title: Drug Discovery from Cold-Adapted Bacteria from Malpeque Bay, Prince Edward Island

contributor: Shaver, Michael (Supervisory Committee Member)

contributor: Chapman, Bob (Supervisory Committee Member)

format: 181 electronic application/pdf

subject:
Biology, Molecular
Biology, Microbiology
Chemistry, Analytical

abstract: Marine bacteria represent an excellent renewable source of novel, bioactive natural products. Cold-adapted bacteria have been under-studied and thus temperate environments represent a largely untapped resource for the discovery of microbial natural products.

abstract: This thesis examined the bacterial diversity of cold-adapted bacteria from seawater and sediment collected from Malpeque Bay, Prince Edward Island, a unique marine environment, which resulted in the discovery of 16 different groups of bacteria. One isolate was fermented from each group in 11 different media, in a high-throughput method using 96-well plates to maximize the number of media conditions used for each isolate. LC-MS analysis was performed on crude extracts and follow-up fermentations were prioritized by LC-MS data analysis. Fermentations of 6 isolates in 2 media were scaled up in 24-well plates and in 250 mL Erlenmeyer flasks for production confirmation and antimicrobial analysis. A psychrotolerant bacterium, Figoribacterium sp., was found to produce a wide variety of cell-associated glycoglycerolipids (GGL) in ACC media. Four glycoglycerolipids, 1-O-acyl-3-[α-D-mannopyranosyl-(1-3)-(6-O-acyl-α-D-mannopyranosyl)]-sn-glycerol (GGL 915, 887, 885a and 885b), including two new analogues which contain  trans-12-methyl-10-tetradecenoic acid and 12-methyltetradecanoic acid were isolated by reverse phase chromatography.

abstract: Structure elucidation was performed by LC-ESI-MS/MS, HR-MS and NMR. NMR characterization involved the use of 1D NMR (1H and  13C), 2D NMR (COSY, HSQC, HMBC, NOESY and ROESY) as well as coupling constant analysis. Fermentation optimization by supplementing ACC media with 20 g/L glucose or glycerol greatly increased production of different GGL analogues. One of the new compounds, GGL 915, was assessed for surface tension, antimicrobial and cytotoxic activities and was found to be inactive. However, GGL 885, 887 and 915 were tested for activity against the Vaccinia and Influenza A viruses, where GGL 887 showed preliminary indications of antiviral activity against Influenza A.

abstract: Source: Masters Abstracts International, Volume: 50-04, page: 2439.

abstract: Adviser: Russell G. Kerr.


title: Drug resistance and toxigenic properties of Campylobacter jejuni and Campylobacter coli isolated from the intestinal tract of chickens on Prince Edward Island

type: Text Dissertation/Thesis

contributor: Kibenge, Frederick (Supervisory Committee Member)

contributor: Markham, R.J. Frederick (Supervisory Committee Member)

contributor: Yason, Carmencita (Supervisory Committee Member)

format: 126 electronic application/pdf

subject:
Biology, Microbiology
Biology, Veterinary Science

abstract: Campylobacter jejuni and C. coli were isolated from 119 (51.5%) of 231 samples of chicken cecal contents.

abstract: Plasmid DNA was isolated from two tetracycline resistant $\rm (TET\sp{r})$ C. jejuni strains RO 28 and RO 33 from broiler chickens using three different protocols: rapid TELT mini-prep, rapid mini-prep with heat, and Promega$\rm\sp{TM}$ mini-prep. Of these three only Promega$\rm\sp{TM}$ mini-prep gave a consistent yield of plasmid DNA. The two $\rm TET\sp{r}$ isolates RO 28 and RO 33 each had a plasmid DNA in the Agarose gel electrophoresis corresponding to the 45 Kbp $\rm TET\sp{r}$ plasmid and a smaller band corresponding to the 12 Kbp of the marker DNA. A $\rm TET\sp{r}$ strain of C. jejuni ATCC 43502 with a 45 Kbp a $\rm TET\sp{r}$ plasmid was used as a control.

abstract: The production of enterotoxin by C. jejuni and C. coli was evaluated by adding cell-free filtrates of 48 hour cultures of the bacteria to CHO-K1 cells grown in Ham's F12 media in 96 well plates. Two human C. jejuni strains 4483 and 6704 were included in each test as positive and negative controls respectively. Of the 119 isolates of C. jejuni strains 4483 and 6704 were included in each test as positive and negative controls respectively. Of the 119 isolates of C. jejuni and C. coli that were tested, 56 (47%) produced toxins that caused elongation of the CHO-K1 cells. Strong toxin effect was observed at dilutions of 1:2, 1:4 and 1:8.

abstract: In conclusion, understanding the rate of carriage of drug resistant and toxigenic C. jejuni by chicken is crucial to the development of control measures to reduce the contamination of the pathogen on poultry meat and thus lower the risk of infection to consumers. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 35-03, page: 0768.

abstract: Adviser: H. Hariharan.


title: Effect of amniotic fluid and meconium in the lung of neonatal Fischer 344 rats

contributor: Horney, Barbara (Supervisory Committee Member)

contributor: Wright, Glenda (Supervisory Committee Member)

contributor: Ireland, William (Supervisory Committee Member)

format: 307 electronic application/pdf

subject:
Biology, Animal Physiology
Health Sciences, Pathology
Biology, Veterinary Science

abstract: Meconium aspiration syndrome (MAS) is a major contributor to neonatal respiratory distress and an important cause of morbidity and mortality in infants. This syndrome has been recognized in foals, calves and puppies and pulmonary lesions in these animals are similar to those described in babies with MAS. There are few reliable animal models to evaluate the lesions and inflammatory response associated with MAS under laboratory conditions. The objectives of this investigation were: (1) to standardize a murine model of MAS using intratracheal inoculation (ITI) in 7-day-old rats. (2) to quantify the cytological and biochemical changes in the bronchoalveolar lavage (BAL) after ITI of amniotic fluid and meconium. (3) to evaluate and quantify the microscopic and ultrastructural changes in the lungs after ITI of meconium.

abstract: Results of this investigation showed that pulmonary alveolar macrophages (PAM) are present in the fetal lung and the numbers increase significantly during the first 3 days of life. After 3 days, the cell counts are comparable to young or adult rats. During the postnatal period, there is a transient influx of neutrophils (PMN) into the bronchoalveolar space. The lungs of normal rat neonates have high activities of alkaline phosphatase (ALP) and lactate dehydrogenase, and gamma-glutamyltransferase (GGT) and protein increase transiently during the first few days of life.

abstract: 20% unfiltered homologous meconium induced a sharp increase in PMN shortly after inoculation. Meconium also induced a significant influx of PAM, vascular sequestration of PMN and aggregation of platelets in capillaries. Meconium caused a transient injury to the cells of the respiratory membrane characterized by a significant increase of enzymatic activity. Ultrastructurally, cell injury was moderate and transient and did not lead to extensive necrosis of epithelial cells. Protein leakage suggesting an alteration of vascular permeability was also detected in the neonates inoculated with meconium. Other meconium-associated changes included atelectasis and hyperinflation and a significant thickening of alveolar septa. Ultrastructurally, alveolar thickening coincided with interstitial edema and sequestration of PMN. The early neutrophilic response progressed into a persistent multifocal histiocytic and granulomatous reaction and some granulomatous foci eventually calcified or became lined by cuboidal cells. There were moderate hypertrophy and hyperplasia of type II pneumocytes, mild interstitial proliferation of mesenchymal cells and focal intraalveolar fibrosis. Topographically, the centriacinar region and neighboring alveoli were the main sites affected by meconium. (Abstract shortened by UMI.).

abstract: Source: Dissertation Abstracts International, Volume: 61-04, Section: B, page: 1888.

abstract: Adviser:  Alfonso Lopez.


title: Effect of dietary enzyme supplementation on digestibility and growth performance of pigs fed hulled or hull-less barley-based diets:  An  in vivo and in vitro study

contributor: Ogilvie, Tim (Supervisory Committee Member)

contributor: Burka, John (Supervisory Committee Member)

contributor: Lofstedt, Jeanne (Supervisory Committee Member)

format: 105 electronic application/pdf

subject: Agriculture, Animal Culture and Nutrition

abstract: The effect of xylanase and β-glucanase supplementation on nutrient digestibility, growth performance and Carcass characteristics of pigs fed hulled and hull-less barley-based diets was determined by a metabolism trial, a growth trial and in vitro methods.

abstract: A metabolism trial was conducted using eighteen gilts [47 ± 2 kg (SD)]. randomly assigned to one of six dietary treatments. The experimental diets consisted of hull-less or hulled barley supplemented with xylanase (xyl) or xylanase + β-glucanase (xyl + β-glu) or without enzyme.

abstract: The three-stage in vitro method proposed by Boisen (1991) (Method A) was carried out with modifications (Methods B, C and D) using amylase, lipase, cellulase, hemicellulase and Viscozyme® for the prediction of in vivo fecal digestibility for dry matter (DM), nitrogen (N) and digestible energy (DE) of ten swine diets.

abstract: Although no significant effects were observed between types of barley or enzyme supplementation in growth trials, the improvements in nutrient digestibility with hull-less barley and xylanase supplementation were encouraging. The lack of a large number of samples for which in vivo digestibility is known and the narrow range in digestibility of common swine rations make the development of an in vitro method difficult.  (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 38-03, page: 0618.

abstract: Adviser:  Ted Van Lunen.


title: Effect of pretreatment with an adenosine analogue, N(6)-cyclopentyladenosine (CPA), on stroke outcome in rats

contributor:
Campbell, D. Scott (author)
Sweeney-Nixon, Marva (Thesis advisor)
(Supervisory Committee Member)

format: 134 electronic application/pdf

subject: Health Sciences, Pharmacology

abstract: Adenosine A1 receptor agonists, such as N6-cyclohexyladenosine (CHA), N6-(R)-phenylisopropyladenosine (R-PIA), and N 6-cyclopentyladenosine (CPA), are neuroprotective when administered prior to a hypoxia-ischemia (H-I). Activation of A1 receptors may also mediate ischemic preconditioning. It was hypothesized, therefore, that a single administration of CPA prior to a H-I insult would provide neuroprotection against H-I induced damage in the rat hippocampus. This thesis examined the neuroprotective response to CPA when it was administered at varying doses and varying time points prior to a H-I insult. Results confirm the neuroprotective effect resulting from activation of adenosine A1 receptors before a H-I insult, against H-I induced damage and suggest a possible therapeutic application for adenosine Al agonists for the prevention of stroke damage. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 42-02, page: 0574.

abstract: Adviser: Marva Sweeney-Nixon.


