 mice primary cell models and inflammatory BALB/c mice model. The potato protein hydrolysates suppressed tumor necrosis factor (TNF)-α release and ROS secretion in the cells. The potato protein hydrolysate produced with ficin (HFic) exhibited a dosage-dependent pattern in inhibiting the release of TNF-α in both cell models. Intraperitoneal administration of HFic to BALB/c mice resulted in the dose-dependent reduction in the amount of cytokines including TNF-α, interleukin (IL)-6 and IL-12 in the mice serum and peritoneal fluid. These finding indicate that the potato protein hydrolysates possess physiological anti-inflammatory properties. The mechanism of anti-inflammatory activity was not clear, but the in vitro and physiological antioxidative activities of the hydrolysates suggest possible interaction with oxidative stress. HFic was found to be potentially stable to gastric proteases based on HPLC analysis, which would encourage future studies on oral delivery of the hydrolysates.


title: Strategies to Improve the Efficacy of Vaccines by Selective Manipulation of the Immune System:  A Translational Study

contributor:
Department of Microbiology & Immunology
Doctor of Philosophy
Dr. Sheila Drover
Dr. Brent Johnston
Dr. David Hoskin
Dr. Jean-Francois Legare
Dr. Kenneth West
Dr. Robert Liwski
Dr. Mohan Karkada
Received
Yes
Not Applicable

subject: vaccine cancer adjuvants antibody

abstract: Novel vaccine technologies are needed to induce protective immunity towards sophisticated diseases for which classical whole-cell vaccines have been inadequate.  Modern vaccine development builds upon intricate understanding of immunology and disease pathology. Subunit vaccines containing highly purified protein or peptide antigens are safer than classical vaccines and can be developed for infectious and non-infectious diseases. Transitioning between in vitro and in vivo systems during pre-clinical development is daunted by the complexity of the vaccine and multifaceted immune response. In this thesis, translational vaccine research was explored with two projects. In the first project, a novel adjuvant system that can boost antibody responses to vaccines was developed in vitro. A combination of TLR agonists, poly I:C (TLR3) and Pam3CSK4 (TLR1/2), resulted in enhanced B cell activation characterized by expression of surface receptors, cytokine production and proliferation. The combination promoted B cell differentiation into antibody-producing plasma cells and increased their capacity to induce CD4+ T cell activation in a mixed lymphocyte reaction. When used as an adjuvant system for vaccines containing anthrax or influenza protein antigens in vivo, the combination resulted in significantly higher serum antibody titers than vaccines containing either agonist alone. Therefore, the poly I:C/ Pam3CSK4 combination is a promising adjuvant system for humoral vaccines containing protein antigens. The second project describes the development of a combinatorial immunotherapy for cancer using an in vivo model. Anti-tumour immune responses induced by vaccines containing tumour associated antigens are thwarted in advanced cancers by tumour-induced immune suppression. To address this, metronomic cyclophosphamide was evaluated as an immune modulator in combination with an HPV16E749-57 peptide vaccine in mice bearing HPV16-induced tumours. The combination provided significant long-term control of tumour growth.  Metronomic cyclophosphamide had a pronounced lymphodepletive effect on the vaccine draining lymph node, yet did not reduce antigen-specific CD8+ T cells induced by the vaccine. This enrichment correlated with increased systemic cytotoxic activity and antigen-specific cytotoxic T cells in the tumour. The results provide important insights into the multiple mechanisms of metronomic cyclophosphamide induced immune modulation in the context of a peptide cancer vaccine that may be translated into more effective clinical trial designs.


title: The dietary phytochemical myricetin induces ROS-dependent breast cancer cell death

contributor:
Department of Microbiology & Immunology
Master of Science
Dr. Karen Bedard
Dr. Brent Johnston
Dr. Brent Johnston
Dr. Rob Liwski
Dr. David Hoskin
Received
Not Applicable
Not Applicable

subject:
breast cancer
myricetin
phytochemical
reactive oxygen species
cell death

abstract: Myricetin is a dietary phytochemical found in a variety of fruits and vegetables. Myricetin has several anti-cancer effects on human cancer cells, including bladder, pancreatic, and colorectal cancers; however, the effect of myricetin on breast cancer cells remains unclear. The goals of this study were to first determine if myricetin caused breast cancer cell death and then to establish the mechanisms underlying myricetin-induced breast cancer cell death. Myricetin decreased the viability of human mammary carcinoma cells, including triple-negative breast cancer cells. Myricetin induced cell death of triple-negative breast cancer cells in a reactive oxygen species (ROS)-dependent manner. Myricetin-induced ROS caused decreased mitochondrial membrane stability, increased DNA damage, and increased p38 MAPK phosphorylation. The myricetin-induced ROS was likely formed by myricetin autoxidation in cell culture medium to form H2O2. The potent anti-breast cancer effect of myricetin argues in favour of further investigation of myricetin as a potential breast cancer therapeutic.


