title:
Agricultural land use impacts
on cool-spring flora and fauna, with an emphasis on freshwater invertebrate diversity and
phenology in spring pools of eastern Prince Edward Island (Canada)

contributor: van den Heuvel, Michael (Thesis advisor)

contributor: Giberson, Donna (Supervisory Committee Member)

contributor: van den Heuvel, Michael (Supervisory Committee Member)

contributor: McCorquodale, David (Supervisory Committee Member)

contributor: Quijon, Pedro (Supervisory Committee Member)

contributor: Giberson, Donna (Examination Committee Member)

contributor: van den Heuvel, Michael (Examination Committee Member)

contributor: McCorquodale, David (Examination Committee Member)

contributor: Quijon, Pedro (Examination Committee Member)

contributor: Colbo, Murray (Examination Committee Member)

contributor: Polson, James (Examination Committee Member)

format: electronic 208 application/pdf PUBLISHED

rights:
In presenting this thesis in partial fulfillment of the requirements for a postgraduate degree
from the University of Prince Edward Island, I agree that the Libraries of this University may
make this thesis freely available for inspection and give permission to add an electronic
version of the thesis to the Digital Repository at the University of Prince Edward Island.
Moreover the author agrees that permission for extensive copying of this thesis for scholarly
purposes may be granted by the professor or professors who supervised my thesis work, or,
in their absence, by the Chair of the Department or the Dean of the Faculty in which my
thesis work was done. It is understood any copying or publication or use of this thesis or
parts thereof for financial gain shall not be allowed without my written permission. It is also
understood that due recognition shall be given to me and to the University of Prince Edward
Island in any scholarly use which may be made of any material in my thesis.

abstract:
Freshwater springs are focused discharge points from groundwater to surface water
environments. Cool springs have consistent temperatures close to the mean annual
temperature for the region and chemical composition that can vary with land use and local
geology. Animal taxa inhabiting these springs must be able to tolerate nearly constant cool
temperatures (<10oC), so springs usually have lower numbers of species than reported in
nearby surface waters. Agricultural activities adjacent to springs add nutrients to
groundwater, and alter benthic sediment structure and adjacent riparian areas, all factors that
affect populations of freshwater plants and invertebrates. High nutrients should increase
invertebrate abundance, but habitat alterations such as sediment addition may depress
abundance. Increased food availability can also affect growth and life history patterns such as
insect emergence timing, which can be disrupted in cool springs due to lack of temperature
cues to synchronize development. Agricultural impacts on springs were examined by
comparing water quality and invertebrate community structure in rheo-limnocrene springs in
forested and agricultural areas in Prince Edward Island, Canada. Twenty springs (10
surrounded by agricultural land and 10 forested) were monitored for water quality and nine
of these (five agricultural and 4 forested) were further examined to explore invertebrate and
aquatic plant patterns. Agricultural sites had open canopies, high nitrogen and sulphur levels,
high amounts of fine sediment, and plant cover dominated by vascular plants. Forested sites
had closed canopies, low nutrient levels, clean gravel substrates, and plant cover dominated
by bryophytes. Invertebrate diversity and abundance were highest in forested springs and
community structure differed between land-use types. Midges (Chironomidae) dominated the
macroinvertebrate community in all sites, but several midge and mite (Hydrachnidiae) genera were most abundant in forested sites. Mayflies (Ephemeroptera) were very rare in the
springs, but stoneflies (Plecoptera) and caddisflies (Trichoptera) were most abundant and
diverse in agricultural sites. Emergence timing was compared between agricultural and
forested sites for the stoneflies, and although most showed the asynchronous emergence
periods expected for constant temperature sites, at least two species began to emerge earlier
in agricultural sites than forested ones. Reduction of the riparian canopy leading to increased
light levels from open cover was a better predictor of plant and invertebrate species
assemblages than either nutrients or sediment patterns in agriculturally impacted springs; the
higher light levels increased the presence and cover of vascular vegetation which altered the
overall invertebrate community.


title: The use of modelling approaches to explore interactions in two aquatic host-pest systems

type: Text Dissertation/Thesis

contributor: Davidson, Jeffrey (Supervisory Committee Member)

contributor: Spangler, Elizabeth (Examination Committee Member)

contributor: Revie, Crawford (Supervisory Committee Member)

contributor: Sanchez, Javier (Supervisory Committee Member)

contributor: Greenwood, Spencer (Supervisory Committee Member)

contributor: Page, Fred (Supervisory Committee Member)

contributor: Grant, Jon (Examination Committee Member)

contributor: Revie, Crawford (Examination Committee Member)

contributor: Greenwood, Spencer (Examination Committee Member)

contributor: Vanderstichel, Raphael (Examination Committee Member)

format: electronic 225 application/pdf PUBLISHED

rights: In presenting this thesis in partial fulfilment of the requirements for a postgraduate degree from the University of Prince Edward Island, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the professor or professors who supervised my thesis work, or, in their absence, by the Chair of the Department or the Dean of the Faculty in which my thesis work was done. It is understood any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Prince Edward Island in any scholarly use which may be made of any material in my thesis.

abstract:
Modelling is a useful tool that has been applied in both human and animal epidemiological research. A model is a simplified system that represents a much more complex phenomenon. Various types of models are available. They are generally used for the purposes of explaining phenomena, making predictions, or exploring different scenarios. Several challenges have been encountered during the construction of models in aquatic animal health and are discussed in the dissertation. The research documented in this dissertation aimed to demonstrate the application of modelling to address specific health and production issues associated with two aquatic animal species (blue mussels and wild Pacific salmon).
The first problem dealt with sea lice infestations in wild Pacific salmon populations on the west coast of British Columbia, Canada. The levels of sea lice infestations on wild chum and pink salmon were described and factors associated with inter-annual variation of the infestations were identified using a multivariable logistic regression model. This model included site information as a random effect, to account for spatial aggregation, which provided further details on the degree of clustering at the site level and suggested that the infestation levels depended on the location of fish. This raised the question as to where the risks were and, as a result, a spatial cluster analysis technique (i.e. spatial scan statistics) was used to identify when and where the clusters (of elevated sea lice infestation levels) occurred. The results from clustering analysis can facilitate the hypothesis-generating process for future studies. The second issue was the problem of mussel loss due to biofouling by tunicates (Ciona intestinalis) on Prince Edward Island mussel farms, which was assessed through the use of a mathematical model to describe the dynamics of C. intestinalis populations over the growing season. The model incorporated temperature dependencies, which allowed for the assessment of population dynamics under different temperatures, and was then used to evaluate the effectiveness of different mitigation strategies, using fewer resources than would be required if field trials were undertaken.
The research documented in this dissertation demonstrates the use of modelling to address production and health issues in the context of aquatic animals. In addition to the use of field-based trials the research also suggests that modelling can be used as an alternative method to investigate various scenarios and facilitate management planning with advantages in time and cost savings.


title:
Light and ultramicroscopical aspects of the in vitro development of
Hematodinium sp. (Dinoflagellata) from Atlantic snow crabs
(Chionoecetes opilio)

contributor: Kibenge, Frederick (Supervisory Committee Member)

contributor: Cawthorn, Rick (Supervisory Committee Member)

contributor: Morado, Frank (Supervisory Committee Member)

contributor: Wright, Glenda (Supervisory Committee Member)

contributor: Conboy, Gary (Examination Committee Member)

contributor: Fast, Mark (Examination Committee Member)

contributor: Speare, David (Examination Committee Member)

contributor: Wright, Glenda (Examination Committee Member)

format: electronic 175 application/pdf PUBLISHED

abstract:
Hematodinium is a parasitic dinoflagellate of numerous crustacean species, including the economically important Atlantic snow crab, Chionoecetes opilio. The parasite was isolated from C. opilio in the fall of 2010 and 2011 and cultured in vitro. Several media were tested, with Nephrops medium yielding superior results. Life stages were characterized using light, scanning and transmission electron microscopy. This is the first time Hematodinium has been isolated from C. opilio and cultured in vitro, and is only the second in vitro study on Hematodinium which used electron microscopy.
Numerous life stages were observed: amoeboid trophonts, sporonts, sheet-like and arachnoid coenocytes, dinospores, post-dinospores, and schizonts. In crab hemolymph, amoeboid trophonts and sporonts were observed. In cultures that were seeded with sporonts, further progression to motile dinospore stages occurred; however, those seeded with amoeboid trophonts did not progress to dinospores, often remaining as amoeboid trophonts or occasionally forming schizonts. Additionally, two types of coenocytes were associated with sporonts: sheet-like and arachnoid coenocytes. Only sheet-like coenocytes were associated with trophonts.
Trophonts that were morphologically different were ultrastructurally similar, thus no distinction between filamentous and amoeboid trophonts was made. Ultrastructurally, trophonts possessed amphiesmal vesicle membranes, nuclei with permanently condensed chromosomes, mitochondria with tubular cristae, lipid droplets, and lipofuscin granules. Lipofuscin granules were characterized by their autofluorescence and ultrastructural similarity to lipofuscin granules found in other invertebrates and vertebrates. Additionally, lipofuscin granules appeared to degranulate or to be expelled from the cell during in vitro cultivation. The exact mechanism of this is unknown. Sporonts possessed all the features noted for trophonts and also had trichocysts. Mature trichocysts were long, rectangular shaped organelles with a width of 223 ± 2.11 nm (n=100) and of unknown length. Trichocyst development was examined ultrastructurally. Developing trichocysts were associated with the Golgi apparatus and first appeared as large vesicles containing a homogeneous, granular material. During development, the granular material condensed to form a crystalline core. Mature trichocysts were characterized by an electron dense crystalline core surrounded with a tightly juxtaposed single membrane.
Early sporonts appeared similar to amoeboid trophonts in morphology; but became more spherical prior to dinospore formation. Late sporonts divided into four daughter cells, indicating a significant replicative step. Dinospores shared all ultrastructural features of sporonts, but possessed two flagella: one transverse and one longitudinal for motility. All dinospores were morphologically identical and resembled the macrodinospores observed in other Hematodinium spp. No microdinospores were observed; this lack of detection is likely due to the low number of observed cultures that progressed to the dinospore stage. After ~ 2 weeks in vitro, dinospores lost their flagella, and became more spherical. Furthermore, the nuclear structure was dissimilar to other stages, with beaded chromatin only evident along the periphery of the nucleus in addition to a single bead in the centre, rather than ubiquitous throughout the nucleus. Thus these were termed ‘post-dinospores’. Additionally, schizonts were noted as very large cells with large, relatively empty lipofuscin granules. Schizonts were only seen in contaminated or old cultures, and were thus considered as an abnormal form. Notably, no viable gorgonlocks or clump colonies were observed as noted in Hematodinium sp. from other crustacean hosts. In the present study, unique filopodia-like structures were observed protruding from early sporonts and trophonts and attached to neighbouring cells.
Cryopreservation of Hematodinium was also attempted on sporonts and trophonts. Although recovery rates were very low, viable Hematodinium survived ~ 3 months in cryostorage. Two cryoprotectants, 3% glycerol and 10% DMSO, yielded positive results. This is the first successful cryopreservation of Hematodinium.