title: Effect of wild blueberry (Vaccinium angustifolium) juice consumption on cardiovascular and inflammatory markers in male participants

contributor: Gottschall-Pass, Katherine (Supervisory Committee Member)

contributor: Sweeney-Nixon, Marva (Supervisory Committee Member)

format: 130 electronic application/pdf

subject:
Health Sciences, Nutrition
Biology, Physiology

abstract: Wild blueberries (Vaccinium angustifolium) are rich in antioxidants and may offer a novel approach to treat heart disease due to anti-inflammatory and anti-diabetic properties. Thus, this study examined the effect of human consumption of wild blueberry juice on markers of cardiovascular disease, metabolic syndrome, oxidative stress, and inflammation. Fourteen middle-aged men with cardiovascular risk factors consumed wild blueberry juice for 3 weeks in a single-blind, randomized, placebo-controlled, crossover trial with a 2-week washout period. Exclusion criteria included use of lipid-altering medications or history of inflammatory disease. Compliance was monitored using 3-day food records. Fasting blood samples were taken at the beginning and end of each treatment period, and serum analyzed. In general, results showed trends toward a reduction in metabolic risk factors, although not always reaching statistical significance. There was a decrease in serum glucose [change from baseline: 0.25 ± 0.13 to -0.11 ± 0.08 mmol/L] (p = 0.037) and a trend towards decreased insulin concentrations (p = 0.088) in the treatment group. Insulin resistance (p = 0.066), estimated using the homeostasis model assessment, decreased in the treatment group whereas it increased in the placebo group. Blueberry tended to lower levels of inflammatory cytokines (IL-6, CRP, TNFα) and there were trends toward an increase in plasma adiponectin (p = 0.095), a hormone that inhibits inflammatory processes and enhances insulin sensitivity. These results suggest that dietary blueberry may exhibit cardio-protective and anti-diabetic properties in men. However, additional research with a greater sample size and longer treatment time is needed to further define efficacy and dose.

abstract: Source: Masters Abstracts International, Volume: 47-06, page: 3531.


title: Effectiveness of teflubenzuron for treating sea lice on Atlantic salmon:  Randomized control clinical trial, historical control clinical trial, and an assessment of outcome measurements and sampling methods

contributor: Spangler, Elizabeth (Supervisory Committee Member)

contributor: Johnson, Gerry (Supervisory Committee Member)

format: 195 electronic application/pdf

subject:
Biology, Veterinary Science
Agriculture, Fisheries and Aquaculture

abstract: A double-blind, randomized clinical trial was performed to investigate the effectiveness of teflubenzuron to control sea lice (Lepeophtheirus salmonis) on cage reared Atlantic salmon (Salmo salar). The teflubenzuron was administered in the feed at a dosage of 10 mg/kg biomass/day for seven days. Chalimus stages in medicated cages were significantly lower than in control cages at one week (79% reduction, p < 0.001), and at two weeks (53% reduction, p < 0.001). Mobile (pre-adult and adult) stages were also significantly reduced in medicated cages at one week (69% reduction, p < 0.01), and at two weeks (40% reduction, p < 0.01). These reductions may underestimate the full potential of teflubenzuron, due to the low parasite levels experienced during the summer of 1996, and due to recruitment from the untreated cages. A historical control clinical trial was also performed at one site using teflubenzuron administered in the feed at a dosage of 10 mg/kg biomass/day for seven days. This study involved the treatment of all nine cages on site. Six of the cages were pre-market size salmon and three cages contained smolt. At one week after the end of treatment chalimus stages were reduced by 92% (p < 0.05) and mobile stages were reduced by 74% (p < 0.05) from pre-treatment levels. Two weeks after the end of treatment chalimus stages were reduced by 41% (p < 0.05) and mobiles were reduced by 61% from pre-treatment levels. Three weeks after the end of treatment chalimus stages were still reduced 36% (p < 0.05) from pre-treatment levels, but mobile stages had increased by this time. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 38-05, page: 1269.

abstract: Advisers:  Ian Dohoo; Larry Hammell.


title: Effects of chloramine-T regime on juvenile rainbow trout (Oncorhynchus mykiss)

contributor: Sims, David (Supervisory Committee Member)

format: 173 electronic application/pdf

subject: Agriculture, Fisheries and Aquaculture

abstract: In this thesis, an experiment was devised to address the effects of chloramine-T on the production performance of juvenile rainbow trout during an 11-week growth trial conducted under conditions which simulated those of intensive aquaculture. Chloramine-T significantly suppressed the growth of treated fish $(\delta =7.3\%).$ The suppressive effects of chloramine-T were most dramatic in the early phase of the growth trial, but persisted throughout its duration. Subsequent studies were designed to address whether growth disturbances in treated fish are related to activation of a stress response and/or changes to gill and skin microanatomy. From these studies we found that exposure of trout to chloramine-T treatment regime used on the growth trial did not cause a significant change in cortisol levels or hematocrit, plasma glucose, sodium and chloride, leading to the conclusion that chloramine-T treatment was non-stressful to the experimental animals in this study. Fish treated with chloramine-T had an upward shift in the ratio of sialic-acid containing mucous cells compared to neutral mucous cells. Chloramine-T caused alterations in the epidermis of treated fish by decreasing its thickness and increasing the number of electron-dense vesicles in epithelial pavement cells. Gill lamellae of treated fish had expanded interstitial spaces and increased numbers of chloride cells. However, treatment did not affect the morphology of the mucous covering of the gill or skin, nor did it change the number of mucous $\rm cells/mm\sp2,$ or the electron density of the mucosomes of the skin. These tissue changes are probably insufficient to be considered as significant mechanisms accounting for the effect of chloramine-T on growth rates, and further study is therefore warranted to derive the mechanism. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 35-03, page: 0730.

abstract: Advisers: D. Speare; G. Johnson.


title: Effects of kainic and domoic acids on the release of glutamate and aspartate from rat brain synaptosomes

contributor: Tasker, Andrew (Supervisory Committee Member)

contributor: Amend, James (Supervisory Committee Member)

format: 146 electronic application/pdf

subject:
Biology, Neuroscience
Health Sciences, Toxicology

abstract: It has been proposed that domoic acid (DOM) and kainic acid (KA) produce neurotoxicity by acting at excitatory amino acid (EAA) receptors, causing a prolonged depolarization which results in death of the postsynaptic neuron. In this work, the effects of KA and DOM on the release of glutamate (GLU) and aspartate (ASP) from isolated presynaptic nerve terminals (synaptosomes) were compared. Responses to KA and DOM were similar. Concentrations of 0.5 and 1.0mM KA and DOM increased GLU release (p $\le$ 0.01), however only 1.0mM KA produced a significant increase in ASP release (p $\le$ 0.05). The calcium dependence of these effects was examined by comparing the effects of 1mM KA and DOM in the presence and absence of calcium. Calcium free media contained 1mM EGTA. It was found that amino acid release stimulated by KA and DOM was calcium independent. Potassium-stimulated GLU and ASP release were also calcium independent in this preparation. Results indicate that GLU and ASP release stimulated by KA and DOM originate from cytoplasmic stores, and may be released by reversal of the acidic amino acid uptake carrier. The high concentrations of agonist required to stimulate release, and similar potencies of KA and DOM suggest that this effect is not of primary importance to the neurotoxic mechanism of these compounds. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 31-03, page: 1156.


title: Effects of pH manipulation on contractility of rainbow trout intestinal smooth muscle in vitro

contributor: Tasker, R.A.R. (Supervisory Committee Member)

contributor: Johnston, C.E. (Supervisory Committee Member)

contributor: Groman, D. (Supervisory Committee Member)

format: 94 electronic application/pdf

subject:
Health Sciences, Pharmacology
Biology, Animal Physiology

abstract: This study was conducted to determine if the contractility of rainbow trout intestinal muscle is sensitive to pH alterations and to begin the investigation into the mechanisms by which pH affects the contractility. Isolated duplicate or triplicate segments of rainbow trout intestine were suspended in organ baths containing modified Krebs-Henseleit solution. The pH was adjusted by varying the concentration of CO$\sb2$ aerating the solution or with HCl. Contractility was determined as response to the administration of 5-hydrozyamine (5-HT), KCl, and transmural stimulation (TS) within the pH range of 6.3 to 8.5. Optimum pH for proximal segments was 7.85 while the range was much wider for distal segments. When associated with decreasing pH, CO$\sb2$ causes a greater inhibition than decreasing the pH in 100% O$\sb2,$ particularly when the tissues are stimulated electrically. This effect is ameliorated as the fish attain sexual maturity, although the mechanisms involved are not clear. The Cl$\sp-$/HCO$\sp{3-}$ exchanger--inhibited by 4-acetamido-4$\sp\prime$-isothiocyanto-stilbene-2-2$\ sp\prime$-disulfonic acid (SITS)-appears to be involved in recovery from acidotic stress, particularly at pH levels below 6.5. The role played by the Na$\sp+$/H$\sp+$ exchanger inhibited by 5-(N-ethyl-N-isopropryl) amiloride (EIPA) is still unclear. Although contractility is inhibited in the presence of EIPA, whether the inhibition is due to blockage of ion transport, or to cytosolic effects is unknown. Lactic acid does not inhibit contractility induced by 5-HT or KCl; however, at physiological concentrations, an inhibition of electrically induced contractions occurred. It can be concluded that the effects of pH on rainbow trout intestinal smooth muscle contractility are exerted primarily on the nerves innervating the gut rather than on the muscle itself. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 34-05, page: 1937.

abstract: Adviser: J. F. Burka.


title: Effects of source of dietary lipid on the fatty acid composition and cholesterol content of tissues, semen cryopreservation and embryo survival in rainbow trout (Oncorhynchus mykiss)

contributor:
Pustowka, Cory V. (author)
McNiven, Mary A. (Thesis advisor)
Richardson, Gavin (Thesis advisor)
(Supervisory Committee Member)

format: 107 electronic application/pdf

subject: Agriculture, Fisheries and Aquaculture

abstract: The objectives of this research were to evaluate the effect of source of dietary lipid on the fatty acid composition and cholesterol content (1) of muscle and liver tissue, (2) of sperm and spermatozoal plasma membranes, (3) and its effect on sperm viability after cryopreservation and (4) and its effect on the fatty acid composition of eggs and developing embryos.

abstract: One hundred two-year-old rainbow trout (Oncorhynchus mykiss) were fed one of the four treatment diets for 16 months. The diets differed only in the additional source of lipid which comprised 12% of the total diet. Herring oil (adequate n-3 fatty acids), menhaden oil (high in n-3 fatty acids), safflower oil (high in n-6 fatty acids) or tallow (high in saturated fatty acids) were the sources of dietary lipid. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 37-03, page: 0831.

abstract: Advisers: Mary McNiven; Gavin Richardson.