title: Population Status of Exploited Marine Fish Populations

contributor:
Department of Biology
Doctor of Philosophy
Dr. Olaf P. Jensen
Dr. Hal Whitehead
Dr. Joanna Mills Flemming
Dr. Sandra Walde
Dr. Ian Jonsen
Dr. Hal Whitehead
Dr. Doug Swain
Not Applicable
Yes
Not Applicable

subject:
fisheries
data poor
cusk
reference points

abstract:
Estimating the population status and trajectory of marine fishes is hampered by limited
data and the assumptions needed to augment these data gaps can have broad
implications. Poor management decisions based on poor inference can have far reaching socio-economic and ecosystem consequences. Here, I examine critical assumptions commonly employed in fisheries models and how they affect our beliefs on the population status of exploited marine fisheries. The assumption that catch rates are
proportional to abundance is a critical assumption that can influence estimates of
stock status. In chapter 3, this assumption is evaluated via a state-space modelling
framework to obtain better estimates of the stock status of cusk (Brosme brosme) by
incorporating multiple population time series in the estimation of population biomass.
By relaxing the assumption that catch rates were directly proportional to population
biomass, I found that the research trawl survey was likely hyperdepleted, thus exaggerating estimates of population decline. Indeed, previous estimates of population
decline based solely on the the research trawl survey were 93% compared to my estimate of 64% once non-proportionality was incorporated in the modelling structure.
In chapter 4, I model the spatial distribution and population trajectory of different
size classes of thorny skate (Amblyraja radiata) to test for density dependent habitat
selection (DDHS). I found large declines in both abundance and distribution for all
size classes with the greatest declines observed in large juvenile and adult size classes.
I found strong evidence for DDHS for the large juvenile and adult size classes, however,
small juveniles exhibited limited changes in distribution associated with changes
in abundance. In chapter 5, I examine how biological reference points used by fisheries
to monitor harvest sustainability compare to those developed by conservation
organizations, such as the IUCN Red List, to estimate extinction risk. I show that the
two approaches frequently arrive at similar categorizations of stock status and differences
are primarily a result of decline thresholds used to trigger conservation action.
Conservation and fisheries metrics aligned well (70.5% to 80.7% for riskier and more
conservative reference points respectively) despite their mathematical disconnect in
decline thresholds. My analyses suggest conservation and fisheries scientists will agree
on the status of exploited marine fishes in most cases, leaving only the question of
appropriate management responses for populations of mutual concern still unresolved.


title: Effect of Temperature on the Wide Angle X-Ray Diffraction of Nanocrystalline Triacylglycerols

contributor: Department of Process Engineering and Applied Science

subject:
Triacylglycerols
Wide Angle X-Ray Diffraction
Temperature

abstract: The peak position of wide angle x-ray diffraction patterns of nanocrystalline triacylglycerols is affected by the temperature. To observe this effect quantitatively, pure triacylglycerols and triacylglycerol mixtures were crystallized in a desired polymorph in capillaries or a Couette system. The crystallized samples were kept at different temperatures and shear rates. The detailed WAXD patterns were obtained using in-house x-ray and synchrotron x-ray sources. When the temperature increased, the d-spacing for the peaks with small d-spacing increased as well. However, the d-spacing for other peaks remained unchanged or just had a very small change. The relationship between differences of d-spacing for the peaks with small d-spacing and temperature can be used to estimate the real sample temperature, especially under higher shear rate. This provides a new way to monitor and control the temperature of the system under study and the effect of high shear rate on nanocrystalline triacylglycerol crystallization.


title: FUNCTIONS AND ORIGINS OF MITOCHONDRION-RELATED ORGANELLES IN ANAEROBIC PROTISTS

contributor: Department of Biochemistry & Molecular Biology

subject:
Anaerobic metabolism
Mitochondrion evolution
Metabolism
Phylogenetic inference

abstract:
Across the diversity of life, organisms have evolved different strategies to thrive in hypoxic environments – microbial eukaryotes (protists) are no exception; protists that experience hypoxia often possess metabolically distinct mitochondria called mitochondrion-related organelles (MROs). Here, I focus on the biochemical adaptations of poorly-studied diverse anaerobic protists with an emphasis on the evolutionary histories of pyruvate, iron-sulfur cluster and respiratory chain metabolism in MROs.
In the absence of oxygen, some organisms use the pyruvate formate lyase (PFL) system for the non-oxidative generation of acetyl-CoA. Through phylogenetic analyses, I showed that PFL is broadly, but patchily, distributed across the tree of eukaryotes. The monophyly of eukaryotes in these analyses suggest that the PFL pathway was first acquired by lateral gene transfer (LGT) into a eukaryotic lineage - from a firmicute bacterial lineage - and that it has since spread horizontally by more recent eukaryote-to-eukaryote transfer events.
Biosynthesis of Fe-S clusters via the iron-sulfur cluster (ISC) system is a near-universally conserved feature of mitochondria and MROs. In contrast, some prokaryotic anaerobes synthesize and repair oxygen-damaged Fe-S clusters using a sulfur mobilization (SUF) system. Based on a transcriptomic survey, I reconstructed the MRO proteome of the protist Pygsuia biforma and found no evidence for the eukaryotic ISC system but instead identified a laterally acquired archaeabacterial-type SUF. Using immunofluorescence microscopy, I showed that SUF localizes to the MRO, representing the first reported case of a mitochondrial SUF system.
In some anaerobes, the ubiquinone analog rhodoquinone (RQ) allows the respiratory complex II to function in reverse, generating succinate from fumarate. Using immunofluorescence microscopy, I demonstrated that a RQ biosynthesis protein (RQUA) localizes to Pygsuia MROs, suggesting the organelle participates in RQ biosynthesis.  Phylogenetic analyses suggest that anaerobic eukaryotes acquired RQUA multiple times via LGT from distinct eukaryotic and bacterial donors.
These studies suggest that crucial metabolic pathways localized to the MROs of anaerobic protists - and involved in their adaption to hypoxia - have been acquired by LGT.  In some cases, these laterally acquired proteins were found to interface with ancestral mitochondrial proteins (e.g., acquired RQUA and the ancestrally mitochondrial complex II in Pygsuia) to create metabolic pathways of mosaic origins.