contributor: McClure, J. Trenton (Supervisory Committee Member)

contributor: McDuffee, Laurie (Supervisory Committee Member)

contributor: Hartwig, Sunny (Supervisory Committee Member)

contributor: Riley, Christopher (Supervisory Committee Member)

contributor: Hartwig, Sunny (Examination Committee Member)

contributor: Laverty, Sheila (Examination Committee Member)

contributor: McDuffee, Laurie (Examination Committee Member)

contributor: McNiven, Mary (Examination Committee Member)

contributor: Hurnik, Dan (Examination Committee Member)

format: electronic 161 application/pdf PUBLISHED

rights: In presenting this thesis in partial fulfilment of the requirements for a graduate degree from the University of Prince Edward Island, the author has agreed that the Robertson Library, University of Prince Edward Island, may make this thesis freely available for inspection and gives permission to add an electronic version of the thesis to the Digital Repository at the University of Prince Edward Island. Moreover the author further agrees that permission for extensive copying of this thesis for scholarly purposes may be granted by the professor or professors who supervised the author’s thesis work, or, in their absence, by the Chair of the Department or the Dean of the Faculty in which the author’s thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without the author’s written permission. It is also understood that due recognition shall be given to the author and to the University of Prince Edward Island in any scholarly use which may be made of any material in the author’s thesis.

abstract:
An in vitro comparison of the osteogenic potential of equine stem cell populations and subpopulations from multiple tissue sources was made to identify the ideal equine donor tissue as a source of MSCs to promote bone healing. Equine muscle tissue– and periosteal tissue–derived cells where characterized as mesenchymal stem cells (MSCs) and their proliferation capacity and osteogenic potential was assessed in comparison with bone marrow– and adipose tissue–derived MSCs. Cells were isolated from skeletal muscle, periosteal, and adipose tissues, and sternal bone marrow aspirates. Morphology, adherence to plastic, trilineage differentiation, and detection of stem cell surface markers CD44 and CD90 were used to characterize cells as MSCs. Osteogenic potential of MSCs was measured by osteocalcin gene expression. Mesenchymal stromal cell cultures were counted at 24, 48, 72, and 96 hours to determine tissue-specific MSC proliferative capacity. Muscle MSCs (MMSCs), periosteum MSCs (PMSCs), and adipose MSCs (AMSCs) proliferated significantly faster than did bone marrow MSCs (BMSCs) at 72 and 96 hours.
Non-equilibrium gravitational field-flow fractionation (GrFFF) was validated as a method for sorting MSCs from four donor sources (muscle, periosteum, bone marrow, and adipose tissue) into subpopulations. Aliquots of MSCs from each tissue source were consistently separated into 6 fractions by continuous flow (GrFFF proprietary system) and these fractions remained viable for use in further assays. Absorbencies (OD) were compared, and trilineage assays performed. Statistical analysis of the fraction absorbencies (OD) revealed a P-value of <0.05 when fraction 2 and 3 were compared to fractions 1, 4, 5, and 6. GrFFF was used to sort MMSCs and BMSCs into subpopulations and perform assays allowing comparison of their osteogenic capabilities. Aliquots of MMSCs and BMSCs were sorted into 5 fractions using non-equilibrium GrFFF. Pooled fractions were cultured and expanded for assays including: flow cytometry, histochemistry, bone nodule assays, and real time PCR to identify upregulation of osteocalcin, RUNX2, and osterix. There was significant upregulation of osteocalcin, RUNX2, and osterix for the BMSC fraction 4 with P<0.00001 indicating high osteogenic potential. Flow cytometry revealed different cell size and granularity for BMSC fraction 4 and MMSC fraction 2 when compared with unsorted controls and other fractions. Histochemistry and bone nodule assays revealed positive staining nodules but no significant differences between tissues or fractions.
It was concluded that 1) equine muscle and periosteum are sources of MSCs that have osteogenic potential comparable to that of equine adipose- and bone marrow–derived MSCs, 2) non-equilibrium GrFFF is a valid method for sorting equine MMSCs, PMSCs, BMSCs, AMSCs into subpopulations that remain viable and 3) subpopulations of MSCs exist and have different osteogenic capacities within equine muscle and bone marrow derived sources. These findings are important contributions to equine stem cell therapy and bone healing in veterinary medicine.


title: The use of interactive whiteboards by Prince Edward Island high school teachers

contributor: McAuley, Alexander (Supervisory Committee Member)

contributor: Miller, Tess (Supervisory Committee Member)

contributor: McAuley, Alexander (Examination Committee Member)

contributor: Miller, Tess (Examination Committee Member)

contributor: MacDonald, Ron (Examination Committee Member)

contributor: Vaughan, Norman (Examination Committee Member)

format: electronic 164 application/pdf PUBLISHED

abstract: This Masters of Education thesis used a questionnaire to examine Prince Edward Island high school teachers’ self-reported practices related to interactive whiteboards in their classrooms and the factors influencing their interactive whiteboard use. Despite research suggesting that interactive whiteboards have the potential to improve student academic achievement, the extent to which this technology can actually achieve these claims was likely dependent on many factors. Factors identified in this thesis as hindering teachers’ interactive whiteboard use and by extension, students’ learning, were the understanding of what interactivity with an interactive whiteboard is, teachers’ attitudes towards using interactive whiteboards, and the theoretical and practical training provided to teachers.


title: On writing and transformation: One story at a time

contributor: Wiebe, Sean (Supervisory Committee Member)

contributor: Lemm, Richard (Supervisory Committee Member)

contributor: Wiebe, Sean (Examination Committee Member)

contributor: Lemm, Richard (Examination Committee Member)

contributor: Moffatt, Lyndsay (Examination Committee Member)

contributor: McLeod, Heather (Examination Committee Member)

format: electronic 103 application/pdf PUBLISHED

abstract:
In this thesis who I am as a writer emerged from the act and art of writing. I set
out to tell two stories (one fiction and one life writing story) and discovered a third— the
story that writing taught me. I employed writing as a means of inquiry and discovered
that the act and art of writing (regardless of the genre I practiced) is a creative process
that involves reflection and holistic awareness and can lead to transformation.


title: Sustainable livelihoods and food and nutrition security of Kenyan smallholder farm women

contributor: Spangler, Elizabeth (Supervisory Committee Member)

contributor: Taylor, Jennifer (Supervisory Committee Member)

contributor: Yeudall, Fiona (Supervisory Committee Member)

contributor: MacLellan, Debbie (Supervisory Committee Member)

contributor: Cole, Donald (Examination Committee Member)

contributor: VanLeeuwen, John (Examination Committee Member)

contributor: Yeudall, Fiona (Examination Committee Member)

contributor: Revie, Crawford (Examination Committee Member)

contributor: VanLeeuwen, John (Supervisory Committee Member)

format: electronic 263 application/pdf PUBLISHED

rights:
In presenting this thesis in partial fulfillment of the requirements for a postgraduate degree from
the University of Prince Edward Island, I agree that the Libraries of this University may make it
freely available for inspection. I further agree that permission for extensive copying of this
thesis for scholarly purposes may be granted by the professor or professors who supervised my
thesis work, or, in their absence, by the Chair of the Department or the Dean of the Faculty in
which my thesis work was done. It is understood any copying or publication or use of this thesis
or parts thereof for financial gain shall not be allowed without my written permission. It is also
understood that due recognition shall be given to me and to the University of Prince Edward
Island in any scholarly use which may be made of any material in my thesis.