title: Effects of temperature on the development of Loma salmonae and resistance to re-infection in rainbow trout (Oncorhynchus mykiss)

contributor: Markham, R.J. Frederick (Supervisory Committee Member)

contributor: Cawthorn, Rick (Supervisory Committee Member)

contributor: Horney, Barbara (Supervisory Committee Member)

contributor: Jones, S. (Supervisory Committee Member)

contributor: Brimacombe, M. (Supervisory Committee Member)

format: 138 electronic application/pdf

subject:
Biology, Zoology
Agriculture, Animal Pathology
Agriculture, Fisheries and Aquaculture

abstract: Loma salmonae, an economically important microsporidian parasite of farm-reared Pacific salmon, causes severe branchial infections. No treatment currently exists to control L. salmonae infections. Consequently, other mechanisms of control are essential. Water temperature has a regulatory effect on the life cycle and development of many pathogens and has been used to control some infectious diseases. It may be used as a means of controlling parasitic infections with Loma salmonae; however, little is known about the relevant pathobiology of this parasite. Objectives of this research were to determine the permissive developmental range for the life cycle of L. salmonae, the effect of temperature on xenoma development rate and the abundance of branchial xenomas that develop, and to examine resistance induction for controlling parasitic infections. Juvenile rainbow trout reared in freshwater were exposed to infective tissue by either intubation or feeding of infective gill material. They were then reared at water temperatures of 5$\sp\circ,\ 7\sp\circ,\ 9\sp\circ,\ 10\sp\circ,\ 11\sp\circ,\ 13\sp\circ,\ 15\sp\circ,\ 17\sp\circ,\ 19\sp\circ,\ 20\sp\circ$ or 21$\sp\circ$C. Since exposure time was known, a polynomial regression model and a thermal unit summation model ($\sp\circ$C-days) were useful for predicting time of xenoma onset. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 37-03, page: 0883.

abstract: Adviser: David Speare.


title: Effects of two acclimation temperatures, 7 and 14 degrees C, on baseline physiological parameters of Atlantic salmon (Salmo salar) parr

contributor: Burka, John (Supervisory Committee Member)

contributor: Ireland, William (Supervisory Committee Member)

contributor: Hammell, K. Larry (Supervisory Committee Member)

format: 125 electronic application/pdf

subject:
Biology, Animal Physiology
Agriculture, Fisheries and Aquaculture

abstract: The purpose of these experiments was to determine baseline physiological parameters in Atlantic salmon (Salmo salar) acclimated to two different temperatures of 7 and 14°C and to look at how these physiological parameters are affected by time and acclimation temperature. Gut contractility, liver enzymes, blood plasma levels of cortisol, sodium, potassium, chloride and glucose, and growth were examined in these studies.

abstract: Initial studies on the isolated intestine were done to determine optimal  in vitro conditions for the experiments. Subsequent studies were done with serotonin (5-HT) and transmural stimulation (TS) in a Krebs-Henseleit solution containing HEPES, buffer maintained at pH of 7.85 and temperature of the experimental group.

abstract: The activities of three liver enzymes, Uridine diphosphate (UDP)-glucuronyl transferase, sulfotransferase and glutathione S-tansferase (GST) and the blood plasma levels of cortisol, chloride, sodium potassium ratio (Na:K), and glucose were studied.

abstract: Growth parameters (weight and fork length) in first section of the study, demonstrated significant differences in month, treatment and month by treatment interaction (p < 0.001). The 14°C group was generally largest. The overall health (condition index) of the groups acclimated at 7 and 14°C groups showed significant differences over temperature (p = 0.032), time and time by temperature interaction (p < 0.001). In the second part of the study, where acclimation histories differed, significant differences were demonstrated for weight and fork length in time, treatment and time by treatment interaction (p < 0.001). Condition factor was not significantly different between treatment, but there was a significant month effect and month treatment interaction (p < 0.001). The specific growth rates, from July to January demonstrated significant differences (p < 0.05).

abstract: The overall summary conclusion from this research is that there is temporal variance in many sets of data. This suggests that time is a potential confound and should be examined in other studies which are carried out over a prolonged period of time. There was little difference between blood indices, gastrointestinal (GI) activity and selected liver enzyme activity of the two temperature treatment groups. Acclimation was demonstrated by the recurrence of seasonal cycling. Many studies have shown seasonal cycling of hormones, GI activity, and liver enzyme activity. It was interesting that similar trends were found in fish maintained at two temperatures, in spite of differences in growth between the two groups. Thew studies lay the groundwork for further research with Atlantic salmon. More study is needed to replicate these experiments using many tanks and fish to determine true baselines for Atlantic salmon at these temperatures as well as throughout the temperature range of these animals. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 38-03, page: 0629.

abstract: Adviser:  J. F. Burka.


title: Effects of uncoupling protein-2 over-expression on the cyclic adenosine monophosphate signaling pathway of glucose-simulated insulin secretion

contributor: Saleh, Tarek (Supervisory Committee Member)

contributor: Ihle, Sherri (Supervisory Committee Member)

contributor: Brosnan, Seab (Supervisory Committee Member)

contributor: Dohoo, Susan (Supervisory Committee Member)

format: 157 electronic application/pdf

subject: Biology, Animal Physiology

abstract: Insulin is a peptide hormone that promotes the removal of glucose from the blood and its storage or metabolism in muscle, liver and adipose cells. Obesity and type 2 diabetes mellitus are two of the largest health concerns facing society today and both metabolic disorders involve abnormalities in the relative level of insulin secretion from pancreatic β-cells. Elucidating the factors that control insulin secretion is vital to the development of effective therapies to counteract abnormal secretion. Uncoupling proteins (UCPs) uncouple electron transport from oxidative phosphorylation and attenuate the production ATP, a key messenger in the insulin secretory cascade. One member of the UCP family, UCP-2, is expressed in pancreatic islets and its overexpression leads to a decrease in both ATP production and glucose-stimulated insulin secretion (GSIS). While many ATP-dependent pathways exist which may be affected, the generation of cAMP and its ability to potentiate GSIS is the focus of this study. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 41-02, page: 0476.

abstract: Adviser: Catherine B. Chan.


title: Electron transfer and supramolecular studies of amphiphilic nickel(II) pendant-arm polyazamacrocycles

contributor:
Rowley, Jimmy E. (author)
Haines, Robert (Thesis advisor)
(Supervisory Committee Member)

format: 120 electronic application/pdf

subject: Chemistry, Physical

abstract: Three nickel(II) pentaazamacrocycles bearing pendant alkyl tails have been synthesized, and the crystal structure of one (bearing an octyl tail) is reported. The redox potentials of the complexes, for oxidation of the nickel(II) centre, is 0.72 V in all cases, indicating that the pendant alkyl tails have no effect on the redox site. The three compounds have been characterized by IR, CHN and ESMS. The kinetics of oxidation of the complexes by aqua(5,5,7, 12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-l-acetato)nickel(III), [Ni(hmca)(OH2)]2+ have been studied. Only minimal differences in the rates for the three complexes are observed indicating that the tail length has only minimal effect.

abstract: The complexes have been studied with regard to their ability to form supramolecular complexes with α- and β-cyclodextrin. Results from ESMS and NMR show evidence of the formation of supramolecular complexes but cannot accurately quantify an association constant. The kinetics of oxidation of the complexes by the above oxidant in the presence of α- and β-cyclodextrin indicate that the rate is slowed by the presence of the cyclodextrins. A derived rate expression allows for association constants to be estimated from the oxidation kinetics.

abstract: The complexes are found to have unusual solvation properties in THF - water mixtures. The solubility of the complexes in various THF - water solution compositions have been studied.

abstract: The synthesis of a number of larger macrocycles (fifteen- and sixteen-membered) were attempted with little success. However, an attempt to synthesise a 16-membered macrocycle by a template method resulted in the formation of large crystals of trans-(bis-acetonitrilo)bis-(1,3-diaminopropane)nickel(II) perchlorate, [Ni(dap)2(MeCN)2](ClO4) 2,which has been characterized cystallographically. The complex cation has two diaminopropane chelating ligands in a square planar arrangement about the nickel(II) ion, with two axially-coordinated acetonitrile ligands.

abstract: Source: Masters Abstracts International, Volume: 43-02, page: 0539.

abstract: Adviser:  Robert I. Haines.


title: Enabling and barrier factors in the development of elementary and consolidated school nutrition policies on Prince Edward Island

contributor:
Freeze, Catherine (author)
(Thesis advisor)
(Supervisory Committee Member)

subject:
Education, Administration
Education, Elementary

abstract: Schools have been identified as promising environments through which to reach large numbers of children and positively influence their health behaviors through nutrition policies. Despite emerging evidence that school nutrition policies are beneficial to the health of children, many schools do not have formal policies. To identify the enabling and barrier factors in the development of nutrition policies in PEI elementary and consolidated schools a document review and a series of interviews were conducted with members of a School Healthy Eating Policy Working Group, principals and teachers who were most involved in developing the policies.

abstract: Several key groups and actions enabled the development of nutrition policies. The policy working group members created an understanding between the school world and the nutrition world and drew upon common philosophical ground in order to work together to champion and lead the change process. The principal was identified as an important champion for change at the school level particularly when they were able to develop a critical mass of interest for change. Navigating the change process during policy development required: building a case for change, testing policies in a real world setting, integrating healthy eating within school life, offering support to schools, engaging participants in the process to reduce the uncertainty of the change and acknowledging the need to weigh the cost and benefit of the proposed change. External pressures on schools and available foods varied in the extent to which they at times enabled or challenged policy development. Finally, resource limitations, competing issues and the use of unhealthy food as a reward were identified as the primary barriers in the development of school nutrition policies.

abstract: Source: Masters Abstracts International, Volume: 46-03, page: 1203.


title: Endoplasmic reticulum stress proteins in chemically mediated cytotoxicity

contributor:
Bedard, Karen (author)
Cribb, Alastair (Thesis advisor)
(Supervisory Committee Member)

format: 177 electronic application/pdf

subject:
Biology, Cell
Health Sciences, Pharmacology

abstract: Endoplasmic reticulum (ER) stress proteins appear to play a role in chemically induced idiosyncratic and direct hepatocellular cytotoxicity. Circulating antibodies directed against ER stress proteins can be found in patients suffering from idiosyncratic adverse drug reactions (ADR) to halothane and sulfamethoxazole. What if any pathological role these proteins or antibodies against them play in these reactions is not clear. In contrast to the potential deleterious involvement of ER stress proteins in idiosyncratic adverse drug reactions, there is substantial evidence that the expression of these ER stress proteins can confer protection against direct toxicity in a number of cell lines. In spite of the central role of hepatocytes in drug metabolism resulting in high exposures to reactive intermediates (RI), no data exists on the protective role of ER stress proteins in hepatocytes.