title: The Relationship between Traditional Cultural Engagement and Health: Data from Miawpukek First Nations Regional Health Survey

contributor:
School of Health & Human Performance
Master of Arts
Dr. Amy Bombay
Dr. Lynne Robinson
Dr. Susan Hutchinson
Dr. Martine Durier-Copp
Dr. Debbie Martin
Dr. Fred Wien
Received
No
No

subject:
First Nation Health
First Nation Culture

abstract: Background: It is widely accepted that culture is an important determinant of health. However, the impact that cultural engagement has on health outcomes among First Nations peoples is not well understood.  Purpose: This study explored the relationships between cultural engagement in traditional activities and health outcomes among a representative sample of adults from Miawpukek First Nations using data from the 2008 First Nations Regional Health Survey. Findings: Although the correlation between traditional activities and health was less than the other variables, traditional activities had significant findings in some of the results, showing that even after considering all the variables included in the other four categories, traditional activities still had significant correlation with the sample as a whole and in several subject groupings. Conclusion: Although this study showed modest correlation between health and cultural engagement, even after including other social determinants it can be said that cultural engagement does impact health.


title: Illocutionary Autonomy:  Moral Responsibility for Disabling Speech Acts

contributor:
Department of Philosophy
Master of Arts
Michael Hymers
Michael Hymers
Susan Dieleman
Letitia Meynell
Not Applicable
Not Applicable
Not Applicable

subject:
illocutionary silencing
illocutionary disablement
speech act theory
moral responsibility
rae langton
tracing condition
collective responsibility
autonomy
oppression

abstract: First, I explain and defend Langton’s theory of illocutionary disablement, corroborate some of the base principles, and introduce a useful vocabulary through the lens of autonomy and oppression. I then address the objection that agreement with her thesis would entail lesser or no moral responsibility accorded to the individuals who did not understand ''no'' as refusal (and acted in subordinating ways accordingly), and could not have, since no refusal would have taken place. I argue along the lines of Kevin Timpe's solution to the tracing condition problem for moral responsibility, in order to maintain that oppressors are culpably ignorant, and thus blameworthy. Finally, I broaden the scope from individual moral responsibility for wrong actions within an oppressive society to the moral-political responsibility we all have towards our society to question the status quo and fight systemic oppression, based on Iris Marion Young's theory about our responsibility for justice. I then explain how these considerations relate back to the autonomy framework by tying in Carol Hay's work on women's moral obligation to confront sexual harassers, and explain what this would mean if we take Langton's illocutionary disablement seriously.

abstract: This thesis evaluates various consequences of adopting Rae Langton's claims about illocutionary silencing, all through the lens of how they relate to autonomy and moral responsibility. Langton sows the seeds for a theory of illocutionary disablement as a form of oppression, which limits persons' autonomy, specifically women's “illocutionary autonomy” to refuse sex. Alexander Bird draws unwarranted conclusions, which can be defended against with a broader theoretical framework of moral and political responsibility. Overall, I defend the theory of illocutionary disablement set out by Langton as not only plausible, but also consistent with a theory of moral responsibility which holds people accountable for both their actions as individuals and as members of a social community, despite the effect of the silencing as systemic oppression: all of this framed in, and elucidated by, considerations of autonomy. Other main philosophers on whom I draw are Kevin Timpe, Iris Marion Young and Carol Hay.


title: A deep learning computer vision system for image based cytometry

contributor:
Faculty of Computer Science
Master of Computer Science
Evangelos Milios
Dirk Arnold
Alan Fine
Thomas Trappenberg
Not Applicable
Not Applicable
Not Applicable

subject:
computer vision
cytometry
deep learning
cell analysis
convolutional neural network

abstract:
A Complete Blood Count (CBC) is one of the most commonly deployed tests for
checking the overall medical condition of a human body. It results in a summary of
blood cell related measures allowing for a quick preliminary detection of common
diseases. Image based cytometry is a modern way of overcoming common efficiency
issues related to current gold standard method of Coulter Counter analysis.
This thesis describes a computer vision pipeline for measuring main components of
CBC based on methods with varied level of human influence in feature design. The low
quality input images are acquired from a prototype lensless microscope. Rule-based
approaches proved sufficient in cases of red blood cells and platelets analysis and their
configuration is explored in more details at the segmentation stage.
Leukocyte differentiation is a subproblem of CBC requiring more sophisticated
classification approach. The comparison of results based on rule-based, classical
and deep learning methods is presented. Support Vector Machines and k-Nearest
Neighbours were chosen as representatives of classical approaches. The deep learning
scheme has the advantage of finding quick solutions to complex problems involving
highly dimensional and hierarchical structure of underlying solutions. It also alleviates
the amount of work needed by human experts to design appropriate descriptors.
The results discussed here include promising enumeration and feature description
of the objects of interest. Their linear dependence with gold standard clinical results
proved their usability for point of care blood analysis. Classification results showed
superiority of convolutional neural networks in several important aspects. Further
analysis explored the learned parameters and analyzed wrongly classified cases in order
to understand better what kind of cytological objects are most fragile for particular
classifier and why.


title: Occupy gardens? A case study of the People's Peas Garden in Toronto, Canada

contributor: School of Resource and Environmental Studies

subject:
Counterculture
Guerilla gardening
Occupy movement
Urban agriculture
Reclaiming the commons

abstract:
The purpose of this study was to investigate the nature of guerilla gardening as a possible means for political change. This study traced the historical roots of the People’s Peas Garden (PPG), a garden planted without permission on Queen’s Park, Toronto, in May 2012 by members of Occupy Gardens Toronto. The PPG was a significant event in Toronto’s urban gardening history as it challenged state control over land and social structure by being planted on a city-owned public park.

