IslandScholar
Not a member yet
16367 research outputs found
Sort by
Mucosal delivery of CpG-ODN mimicking bacterial DNA via the intrapulmonary route induces systemic antimicrobial immune responses in neonatal chicks
No full textThe transition to antibiotic-free poultry production in the face of pathogenic threats is a very challenging task. We recently demonstrated that mucosal delivery of CpG-ODN alone by the intrapulmonary route (IPL) has potential as an effective alternative to antibiotics in neonatal chicks against Escherichia coli septicemia. How exactly mucosal delivery of CpG-ODN elicits, protective antibacterial immunity remained poorly understood. In this study, CpG-ODN or saline was delivered via the intrapulmonary route to day-old chicks (n = 80/group) using a compressor nebulizer in an acrylic chamber (1 mg/mL CpG-ODN for 15 minutes). In the first part of the study, two days after mucosal CpG-ODN delivery, 40 chicks from each group were challenged subcutaneously with 1 × 105 cfu (n = 20) or 1 × 106 cfu (n = 20) of E. coli and the mortality pattern was monitored for seven days. We found significantly higher survival, better clinical conditions and lower bacterial loads in chicks that received mucosal CpG-ODN. To explore the mechanisms behind this protective immunity, we first looked at the kinetics of the cytokine gene expression (three birds/ group/ time for 10 time-points) in the lungs and spleens. Multiplex gene analysis demonstrated a significant elevation of pro-inflammatory cytokine genes mRNA in the CpG-ODN group. Interleukin (IL)-1β robustly upregulated many folds in the lung after CpG-ODN delivery. Lipopolysaccharide-induced tumor necrosis factor (LITAF) and IL-18 showed expression for an extended period in the lungs. Anti-inflammatory cytokine IL-10 was upregulated in both lungs and spleen, whereas IL-4 showed upregulation in the lungs. To investigate the kinetics of immune enrichment in the lungs and spleens, we performed flow cytometry, histology, and immunohistochemistry at 24, 48 and 72 hrs after CpG-ODN delivery. CpG-ODN treated lungs showed a significant enrichment with monocytes/macrophages and CD4+ and CD8+ T-cell subsets. Macrophages in CpG-ODN treated group demonstrated mature phenotypes (higher CD40 and MHCII expression). Importantly, mucosal delivery of CpG-ODN via the intrapulmonary route significantly enriched immune compartment in the spleen as well, suggesting a systemic effect in neonatal chicks. Altogether, intrapulmonary delivery of aerosolized CpG-ODN orchestrates protective immunity against E. coli septicemia by not only enhancing mucosal immunity but also the systemic immune responses.Natural Sciences and Engineering Research Council of CanadaWestern Economic Diversification CanadaChicken Farmers of SaskatchewanCanadian Poultry Research Council and Alberta Livestock and Meat Agency Ltd
Perspectives institutionnelles sur le développement du corps professoral pour l'éducation numérique au Canada
No full textAs digital education at the post-secondary level continues to grow, robust professional development that prepares faculty to teach in online and blended settings is necessary. In this study we analyze open-ended comments from the Canadian Digital Learning Research Association’s annual survey of Canadian post-secondary institutions (2017-2019) to deepen our understanding of faculty training and support for digital education as articulated by higher education institutions. We find that 1) digital education orientation or on-boarding processes for faculty vary widely; 2) institutions employ an extensive array of professional development practices for digital education; 3) institutions report culture change, work security, and unclear expectations as challenges in providing digital education training and support; and 4) institutions articulate aspirations and hopes around professional development investments in order to build digital education capacity. These findings have significant implications for research and practice and we describe these in the article
Governmental policy capacity and policy work in a small place: Reflections on perceptions of civil servants in Prince Edward Island, Canada from a practitioner in the field
No full textThe body of public administration literature is missing contributions from practitioners in the field. Emic or insider-led studies of public administration can act as powerful mechanisms to generate new knowledge. This article studies the relationship between place, perceptions and policy work by drawing on the author’s own public administration experience and interviews with civil servants. The results show that societal factors such as political culture and reduced anonymity associated with small place create challenges when developing public policy. However, expedited public engagement and problem identification were perceived by civil servants to be enhanced by a small context. This means that small place can be both limiting and beneficial for high levels of policy capacity. Overall, this article finds that geospatial factors such as smallness impact perceptions of policy work and capacity. Furthermore, this article finds that insider-led studies of public administration can indeed make important and unique contributions to the body of literature and are therefore deserving of more serious methodological consideration