abstract: Antibodies to ER stress proteins as well as organ toxicity are reported in immune-mediated ADR to sulfonamides and in the Long Evans Cinnamon (LEC) rat strain. It is not what, if any, role these circulating antibodies play in the accompanying toxicities. To investigate this, the onset of histological and biochemical evidence of liver damage in the LEC rat was compared temporally with the onset of circulating antibodies to ER proteins. In this study, toxicity was found to occur in the absence of these antibodies.

abstract: This work expands existing knowledge of the protective effects of ER stress proteins. The expression level of ER stress proteins was pharmacologically increased in the porcine kidney cell line LLC-PK1, the human hepatocyte cell line HepG2 and the rat hepatocyte cell line H4IIE. In contrast to the broad protection ER stress proteins confer to the kidney cell line LLC-PK1, it was demonstrated for the first time that ER stress provides only limited protection to human and rat hepatocytes. This limited hepatocellular protection was further explored by examining the effect of ER stress protein induction on calcium disturbances evoked by model toxins. The toxins differed in their effect on cytosolic calcium and pre-ER stress prevented the rise in cytosolic calcium. Finally, the protective effects of one specific ER stress protein, protein disulfide isomerase (PDI), was considered by developing kidney and hepatocyte cell lines that over-express the protein. In both transient and stable overexpressing cell lines, there was a production of the transfected mRNA, but there was no detectable increase in the expression of the PDI protein, therefore no conclusions could be drawn regarding the ability of this ER stress protein to confer cytoprotection against RI.

abstract: Source: Dissertation Abstracts International, Volume: 64-07, Section: B, page: 3204.

abstract: Adviser: Alastair Cribb.


title: Enhancing family literacy in rural Prince Edward Island

contributor:
MacGillivray, Tracy A. (author)
Timmons, Vianne (Thesis advisor)
(Supervisory Committee Member)

format: 144 electronic application/pdf

subject: Education, Elementary

abstract: This qualitative study investigated the impact a family literacy program had on 10 families in the rural community of Alberton, Prince Edward Island. The project builds on the research that was done in a literacy needs assessment in 2002. The results from the assessment helped construct a comprehensive family literacy program for which the families in this study participated in. The study was twofold as it researched both the impact on literacy levels of the children involved, and the impressions it made on the families. Pre and post reading assessment tests were used to measure the literacy levels, and written evaluations and follow up interviews were used to gather the families' perceptions of the program. The reading assessments revealed that all of the children increased in at least one of the three areas tested. The evaluations and interviews disclosed the families' satisfaction with the structure and outcome of the program. The participants reported that they used the strategies taught, and they saw significant improvements in their children as a result of the program. Recommendations are suggested for future research in the field of family literacy at the conclusion of this study.

abstract: Source: Masters Abstracts International, Volume: 44-03, page: 1111.


title: Enhancing the rumen stability of MB-1, a de novo protein with potential application in ruminant nutrition

contributor: Nijjar, M.S. (Supervisory Committee Member)

format: 143 electronic application/pdf

subject: Chemistry, Biochemistry

abstract: MB-1, or Milk Bundle-1, is a de novo protein with potential application in ruminant nutrition. Its artificially high content of the essential amino acids methionine, threonine, lysine, and leucine renders it a high quality source of limiting nutrients for the animal. However, whether expressed in rumen microbes or grown in transgenic crops, MB-1 is not stable enough for its intended use. In fact, it is labile at rumen temperature and would be rapidly degraded if exposed to rumen enzymes. With the goal of enhancing the rumen stability of MB-1, three mutants were designed and analyzed.

abstract: The first mutant, MB-1-Cys, was designed to have an exposed cysteine residue and be capable of forming an intermolecular disulfide bond.

abstract: Construction of the second mutant involved the introduction of two cysteine mutations in such a way that they would be capable of forming an intramolecular disulfide bond and potentially increasing the thermal stability of the protein. For the third mutant, MB-1-Trp, the lone tyrosine in MB-1 was designed to be replaced by a tryptophan in order to improve the spectral properties of the protein and possibly increase its thermal stability.  (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 38-03, page: 0707.

abstract: Advisers:  Marc Beauregard, Fred Kibenge.


title: Environmental epidemiology of type 1 diabetes mellitus in Prince Edward Island

contributor: Somers, George (Supervisory Committee Member)

contributor: Dohoo, Ian (Supervisory Committee Member)

contributor: McKinney, Patricia (Supervisory Committee Member)

contributor: Van Til, Linda (Supervisory Committee Member)

format: 318 electronic application/pdf

subject: Health Sciences, Epidemiology

abstract: The main objective of this thesis was to examine the relationship between type 1 diabetes mellitus (T1D) and dietary nitrate intake from both drinking water and food sources in Prince Edward Island (PEI), Canada at the ecological level, and at the individual level in a case-control study. Historical data on ground water nitrate concentrations and land use patterns were utilized to examine temporal and spatial assumptions made in these two T1D studies. Ground water nitrate concentrations were assessed temporally, and the association between ground water nitrate and local land use was assessed spatially, comparing areal aggregation methods. The relationship between average nitrate concentration in ground water and T1D incidence at the watershed level was assessed, taking into account the population-at-risk and average household income. A case-control study compared drinking water chemistry, food frequency and average dietary component (e.g. nutrients) consumption between patients diagnosed with T1D during a four year period, and their age and sex matched controls, with an emphasis on nitrate concentrations and its derivatives. Some environmental and genetic-based factors were evaluated and controlled for where appropriate.

abstract: Average monthly values in nitrate-nitrogen concentration for 54 wells across PEI over a three year period ranged from 3.80 mg L-1 in April to 4.08 mg L-1 in January, and annual values ranged from 2.12 mg L-1 in 1987 to 2.73 mg L-1 in 1983 for 167 wells over a 16-year period, with monthly measurements significantly differing over time. Local land use had a major influence on average nitrate concentrations: agricultural areas, particularly where row-crops grew, had higher nitrate concentrations than both residential and 'pristine' areas, and this was somewhat dependent on season. Specifically, potato, grain, and hay land coverage were significantly and positively related to average ground water nitrate concentrations (compared to 'pristine' areas), regardless of method of data aggregation. Blueberry land coverage was negatively associated with ground water nitrate concentrations using two of the three aggregation methods. Watersheds were the preferred method of nitrate aggregation at the area level when compared to freeform polygons and 500 m buffer zones around each well, due to the method of creation (hydrological boundaries), being large enough to accurately determine average nitrate concentration, and being able to explain the most amount of nitrate concentration variation. The results from these historical data indicate that the assumptions made in the T1D incidence and risk studies were valid: there were minimal temporal differences but substantial spatial differences in ground water nitrate concentrations.

abstract: The incidence of T1D at the watershed level was not associated with ground water nitrate concentrations either before or after adjusting for average household income (a proxy for socioeconomic status), but a weak trend of higher nitrate concentrations being positively associated with T1D risk was present, especially after controlling for average household income.

abstract: A case-control study comprising of 57 T1D cases and 105 controls, matched by age at diagnosis and sex, concluded that the risk of T1D was increased when regular soft drinks or eggs were consumed at 'least once per week', compared to 'less than once per week'. The intake of dietary nitrate was marginally significant and positively associated with T1D (p = 0.13). An increased intake of total carbohydrates and caffeine were also associated with an increased risk of T1D, whereas the increased intake of vitamin A, vitamin B12, folate, and zinc were associated with a decreased risk. A family history of T1D and having five or more infections during the first two years of life significantly increased the risk of T1D, whereas residential remoteness was associated with a reduced risk of T1D. Father's education was also related to the risk of T1D, but the direction of the relationship was not clear.

abstract: In summary, ground water nitrate concentrations in PEI were influenced by local land use more than temporal factors. Nitrate from food had a marginally significant dose-response relationship with T1D risk at the individual level, and T1D incidence was positively but not significantly associated with nitrate concentrations in ground water at the area level. Other environmental and dietary factors had a greater influence on T1D risk at the individual level.

abstract: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0186.


title: Epidemiological investigation of health and performance of Holstein dairy heifers

contributor: McNiven, Mary (Supervisory Committee Member)

contributor: Bate, Luis (Supervisory Committee Member)

contributor: Montgomery, Dave (Supervisory Committee Member)

format: 132 electronic application/pdf

abstract: A prospective cohort study was undertaken to determine calf-level factors that affected calf health status and performance (growth) from birth to 14 months of age. A convenience sample of approximately 3300 Holstein calves from two large Florida dairy farms were used for the study. Data collected on each calf at birth included farm of origin, weight, height at the pelvis, birth date, and serum total protein (a measure of colostral immunoglobulin absorption). Birth season was dichotomized into summer and winter using meteorological data collected by University of Florida Agricultural Research Stations. Data collected at approximately 6 and 14 months included age, weight, height at the pelvis, and height at the withers. Growth in weight and stature (height) was calculated for each growth period; growth period 1 (GP1) = birth to 6 months and growth period 2 (GP2) = 6 to 14 months. Health data including date of initial treatment and number of treatments were collected monthly for the diseases diarrhea, omphalitis or 'navel infection', septicemia, pneumonia and keratoconjunctivitis or 'pinkeye'. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 33-01, page: 0118.

abstract: Adviser: Ian R. Dohoo.


title: Epidemiology of Neospora caninum in Canadian dairy farms

contributor: Spangler, Liz (Supervisory Committee Member)

contributor: Tremblay, Rob (Supervisory Committee Member)

contributor: Markham, Fred (Supervisory Committee Member)

contributor: Keefe, Greg (Supervisory Committee Member)

format: 175 electronic application/pdf

subject:
Agriculture, Animal Pathology
Biology, Veterinary Science

abstract: Neospora caninum was first recognized in dogs in Norway in 1984 and in 1988, a new protozoan species, N. caninum, was proposed under a new genus, Neospora. It is an apicomplexan protozoan, with dogs and coyotes as the definitive host.

abstract: The overall objective of this thesis was to acquire a more complete appreciation of the epidemiology of N. caninum infection in Canadian dairy farms, by answering important questions about the epidemiology of this disease. The epidemiology of neosporosis was investigated through four different studies and one extensive literature review.

abstract: The review covers the life cycle of the agent, its mechanisms of transmission, clinical signs, and tests for diagnosing the infection. Data on the prevalence of the infection in Canadian dairy and beef cattle are reviewed and briefly compared with estimates from other parts of the world. Most importantly for Canadian bovine practitioners, the impacts of the infection, risk factors for its occurrence and methods of control are also discussed.