Contact Author

abstract:
There is limited scientific information on relationships among smallholder dairy group membership duration, sustainable livelihoods, food and nutrition security in developing countries, and whether nutrition education of women dairy farmers enhances the nutritional benefits of being a dairy group member.
The objectives of this thesis research were: 1) to identify associations among sustainable livelihood (SL) measures and dairy group membership duration; 2) to identify determinants of food and nutrition security; 3) to determine effects of a nutrition education intervention; and 4) to explore factors influencing food choices to help explain intervention results.
A cross sectional survey was used to collect data from smallholder farmers in Kenya. Wakulima Dairy (WDL) members (n=88), across four membership duration groups (1-3, 4-6, 7-9 and 10+ years), and non-members (n=23) were interviewed about SL assets (human capital e.g. education, household size; physical capital, e.g. livestock, consumer assets; natural capital e.g. land holdings; social capital e.g. women’s group affiliation), and outcomes (e.g. income, food and nutrition security). Members and non-members were randomly assigned to nutrition education intervention and control groups and re-interviewed five months post-intervention to assess nutrition security and factors influencing food choices.
SL assets and outcomes were described and associations among these measures and membership duration examined. Determinants of food and nutrition security were identified among SL measures. Pre- and post-intervention nutrition knowledge and diet quality indices were compared and examined for an interaction of membership and intervention status.
vi
Dairy herd size, per-cow daily milk production, and HFS were intermediate for the one-to-three year WDL members, and higher among the greater-than-three year members. Enhanced well-being of the greater-than-three year members was suggested by improved household characteristics (e.g. accessible water, latrine, floor construction), and may result from dairy income, although identification of causal relationships is limited by the cross-sectional approach.
Higher odds of HFS was associated with milk production however, average milk production was low (6.5 kg/cow/day). HFS was also significantly associated with women’s group affiliation, greater-than-primary education, smaller household size, and consumer asset holdings.
WDL member women had higher milk and energy intakes, dietary diversity, and prevalence of overweight-status compared to non-member women. Longer membership duration was associated positively with milk-source nutrient intakes and percent energy from animal source foods (%ASF). Dietary diversity was positively associated with women’s group membership and not with milk productivity or HFS. Diet quality measures, although better for WDL members, demonstrated micronutrient deficient diets.
Nutrition education may help address inadequate micronutrients intakes for members and non-member women as demonstrated by a high proportion of intervention-group women that adopted strategies to increase iron and zinc bioavailability. Intervention results for dietary diversity and intakes of vitamins A and C were dependent on WDL membership status. Greater dietary diversity was found for intervention group women that were WDL members. In contrast, higher intakes of
vii
vitamin A and C were found for intervention group women that were not WDL members.
Overall, WDL members had strengthened livelihood measures particularly after 3 years. The intermediate status of the 1-3 years of members may be significant in setting realistic measurable development project goals. Findings provide evidence of the need to improve diet quality.


title: Education, interrupted: an autoethnographic exploration of barriers to accessing higher education for a student with psychiatric diagnoses

contributor: Thorne, Carolyn (Examination Committee Member)

contributor: Snow, Kathy (Examination Committee Member)

contributor: Gilham, Chris (Examination Committee Member)

format: electronic 168 application/pdf

abstract: In this thesis, I set out to answer a single overarching research question: in what ways does having a mental illness affect options regarding higher education? Given the prevalence of serious mental illness (SMI) in both the United States and Canada, and its frequent emergence during the late teens, it is both urgent and essential to identify barriers to reaching postsecondary education for students with SMI. Situating the work within a poststructuralist theoretical framework, I conducted autoethnographic research into my experiences of attempting to re-access postsecondary education after my initial attempt was derailed due to schizoaffective disorder. The autoethnographic writing—both method and product—incorporated analysis that considers the individual experience in the context of the university and society at large and how the discourse made available by the cultural context impacts the achieved identity of a student living with SMI. I produced new autoethnographic writing; analyzed excerpts from previous creative writing addressing my experience with schizoaffective disorder; and engaged with memoir by writers who have accessed higher education while living with SMI. The findings showed both psychological barriers, such as destabilized sense of self, and financial barriers, such as loss of scholarship opportunities, to accessing higher education for students with psychiatric diagnoses.


title: L’éducation postsecondaire chez un groupe de finissants de la région Évangéline: deux voies

contributor:
Bouchard, Véronique (author)
Turnbull, Miles (Thesis advisor)
Cormier, Marianne (Thesis advisor)
(Committee member)
(Supervisory Committee Member)
(Examination Committee Member)

format: print 246 application/pdf PUBLISHED

abstract:
Cette étude qualitative comporte deux objectifs: 1) examiner les raisons qui motivent le choix d’un établissement postsecondaire chez sept finissants d’une école de langue française dans la région Évangéline à l’Île-du-Prince-Édouard; et 2) explorer l’expérience vécue par ces jeunes lors de cette période de transition qu’est l’entrée au collège ou à l’université. Les données ont été recueillies à l’aide d’entretiens semi-dirigés effectués à deux moments précis: à la fin de la 12e année et à la fin du premier semestre universitaire/collégial. Des courriels ont aussi été échangés durant le semestre. L’analyse des données s’appuie sur quatre concepts fondamentaux qui constituent le cadre théorique de l’étude : la vitalité ethnolinguistique, l’hybridité identitaire, l’insécurité linguistique et la valeur marchande de la langue.
L’analyse pertinente au premier objectif de l’étude se présente sous forme de comparaison entre les propos tenus par les participants ayant opté pour un établissement anglophone et ceux ayant choisi une institution francophone. L’analyse révèle que les raisons identifiées par les participants pour justifier leur choix d’établissement postsecondaire confirment les mêmes tendances que celles citées par d’autres chercheurs et vont aussi de pair avec celles mentionnées par les finissants franco-ontariens de l’étude de Lamoureux (2007) ; la réputation perçue du programme ou de l’institution et les raisons d’ordre financier (proximité géographique et bourses d’études) sont des facteurs omniprésents.
L’analyse de l’expérience vécue par les participants s’organise principalement autour du facteur linguistique dans deux contextes essentiels de l’expérience postsecondaire : la vie académique et la vie sociale. L’étude révèle que globalement, les sept participants ont vécu une expérience positive lors de leur premier semestre au niveau postsecondaire. Aucune difficulté ou problème majeur n’a été décelé, autre que la période d’adaptation nécessaire et normale qui accompagne le processus de transition école secondaire-université/collège.


title: “We'll have to re-write history”: Postcolonial education on the island state of the Commonwealth of Dominica

contributor: Krautwurst, Udo (Supervisory Committee Member)

contributor: Mitchell, Jean (Supervisory Committee Member)

contributor: Preston, Jane (Supervisory Committee Member)

contributor: Krautwurst, Udo (Examination Committee Member)

contributor: Mitchell, Jean (Examination Committee Member)

contributor: Preston, Jane (Examination Committee Member)

contributor: Vannini, Phillip (Examination Committee Member)

format: electronic 183 application/pdf PUBLISHED

abstract:
This ethnographic study examines the relationships between colonialized education, cultural negotiation, and migration within the context of the colonial/postcolonial island of Dominica. Using postcolonial theory, the overarching aim was to gain understanding of how people of the former colonial island relate to the education they received and how that relationship influenced people’s interactions with their home. The two-month field study consisted of observational notes and 12 semi-structured one-on-one interviews with Dominican-born citizens who attended secondary school on the island. Participants ranged in when they attended secondary school: some attended prior to Dominica’s 1978 independence from Britain; some began before independence, but ended after; and some attended only after independence.
The conclusions of this study encompass (1) how participants feel their education reflected and perpetuated Dominican cultural identity, (2) how participants feel their education impacted their perceptions of the needs to emigrate, and (3) how these notions of cultural identity and emigration bolster or diminish each other. Participants felt their cultural identity was, at most, a secondary thought of the education system or was not represented by the education system at all. Some participants saw emigration as needed in order to use their education to become financially successful; others believed that education was a tool for making emigration possible, but only to gain more knowledge before returning to contribute to Dominica. These viewpoints led to questions of nationalism, transnationalism, and cosmopolitanism, concepts which appeared throughout this study. Regardless of a participant’s place on this spectrum of perspectives, attitudes involved cultural negotiation and notions of modernity, and came to be seen as a duality where individuals simultaneously cherished cultural identity while striving to meet standards of modernity that threaten or force adaptation upon said cultural identity.


title: Renewable energy in the food, energy, water Nexus of the Bahamas

contributor: Nagarajan, Palanisamy (Supervisory Committee Member)

contributor: Bartmann, Barry (Supervisory Committee Member)

contributor: Nagarajan, Palanisamy (Examination Committee Member)

contributor: Bartmann, Barry (Examination Committee Member)

contributor: Fook, Tanya Chung Tiam (Examination Committee Member)

format: electronic 179 application/pdf PUBLISHED

abstract:
As the global population increases, so does global demand for energy, water and food
expand. Meeting this continual spike of demand presents a tremendous challenge to Small
Island States, given competing needs for limited resources amid heightened climate change.
In order to overcome the increasing constraints that Small Island States encounter, serious
consideration must be given with respect to how Small Island States produce and consume
energy, produce water and provide food to their citizens. This critical tri-partied interaction
is known as the Nexus. The interlinkage between the water, energy and food supply systems
is a major consideration in countries’ sustainable development strategies. Rapid economic
growth, expanding populations and increasing prosperity are driving up demand for energy,
water and food, especially in the Small Island States in the developing countries.
Advancements in renewable energy technologies provide access to cost-effective, secure and
environmentally sustainable supplies of energy. Their rapid technology advancements can
have substantial spill-over effects in the water and food sectors. Yet detailed knowledge on
the role renewables can play in the management of the Nexus remains limited and widely
dispersed, let alone aggressively practiced or not practiced in small island countries such as
the Bahamas. Renewable energy technologies could address some of the trade-offs between
water, energy and food, bringing substantial benefits in all three sectors.
The objective of the Thesis is to explore whether Small Island States such as the Bahamas are
taking full advantage of the current technology available to manage their Nexus. The Thesis
primarily uses government policies and press reporting on Bahamian renewable energy projects,
and how these programs influence the water, energy and food requirements for the Bahamas. The term "energy-water-food Nexus" refers to the complex interdependencies between energy, water and agriculture that vary by geography. The Nexus refers to the web of interactions that link energy, water and food in a common system, as growing food requires water, processing water requires power, and hydro-electric power generation requires water. Depleting the natural resources of islands to the point of annihilation
is verifiable in island countries such as the Easter Islands. Small islands are a microcosm of the
Earth. To study small island Nexus topics is an opportunity to understand the challenges
experienced all over the world.