A case study was conducted using semi-structured interviews to elicit the perspectives of PPG participants, Toronto food activists, and City of Toronto government officials. Participants perceived unjust distributional inequalities in the capitalist food system and experimented with ‘reclaiming’ the commons. Additionally, this research sheds broader insight on the potential of guerilla gardening as a means of addressing broader political, social and economic change.


title: Fully Dynamic Graph Orientation

contributor:
Faculty of Computer Science
Master of Computer Science
Dr. Evangelos E. Milios
Dr. Michael McAllister
Dr. Alex Brodsky
Dr. Norbert Zeh
Dr. Meng He
Not Applicable
No
No

subject: Graph Orientation

abstract:
In this thesis we consider the problem of edge orientation, where the goal is to orient
the edges of an undirected dynamic graph with n vertices so that the out-degree of
every vertex is bounded, typically by a function of the graph's arboricity.


title: PHOSPHORUS RETENTION IN ON-SITE WASTEWATER SYSTEMS IN NOVA SCOTIA

contributor:
Department of Environmental Engineering
Master of Applied Science
Dr. Hany El Naggar
Dr. Anne Marie Ryan
Dr. Craig Lake
Dr. Rob Jamieson
Not Applicable
Not Applicable
Not Applicable

subject:
on-site wastewater systems
phosphorus

abstract: The use of residential on-site wastewater systems (OWS) is one of the main non-point sources of phosphorus (P) loading to aquatic systems, which is the primary cause of accelerated blue-green algal growth and eutrophication of surrounding aquatic systems. Reseach is lacking on the long term treatment performance of the OWSs currently used in Nova Scotia. This study examines how P is removed and retained within OWS disposal fields to gain a better understanding of how to limit P loading to surrounding aquatic systems and aid in the management of OWSs across Nova Scotia in regards to P loading. The first phase utilized an existing set of field scale OWSs at the Bio-Environmental Engineering Center in Truro, Nova Scotia. Two types of disposal fields, which had been receiving wastewater for 4-8 years, were sampled. These included C2 raised contour trench systems (C2R) and lateral flow sand filter (LFSF) systems. The second phase of the sampling was conducted in the Thomas Brook Watershed (TBW) located in Berwick, Nova Scotia. Three full-scale on-site wastewater systems that range in age from 10-20 years old were selected for sampling. Soil samples were taken at various depths, and at various spatial locations, within each disposal field to assess the spatial distribution of the P in the disposal field. The three full-scale systems in Berwick each had 6 piezometers installed in the disposal field for the collection of water samples on a monthly basis for one year to capture seasonal variations in P concentrations. Electron microprobe analysis and back scattered electron images were used to identify P-rich solids on soil grains to determine if mineral precipitation reactions involving P could be occurring within the disposal field as a possible long term treatment mechanism. This study highlights the importance of the physical and chemical characteristics of the sand media used in the disposal fields to increase P treatment. The soil media used in the OWSs observed in this study showed a minimal amount of P treatment as they mature, which should be taken into account particularly in watersheds that are currently experiencing water quality issues and are at risk for eutrophication of surrounding surface water.


title: Shigella Effector IpaH9.8 Interacts with Autophagy Transcription Factor ZKSCAN3 and Increases Autophagy During Infection

contributor:
Department of Microbiology & Immunology
Master of Science
Karen Bedard
Brent Johnston
Roy Duncan
Jim Fawcett
John Rohde
Not Applicable
Not Applicable
Not Applicable

subject: bacteria microbiology shigella autophagy T3SS effectors

abstract:
Shigella spp. cause severe diarrheal disease known as shigellosis and are a major
problem is countries where clean water and sanitation are lacking. Shigella spp. use a
Type 3 Secretion System to deliver effector proteins into the cytosol of infected human
cells. My thesis focuses on an effector of Shigella flexneri, IpaH9.8, and its role in
pathogenesis. IpaH9.8 is a member of a structurally related family of enzymes called the
novel E3 ligases (NELs). NEL-domain proteins are E3 ubiquitin ligases that target host
proteins to alter their fate. I show that IpaH9.8 ubiquitinates ZKSCAN3, a negative
regulator of genes required for autophagy, in a cell free system and induces autophagy in
vitro. My results are consistent with a model where S. flexneri uses IpaH9.8 to induce
autophagy resulting in degradation of host proteins to produce free amino acids and
down-regulate the activity of immune complexes.


title: THE EXPERIENCES OF CHRONICALLY ILL PATIENTS AND REGISTERED NURSES WHEN THEY NEGOTIATE PATIENT CARE IN HOSPITAL SETTINGS

contributor:
School of Nursing
Doctor of Philosophy
Dr. Alex Clark
Dr. Marilyn Macdonald
Dr. Ruth Martin-Misener
Dr. Grace Warner
Dr. Deborah McLeod
Dr.Megan Aston
Received
Not Applicable
Not Applicable

subject:
Chronically ill patients
Registered Nurses
Negotiation
Power Relations
Feminist Post-Structuralism
Foucault

abstract:
Positive hospital experiences and health outcomes for chronically ill patients are dependent on effective negotiations of care that are built on partnerships and mutual goal setting.  However, studies suggest that many nurse-patient relationships continue to be dominated by paternalistic models of care and lead to negative patient experiences. Nurses are often expected to change their practice with less attention given to the contribution of institutional contexts. Furthermore, little attention has been given to the role of patients in the process.
The aim of this study was to look at the experiences of chronically ill patients and registered nurses when they negotiated care in hospital. Feminist post-structuralism informed by discourse analysis was used to explore how social and institutional discourses shaped power relations and negotiation of patient care.  A total of 18 indepth interviews were conducted with eight chronically ill patients and ten registered nurses. Five themes emerged from the analysis. These themes were: getting to know each other, they are not the sickest people, the two faces of patriarchy, the challenges of looking after chronically ill patients and finding time to listen.
Overall both nurses and patients commented favorably about their experiences. Nurses got to know patients on a personal level, power relations were shared and most negotiations were successful. However, negotiations were not always positive. Certain institutional practices were still based on a patriarchal system that gave priority to acute illness or reinforced the traditional nurse-patient relationship. Patients exercised their agency in creative ways to ensure that they were not marginalized by such discourses.  Nurses also faced challenges negotiating care with some chronically ill patients and at times felt compelled to use their authoritative position to ensure positive outcomes.  Other nurses listened to patients and effectively addressed their concerns. This approach was rewarding for both patients and nurses.
This study offered an innovative way of unpacking negotiation of care between chronically ill patients and registered nurses. It exposed how social and institutional discourses play a pivotal role in shaping negotiations. By shifting the blame from nurses and patients to relations of power and institutional contexts, problematic areas were identified.