abstract: A total of 6,662 blood samples were collected from cows on 240 dairy farms selected randomly from 6 provinces in Canada. Enrollment in a monthly, individual milk-testing regimen through a dairy herd improvement (DHI) program was a prerequisite for participation. Serum samples were stored at -20°C, and then tested for antibodies to N. caninum using an indirect ELISA.

abstract: The overall Canadian cow level prevalence was 11.9%, while for the maritime provinces it was 19.5% and for the western provinces it was 10.4%. The herd level, prevalence was 81.9% at the national level, and 86.7% and 80.0% for maritimes and western provinces, respectively. N. caninum infection was spatially clustered in both western and maritime Canadian provinces, occurring more commonly in Alberta in the western provinces and New Brunswick in the Maritimes.

abstract: A study was carried out to investigate the impact of serostatus for  Neospora caninum (NC), bovine viral diarrhea virus (BVDV), bovine leukosis virus (BLV) and Mycobacterium avium subspecies  paratuberculosis (MAP) and their possible interactions on reproductive efficiency (specifically, the ability to conceive and assumed fetal loss) in dairy cows. A Cox proportional hazards model with shared (herd-level) frailty was used to analyze the calving to conception interval data while controlling for herd-clustering effects. In this model, only BLV serostatus was associated with calving to conception intervals (CCI). Peak milk production before 73 days, SCC (linear score) and peak milk production after 73 days also had significant effects on the interval between calving and conception.

abstract: Logistic regression models of CCI greater than 200, 250, and 300 days were built, controlling for herd as a random effect. N caninum-seropositive cows had a 1.27 times higher risk of exhibiting a CCI exceeding 200 days, a 1.37 times higher risk of a CCI exceeding 250 days, and a 1.54 times higher risk of a CCI exceeding 300 days. BLV status also interacted with lactation numbers in the CC1200 model only, with older seropositive cows being less likely to have a CCI over 200 than 1st lactation seropositive cows. Neither BVDV nor MAP showed any significant effect in the models.

abstract: A logistic regression model of first service conception (FSC) revealed a significant interaction between N. caninum and BVDV infections. Increased peak milk production also reduced FSC. BLV and MAP had no significant impact on FSC.

abstract: Another study had the objective of determining important cow and herd level risk factors for seroprevalence for N. caninum in a population of randomly selected Canadian dairy cattle. A mixed logistic regression model was built using N. caninum serostatus at the cow level as the outcome variable, with herd as a random effect and province as a fixed effect. BLV serostatus was the only cow-level variable that remained in the model. Dogs being present on the farm, but not eating placentas and/or fetuses increased the odds of a farm having N. caninum by a factor of 1.54. If the dogs also ate placentas and/or fetuses, the odds ratio was 2.22. Other variables that remained (and appeared to be protective) in the final model included: "farmer asks for BVDV-negative exam before introduction of animal"; "number of milk cows on farm"; "dry cows receive Rumensin (monensin) in diet"; "embryo transfer used on farm"; "area of farm used for forage production per cow"; and "heifers have nose-to-nose contact with calves". These findings indicate management factors that could be considered to help control  N. caninum seroprevalence and its related impacts.

abstract: An economic analysis that estimated the production losses (and their ranges) due to N. caninum in the Canadian dairy industry and the possible range of losses for individual Canadian dairy herds was conducted. For the Canadian dairy industry, annual losses attributable to N. caninum were estimated to be $1,838.76 per 100 cows ($18 per cow) (95% CI = $7 to $32 per cow). For herds (assumed to be 61 cow herds), losses were estimated to be $1,494.38 but there was a wide range of losses (95% CI = $37 to $5,309), primarily due to the variation in the within-herd prevalence.

abstract: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0140.


title: Epidemiology of Neospora caninum in dairy cattle and wild canids on Prince Edward Island

contributor:
Wapenaar, Wendela (author)
(Thesis advisor)
(Supervisory Committee Member)

format: 133 electronic application/pdf

abstract: The main aim of the studies described in this thesis was to obtain more epidemiological information on Neospora caninum and the purported sylvatic life cycle of this parasite.

abstract: The significance of N. caninum in dairy herds on Prince Edward Island (PEI) is reported in Chapter 2, by testing bulk milk samples. The prevalence of dairy farms with a within-herd seroprevalence ≥15% on PEI was 10.2% in June 2005. In 11 farms that were considered positive based on bulk milk samples, blood samples were collected of all adult cows in September 2005, in conjunction with a fourth bulk milk sample on the same day. The results of this study demonstrate that the prevalence of N. caninum in dairy farms can be estimated using a bulk milk enzyme linked immunosorbent assay (ELISA).

abstract: Three ELISAs, 2 indirect fluorescent antibody tests (IFATs) and 1  N. caninum agglutination test (NAT) were compared using sera of randomly collected dairy cattle from Atlantic Canada. One IFAT performed well (sensitivity and specificity: 0.97 and 0.97) using reference sera, therefore results from this IFAT could subsequently be used as reference standard to calculate test characteristics for the other assays. Sensitivity was ≥0.89 for all assays except the NAT which had a significantly lower sensitivity (0.66). Specificity was high (>0.94) for all assays except for one indirect ELISA (specificity=0.52). The performance characteristics observed for most assays in this study (Chapter 3) make them useful for screening antibodies to N. caninum in cattle.

abstract: The effect of hemolysis on serological assays was studied in Chapter 4 and demonstrates that an indirect ELISA produced better test characteristics using hemolysed fox sera. A competitive ELISA had the advantage of not being species specific, and performed equally well with non-hemolysed sera from cattle and foxes. However, caution is required when using this competitive ELISA with hemolysed fox sera, because it had a significantly reduced specificity.

abstract: Chapter 5 describes the population structure and habitat characteristics of wild canids on PEI. The average age of foxes was 1.5 years (range 0.5-13.5, median 0.5) and for coyotes 2.1 years (range 0.5-13.5, median 1.5). The proportion of juvenile (less than a year of age) foxes and coyotes was 58 and 48%, respectively. The observed sex-ratio was equal, and average litter size for foxes and coyotes was 5.0 (range 0-7) and 5.2 (range 0-11), respectively. The main habitat for foxes was agricultural land and forest was the main habitat for coyotes.

abstract: Chapter 6 documents the occurrence of antibodies to N. caninum  in wild canids from PEI, however the observed seroprevalence in foxes (2.6%) and coyotes (2.5%) was low. The serologic evidence of  N. caninum infection in the foxes and coyotes poses questions about the relative importance of transmission of N. caninum between wildlife and livestock.

abstract: Chapter 7 describes the findings of oocysts morphologically and morphometrically similar to oocysts of N. caninum in 2 fox and 2 coyote fecal samples. DNA was extracted from these samples and found positive on nested PCR utilizing primers to the N. caninum-specific Nc5 genomic sequence. PCR using primers specific for Hammondia heydorni failed to yield an amplification product from these DNA samples.

abstract: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0143.


title: Epidemiology of infectious salmon anemia in New Brunswick Atlantic salmon farms

contributor: MacPhee, Dan (Supervisory Committee Member)

contributor: Kibenge, Fred (Supervisory Committee Member)

subject: Biology, Microbiology

subject: Biology, Veterinary Science

subject: Agriculture, Fisheries and Aquaculture

abstract: Infectious Salmon Anemia (ISA) is a recently described disease in farmed Atlantic Salmon, Salmo salar. A member of the newly identified Orthomyxovirus genus Isavirus, Infectious Salmon Anemia Virus (ISAV), has been identified as the causative agent. Virally infected Atlantic salmon experience lethargy, anorexia, severe anemia, exopthalmia, pale gills, ascites, and internal organ damage. Financial losses to the New Brunswick industry have been estimated to be $45M since 1997. The epidemiology of ISA in New Brunswick was investigated through five different studies.

abstract: Sensitivity and specificity of ISA diagnostic tests were evaluated as individual tests and in combinations, using data collected by the provincial government surveillance program. Depending on the test's cut-off value, the sensitivity and specificity for histopathology ranged from 30% to 73% and 72% to 99% respectively. IFAT had sensitivities and specificities in the range of 64% to 83% and 96% to 100% respectively. For the RT-PCR, sensitivity and specificity were 93% and 98% respectively. Test performances were also evaluated in series and parallel combinations. Sensitivities are maximized when tests are evaluated in parallel and ranged from 75% to 98%. Specificities are maximized when the tests are evaluated in series and ranged from 99% to 100%.

abstract: The prevalence of ISAV in cages experiencing an outbreak was compared with healthy cages from the same farm, neighboring farms, and distant farms. Salmon from five different groups were tested using an RT-PCR test. Groups included moribund fish from a cage experiencing an outbreak (A), healthy fish from an outbreak cage (B), healthy fish from a negative cage from a farm experiencing an outbreak in a different cage (C), healthy fish from a negative farm near an outbreak farm (D), and healthy fish sampled at a negative farm located in an area with only negative farms (E). Apparent prevalences (standard error) for the different groups (A–E) were 0.94 (.026), 0.41 (0.062), 0.29 (0.040), 0.08 (0.037), and 0.08 (0.037) respectively. All groups were significantly different (p < 0.002) from each other except between groups B and C and between groups D and E. (Abstract shortened by UMI.).

abstract: Source: Dissertation Abstracts International, Volume: 65-09, Section: B, page: 4454.

abstract: Advisers: Larry Hammell; Ian Dohoo.


title: Equilibrium mechanical properties of two noncollagenous cartilages in the sea lamprey, Petromyzon marinus

contributor:
Courtland, Hayden-William C. (author)
DeMont, Edwin (Thesis advisor)
Wright, Glenda (Thesis advisor)
(Supervisory Committee Member)

format: 135 electronic application/pdf

subject:
Biology, Anatomy
Applied Mechanics

abstract: In contrast to all other vertebrate cartilages, the major extracellular matrix protein of lamprey cartilage is not collagen. Instead, the majority of cartilaginous elements in the lamprey (e.g., cranial and annular cartilages) contain a noncollagenous protein (lamprin) with sequence similarities to mammalian and avian elastins. The branchial and pericardial cartilages also possess noncollagenous, elastin-like extracellular matrix proteins, but these demonstrate different amino acid compositions from lamprin. Thus, lamprey possess a unique family of noncollagenous structural proteins, the significance of which is not completely understood. The purpose of this study was to quantify the equilibrium mechanical properties of adult lamprey annular and pericardial cartilages in order to relate them to age, morphology, and biochemistry. A custom-built uniaxial testing apparatus was used to quantify the equilibrium stress-relaxation behavior of pericardial cartilages tested in tension and annular cartilages tested in compression. Stress-relaxation data and cartilage specimen dimensions were used in the calculation of moduli (stiffnesses) and Poisson's ratios. In addition, light and electron microscopy were used to characterize cartilage morphology before and after testing. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 40-03, page: 0719.