title: Archipelagic matters: The case of the United Nations Convention on the Law of the Sea and the Republic of the Philippines

contributor: Baldacchino, Godfrey (Examination Committee Member)

contributor: Campanaro, Richard (Examination Committee Member)

contributor: Baldacchino, Godfrey (Supervisory Committee Member)

format: electronic 211 application/pdf PUBLISHED

abstract:
The United Nations Convention on the Law of the Sea (UNCLOS) contained a specific section for “Archipelagic States” (Part IV) which are given many rights under the archipelagic regime including, if desired, to designate archipelagic sea lanes (ASLs) through their archipelagic waters. While designation of ASLs is optional, regardless of ASL status, the right of archipelagic sea lane passage (ASLP) for all maritime users is guaranteed. This thesis examines the case of the Republic of the Philippines in designating ASLs and the influences impacting this process at the state and international levels.
This thesis argues that the process of adoption of archipelagic sea lanes by mid-ocean archipelagic states is one which favours the maritime powers over the archipelagic states. Further, in relation to the Philippine case, the efforts of the Republic of the Philippines in repeating some actions undertaken by Indonesia during its case, will strengthen the international system bias and end in a result which will be the by-product of interests other than that of the Philippine state.


title: Teaching with care: An auto-ethnography about teaching, blogging and caring

contributor: Moffatt, Lyndsay (Supervisory Committee Member)

contributor: Wiebe, Sean (Supervisory Committee Member)

contributor: Moffatt, Lyndsay (Examination Committee Member)

contributor: Wiebe, Sean (Examination Committee Member)

contributor: McAuley, Alexander (Examination Committee Member)

contributor: Nellis, Robert (Examination Committee Member)

format: electronic 160 application/pdf PUBLISHED

abstract: Using the art of living inquiry, through the form of auto-ethnographic narrative, this research explores the question: in what ways has auto-ethnographical blogging made me more aware of the need for an ethic of care in my teaching practice? The research I have conducted is concerned with lived experience as archived on my blog, The Pursuit of a Joyful Life, a space where I often write reflectively as a teacher. Throughout my inquiry, I look at several blog entries written in order to uncover the ways in which blogging has strengthened my commitment to the ideals of the profession, as well as studied in order to discover what influence my choice, to engage in an on-line reflective blogging format focused on ethic of care, has had on my thinking. I nurture the ideas I have come to embrace about the ethic of care and reflect on my learning about pedagogies of love. In chronicling my writing, I am coming to find my true calling, both in the blogosphere as well as in the educational profession.


title: Molecular assays for the detection of invasive tunicates and phylogeography of a tunicate invasion in Prince Edward Island

contributor: Davidson, Jeff (Supervisory Committee Member)

contributor: Darling, John (Examination Committee Member)

contributor: Greenwood, Spencer (Supervisory Committee Member)

contributor: Landry, Thomas (Supervisory Committee Member)

contributor: Markham, Fred (Supervisory Committee Member)

contributor: Kibenge, Fred (Supervisory Committee Member)

contributor: Davidson, Jeff (Examination Committee Member)

contributor: Groman, David (Examination Committee Member)

contributor: Markham, Fred (Examination Committee Member)

contributor: Speare, David (Examination Committee Member)

format: print 192 application/pdf PUBLISHED

rights:
The author has agreed that the Library, University of Prince Edward Island, may make this thesis freely available for inspection. Moreover, the author has agreed that permission for extensive copying of this thesis for scholarly purposes may be granted by the professor or professors who supervised the thesis work recorded herein or, in their absence, by the Chairman of the Department or the Dean of the Faculty in which the thesis work was done. It is understood that due recognition will be given to the author of this thesis and to the University of Prince Edward Island in any use of the material in this thesis. Copying or publication or any other use of the thesis for financial gain without approval by the University of Prince Edward Island and the author"s written permission is prohibited.
Requests for permission to copy or to make any other use of material in this thesis in whole or in part should be addressed to:
Chair of the Department of Pathology and Microbiology
Faculty of Veterinary Medicine
University of Prince Edward Island
Charlottetown, P. E. I.
Canada C1A 4P3

abstract: There are currently four invasive tunicate species which are causing significant challenges to the aquaculture industry in Atlantic Canada: Ciona intestinalis, Styela clava, Botryllus schlosseri and Botrylloides violaceus. These tunicates foul mussel socks, aquaculture gear, boat hulls and wharves. As with many aquatic invasive species, detection of these tunicates mostly occurs once adult populations have reached significant population sizes. However, once populations have reached these levels, there is often little that can be done to stop or slow the invasion. Having efficient and sensitive assays that could detect invasive tunicates at microscopic stages would be advantageous as management strategies could be implemented before populations spike to invasive levels. Such an assay would also be useful in monitoring mussel processing plant effluent so that invasive tunicate eggs and larvae are not spread through effluent water discharge to adjacent bays. Molecular assays have been developed in this study that can detect the four invasive tunicate species in both mussel processing effluent water and in bay water surrounding mussel leases. These assays are highly specific and have a sensitivity of detection of 1-5 eggs and/or larvae per water sample. In addition qRT-PCR assays have been developed that can detect and distinguish between different life stages of Ciona intestinalis (egg and larvae) in water samples. This qRT-PCR assay also has the capacity to evaluate viability of free swimming larvae so that nonviable larvae do not cause false positives during mussel processing plant effluent monitoring. The high throughput capacity, high specificity and sensitivity of these assays shows excellent potential for use as a monitoring tool for aquatic invasive species in screening ballast water, effluent waste from shellfish processing plants, as well in local bays and rivers. This study also used phylogenetic analyses of the cytochrome oxidase 1 gene to determine that populations of Botryllus schlosseri in Prince Edward Island have low genetic diversity. Only two haplotypes of B. schlosseri were found in this study in PEI, one which was found in all aquaculture bays tested and the other found only on native substrate in one bay. It is likely that local activity spread this species to other areas of Prince Edward Island after the initial invasion. Phylogeographic analysis suggests that this species was likely transported from Massachusetts to Nova Scotia and then was transported to Prince Edward Island via local boating activity or through the movement of aquaculture species. Through the development of these efficient detection methods and by determining source populations and possible vectors responsible for transporting invasive species to this region, it is hoped that new invasions of aquatic invasive species can be prevented and/or managed before they pose a risk to the aquaculture industry in Prince Edward Island.


title: Heterologous production of bioactive terpenes and discovery of novel natural products from members of the genus Kitasatospora

contributor: Burka, John (Supervisory Committee Member)

contributor: Kerr, Russell (Supervisory Committee Member)

contributor: Cawthorn, Rick (Supervisory Committee Member)

contributor: McCallum, Jason (Supervisory Committee Member)

contributor: Saleh, Tarek (Examination Committee Member)

contributor: Kerr, Russell (Examination Committee Member)

contributor: Greenwood, Spencer (Examination Committee Member)

contributor: Kirby, Christopher (Examination Committee Member)

contributor: Jakeman, David (Examination Committee Member)

format: electronic 283 application/pdf PUBLISHED

abstract:
Nature has provided scientists with numerous bioactive molecules with great potential as therapeutic agents for a range of human and animal diseases. Exploring terrestrial and marine environments for macro- and microorganisms capable of producing these valuable secondary metabolites remains an important source of new drug-leads. Unfortunately, the development of many natural products into full-fledged pharmaceutical products is frequently hindered by the inability of the natural source to provide sufficient quantities to support clinical evaluation.
To address the supply issue hindering the development of many terpenes, a heterologous expression platform capable of high-level production of bioactive terpenes was developed. The metabolic profile of Streptomyces lividans TK24 was first improved by genetically disrupting the production of actinorhodin and undecylprodigiosin via markerless deletions. This removed any interference from these metabolites during biological and chemical assays and eliminated competition for common biosynthetic precursors. Terpentecin biosynthetic genes were then expressed in the genetically modified S. lividans host under the control of a constitutive promoter, though no detectable yield of the diterpene were present in the heterologous host.
This work led to the identification of two new glucosylated polyketides, satosporin A and B, isolated from the strain Kitasatospora griseola MF730-N6. Structure elucidation and stereochemical assignments were performed using spectroscopic analyses, computational methods and chemical derivatizations. Satosporins possess an unprecedented tricyclic ring system comprising an oxo-decalin unit fused to an 8-membered lactone and 11 chiral centers. The aglycone, satosporin C, was selectively obtained by enzymatic deglucosylation of satosporin A using β-glucosidase from almonds.
The satosporing biosynthetic gene cluster was identified from the K. griseola genome via a combination of degenerate primers and Illumina® and Pacific Biosciences® sequencing technologies. The DNA sequences were analyzed by antiSMASH and BLAST® and revealed a 67 kb region that putatively encoded a cytochrome P450 monoxygenase, two large multimodular polyketide synthases, a unique fused ketosynthase-cytochrome P450 monoxygenase, a glycosyltransferase as well as regulatory and self-resistance genes. A knock-out experiment within module 1 of a polyketide synthase (satB) confirmed the involvement of this gene cluster in satosporin biosynthesis as production ceased following gene disruption.
The Pacific Biosciences® sequencing data along with closure of gaps by sequencing overlapping amplicons led to the draft genome of K. griseola in 8 contigs totalling 7,966,157 bp and an overall G + C content of 72.7%. Annotation using RAST revealed 9 complete + 5 incomplete rRNA operons and 7,226 protein encoding sequences. The K. griseola genome was similar to other kitasatosporae and streptomycetes in terms of developmental and regulatory genes and antiSMASH analysis revealed 23 secondary metabolite biosynthetic gene clusters, 15 of which had unknown products.
Over 75% of the bioactive metabolites produced by actinomycete bacteria are from members of the genus Streptomyces. There is, however, a growing interest in bioprospecting from “rare” or non-streptomyces actinomycetes such as kitasatosporae. Twelve kitasatosporae were thus cultured in two media and metabolomic analysis using principal component analysis was used to rapidly identify putatively new natural products. Through collaborative work with MMS student Krista Gill, cystargamide and cystargolide A and B were identified as new compounds.