title: Modification of steelmaking slag by additions of salts from aluminum production

subject:
Slag
Steelmaking
Steel--Metallurgy
Aluminum--Metallurgy
Materials science

abstract: The most common slag fluidizer in steelmaking is fluorspar, a mineral primarily composed of CaF2. Because of increasing consumption and decreasing availability of cheap fluorspar, steelmakers are seeking alternative means of achieving slag fluidity. One possible alternative to fluorspar is spent salt from secondary aluminum production. This salt is obtained from the used flux in remelting aluminum scrap and dross. This material is widely available and considered toxic (meaning that use in steelmaking helps to reduce environmental impacts from diposal). This project is an investigation of spent salt as a replacement for fluorspar in slag-fluidizing applications by viscosity measurements and weight loss measurements at high temperatures (to evaluate the      amounts of gases are formed). In addition, characterization of raw materials and melted slags by XRD, chemical analysis, and EPMA have been undertaken. The spent salt addition has a positive effect on slag fluidity, and shows promise for use in slags.


An airborne laser scanning approach to mapping and modelling surface moisture in an agricultural watershed in Nova Scotia


title: Effect of microwave irradiation on the aspect ratio of treated mica

subject:
microwave
mica
microwave irradiation

abstract: Muscovite mica is a plate-like mineral composed of potassium and aluminum silicate. The mica morphology, characterised by aspect ratio, allows this mineral to be used as structural filler in plastics, adding rigidity and dimensional stability. In this study, two chemical leaching experiments were designed to examine their effect on mica aspect ratio. After chemical treatment, the mica underwent microwave irradiation and grinding. After leaching with concentrated HCl, the aspect ratio of mica was examined with and without microwave irradiation. In a separate experiment, the aspect ratio of mica was examined after leaching with lithium nitrate, with and without microwave irradiation. The aspect ratio of the mica was calculated by dividing the average particle size (d50) of the ground mica by the average mica plate thickness. Average particle size was determined using laser diffraction, while average plate thickness was determined using SEM imagery. The HCl treatment-microwave irradiation did not increase the aspect ratio of the mica plates. However, the lithium nitrate treatment-microwave irradiation resulted in mica plates with a higher aspect ratio than lithium nitrate treatment alone


title: TRIBOLOGICAL BEHAVIOR OF POROUS AL ALLOYS

subject: Tribology

abstract:
Aluminium alloys are becoming attractive for critical structural applications for their light weight, high
specific strength, high corrosion resistance and good heat conductivity. It is suitable for manufacturing
many components such as clutch housings in the automotive industry. These alloys can be fabricated using
powder metallurgy techniques in which porosity is a common feature. The presence of pores is responsible
for decreasing the effective load bearing cross-sectional area and act as a stress concentration site for strain
localization and damage, decreasing both strength and ductility. Not only the total area percentage of
porosity influences the degradation in properties but the size, shape and inter connectivity of the porosity
also play an important role. The present study aims to establish a better understanding of the relationship
between surface porosity and corresponding wear behavior. In this study, porous specimens were
produced using powder metallurgy techniques. The extent of wear damage and the type of wear was
investigated under low load range of 1.5-5N against a AISI 52100 bearing steel ball using a reciprocating
ball-on-flat wear configuration and frequency of 10 Hz. Scanning electron microscopy of the wear tracks
and wear debris was carried out to identify wear mechanisms. This study revealed that due to the combined
effect of the real area of contact and subsurface cracking, wear rate increased with increasing porosity
content. The friction and wear behavior of Al A380M, pure Al and Al 6061 as a function of porosity
content can be attributed to their hardness and corresponding wear mechanism.


title: Signal Extrapolation with Linear Prolate Functions

contributor: Department of Electrical & Computer Engineering

subject:
Signal extrapolation
Linear prolate functions
Overlap integral
High precision numerical integration

abstract: A simple, efficient and reliable method for bandlimited signal extrapolation valid up to basically an arbitrarily high range of frequencies is proposed. The orthogonal properties of linear prolate functions (LPFs) are exploited to form an orthogonal basis set needed for synthesis. A significant step in the process is the higher order piecewise polynomial approximation of the overlap integral required for obtaining the expansion coefficients accurately with very high precision. Two sets of LPFs, one relatively with lower Slepian frequency and the other with higher Slepian frequency, are considered. Numerical results of extrapolation of some standard test signals using our algorithm for the two sets are discussed in detail. Further comparisons show that the proposed method performs optimally over other recent techniques used. The possibility of using our algorithm for extrapolating real experimental signals is also explored. Though it is not fully usable for extrapolating real signals as such, there were some interesting observations made during this study which could be of some help for the future works in this field.