abstract: Advisers:  Glenda Wright; Edwin DeMont.


title: Estrogen-induced neuroprotection is mediated by an increase in caspase-12-associated apoptosis following MCAO

contributor: Saleh, Tarek (Supervisory Committee Member)

contributor: Cribb, Alastair (Supervisory Committee Member)

contributor: Chan, Cathy (Supervisory Committee Member)

contributor: Lopez, Alfonso (Supervisory Committee Member)

subject:
Biology, Neuroscience
Biology, Cell

abstract: Estrogen has received considerable attention over the past decade as a potential therapeutic agent against various forms of neurodegenerative diseases including stroke. Experimental data in animal models of stroke have provided exhaustive evidence of the neuroprotective properties of this steroid hormone. Our laboratory in particular has demonstrated that estrogen significantly reduces (∼50%) ischemic cell death resulting from permanent occlusion of the middle cerebral artery (MCAO). However, the cellular and molecular mechanisms implicated in the protective actions of estrogen in this experimental model have yet to be elucidated. Accumulating evidence suggests that endoplasmic reticulum stress-induced apoptosis is linked to ischemic cell death and that estrogen interacts with various components of the endoplasmic reticulum stress response. We therefore hypothesized that estrogen enhances endoplasmic reticulum stress-associated apoptosis via activation of caspase-12 to decrease necrotic cell death, thus limiting infarct volume. Estrogen significantly decreased procaspase-12 expression in both the infarct and peri-infarct regions at 1 hour post-MCAO and this corresponded with an increase in active caspase-12 at 2 and 3 hours post-MCAO. An increase in m-calpain expression was observed in the infarct region at 1 hour post-MCAO with estrogen treatment, suggesting m-calpain may play a role in activating caspase-12 following MCAO. TUNEL staining of brain sections showed a significantly higher number of TUNEL positive cells in estrogen treated animals at 4 hours past-MCAO compared to those treated with saline. The amount of necrotic cell death following MCAO was assessed by the presence of lactate dehydrogenase (LDH) in the cerebrospinal fluid (CSF) surrounding the frontal cortex and the results indicated a significant elevation in LDH levels following MCAO compared to sham occlusion. However, estrogen treatment did not decrease the concentration of LDH in the CSF following MCAO when compared to saline treatment. Overall, these data are consistent with the hypothesis that the protective actions of estrogen observed following permanent MCAO in male rats involve an increase in caspase-12 mediated apoptotic cell death.

abstract: Source: Masters Abstracts International, Volume: 45-03, page: 1394.


title: European Corn Borer (Ostrinia nubilalis) in Potatoes (Solanum tuberosum) and the use of Trichogramma  Species as an Agent for Biological Control

contributor:
Dau-Schmidt, Kathryn Jane (author)
(Thesis advisor)
(Supervisory Committee Member)

format: 77 electronic application/pdf

subject:
Agriculture, Agronomy
Biology, Entomology
Agriculture, Plant Culture

abstract: The European corn borer (Ostrinia nubilalis, ECB) has been observed at pest levels in potato crops on PEI since 1987 and is now considered a primary pest of potatoes in the Maritimes. ECB egg masses are currently used as an indicator of the level of ECB infestation in potatoes, with crop scouts using 2 egg masses per ten plants as an action threshold. Research plots using different artificially created ECB egg mass levels were established at the Harrington Research Farm using two potato varieties, Russet Burbank and Shepody. While the relationship between increasing ECB egg mass levels and larvae numbers is clear and significant (p<0.05), the effect of increasing ECB egg mass levels on tuber yields is less clear. There is evidence that the control threshold can be raised to 4 egg masses per ten plants in both Russet Burbank and Shepody potatoes without affecting tuber yields.

abstract: There is a significant linear relationship between ECB larval holes and larval tunnels (R2 = 0.83-0.93, p<0.001), as well as between ECB larval holes and larvae (R2= 0.70-0.74, p<0.001) for both Shepody and Russet Burbank potatoes. Regression equations were calculated for these two relationships which make it possible to estimate ECB damage, in the form of tunnels, and ECB larval levels from the number of ECB larval holes in potato stems.

abstract: Trichogramma wasps are internal parasites of primarily lepidopteran insect eggs, which makes them attractive as biological control agents of insect pests such as the European corn borer. Three species of  Trichogramma, T. brassicae, T. pretiosum, and T. minutum  were tested as biocontrol agents of European corn borer in potatoes both in laboratory choice tests and in small scale trials in potato fields. Mated T. brassicae females showed some interest in parasitizing ECB eggs when given a choice between them and the eggs of the facultative host, Ephestia kuehniella, although they still preferred the eggs of E. kuehniella 2 to 1 over ECB eggs. In an initial trial in organic research plots T. brassicae showed a significant (p<0.05) reduction of ECB larval holes, tunnels, and larvae, but these results were not repeated in field and cage trials in organic and conventionally managed potato fields.

abstract: Source: Masters Abstracts International, Volume: 50-04, page: 2255.


title: Evaluation of ELISA and fecal culture strategies for diagnosis of Mycobacterium avium subsp. paratuberculosis

contributor: Hanna, Paul (Supervisory Committee Member)

contributor: McClure, J (Supervisory Committee Member)

contributor: VanLeeuwen, John (Supervisory Committee Member)

format: 210 electronic application/pdf

abstract: Johne's Disease (JD) is a chronic, infectious, enteritis of ruminants caused by Mycobacterium avium subsp.  paratuberculosis (Mptb). In the clinical stage of this disease, the infection causes severe diarrhea and wasting of the affected animal. The subclinical infection with Mptb also has a detrimental effect on productivity of cattle. In ELISA-positive cattle, there is a 2.4 times increase in the risk of culling, and lactational 305d milk production is decreased by at least 370 kg. Reduced slaughter value and premature culling accounts for losses of CD$ 1330 per year per infected 50-cow herd. Research has failed to show a consistent association between Mptb test status and reduced fertility or risk of clinical/subclinical mastitis. Host level factors for becoming infected include age of exposure and level of exposure, along with source of exposure such as manure, colostrum or milk. Agent factors involve the dose of infectious agent and strains of bacteria. Environmental management factors influence the persistence of the bacteria and the level of contamination in the environment. Emphasizing a risk factor approach is the design of various control strategies at a national level in many countries throughout the world, specifically Australia, The Netherlands and the United States.

abstract: Control of JD historically has been based upon identification of infected animals and either segregation or removal from the herd. The focus of this study was to investigate two diagnostic methods for detection of  Mptb: ELISAs and culture. The first goal was to compare the diagnostic characteristics of various ELISAs for Mptb using the most appropriate gold standard. Then a comparison was done on the two commonly used gold standards: tissue and fecal culture. Additionally, pooled fecal culturing was examined to determine sensitivity of various pools sizes and use that information to estimate herd sensitivity.

abstract: A commonly used diagnostic modality is an ELISA to test for antibodies to Mptb, however, the licensed assays in North America have poor sensitivity for sub-clinically infected cattle that are not heavily fecal shedding. A European ELISA has shown some improvement in sensitivity in testing done in Germany. In order to test this ELISA against the North American ELISAs, a slaughterhouse study was conducted to obtain serum from culled dairy cows along with tissue and feces to be cultured as a gold standard comparison.

abstract: The European ELISA had a slight advantage in sensitivity over one of the North American ELISAs, but overall there was no dramatic improvement in test accuracy and agreement among the three assays was poor. Comparison of tissue culture and fecal culture indicated that fecal culture was not as sensitive as tissue culture and therefore may be a poor gold standard for JD test evaluation.

abstract: The feces collected allowed for a unique opportunity to investigate the validity of pooled fecal culture as a herd level diagnostic tool in conjunction with control programs. This testing modality is already in place in many countries and would be a component of the proposed Canadian Voluntary Johne's Control Program. The results of this research support the validity of utilizing pooled fecal culture as a herd level testing modality and also provides some credibility to minimizing the use of ELISA testing in control programs.

abstract: Source: Dissertation Abstracts International, Volume: 66-12, Section: B, page: 6473.


title: Evaluation of NMDA receptor-mediated neuroprotection in the endothelin-1 model of upper extremity impairment in stroke

contributor: Dawson, Susan (Supervisory Committee Member)

contributor: Doucette, Tracy (Supervisory Committee Member)

contributor: Côté, Etienne (Supervisory Committee Member)

format: 176 electronic application/pdf

subject:
Biology, Neuroscience
Psychology, Behavioral
Health Sciences, Pharmacology

abstract: Upper extremity impairment after focal ischemic stroke represents the most prominent functional deficit for surviving stroke victims. Recently, this condition has been modeled in rats by injecting the vasoconstrictive peptide endothelin-1 (ET-1) to forelimb representation areas of the brain, such as the forelimb sensorimotor cortex and the dorsolateral striatum. This ET-1 model may be a valuable experimental tool for investigating functional neuroprotection after ischemia-induced forelimb impairment in rats. However, there are only a few published studies regarding the use of this model for neuroprotection in stroke research, and compounds that target NMDA receptor-mediated excitotoxicity remain to be tested in this model. Using adult, male Sprague-Dawley rats, initial experiments were performed using different volumes, concentrations, and stereotaxic coordinates of injected ET-1 to the forelimb sensorimotor cortex and dorsolateral striatum. During these preliminary studies, rats were subjected to a behavioural test battery that measured various aspects of forelimb sensorimotor function.

abstract: Using the surgical and behavioural protocols developed during preliminary experimentation, the ET-1 model was then evaluated for neuroprotection using a single dose of MK-801 (5mg/kg i.p.) and R025-6981 (6mg/kg i.p.). Results revealed that both compounds conferred marked neuroprotection to the cortex and improved forelimb function relative to a vehicle control group when measured over two weeks post-stroke. Using a separate group of rats, an ET-1-induced lesion was placed in the homotopic contralesional hemisphere in order to investigate its functional contribution to forelimb recovery subsequent to the initial lesion. Whether the functional neuroprotection provided by R025-6981 was related to diminished contralesional hemispheric involvement during recovery was also examined. Results from this experiment demonstrated that the introduction of a second, homotopic lesion significantly reinstated forelimb impairment when measured 3 hr post-stroke.

abstract: In conclusion, the primary finding from this thesis is that the ET-1 model of upper extremity impairment in stroke is suitable for neuroprotection studies using NMDA receptor antagonists as therapeutic compounds. Thus, given its experimental advantages, the ET-1 model may be a useful tool for investigating the therapeutic effect of NMDA receptor antagonists on forelimb recovery after focal cerebral ischemia in the rat.

abstract: Source: Masters Abstracts International, Volume: 48-06, page: 3538.