title: Study of shedding patterns of Mycobacterium avium subspecies paratuberculosis in feces, milk, and colostrum of dairy cows and the development of novel early detection methods for Johne's Disease

contributor: McClure, J. Trenton (Supervisory Committee Member)

contributor: Keefe, Greg (Supervisory Committee Member)

contributor: McKenna, Shawn (Supervisory Committee Member)

contributor: Bach, Horacio (Supervisory Committee Member)

contributor: Chaffer, Marcelo (Supervisory Committee Member)

contributor: Rodriguez-Lecompte, Juan Carlos (Supervisory Committee Member)

contributor: Sanchez, Javier (Supervisory Committee Member)

contributor: Spangler, Liz (Examination Committee Member)

contributor: VanLeeuwen, John (Examination Committee Member)

contributor: Rodriguez-Lecompte, Juan Carlos (Examination Committee Member)

contributor: McKenna, Shawn (Examination Committee Member)

contributor: Bissonnette, Nathalie (Examination Committee Member)

format: electronic 259 application/pdf PUBLISHED

abstract:
The focus of this research was to improve Mycobacterium avium subsp. paratuberculosis (MAP) control and management programs through increased understanding of the diagnostic detection ability of common pathogen and antibody assays over seasons and lactation stages, as well as through the novel use of MAP-specific proteins and a cell-transport media for early diagnostic potential.
Solid and broth cultures, real-time PCR (qPCR), and ELISA diagnostic tests were used to assess a 12-month period of fecal, milk, and colostrum sampling from 51 MAP-infectious dairy cows and 52 consistently test-negative cows from four farms in New Brunswick and three farms in Prince Edward Island, Canada.
For all fecal, milk, and colostrum samples, improved detection ability for MAP was observed with qPCR over culture methods. The bacteria was four times more likely to be detected in feces than in milk with the same testing method in both sample types, but MAP was two times more likely to be detected in feces than in colostrum with qPCR testing. Milk ELISA detected antibodies three out of ten sampling times, but detection ability improved as fecal shedding or host age increased.
Seasonal effects were observed for qPCR and milk ELISA results. Higher detection ability occurred in winter and spring for fecal qPCR, in summer for milk qPCR, and in winter for milk ELISA. Summer held the best agreement between milk and fecal samples collected within the same month. In addition, milk ELISA showed better detection levels in late lactation animals. MAP virulence proteins, including protein tyrosine phosphatase A (PtpA) and protein kinase G (PknG), were evaluated for use in a novel ELISA antigen-coating in milk and serum samples and as antigens for the interferon-gamma (IFN-γ) assay. In addition to the previous samples, extra serum and colostrum samples from cows from the same herds, and serum samples from cows from a test-negative herd were assessed. Improved detection of PtpA was seen in milk and PknG in colostrum, but results were inconsistent and variable. Production of IFN-γ was detected in interleukin-12 (IL-12) p40-potentiated PtpA and PknG whole blood samples. However, small sample size, low protein availability, and inconsistent results in the infected (two cows) and non-infected (two cows) animals biased the apparent benefit of these virulence proteins.
In addition, a novel cell transport media was assessed for improving the utilization of the IFN-γ assay. Whole blood samples from ten healthy cows were each divided into test and control samples, stimulated with the mitogens pokeweed and concanavalinA (ConA), as well as IL-12 p40, on days 1, 5, and 8 post-sampling. Functional immune response was assessed through IFN-γ production (ELISA) and mononuclear cell viability (propidium-iodide flow cytometry). Addition of the transport media improved ConA-dependent IFN-γ secretion and improved mononuclear cell viability up to eight days post-collection.
Improving our knowledge of factors affecting the interpretation of diagnostic assays could benefit Johne’s disease management programs through more effective diagnostic strategies and increased producer participation. Results of this research support the use of qPCR in a Johne’s herd control program, particularly to help minimize MAP exposure to calves. Furthermore, a simple method to extend white blood cell viability in vitro can enhance the practicality of the IFN-γ test as another means of detecting MAP exposure and future risk of MAP infection and transmission within a herd.


title: The use of epidemiology for evaluating the performance and administration strategies of topical drugs for controlling sea lice in Chile

contributor: Arriagada Acevedo, Gabriel Alejandro (author)

contributor: St-Hilaire, Sophie (Supervisory Committee Member)

contributor: Fast, Mark (Supervisory Committee Member)

contributor: Rees, Erin (Supervisory Committee Member)

contributor: Stryhn, Henrik (Supervisory Committee Member)

contributor: Davidson, Jeff (Examination Committee Member)

contributor: Peeler, Edmund (Examination Committee Member)

contributor: Revie, Crawford (Examination Committee Member)

contributor: Fast, Mark (Examination Committee Member)

contributor: Stryhn, Henrik (Examination Committee Member)

format: electronic 195 application/pdf PUBLISHED

abstract:
Sea lice is considered the most important ectoparasite that affects salt water farmed salmonids around the
world. Its high economic impact has motivated efforts for its control. Caligus rogercresseyi is the sea lice
species of major economic importance for the salmon industry in Chile. Sea lice control in Chile is largely
based on chemotherapeutants administered as immersion treatments, synthetic pyrethroids and
organophosphates being the most used drugs at the present. In recent years, farmers have reported
decreased performance of pyrethroid-based treatments. Main causes for treatment failures may be low
sensitivity of sea lice to the anti-parasitic drug, failures in the administration of the product, or reinfestation
from external sources (i.e. neighbouring farms) after the treatment, especially in areas with
intensive salmon farming. The general objective of this thesis was to evaluate the performance of topical
drugs administered as immersion treatments and to evaluate area-level treatment strategies using field
data under an epidemiological approach which considered the multi-factorial nature of the sea lice
dynamics at the farm and the farm management area level. The specific objectives of this thesis were: 1)
to assess the performance of the synthetic pyrethroids deltamethrin and cypermethrin on different life
stages of C. rogercresseyi (Chapter 2), 2) to explore the spatial and spatio-temporal variation of C.
rogercresseyi‘s response to pyrethroid treatments and examine factors related to this variability (Chapter
3), and 3) to evaluate the effect of treatment synchronization on adult sea lice levels up to 8 weeks after
treatment (Chapter 4).
In Chapters 2 and 3 we used the sea lice level one week after treatment as the variable of interest, while in
Chapter 4 we included sea lice levels from week 2 to 8 after the procedure. Pre-treatment sea lice levels,
environmental and management factors were included as predictors in the three cases. In Chapter 2 we
compared the treatment performance between three pyrethroid based products available for the Chilean
industry and with a negative control (i.e. non-treated pen). In Chapter 3 we calculated residuals at the
treatment level and farm effects from a multi-level regression model. Farm effects were subjected to a global cluster analysis (Moran‘s I) and to a purely spatial analysis in order to detect clusters of high sea
lice levels in the study area. Residuals at the treatment level were included in a spatio-temporal analysis.
In Chapter 4 we tested the effect of three different measures of treatment synchronization on the adult lice
levels up to 8 weeks after treatment.
Pens treated with any of the three pyrethroid products had significantly lower mean juvenile, mobile
adult, and gravid female sea lice abundance after treatment compared to the untreated pens; however, the
effect on juvenile lice was less than on mobile stages. No significant differences were observed in the
numbers of juvenile, adult male, and non-gravid female when the three products were compared to each
other; however, cypermethrin exhibited a small, yet significantly greater effect on the gravid female
group.
The global cluster analysis revealed treatment performance was clustered in space, while the scan spatial
statistic found two areas where the post-treatment adult lice level attributed to the farm effect was
significantly higher than in the rest of the study area. These spatial clusters remained even once we
adjusted for environmental and management predictors. In the spatio-temporal analysis, we found three
clusters; however, they become non-significant when predictors were included in the model.
The model containing the treatment synchronization variable, expressed as the number of farms within a
window of 1 week and 10 km seaway distance that reported treatment against sea lice, fitted the model
the best. Higher intensity of treatment synchronization was significantly associated with lower adult lice
levels at weeks 5 and 6 after treatment. This relationship appeared to be linear, suggesting that higher
levels of synchronization may result in lower sea lice levels at these weeks.
Findings of this thesis suggest that during 2011 and 2012 approved pyrethroids in Chile were more
effective on adult than juvenile lice. In general, the three products in evaluation showed a similar
performance, but cypermethrin was associated with better results in the gravid female lice group.
We also found treatment performance was clustered in space, and two areas of poor treatment performance were located. These spatial clusters remained even once we adjusted for environmental and
management predictors, suggesting unknown factors were causing the clustering in these areas. Potential
factors that may explain these clusters include lower sensitivity of sea lice populations to pyrethroids and
problems with the application of the product; however, further research is needed to clarify this situation.
With respect to strategies of treatment at the area level, our results suggest that treatment synchronization
reduced adult lice levels between weeks 5 and 6 after treatment, which could mean a two-week delay in
the rise of sea lice levels after a treatment.