title: "How To Be a Man": American Masculinities, 1960-1989

contributor:
Department of English
Doctor of Philosophy
David M. Earle
Carrie Dawson
Len Diepeveen
Anthony Enns
Lyn Bennett
Jason Haslam
Not Applicable
Not Applicable
Not Applicable

subject:
American Literature
American Studies
Gender Studies
Periodical Studies
Cultural Studies

abstract: The editors of Esquire, America’s longest-running men’s interest magazine, announced the publication’s mission statement in its inaugural issue: “Esquire aims to be the common denominator of masculine interests—to be all things to all men.” Throughout the majority of its publication history, being all things to all men has involved providing its male readers with fiction by canonical male authors. As such, this study examines the role of masculinity in works of American prose and fiction by canonical male authors, as they were originally published in Esquire magazine. Esquire can fruitfully be used as a tool for textual analysis, a lens through which historically and culturally specific arguments about particular constructions of masculinity can be made. In particular, I argue that situating these texts in the pages of Esquire, among its fashion advertisements and editorial content, is valuable for demonstrating how masculinities are constructed in relation to the marketplace. Reading specific texts within the frame of Esquire, I show that the works of contemporaneous authors—specifically Norman Mailer, James Baldwin, Raymond Carver, Truman Capote, Tim O’Brien, and Don Delillo—are complicit with, struggle against, or attempt to subvert the masculine codes and behaviours promoted by the magazine. I demonstrate that gender is an always-present and always-contested factor in writing, sometimes obvious but sometimes subtle, and that the gendered subtexts of written works can be brought to the surface when read as part of a project dedicated to explicating “How to Be a Man.” Furthermore, this study reveals the value of conceiving of masculinity in relation to hegemony—that is, in viewing the construction and maintenance of masculinities relationally, and as a part of a historic process inseparable from other historic processes, such as the processes of the marketplace, but that is in fact thoroughly imbricated in them. In so doing, “How to Be a Man” concludes that the market is a place in which the discourse of masculinity is contested, and that the prose and fiction of American authors contributes to, and shapes, that very discourse.


title: Investigation of Disinfection By-Product Formation Potential Test Methodologies in Drinking Water Systems

contributor:
Department of Civil Engineering
Master of Applied Science
Hany El Naggar
Mark Gibson
Jennie Rand
Margaret Walsh
Not Applicable
Not Applicable
Yes

subject:
Disinfection By-Products
NOM
UFC
SDS

abstract: Natural organic matter (NOM) is present in all surface waters and is a major issue in drinking water treatment plants. If introduced into the distribution system, NOM will react with chlorine to form harmful disinfection by-products (DBP), some of which are known human carcinogens. Monitoring DBPs in drinking water treatment utilities is extremely important to public health. This study investigated DBP formation potential testing methods, specifically the uniform formation conditions (UFC) test and the simulated distribution system (SDS) test. From this analysis, a modified SDS test was proposed which simulates chlorine booster stations within a distribution system. Varying conditions of pH and temperature were tested on the proposed modified SDS test in order to investigate its effect on chlorine decay and DBP formation. The results of this study suggest that modeling chlorine boosting in SDS testing will result in slightly higher DBP formation concentrations. Both pH and water temperature test conditions for the proposed modified SDS method were found to impact DBP concentrations and free chlorine residuals, and should be considered as important variables in evaluating DBP formation potential in distribution systems that practice chlorine boosting


title: Using Social Media Data to Improve Navigation within Websites

contributor:
Faculty of Computer Science
Doctor of Philosophy
Dr. Kelly Lyons
Dr. Evangelos Milios
Dr. Anatoliy Gruzd
Dr. Bonnie MacKay
Dr. Carolyn Watters
Received
Not Applicable
Not Applicable

subject:
Website Navigation
Social Media
User Experience

abstract:
People often use navigation mechanisms such as menus, search, links and browser tools to find information within websites. The purpose of this research was to explore how user-generated content on social media can be used to help users find information within websites. In particular, we have examined the use of links (i.e., web page URLs) shared on social media sites, such as Twitter, and the use of this information to recommend relevant and popular web pages to the website visitors.

Our preliminary study explored how users use current navigation tools within websites. Our next study focused on the Twitter messages (“tweets”) to identify characteristics of websites that may benefit from the links shared on social media. Using Netlytic, we captured and analyzed tweets about four popular events. The results indicated that 25-47% of tweets across all four events contained a link to web pages. The majority of these web pages were several clicks deep (requiring more than two clicks from the home page). Based on these findings, we developed guidelines and a prototype - a Social Media Panel (SMP). This prototype displayed popular web pages as page thumbnails based on the aggregated information trending on social media sites.

A mixed methodological approach was followed for our final study which included a focus group and a user study. The focus group was used to solicit feedback on the prototype. The prototype was refined based on these findings and evaluated through a user study. The prototype was compared against the current navigation tools and we examined its effectiveness, efficiency and user engagement between the fact finding and browsing tasks.

Through questionnaires and semi-structured interviews, we concluded that participants found SMP to be effective, efficient and engaging for browsing tasks. The analysis of logs and participants’ on-screen activity, revealed that they performed the fact finding tasks faster than the browsing tasks. It was statistically proven that it took fewer clicks to complete the task using SMP. However, the use of SMP did not prove to make a significant difference in expediting the completion of the task.

The combined results from these studies provided a set of guidelines, and recommendations for the SMP. The research helped us develop a website link navigation model and refine the web information classification model for the two types of information seeking tasks: fact finding and browsing. We see the potential of this research to assist website visitors to discover and connect with other social media users who are interested in similar topics and eventually lead these users to topic driven online communities.


title: Sex Work and the City: Creating Municipal Licensing Regimes for Brothels

contributor:
Faculty of Law
Master of Laws
Jocelyn G. Downie
Joanna Erdman
Steve Coughlan
Elaine Craig
Not Applicable
Not Applicable
Not Applicable

subject:
sex work
municipal law

abstract:
The debate over how to regulate sex work in Canada has long occupied courts,
governments, policymakers, sex workers and activists. In the aftermath of the Supreme
Court decision in Bedford v Canada and the enactment of the constitutionally suspect
Protection of Communities and Exploited Persons Act, this thesis examines municipal
law’s potential role in regulating brothels. Municipalities already grant licenses to adult
service providers, the licensing of brothels is a natural extension of their powers. The
current licensing regimes are in need of reform, both for adult services and before any
attempts to license brothels. This thesis uses New Zealand as an example of an effective licensing regime. By treating the sex trade akin to other industries and respecting the
expertise of those who work in it, there are minimal disruptions in communities and safer working conditions for employees.