title: Evaluation of diagnostic tests for infectious salmon anaemia (ISA)

contributor:
Nerette, Pascale (author)
Dohoo, Ian (Thesis advisor)
(Supervisory Committee Member)

format: 220 electronic application/pdf

abstract: Reverse transcriptase polymerase chain reaction (RT-PCR), virus isolation (VI) and indirect fluorescent antibody tests (IFAT) are three assays currently used by the salmon industry to identify fish infected with the infectious salmon anaemia virus (ISAv). It is important to know the accuracy (sensitivity and specificity) and precision (repeatability and reproducibility) of these diagnostic assays currently used for disease control and research programs by the aquaculture industry in Canada. It is also important to know the effect of freezing on RT-PCR and VI as samples are often stored at -20°C (RT-PCR) or -80°C (VI) before they are processed for diagnostic and research purposes (-80°C).

abstract: In order to evaluate these test characteristics, 5 laboratories participated in a blinded study. To ensure that salmon from all states of infection were included in the study and that populations with different infection prevalence were included, salmon were selected from 4 groups assumed to have a different prevalence of infection. A total of 403 fish (100 per group except for one group with 103) were sampled. Each fish had multiple samples taken, which could be submitted to multiple laboratories for multiple tests. Assay methods evaluated included IFAT (1 lab), RT-PCR (3 labs), and VI (2 labs). Each laboratory used its own testing protocols.

abstract: Results indicated that freezing did not affect VI but improved the sensitivity of RT-PCR. The repeatability and reproducibility of VI was almost perfect. There were substantial differences in repeatability of RT-PCR among the three laboratories (kappa ranging from 0.5 to 0.96) and consequently there was only a moderate reproducibility between these laboratories (it ranged from serious disagreement to substantial disagreement). The repeatability of IFAT was moderate (kappa=0.68) when the IFAT results were analyzed using 1+ and above as positive result.

abstract: Due to the absence of a gold standard we used latent class models to evaluate the sensitivity and specificity. To use the method, three main assumptions needed to be met. We formally assessed those assumptions using pseudogold standards. Our results suggested that there was a conditional dependence between IFAT and VI and between IFAT and PCR. We accounted for the conditional dependence by incorporating into our analysis covariance between tests using maximum likelihood and Bayesian methods. The estimates obtained from this study suggested that RT-PCR was the most sensitive assay (range from 77-99%), followed by VI (range from 80-89%). IFAT was the least sensitive method (62%). Except for RT-PCR performed by one laboratory, the three tests had similar high specificities (range from 98-100%).

abstract: Different testing strategies (single testing, multiple testing interpreted in series or in parallel) were evaluated using the estimates of the sensitivity and specificity previously computed. Our analyses showed that the best testing strategy depends on the production phase. If sampling is to be carried out in a freshwater facility, then broodstock should be tested by VI alone, while pre-smolts should be tested with IFAT and VI used in series. For fish reared in saltwater, parallel testing with VI and RT-PCR or testing with VI alone, are appropriate testing strategies for broodstock. For market-fish. PCR by itself is a good screening option. If one assumes the prevalence in moribund fish is at least 50%, then a maximum of 5 fish (at a cut-point of (1)need to be tested at a cost of $220 to detect ISA in a cage. If one desired to have a perfect GSp (i.e. no false positive cage designations), serial testing with IFAT and VI is a better option. However, now a maximum of 9 fish (at a cut-point of 1) need to be tested at a cost of $472.

abstract: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0141.


title: Evaluation of raw and roasted lupins as protein supplements for lactating cows

contributor: Fredeen, Alan H. (Supervisory Committee Member)

contributor: Robinson, Peter H. (Supervisory Committee Member)

contributor: Pringle, John (Supervisory Committee Member)

contributor: Markham, R.J. Frederick (Supervisory Committee Member)

format: 103 electronic application/pdf

subject: Biology, Veterinary Science

abstract: The objective of this study was to evaluate lupin seeds (Lupinus albus), raw or commercially roasted, as a protein supplement for lactating dairy cows. Heat treatment of lupins may be beneficial to reduce the proportion of rapidly degrading protein, decrease the rate of ruminal degradation, and increase the undergraded intake proteins (UIP). The evaluation of raw lupins (RL) and roasted lupins (ROL) was done by comparing (1) nitrogen (N) fractions of RL and ROL with solvent-extracted soybean meal (SBM) by chemical, in vitro and in situ methods (2) rumen fermentation characteristics and digestibility of nutrients in the whole tract of cows fed RL, ROL and SBM as supplements and, (3) production performance (milk yield, milk composition and efficiency of feed utilization) of lactating cows fed RL or ROL with SBM as protein supplements.

abstract: Considering the overall performance, it was concluded that coarsely ground RL can be a satisfactory protein supplement to replace SBM in the ration of lactating cows and ROL was a superior supplement compared to SBM. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 31-02, page: 0675.


title: Evaluations of behavior, neurochemistry, inflammation and cellular function in MPTP-induced models of Parkinson's disease: Effects of eicosapentaenoic acid (EPA) treatments

contributor:
Luchtman, Dirk Willem (author)
Song, Cai (Thesis advisor)
Tasker, Andrew (Thesis advisor)
Zidichouski, Jeffrey (Thesis advisor)
Ryan, Catherine (Thesis advisor)
Wang, Yanwen (Thesis advisor)
Bate, Louis (Thesis advisor)
(Supervisory Committee Member)

subject: Biology, Neuroscience

abstract: Parkinson's disease (PD) is a progressive neurodegenerative disorder, characterized by motor and cognitive impairments. The neuropathological hallmark of PD is the loss of nigrostriatal dopamine (DA), driven by inflammation, oxidative stress and apoptosis. The 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP) model of PD has been widely used to test new treatments for PD, since there is no compound that can effectively halt PD development. Thus, the present thesis explored, and provided new insights into the behavioural impairments and neuropathology induced by in-vivo and in-vitro  MPTP models of early and late stage PD. The main objective was to investigate whether omega-3 fatty acid eicosapenatenoic acid (EPA), which has neuroprotective effects, can protect in these models.

abstract: In an exploratory study, it was found that motor performance was surprisingly different between an acute, sub-acute and chronic dosing regimen of the MPTP mouse model, while dopaminergic neurochemistry in the striatum was similarly affected. Regimen differences on non-dopaminergic and extra-striatal neurochemistry, a major aspect of PD neuropathology, explained some of the behavioural differences. The chronic MPTP/probenecid regimen (probenecid delays the renal excretion of MPTP), a new in-vivo model of late stage PD, was the most valid of the three dosing regimens, showing motor (but not cognitive) dysfunction, significant changes in dopaminergic and non-dopaminergic neurochemistry in the striatum, frontal cortex and hippocampus, and increased striatal cytokine production. Although EPA feeding of mice attenuated the MPTP/P induced motor impairment, it did not improve the depletion of striatal DA. Nonetheless, EPA ameliorated additional striatal and extra-striatal neurochemical dysfunctions, attenuated increases in pro- and anti-inflammatory cytokines and attenuated pro-apoptotic conditions (attenuated an increase of the bax:bcl-2 ratio).

abstract: In a model of early stage PD, in which brain slices were acutely treated with MPP+ (the active metabolite of MPTP), dopaminergic and noradrenergic neurochemistry was affected in the striatum, frontal cortex and hippocampus, suggesting that, in the acute stage, MPP+ can already affect striatal and extra-striatal neurochemistry. MPP+ also triggered pro-inflammatory conditions, including an increase in cytosolic phospholipase A2 (cPLA2) mRNA, and mild increases in expression of apoptosis genes bax and caspase-3. Although EPA attenuated the changes in striatal dopaminergic neurochemistry and the increases of apoptosis genes, it did not prevent the striatal DA loss. The acute pro-inflammatory changes caused by MPP+ may be the initial trigger for chronic inflammation and PD development.

abstract: Administration of MPP+ to fully differentiated SH-SY5Y cells, another in-vitro model, decreased cell viability and mitochondrial membrane potential, and triggered apoptosis and pro-inflammatory conditions in the cells. EPA attenuated the loss of cell viability, but not the decrease of mitochondrial membrane potential. EPA also reduced apoptosis (by' reducing the bax:bcl2 ratio and decreasing caspase-3 mRNA expression and cytochrome-c release), and pro-inflammatory conditions (by reducing cPLA2 and cyclo-oxygenase 2 (COX-2) mRNA expression).

abstract: In summary, the present thesis further validated the MPTP/probenecid mouse model, provided new insights into the relationship between behaviour, neurochemistry and inflammation in the mouse model, and demonstrated how neurochemistry, inflammation and apoptosis are affected in the acute stage of MPP+ toxicity. EPA provided some protection against acute and chronic MPTP/MPP+, by modulating neurochemistry, inflammation and apoptosis.

abstract: Source: Dissertation Abstracts International, Volume: 71-08, Section: B, page: 4663.


title: Evidence for partial homology: Examining the morphological and molecular relationships between shoot and leaf development in watermilfoil (Myriophyllum aquaticum)

contributor:
Bourque, Laura A. (author)
Lacroix, Christian (Thesis advisor)
(Supervisory Committee Member)

format: 105 electronic application/pdf

subject:
Biology, Molecular
Biology, Plant Physiology

abstract: There is evidence from both morphological and molecular studies that many shoots and leaves have analogous developmental characteristics which transcend their classical categorization. An example of this can be found in the expression patterns of the KNOX1 family of homeobox genes which function in maintenance of indeterminate growth and are expressed in both dissected leaves and shoots. Shoot and leaf morphological parallels were characterized in the aquatic angiosperm Myriophyllum aquaticum (Vel.) using a combination of scanning electron microscopy and standard light microscopy. A KNOX1 gene fragment was also sequenced from M. aquaticum  and its pattern of expression was mapped at the shoot tip using RNA in situ hybridization as the primary technique. Leaves were found to develop lobes in an alternating basipetal fashion and originated from distinct generative centers at the leaf base. Within the tissues of the developing shoot, KNOX1 expression was found to be localized to the developing stem, provascular strands, dermal tissues of internodes, and between developing leaf bases. KNOX1 expression was also found within developing leaves where patterns varied depending on the age of the primordium. In leaves between plastochrones 1 and 3, KNOX1 is evenly expressed throughout the primordium. In older plastochrones, expression becomes localized the more recently developed lobes. By plastochrone 9, expression signal is no longer visible. The presence of distinct lobe forming centers at the base of the leaf and the corresponding KNOX1 expression during leaf and shoot development is indicative of developmental parallels between traditionally non homologous structures.

abstract: Source: Masters Abstracts International, Volume: 47-06, page: 3440.