title: Emerging technologies for the assessment of bovine immunoglobulins in biofluids

contributor: McClure, Trenton (Supervisory Committee Member)

contributor: Keefe, Greg (Supervisory Committee Member)

contributor: Markham, Fred (Supervisory Committee Member)

contributor: Riley, Chris (Supervisory Committee Member)

contributor: Shaw, Anthony (Supervisory Committee Member)

contributor: McClure, Trenton (Examination Committee Member)

contributor: Heider, Luke (Examination Committee Member)

contributor: Markham, Fred (Examination Committee Member)

contributor: Godden, Sandra (Examination Committee Member)

contributor: Spangler, Elizabeth (Examination Committee Member)

abstract:
Measurement of bovine serum and colostrum immunoglobulin G (IgG) concentration is critical for colostrum and calf health monitoring in order to determine the colostrum quality and failure of transfer of passive immunity (FTPI), which is considered the main reason for increased morbidity and mortality rates in newborn calves. Several qualitative and quantitative assays are available, but radial immunodiffusion assay is acknowledged as the reference method. However, it is expensive and takes a long time to obtain the results, which prevents the identification of calves with FTPI prior to gut closure. As a consequence, there is a demand for rapid, accurate and inexpensive diagnostic assays for IgG. The objectives of this thesis were: (1) to develop and validate an infrared (IR) spectroscopy based assay for quantification of bovine serum and colostrum IgG concentration, and (2) to validate a novel and rapid on-farm tool for detection of FTPI in dairy calves and for assessing colostrum quality of dairy cows.
Infrared spectroscopy has recently emerged as a powerful, reagent-free diagnostic tool for the quantitative characterization of biological fluids in human and veterinary medicine. We set out to develop a quantitative assay based on IR spectroscopy to measure bovine serum and colostrum IgG concentration and to compare the values with that of the RID assay. Although there are a number of IR spectroscopic sampling techniques, in this research, transmission-IR and attenuated total reflectance (ATR-IR) spectroscopy were used. For quantification of bovine serum IgG concentration, transmission-IR and ATR-IR assays were developed using 250 serum samples collected from calves. The IgG concentration measured by both assays showed excellent correlation with RID-measured IgG. Also, both IR-based assays showed potential for detection of FTPI with good to excellent sensitivity, specificity and accuracy. The transmission-IR assay showed slightly higher precision than the ATR-IR assay. However, the ATR-IR assay is more appropriate for farm and veterinary clinic use. For quantification of colostral IgG concentration, a transmission-IR assay was developed using 251 colostrum samples. The IgG measured by the IR assay showed excellent levels of agreement with the RID assay. The results suggest that IR spectroscopy may be a useful method for colostrum monitoring programs.
Evaluation of an initial version of ZAPvet Bovine IgG test for detection of calves with and without FTPI revealed that the ZAPvet test is relatively sensitive and would be acceptable as an initial screening test for diagnosis of FTPI in dairy calves. However, the low specificity of ZAPvet test would result in over prediction of FTPI incidence, which could result in unnecessary interventions for calves with adequate transfer of passive immunity.
Validation of refractometers, either digital Brix (Atago Co. Ltd; WA) or optical STP (Westover RHC-200ATC handheld refractometer, Woodinville, WA), for detection of FTPI in 202 dairy calves, and digital Brix (Atago Co. Ltd; WA) or optical Brix (model 300001; SPER Scientific, Scottsdale, AZ), for assessing of quality of 251 colostrum samples, revealed that the digital and optical refractometers have good potential for being a useful and practical on-farm management tools to be included in colostrum and calf health monitoring program on dairy operations. Furthermore, the two refractometers performed similarly for detection of FTPI in dairy calves and for assessing of colostrum quality of dairy cows with cut-points slightly higher than that reported in recent studies.


title: Exploring the influence of oral health literacy and oral health chronic disease knowledge on older adults oral care behaviours

contributor: Weeks, Lori (Supervisory Committee Member)

contributor: Montelpare, William (Supervisory Committee Member)

contributor: Compton, Sharon (Supervisory Committee Member)

contributor: Weeks, Lori (Examination Committee Member)

contributor: Compton, Sharon (Examination Committee Member)

contributor: Montelpare, William (Examination Committee Member)

contributor: MacQuarrie, Colleen (Examination Committee Member)

contributor: Hsiao, Amy (Examination Committee Member)

format: electronic 153 application/pdf PUBLISHED

abstract:
Unlike previous generations, baby boomers are keeping their own natural teeth as they
enter into older age. There is a growing body of research demonstrating the link between
oral diseases and common chronic diseases. Therefore, it is imperative that older adults
possess the necessary skills and knowledge, and participate in preventive oral health
behaviours to remain healthy. The purpose of this exploratory, mixed-methods online
study was to explore the influence of oral health literacy (OHL) and oral health chronic
disease knowledge (OHCDK) on oral care behaviours (OCBs). A convenience sample of
69 community dwelling men (n=19) and women (n=50) was recruited to participate in the
Oral Health Chronic Disease Knowledge Study. This Internet based study utilized 4
separate questionnaires: The Oral Health Literacy-Adult Questionnaire, The Oral Health
Chronic Disease Knowledge Questionnaire, The Background Information Questionnaire,
and The Oral Care Behaviours Survey. Findings from The Oral Care Behaviours Survey
were further categorized to create the dependent variable: dental care behaviours, and the
independent predictor variable: home dental aid use behaviour group. In addition,
qualitative data was collected through the use of 9 open-ended questions. Participants
ranged in age from 50 to 69 years, and were further subdivided into early boomers (n=34)
with an average age of 63.9, and late boomers (n=35) with an average age of 54.4. All
participants had achieved higher than high school education; over half of all participants
(52 %) reported living in an urban setting, and 46 % had an annual household income of
greater than $75,000. All participants had some natural teeth and 72 % had access to
private dental insurance. The mean OHL score for the total sample was 13.36, 95% CI
[12.62, 14.10] and the mean OHCDK score was 10.01, 95% CI [9.13, 10.89]. Based on a Pearson product moment correlation co-efficient procedure there was a low but positive
correlation between total population OHL and OHCDK scores [r = 0.31, n =69, p =
0.008]. A dental care behaviours score was determined by adding together individual’s
total points related to the self-reported frequency of dental visits plus frequency of
brushing and frequency of flossing. Scores could range from a maximum of 10 to a
minimum score of 3, and higher scores denote less participation in positive dental care
behaviours. The mean dental care behaviours score was 5.60, 95% CI [5.36, 5.84]. A
backward step regression analysis determined the significant predictor model for dental
care behaviours included: (1.46) dental insurance + (0.85) age cohort + (0.6) level of
education. (F(3) = 311.87, p = < 0.0001, R2 = 93.5%). Early boomers with some
college/trade school education and access to private dental insurance had better dental
care behaviours scores. Qualitative content analysis revealed five major themes: relying
on dental professionals, knowing part of the story, living with the consequences,
practicing and valuing oral health, and identifying barriers to care. Triangulation of both
data sets supported the findings that participants had adequate OHL, yet were lacking in
OHCDK. Comparing and contrasting of the data further highlighted the influential role
that private dental insurance has on dental care behaviours. Future research should focus
on a larger sample sizes from diverse socioeconomic backgrounds with equal numbers of
men and women. It would be beneficial to conduct focus groups to gain further insight
into what factors baby boomers believe will impact their future access to dental care.


title: Use of Fourier-transform infrared spectroscopy to determine immunoglobulin status in camelid and equine species

contributor: Keefe, Gregory (Supervisory Committee Member)

contributor: McClure, J. Trenton (Supervisory Committee Member)

contributor: Riley, Christopher (Supervisory Committee Member)

contributor: Markham, Frederick (Supervisory Committee Member)

contributor: McClure, J. Trenton (Examination Committee Member)

contributor: Shaw, Anthony (Examination Committee Member)

contributor: Lofstedt, Jeanne (Examination Committee Member)

contributor: Muirhead, Tammy (Examination Committee Member)

contributor: Hurnik, Daniel (Examination Committee Member)

format: electronic 167 application/pdf PUBLISHED

abstract:
Measurement of systemic immunoglobulin (Ig) concentrations in horses and camelids is important for early and accurate diagnosis of immunodeficiencies in order to provide proper medical intervention. As a consequence, there is a demand for up-to-date, economic, rapid and precise diagnostic assays for Igs. Accordingly, multiple methods for the evaluation of Ig concentrations have been evaluated in equine and camelid species, each with particular advantages and disadvantages.
Fourier-transform infrared (FTIR) spectroscopy has recently emerged as a powerful diagnostic tool for the quantitative characterization of biological fluids in human and veterinary medicine. In particular, FTIR spectroscopy has proven to be an accurate, economical and reagent-free method for immunoglobulin G (IgG) quantitation in horses. Further research to investigate its potential application in the quantitation of other equine Ig isotypes and IgG subclasses is warranted. Additionally, as rapid quantitative assays for the measurement of camelid serum IgG are limited, further work to assess the use of FTIR spectroscopy in this area is desirable.
The objectives of this thesis were: (1) to develop an FTIR-based assay for the measurement of IgG concentrations in alpaca serum and to compare its performance to that of the radial immunodiffusion (RID) assay, and (2) to develop FTIR-based assays for the measurement IgGa, IgGb, IgG(T), IgA, and IgM for equine plasma using ELISA assays as reference tests.
The first objective of this thesis was achieved by performing RID IgG assays and collecting FTIR spectra for 175 alpaca serum samples. A FTIR-based assay was built using partial least squares regression to convert the spectroscopic data into quantitative IgG values which were compared to the RID results. Correlation coefficients and scatter plots indicated good to excellent levels of agreement between the assays. The results suggest that FTIR spectroscopy may be a useful method for IgG measurement in alpaca serum.
For the second objective, IgGa, IgGb, IgG(T), IgA, and IgM concentrations were determined by ELISA assays and FTIR spectra were collected for 100 equine plasma samples. The spectra were randomly divided into training and prediction sets. The training set was used to build a calibration model for each Ig isotype or IgG subclass using partial least squares regression, while the prediction set was used to test the performance of the developed models. Pearson correlation coefficients and scatter plots displayed moderate to good agreement between FTIR and ELISA IgGb assay results but poor overall agreement for IgGa, IgG(T), IgA and IgM assay results. As well, significant differences were noted between the ELISA results of this study and the reviewed studies from the published literature. At present, a FTIR spectroscopic approach is an inaccurate technique for the measurement of Ig isotypes or IgG subclasses in equine plasma.