title: Determining Mean Corpuscular Hemoglobin from a Drop of Blood using Contact Optical Microscopy

contributor:
Department of Biomedical Engineering
Master of Applied Science
Steven Beyea
Janie Wilson
Paul Gratzer
Ian Hill
Peter Gregson
Alan Fine
Received
Not Applicable
Not Applicable

subject:
point of care
hemoglobin
microspectrophotometry
microscopy
lensless microscopy
complete blood count
optics
blood
diagnostics
red blood cell

abstract:
Contact optical microscopy (COM) is a novel and highly compact imaging technology that has the potential to deliver a point-of-care complete blood count, which could strongly impact many fields of medicine. It was hypothesized that by using COM, Mean Corpuscular Hemoglobin (MCH) can be measured as a component of a CBC, with clinically acceptable accuracy and precision, from a drop of blood.
A physical COM system, a microspectrophotometry equation, and a computer-vision algorithm were developed to extract the MCH from COM images of films of blood containing intact red blood cells. The MCH of 15 human blood samples from different subjects was measured using both a standard-of-practice Sysmex XN-10 machine and the COM system.  A coefficient of variation of 4% was obtained, surpassing the clinical target of 5%.  The results showed that MCH can be measured precisely using COM-based microspectrophotometry and suggest that there is potential for further precision gains.


title: Towards Accountability in Democratic Network Governance

contributor:
Department of Political Science
Master of Arts
Katherine Fierlbeck
Louise Carbert
Kristen Good
Katherine Fierlbeck
Not Applicable
Not Applicable
Not Applicable

subject:
Governance
Network Governance
Accountability
Canada

abstract: Network governance is becoming a dominant governing paradigm. Through this governing form, lateralized, pluricentric, and interconnected public, private, and semi-public actors make policy decisions. The application of power, through the act of governing, becomes departed from traditional democratic accountability mechanisms. Three Canadian cases are explored to make this point: the Urban Aboriginal Strategy (UAS), the Homelessness Partnering Strategy (HPS), and the Canadian Partnership Against Cancer (CPAC). The problem of democratic accountability within network governance is the crux of my thesis. This thesis examines how those granted power, in a networked governing context, could be held to account. Existing approaches to this problem are limited due to a reliance on the idea of accountability as hierarchical and bureaucratic in nature, and as having a unidirectional ‘principal-agent’ foundation.  This thesis moves the discussion towards a postliberal re-theorizing of new accountability frameworks that democratically qualify governance networks.


title: CLIMATE-CHANGE VULNERABILITY ASSESSMENT FOR SELECTED SPECIES IN THREE NATIONAL PARKS IN EASTERN CANADA

contributor: School for Resource & Environmental Studies

subject:
climate change
protected area
conservation

abstract: Canadian protected areas have been established with a premise of static distributions of different ecosystems, an assumption invalidated by climate change. In the Maritimes, there are few local case studies on how to consider and manage protected areas with potentially vulnerable ecosystems. Assuming two climate-change scenarios in the 2080s, we conducted climate-change vulnerability assessments (CCVAs) for a range of species in three national parks as case studies in the face of climate change. Specifically, we had two main goals: (1) to conduct CCVAs, including NatureServe’s climate change vulnerability index, for terrestrial species in these areas, and (2) to explore adaptation opportunities. Our study then identified some of the most vulnerable species (e.g., American marten and brook trout) but also species that are adaptable to climate change. Identification of species’ vulnerability to a changing climate is the first step in trying to identify potential adaptation opportunities for these species.


title: Salt tectonics of the Abenaki Graben and central Sable Subbasin: insights from regional seismic interpretation and 4D scaled physical experiments

subject: Salt tectonics -- Scotian Shelf

subject: Geology, Stratigraphic

subject: Sedimentation and deposition -- Scotian Shelf -- Simulation methods

abstract:
The tectono-stratigraphic evolution of the Abenaki graben and central Sable Subbasin of the north-central Scotian margin has been highly influenced by salt deformation. Shimeld (2004) has identified five salt subprovinces defined by varying salt structural styles across the margin. Although it has been hypothesized these varying structural styles are the result of complex salt basin morphologies and variable Mesozoic post-rift sedimentation patterns, there is still a lack of understanding of how these first order controlling factors specifically controlled the tectono-stratigraphic evolution across the margin. Disappointing petroleum exploration results from the last round of deepwater drilling supports the further need to investigate how variable salt basin morphologies, and depositional rates and patterns controlled salt deformation as well as the evolution of the margin.

The purpose of this project is to integrate regional 2D seismic reflection data including the ION-GXT NovaSPAN dataset, with 4D scaled physical experiments to better understand the tectono-stratigraphic evolution of the Abenaki Graben and central Sable Subbasin. The study area is located in Shimeld's salt Subprovince III that comprises an extensive salt tongue-canopy system that has spread upwards of 80 km on the secondary detachment level. Seismic interpretation indicates an original salt basin characterized by a landward tapering wedge representing the Abenaki Graben, an intermediate high referred to as the North Sable High (NSH), and a symmetric graben with basin step representing the Sable Subbasin. The geometry of the salt basin floor is composed of rifted basement blocks and syn-rift fill that was originally been infilled with upwards of 2 km of Argo salt.