title: Expanding our horizons: An exploration of the implementation of the International Baccalaureate Programme in Prince Edward Island

contributor: MacLeod, Kevin (Supervisory Committee Member)

contributor: DiGiorgio, Carla (Supervisory Committee Member)

format: 162 electronic application/pdf

subject: Education, Higher

abstract: The International Baccalaureate Organization offers an internationally recognized curriculum designed to provide a rigorous international education. The IB Diploma Programme is committed to literacy, academic freedom, and education as cultural action. This ethnographic case study explores the history and critical incidents leading to the initial implementation of the International Baccalaureate Diploma Programme in Prince Edward Island, Canada, in 2008-2009. From the perspective of a new IB Coordinator, this study traces the challenges of implementing the IB Programme in a typical high school. This study relies on historical investigation, document analysis, and interviews to detail the evolution of the IB from vision to educational reality.

abstract: Source: Masters Abstracts International, Volume: 48-06, page: 3286.


title: Mega-bites and ABC's: An examination of the use of integrated technology in an early literacy healthy eating kindergarten program

contributor:
Roach O'Keefe, Alaina L. (author)
Doiron, Ray (Thesis advisor)
Taylor, Jennifer (Thesis advisor)
(Supervisory Committee Member)

format: 202 electronic application/pdf

subject:
Education, Early Childhood
Education, Health
Education, Technology of

abstract: Major efforts are made to improve the healthy eating habits and literacy levels among young children, most often through intervention-type programs. This research project emerged out of a larger study called Eating Between the Lines: A Healthy Eating Literacy Program for Preschool Children and their Families (EBTL) which used an emergent literacy approach, teaching children about nutrition concepts. Based on the premise of literacy as a social practice and that active learning is most effective in early childhood education, the goal of my research was to include technology as an integral component in the EBTL program. A series of technology-based activities was embedded within the program where children gained experience and new knowledge using slideshows, Internet, scanners, drawing, and word processing programs. Questionnaires and interviews with parents probed what evidence existed to demonstrate that knowledge exchange was taking place in the context of the home environment.

abstract: Results from observational field data show that students made meaningful connections with each other and with new concepts and ideas. A clear theme that prevailed was the consistent use of oral language and vocabulary development. Children applied new nutrition knowledge while engaging with literacy activities using technology as a literacy tool. Additionally, interviews with parents indicated that there was uptake and meaningful transfer in the home environment with parents, siblings, and peers. Future research may include an EBTL @ Home component, and the potential of extending EBTL into the provincial curriculum.

abstract: Source: Masters Abstracts International, Volume: 47-06, page: 3143.


title: Metabolic oxygen requirements of small, pleuronectid flatfish under simulated aquaculture conditions

contributor: Burka, John (Supervisory Committee Member)

contributor: Horney, Barbara (Supervisory Committee Member)

contributor: Johnson, Gerry (Supervisory Committee Member)

format: 87 electronic application/pdf

subject: Biology, Animal Physiology

abstract: The metabolic requirements of small, pleuronectid flatfish were determined by measuring routine oxygen consumption (ROC). ROC rates were measured using single-pass, flow-through respirometry tanks designed to simulate land-based aquaculture holding conditions. The influence of each test parameter was affected by temperature. Interactions between test parameters and oxygen consumption rate were significant according to ANOVA $(P < 0.05).$ In the first experiment the highest ROC rates (mg O$\sb2 \cdot$ kg$\sp{-1} \cdot$ h$\sp{-1})$ of yellowtail flounder, Pleuronectes ferruginea, and winter flounder, Pleuronectes americanus, followed a parabolic response over the temperature range tested (2-14$\sp\circ$C). Peak metabolism was at approximately 11$\sp\circ$C. The ROC rates of American plaice, Hippoglossoides platessoides, did not follow a parabolic response. In the second experiment winter flounder weighing 75-455 g had decreased ROC (mg O$\sb2 \cdot$ kg$\sp{-1} \cdot$ h$\sp{-1})$ as body size increased. The decrease in oxygen consumption tested over three temperatures was best described with a linear equation where MO$\sb2$ = 118.9 + 1.05(T) $-$ 0.16(W) + 14.3(R) $-$ 22.1(C). W was mean fish size (g), T was temperature ($\sp\circ$C), R was trial and C was tank. In the third experiment the ROC rates of winter flounder were determined at three stocking densities (5 kg $\cdot$ m$\sp{-3}$, 25 kg $\cdot$ m$\sp{-3}$, 50 kg $\cdot$ m$\sp{-3})$ and at 2.2 and 9.7$\sp\circ$C. Oxygen consumption and stocking density were inversely related. At 2.2$\sp\circ$C, the highest ROC rate was observed in the 5 kg $\cdot$ m$\sp{-3}$ group and lowest in the 50 kg $\cdot$ m$\sp{-3}$ group. At 9.7$\sp\circ$C the highest oxygen consumption rate was observed in the 25 kg $\cdot$ m$\sp{-3}$ group and the lowest in the 50 kg $\cdot$ m$\sp{-3}$ group. These data provide the minimum aerobic requirements of flounder during the on-growing phase of production. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 36-02, page: 0453.

abstract: Advisers: David J. Speare, Greg P. Goff.


title: Mid-infrared spectroscopy of equine synovial fluid from normal and diseased joints

contributor: McDuffee, Laurie (Supervisory Committee Member)

contributor: Etkin, Nola (Supervisory Committee Member)

format: 233 electronic application/pdf

subject: Biology, Veterinary Science

abstract: Infrared (IR) absorption patterns of equine synovial fluid (SF) were studied. The objectives were to: (1) develop and optimize laboratory protocols suitable for mid-infrared (MIR) spectroscopic analysis of equine SF, (2) identify significant differences among MIR spectra of SF from anatomically different types of equine joints, and (3) determine the feasibility of using MIR spectroscopy and classification algorithms for the differentiation of SF samples from diseased and control joints.

abstract: The technique of MIR spectroscopy of dried films was optimized for equine SF. Suitable MIR spectra of equine SF were obtained from the 8 μL aliquots of 3:1 SF to aqueous potassium thiocyanate solution deposited onto a silicon microplate by using an optimal spectral acquisition protocol. The overall MIR absorption pattern of equine SF is similar to the MIR absorption pattern of human SF reported in literature. The laboratory methods used in the current research for collecting the MIR spectra are technically straightforward and economical.

abstract: Inter-articular variability among 3 clinically normal high motion joints (antebrachiocarpal (AC), midcarpal (MC) and tarsocrural (TC)) was investigated. Statistical comparisons of MIR absorption patterns of SF from study joints were made. Samples from the contralateral pairs were likely to yield a similar MIR absorption pattern. Differences in spectral features between ipsilateral AC and MC were detected, and comparisons between the spectra of the carpal and TC joints revealed more widespread discriminatory absorption bands. The results suggested that inter-articular variation should be considered when using this technique.

abstract: The feasibility of the use of IR spectroscopy combined with statistical classification algorithms was assessed by using SF samples from joints with traumatic arthritis (TA) and control joints. The MIR absorption patterns of SF from joints with TA differed significantly from corresponding patterns for controls. A classification model was developed based on characteristics of 3 optimal MIR regions, and yielded an overall accuracy of 97% (sensitivity 93%; specificity 100%) in the calibration dataset. The same model with cost-adjusted prior probability of 0.60:0.40 produced an overall accuracy of 89% (sensitivity 83%; specificity 100%) for a validation dataset, and 100% correct classification for a second validation set of normal control SF.

abstract: The feasibility of this technique was further confirmed by comparing SF samples from tarsocrural joints with osteochondrosis (OC) and control joints. Disease-associated characteristics within MIR spectra of SF were identified by the use of statistical modeling. The classification model developed was based on the characteristics of 6 optimal MIR regions, and yielded an overall accuracy of 77% (73% sensitivity; 81% specificity).

abstract: The feasibility of IR and statistical classification algorithms for the differentiation of spectra derived from samples of diseased and control joints were demonstrated in this current research project. These findings favor the further development of this method for diagnosis of equine joint disease. Further recruitment of samples from both diseased and normal equine populations is required to evaluate the clinical usefulness of IR spectroscopy in diagnosis of equine joint diseases.

abstract: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0143.


title: Milk urea nitrogen:  Quality control of testing, individual cow factors, and correlations with bulk tank testing

contributor: Spangler, Elizabeth (Supervisory Committee Member)

contributor: Keefe, Greg (Supervisory Committee Member)

contributor: Fredeen, Alan (Supervisory Committee Member)

format: 150 electronic application/pdf

subject: Biology, Veterinary Science

abstract: Milk urea nitrogen (MUN) has been used to assess the nutritional status of dairy cows. However, in any program using MUN values to monitor nutrition in a dairy herd, other factors need to be evaluated and considered. These factors include the reliability of method of determination of MUN, the role of a variety of cow level factors and seasonal variation.

abstract: The first objective of this study was to evaluate the repeatability, precision and accuracy of the testing technology for measurement of milk urea nitrogen levels.

abstract: The second objective of this study was to evaluate the effect of cow factors on MUN. The dataset consisted of 68,158 observations for 10,688 lactating Holstein cows in 177 herds that participated in the Atlantic Dairy Livestock Improvement Corporation (ADLIC) production recording service.

abstract: The third objective of this study was to determine seasonal variation in bulk tank milk urea nitrogen (BTMUN) concentration in PEI dairy herds, and to evaluate the relationship between BTMUN and the weighted herd average of individual cow MUN levels (WHMUN). (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 40-03, page: 0657.

abstract: Advisers:  John VanLeeuwen; Ian Dohoo.


title: Molecular and pathologic characterization of Canadian avian reovirus field isolates

contributor: Bellamy, James (Supervisory Committee Member)

contributor: Long, J.R. (Supervisory Committee Member)

contributor: Lopez, Alfonso (Supervisory Committee Member)

format: 126 electronic application/pdf

subject:
Biology, Molecular
Biology, Microbiology
Health Sciences, Pathology

abstract: Fourteen isolates of avian reovirus previously grown in chicken embryo liver cells were adapted to replicate in an African green monkey (Vero) cell line. The growth curves of five viruses studied in Vero cells showed them to be highly cell-associated. Different procedures were examined for releasing the cell-associated virus following propagation in Vero cells, including several freeze-thaw cycles, treatment with sterile distilled deionized water (ddH$\sb2$O), freon extraction, and trypsin treatment. It was observed that treatment of virus infected cultures with ddH$\sb2$O was the most effective, and trypsin treatment was the least effective procedure for dissociation of virus from cells.

abstract: Experiments were undertaken to characterize the trypsin sensitivity of 14 avian reoviruses in relation to their genotypes, serotypes, and pathogenicity in day-old chicks in an attempt to develop a rapid method for differentiation of pathogenic from non-pathogenic virus strains. (Abstract shortened by UMI.).

abstract: Source: Masters Abstracts International, Volume: 31-03, page: 1148.