title: Monitoring effectiveness of emamectin benzoate for the treatment of sea lice (Lepeophtheirus salmonis) on farmed Atlantic salmon (Salmo salar)

contributor: Davidson, Jeff (Examination Committee Member)

contributor: Revie, Crawford (Examination Committee Member)

contributor: Fast, Mark (Examination Committee Member)

contributor: Hammell, Larry (Supervisory Committee Member)

contributor: Revie, Crawford (Supervisory Committee Member)

contributor: Westcott, Jillian (Supervisory Committee Member)

contributor: Burka, John (Supervisory Committee Member)

contributor: Fast, Mark (Supervisory Committee Member)

contributor: Whyte, Shona (Examination Committee Member)

contributor: Rees, Erin (Examination Committee Member)

format: electronic 149 application/pdf PUBLISHED

rights:
The author has agreed that the Library, University of Prince Edward Island, may make this thesis freely available for inspection. Moreover, the author has agreed that permission for extensive copying of this thesis for scholarly purposes may be granted by the professor or professors who supervised the thesis work recorded herein or, in their absence, by the Chair of the Department or the Dean of the Faculty in which the thesis work was done. It is understood that due recognition will be given to the author of this thesis and to the University of Prince Edward Island in any use of the material in this thesis. Copying or publication or any other use of the thesis for financial gain without approval by the University of Prince Edward Island and the author’s written permission is prohibited.
Requests for permission to copy or to make any other use of material in this thesis in whole or in part should be addressed to:
Chair of the Department of the Department of Health Management
Faculty of Veterinary Medicine
University of Prince Edward Island
Charlottetown, P. E. I.
Canada C1A 4P3

abstract:
Resistance development to parasiticides has been a problem in both terrestrial and aquatic environments. A major challenge exists in early detection of resistance emergence due to the low frequency at which resistant organisms can occur initially within a population and the difficulty in detecting these organisms. Emamectin benzoate is an avermectin compound which has been used effectively in the treatment of sea lice on farmed salmonids around the world. The main purpose of this thesis was to examine field collected sea lice abundance data and treatment records to estimate changes in the effectiveness of emamectin benzoate for treatment of sea lice (Lepeophtheirus salmonis) infestations on farmed Atlantic salmon (Salmo salar).
The objectives of this thesis were: (1) to review and describe methods for the evaluation of sea lice treatment effectiveness, (2) to evaluate and establish if changes in effectiveness of emamectin benzoate for the treatment of sea lice (L. salmonis) on farmed Atlantic salmon in New Brunswick, Canada, had occurred from 2004 to 2008, and (3) to determine if there was evidence of differences in the temporal development of resistance to emamectin benzoate across L. salmonis life stages using data collected in both Canada and Scotland.
Field collected data from New Brunswick salmon farms (2004 to 2008) were examined for temporal and spatial changes in treatment effectiveness in populations of L. salmonis. Data analysis was carried out in two parts: examination of trends in treatment effectiveness and L. salmonis abundance and an examination of multiple factors influencing post-treatment L. salmonis abundance and treatment outcome through the use of statistical models (linear and logistic regression). A reduction in treatment effectiveness was found from 2004 to 2008 and treatment effectiveness was found to vary by location.
Further analysis was carried out to examine for possible differences in treatment effectiveness between different sea lice life stages. Life stages were categorized into two groups: adult females (gravid and non-gravid) and other mobile stages (pre-adult female, pre-adult male, and adult male). Sea lice abundance records following emamectin benzoate treatments from the west coast of Scotland (2002 to 2006) and from New Brunswick, Canada (2004 to 2008) were examined. Differences in treatment effectiveness were found between the two groups by year and location. Changes in sea lice sensitivity to emamectin benzoate were not synchronized in all life stages. A difference in the rates of resistance development between locations was noted, with resistance developing more rapidly in New Brunswick than in Scotland.
In summary, this research examined methods for the evaluation of emamectin benzoate effectiveness for the control of sea lice. A reduction in emamectin benzoate effectiveness occurred over time and varied by location. In addition, resistance development was not synchronized in all sea lice life stages. These methods could help aid in the detection of resistance development in parasites. However, no single method is likely to suffice for monitoring changes in sea lice sensitivity. In future, coordinated analyses from both laboratory and field studies will likely yield the best results.


title: Comparative immunological development and responses in lower vertebrates: sturgeon

contributor: Kibenge, Frederick (Supervisory Committee Member)

contributor: Wright, Glenda (Supervisory Committee Member)

contributor: Markham, Fred (Supervisory Committee Member)

contributor: Speare, David (Supervisory Committee Member)

contributor: Burton, Shelley (Examination Committee Member)

contributor: Wright, Glenda (Examination Committee Member)

contributor: Rodriguez, Juan Carlos (Examination Committee Member)

contributor: Speare, David (Examination Committee Member)

format: electronic 146 application/pdf PUBLISHED

rights: In presenting this thesis in partial fulfillment of the requirements for a postgraduate degree from the University of Prince Edward Island, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the professor or professors who supervised my thesis work, or, in their absence, by the Chair of the Department or the Dean of the Faculty in which my thesis work was done. It is understood any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Prince Edward Island in any scholarly use which may be made of any material in my thesis.

abstract:
Sturgeon are harvested worldwide for their meat and eggs, sold as caviar and are among the most economically important fish species worldwide. A generally low physiological response to external stimuli/stressors has been documented in these phylogenetically primitive species.
Considering how little is known about sturgeon immune responses, it is important to study how they respond to such stimuli/stressors. The culture of sturgeon larvae is associated with a high mortality rate during and after yolk sac absorption and onset of feeding. Therefore, it is relevant to study the immune competence of larvae and juvenile sturgeon and determine when their immune organs first appear and how they develop. The meningeal myeloid tissue, the spleen and the thymus were characterized morphologically by light microscopy (LM) and transmission electron microscopy (TEM) in Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) during the first 5 months of life (until 2895 growing degree days, °C.day (dd)). In sturgeon, the spleen was first visible approximately 400 dd after the onset of feeding (at 541 dd) and the meningeal myeloid tissue and the thymus at 768 dd after the onset of feeding; these first appeared between 541 dd and 768 dd, respectively. Heterophil and eosinophil percentages were significantly greater in the meningeal myeloid tissue of larger fish (950 and 2895 dd, respectively) when compared with the smaller fish. The percentages of reticular cells were significantly higher in the smallest fish than in the larger fish and the undifferentiated cells were higher in the youngest animals compared to the older age groups. Likewise, the splenic heterophil percentages were significantly higher in the oldest fish (2895 dd) compared to the youngest fish (768 dd). The splenic undifferentiated cell percentages were significantly higher in the younger fish compared to the oldest. This emphasizes less developed immune organs in the smaller animals. Lymphocyte percentages did not change over time in these tissues. In the thymus, lymphocytes were the predominant cell type and only the undifferentiated cell percentages were significantly different and highest in the oldest group, possibly reflecting a more proliferative thymus in these animals.
In order to characterize changes in cell populations in relevant immune organs, a temperature trial was done in juvenile shortnose sturgeon (Acipenser brevirostrum), kept at 11°C or at 20°C. Relevant immune organs such as the meningeal myeloid tissue, the spleen, the thymus and the skin were studied. A higher temperature had a significant positive influence on the immune cell production in the meningeal myeloid tissue (higher lymphocyte, eosinophil and heterophil percentages). Likewise, temperature resulted in an initial but transient increase in splenic white pulp percentage. A similar effect was seen for splenic expression of interferon regulatory factors 1 and 2 (IRF-1 and IRF-2) and no changes occurred in matrix metalloproteinase 9 (MMP-9) expression for both spleen and skin. IRF-1 and IRF-2 expression in the skin were significantly higher expression in the fish kept at 11°C at 3 and 6 weeks post temperature change. There were no differences in thymus size between the different groups. Further research is required to better characterize the nature of these immune responses in these organs.
These findings suggest that an effective immune response may not occur in early life stages prior and during the onset of feeding but further research is needed to further assess this. Rearing sturgeon juveniles at higher temperatures (up to 20°C) may be beneficial for sturgeon aquaculture, since it maximizes growth rates and positively influences immune cell percentages in relevant immune organs.


title:
Developing global citizenship in higher education through
international experiential learning: an interpretive case study

contributor: Guo, Linyuan (Supervisory Committee Member)

contributor: Favaro, Basil (Supervisory Committee Member)

contributor: Guo, Linyuan (Examination Committee Member)

contributor: Favaro, Basil (Examination Committee Member)

format: electronic 119 application/pdf PUBLISHED

rights:
In presenting this thesis in partial fulfilment of the requirements for a graduate degree from the
University of Prince Edward Island, the author has agreed that the Robertson Library, University of
Prince Edward Island, may make this thesis freely available for inspection and gives permission to add an
electronic version of the thesis to the Digital Repository at the University of Prince Edward Island.
Moreover the author further agrees that permission for extensive copying of this thesis for scholarly
purposes may be granted by the professor or professors who supervised the author’s thesis work, or, in
their absence, by the Chair of the Department or the Dean of the Faculty in which the author’s thesis
work was done. It is understood that any copying or publication or use of this thesis or parts thereof for
financial gain shall not be allowed without the author’s written permission. It is also understood that
due recognition shall be given to the author and to the University of Prince Edward Island in any
scholarly use which may be made of any material in the author’s thesis.

abstract:
This case study investigates the correlation between international experiential learning
and the development of global citizenship characteristics through understanding the lived
experiences of 10 University of Prince Edward Island students who took part in two different
forms of international experiential learning (IEL) programs. A review of the literature around
international education, international experiential learning, global citizenship, and
internationalization within higher education is presented. A small demographic survey, predeparture
and re-entry focus groups, and reflective journaling were used to collect data about
participant experience. Several questions were addressed: What does global citizenship mean for
participants? What are participants‟ lived experiences during the international experiential
learning process? What practices and strategies adopted by the international experiential learning
programs facilitate students' development as global citizens? This research will determine
whether or not students understand global citizenship. It will also serve as a vehicle to
understand and explore whether or not there is a connection between IEL and the development of
global citizenship characteristics. In total, 10 students took part in the study. The findings reveal
students' understanding of global citizenship and suggest that a global citizenship objective has
to be explicit and woven into international experiential learning programs in order to help
students in higher education become responsible global citizens. Mandatory reflection, more
IEL opportunities, and the incorporation of IEL into curriculum are just a few of the
recommendations put forth to better support and promote the development of global citizens in
today‟s globalized age.