Scaled 4D physical experiments simulating the study area indicate the presence of 4 kinematic domains from the shelf to slope including a: (1) Salt Weld and Pillow, (2) Normal Fault and Reactive Diapir, (3) Passive Diapir and Expulsion Rollover, and (4) Contractional Salt and Allochthonous Salt-Tongue Canopy domain. Experiment results indicate early deposition focused in the Abenaki Graben, later shifting across the NSH into the Sable sub-basin as increased sediment supply and progradation occurred from the Late Jurassic to Early Cretaceous. Experiment evolutions replicated diapir and canopy evolutions with early-inflated salt complexes in the downdip contractional domain focused at changes in the basin-floor and original salt thickness. The inflated salt complexes later evolved into passive diapirs and eventual extensive salt tongue-canopy systems during subsequent sediment progradation.

Derived kinematic concepts from the physical experiments successfully explain the regional structural and related depocentre evolution of the margin form the early post-rift stage to the modem margin. Understanding the tectono-stratigraphic evolution, from early salt mobilization to late stage salt tongue-canopy formation, aids in developing new concepts for reservoir distribution and trap formation for the Abenaki Graben and Sable Subbasin area.


title: Improved functional magnetic resonance imaging at 4.0 T

subject:
magnetic resonance imaging
MRI

abstract:
Functional magnetic resonance imaging (fMRI) is an important tool for the study of the human brain. When performed at higher field strengths, fMRI offers increased signal strength and sensitivity to activation. Unfortunately, traditional fMRI using echo-planar imaging (EPI), or spiral-out also suffers from increased image artifact at higher fields. The most significant artifact is signal dropout occurring near areas where the magnetic susceptibility of a material changes rapidly (for example, at air-tissue interfaces such as sinuses). As a result, signal in several important cognitive areas is often lost. In response to this problem, several new methods for dealing with these susceptibility artifacts have been developed. Modified pulse sequences such as spiral-in are the most common and tend to be the most effective at recovering signal. In order to fully understand these spiral techniques the differing artifact patterns and signal displacement behaviour of spiral-out and spiral-in due to susceptibility field gradients were first modeled and explored. Spiral-in was found to have superior signal recovery in SFG regions due to to increased intravoxel phase coherence.

A new pulse sequence called asymmetric spin-echo (ASE) spiral, based on the spiral-in sequence, was designed to more efficiently recover signal and fMRI activation lost to susceptibility artifacts. ASE spiral has reduced geometric distortion, increased SNR over the whole brain and optimized BOLD weighting. The additional optimization of ASE spiral, via the addition of z-shim gradients, was also explored, but found to be unnecessary as z-shim did not offer significant benefits at the group level when added to spiral-in techniques. This work also examines the changes in R 2 and [Special characters omitted.] -weighting present in ASE spiral images and the subsequent effects on the specificity and sensitivity of the fMRI activation with later ASE images having increasing specificity compared to traditional gradient-echo sequences. ASE spiral can be used as both a SFG-insensitive technique, and as a technique more specific to extravascular (i.e. tissue) sources. This thesis will aid in the continuing development of fMRI by providing important information and tools that can be used by both clinicians and researchers for understanding brain function and treatment of disease.


title: Modelling the spatial effects of the signal transduction process

contributor: Department of Mathematics & Statistics - Math Division

subject:
Cell signalling
Matched asymptotic expansions
Cell Signal Transduction
Applied Math
Differential Equations

abstract: In this thesis we construct and analyze a cell signal transduction model for a biological cell which takes into account three dimensional geometry, diffusion, and spatial separation and localization of activating and deactivating enzymes. The deactivation of signalling proteins occurs throughout the cytosol and activation is localized to specific sites in the cell. The model consists of a system of linear reaction diffusion equations (PDEs) and nonlinear boundary conditions defined over a spherical domain with spherical compartments within its interior. Using asymptotic methods we obtain steady state solutions and determine their stability. We also find asymptotic time dependent solutions to the PDE model. We do this analysis for a model with and without delay. The delay is used to model the time lapse during enzyme reactions and also the recovery times associated with conformational changes during the phosphorylation process.  For the model without delay, the full PDE system is approximated by a system of differential algebraic equations. The full model with delay is approximated by a system of delay differential algebraic equations. From our results we can detect complex signalling behavior such as bistability, robust switches, and sustained oscillations which all come about from different bifurcations. The simulations of the full three dimensional systems correspond well with simulations of the approximating  differential algebraic systems. In this thesis we also introduce a model with cell surface receptors. We model the clustering of these receptors by introducing circular patches on the surface of the sphere. We then investigate the effect that  the number of clusters has on the signalling pathway.


title: Post-Surgical Natural Killer T Cell Activation as a Potential Therapy for Metastatic Breast Cancer

contributor:
Department of Microbiology & Immunology
Master of Science
Dr. Jason Berman
Dr. Brent Johnston
Dr. Jean Marshall
Dr. David Hoskin
Dr. Brent Johnston
Received
Yes
Not Applicable

abstract: Natural Killer T (NKT) cells are a specialized group of immune-regulatory T lymphocytes. NKT cells have been shown to limit primary tumor growth and target distant metastatic disease in murine cancer models and in human clinical trials. The focus of this work was to utilize NKT cell activation as a post-surgical immunotherapy in models of metastatic breast cancer. In our model, mammary carcinoma cells were injected into the mammary fat pad of syngeneic mice and primary tumors were resected twelve days later. The following day, mice were treated with NKT cell-activating glycolipids or glycolipid-loaded dendritic cells (DCs) to examine the effect on metastatic disease. Treatment with free glycolipids transiently reduced metastatic disease but did not enhance survival. In contrast, treatment with glycolipid-loaded DCs was effective in limiting metastasis, prolonging survival, and decreasing tumor-associated immune suppression. Our data suggest that NKT cell activation via transfer of glycolipid-loaded self-DCs holds promise as an immunotherapy for metastatic breast cancer.