title: Evaluation of factors affecting performance of diagnostic tests for infectious salmon anaemia virus

contributor: Sanchez, Javier (Examination Committee Member)

contributor: Gardner, Ian (Examination Committee Member)

contributor: Wright, Peter (Examination Committee Member)

contributor: Revie, Crawford (Examination Committee Member)

contributor: Hammell, Larry (Examination Committee Member)

format: print 354 application/pdf PUBLISHED PUBLISHED PUBLISHED PUBLISHED

rights:
In presenting this thesis in partial fulfillment of the requirements for a postgraduate
degree from the University of Prince Edward Island, I agree that the Libraries of this
University may make it freely available for inspection. I further agree that permission
for extensive copying of this thesis for scholarly purposes may be granted by the
professor or professors who supervised my thesis work, or, in their absence, by the
Chair of the Department or the Dean of the Faculty in which my thesis work was done.
It is understood any copying or publication or use of this thesis or parts thereof for
financial gain shall not be allowed without my written permission. It is also understood
that due recognition shall be given to me and to the University of Prince Edward Island
in any scholarly use which may be made of any material in my thesis.
Address: AVC-Centre for Aquatic Health Sciences & Department of Health Management
Atlantic Veterinary College
University of Prince Edward Island
Charlottetown, Prince Edward Island, Canada
C1A 4P3

abstract:
To secure the safety of international trade of animal and their derived products, it is
required that animals should be proven infection-free using a validated diagnostic test
certified by the World Organization for Animal Health (OIE).  Test validation involves a
multi-step evaluation process to assess test accuracy and its fitness for a specific
purpose. Contrary to common understanding, diagnostic accuracy is not constant for
each test and may vary within and between populations according to the distribution of
biological factors that influence the pathophysiology of the disease. Diagnostic test
accuracy combines the precision (repeatability & reproducibility) and the trueness of the
test (diagnostic sensitivity, DSe, & specificity, DSp).
The objective of this research program was to extend diagnostic test evaluation
methods by estimating accuracy specifically for influential covariate factors. This
research was applied to reverse-transcriptase polymerase chain reaction (RT-PCR) for
infectious salmon anaemia virus (ISAV). Early detection of ISAV is the base of an
efficient control of this devastating disease for salmon aquaculture industries.
RT-PCR accuracy was shown to differ among stages of infection, revealing
substantial variation of test precision across prevalences of infection stages in the tested
populations. Submission factors such as homogenization and testing laboratory also
significantly impacted the precison and were accounted for to predict test result
agreement across prevalences. Latent Class Modeling (LCM) was used to evaluate test
trueness in absence of true status information. LCM assumes that DSe & DSp are
constant across populations, which was revealed as an invalid assumption. Extending to
3-class LCM revealed different DSe between low- and high-infected salmon. Finally,
the selection of the proper cutpoint for the real-time version of RT-PCR was dependent
on the distribution of infection stages in the target population. Both analytical and
epidemiological approaches to select the cutpoint were reviewed to improve the fit for
intended purpose of the test.

Potential applications for specific estimates of test accuracy and new perspectives on
diagnostic test evaluation and use were discussed.


title:
Bridging ‘Islands Of Medicine’: Balancing medical pluralism on La Isla
De Chiloe

contributor: Krautwurst, Udo (Supervisory Committee Member)

contributor: Mitchell, Jean (Supervisory Committee Member)

contributor: Krautwurst, Udo (Examination Committee Member)

contributor: Mitchell, Jean (Examination Committee Member)

contributor: Walton, Fiona (Examination Committee Member)

contributor: Widmer, Alexandra (Examination Committee Member)

contributor: Walton, Fiona (Supervisory Committee Member)

contributor: Widmer, Alexandra (Supervisory Committee Member)

format: electronic 193 application/pdf PUBLISHED

rights:
In presenting this thesis in partial fulfilment of the requirements for a graduate degree
from the University of Prince Edward Island, the author has agreed that the Robertson
Library, University of Prince Edward Island, may make this thesis freely available for
inspection and gives permission to add an electronic version of the thesis to the Digital
Repository at the University of Prince Edward Island. Moreover the author further agrees
that permission for extensive copying of this thesis for scholarly purposes may be granted
by the professor or professors who supervised the author’s thesis work, or, in their
absence, by the Chair of the Department or the Dean of the Faculty in which the author’s
thesis work was done. It is understood that any copying or publication or use of this
thesis or parts thereof for financial gain shall not be allowed without the author’s written
permission. It is also understood that due recognition shall be given to the author and to
the University of Prince Edward Island in any scholarly use which may be made of any
material in the author’s thesis.

abstract:
This thesis brings together the study of islands, anthropology, and postcolonialism;
it discusses (1) how global assemblages, such as colonial interactions and
neoliberal economies influence individual well-being and local health care ontologies as
practice on islands, and (2) the space and place of medical plurality on islands.
Ethnographic research took place over four months on Chiloé Island, Chile. The research
included interviews with members of the Williche Council of Chief’s health program,
medical practitioners in the public health system, and health service employees with the
government. An examination of the integration between the Council’s health program
and public health care clinics in the archipelago is central to this thesis. This intercultural
approach to health care is compared to that of the institutionalization of indigenous
medicines within the South Pacific. The relationship among health, economies, and
ecosystems on islands, serves as a framework for gaining a different perspective on how
medical pluralism occurs on islands.


title: Evaluation of a 3M Petrifilm on-farm milk culture system for use in selective dry cow therapy

contributor: McKenna, Shawn (Supervisory Committee Member)

contributor: Keefe, Gregory (Supervisory Committee Member)

contributor: Dohoo, Ian (Supervisory Committee Member)

contributor: Domike, Reuben (Supervisory Committee Member)

contributor: Roy, Jean-Philippe (Supervisory Committee Member)

contributor: Domike, Reuben (Examination Committee Member)

contributor: Heider, Luke (Examination Committee Member)

contributor: McKenna, Shawn (Examination Committee Member)

contributor: Rajala-Schultz, Päivi (Examination Committee Member)

contributor: Spangler, Elizabeth (Examination Committee Member)

format: electronic 244 application/pdf PUBLISHED

rights: In presenting this thesis in partial fulfilment of the requirements for a graduate degree from the University of Prince Edward Island, the author has agreed that the Robertson Library, University of Prince Edward Island, may make this thesis freely available for inspection and gives permission to add an electronic version of the thesis to the Digital Repository at the University of Prince Edward Island. Moreover the author further agrees that permission for extensive copying of this thesis for scholarly purposes may be granted by the professor or professors who supervised the author‘s thesis work, or, in their absence, by the Chair of the Department or the Dean of the Faculty in which the author‘s thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without the author‘s written permission. It is also understood that due recognition shall be given to the author and to the University of Prince Edward Island in any scholarly use which may be made of any material in the author‘s thesis.

abstract:
As an alternative to blanket dry cow therapy (BDCT), selective dry cow therapy (SDCT) is considered a more judicious approach to antimicrobial use for the purpose of mastitis control during the non-lactating period. The purpose of this research was to evaluate the utility of a 3M Petrifilm-based on-farm milk culture system (OFCS) for use in a SDCT program. A randomized clinical trial was conducted using 16 low bulk tank somatic cell count (<250,000 cells/mL) dairy herds from Prince Edward Island (n = 10) and Quebec (n = 6), Canada. When used to detect intramammary infection (IMI) in cows at drying off, the OFCS performed well with a sensitivity of 85% and specificity of 73%. By comparing producer-derived Petrifilm results to those obtained using an accurate automated reader, it was determined that producers were able to correctly interpret Petrifilm results with an observed agreement of 91% and kappa value of 0.82. The study groups comprising the clinical trial were a positive control group consisting of cows receiving blanket application of dry cow therapy (DCT) with the addition of an internal teat sealant (ITS), and the OFCS group consisting of cows selectively treated at drying off based on OFCS results with ITS alone (Petrifilm negative) or DCT + ITS (Petrifilm positive). No significant differences in postcalving IMI risk and risk of clinical mastitis in the first 120 days of the subsequent lactation were detected between the study groups. Furthermore, no significant differences were observed between study groups regarding test day milk yield and somatic cell count in the first 180 days of the subsequent lactation. Petrifilm-OFCS-based SDCT enabled a reduction in DCT of 21% as compared to BDCT. The effect of ITS on the interdependence of quarters towards the acquisition of new IMI (NIMI) with coagulase negative staphylococci (CNS) over the dry period was also investigated. It was demonstrated that in cows that were infused with ITS, the presence of CNS in another quarter at drying off was a risk factor for CNS NIMI, but this association was absent in cows without ITS infusion. This unexpected finding may have resulted from inadvertent introduction of CNS during ITS infusion. In quarters of cows without a CNS IMI at drying off (i.e. without a source of contagious CNS), ITS was protective against CNS NIMI suggesting that CNS infection over the non-lactating period can be partly attributed to CNS species located within the environment.
According to economic analyses, OFCS-based SDCT resulted in a marginally higher total cost per cow than BDCT. However, OFCS-based SDCT provided the combined benefits of lowering DCT treatment risk without increasing the risk of postcalving IMI, and was superior economically to a SDCT program based on somatic cell count and clinical mastitis history. Overall, the Petrifilm OFCS was an accurate diagnostic tool that was effective in reducing DCT use without compromising the health, welfare, and future milk production of the cow.