Migration patterns of Atlantic halibut captured in the southern Gulf of St. Lawrence as assessed with pop-up satellite archival and Floy tags
No full textThis study provides evidence of two subpopulations of Atlantic halibut (Hippoglossus hippoglossus) in the southern Gulf of St. Lawrence. The migrations of 20 Atlantic halibut captured in the coastal waters of Prince Edward Island, Canada, were evaluated using pop-up satellite archival tags (PSAT). Geolocation data showed that Atlantic halibut migrated north to the Laurentian Channel via distinct eastern or western routes. Floy tagging and recapture (recapture of 18.4%) showed that less than 7.0% of Atlantic halibut exhibited dispersive behaviour outside of their annual migratory route. Overwintering occurred on the slope and in the deepest waters of the Laurentian Channel. Atlantic halibut in the deepest waters of the Laurentian Channel exhibited rapid, ∼100 m rises, presumed to be associated with spawning from January to March. The eastern and western migratory cohorts exhibited this behaviour ∼350 km apart, suggesting reproductive isolation as the basis of subpopulations. The results of this study indicate a need to reconsider the management of Gulf of St. Lawrence Atlantic halibut as one continuous population.Atlantic Canada Opportunities AgencyEI Atlantic Shrimp Corp. Inc.EI Aquaculture and Fisheries Research InitiativePEI Department of Fisheries Aquaculture & Rural DevelopmentFisheries and Oceans CanadaPEI Fishermen’s Association; local Fishermen’s Associations including Eastern Kings, North Shore, Southern Kings and Queens, Western Gulf, and Prince CountyOcean Frontier InstituteNSERC Strategic Partnership Gran
Remote sensing applications for insurance: A predictive model for pasture yield in the presence of systemic weather
No full textA robust predictive model for crop yield is essential for designing a commercially viable index-based insurance policy. Index-based insurance for crops is still at a relatively infant stage, and more research and development is needed in order to address a main limitation, which is referred to as basis risk. Traditionally, ground weather station measurements have been the most common approach used in weather indices, and this approach has often led to high levels of basis risk. Recent advances in satellite-based remote sensing provide new opportunities to use publicly available and transparent “big data,” to potentially make index-based insurance policies more relevant by reducing basis risk. This is the first article to provide a comprehensive comparison of 13 pasture production indices (PPIs), including those developed based on satellite-derived vegetation and biophysical parameter indices using data products from the Moderate Resolution Imaging Spectroradiometer (MODIS). A validation protocol is established, and a unique dataset covering the period 2002 to 2016 from a network of pasture clip sites in the province of Alberta, Canada, is used to demonstrate new applications for insurance based on remote sensing–derived data. The results of the satellite-derived PPIs are compared to PPIs based on ground weather station data as benchmarks, which to date are the most common design for index-based insurance. Overall, the satellite-based indices report higher correlations with the ground truth forage yield data compared to the weather station PPIs. As an example, in 2015 and 2016 the best performing satellite-based PPIs produced correlations close to 90%. When considering the whole sample period, the highest overall average correlation is 62.0% for the biophysical parameter PPI based on FPAR 500-m MODIS, and the lowest overall average correlation is 43.8% for the vegetation PPI based on EVI 250-m MODIS. Comparatively, the highest correlation reported for the weather station indices is for precipitation, at 12.51%. Other predictive models based on principal component analysis and shrinkage methods (such as lasso, ridge regression, and elastic net) are considered to address the issues of variable selection and dimension reduction in insurance design. This research makes an important contribution to the field of actuarial science and insurance, because it highlights potential new opportunities for insurance design and predictive analytics using large and comprehensive satellite datasets that remain relatively unexplored to date in insurance practice. Though forage is used as the example here, the research could be extended to other crops, and other areas in the property and casualty sector, including for fire and flood
Increasing the COP of a refrigeration cycle in natural gas liquefaction process using refrigerant blends of Propane-NH3, Propane-SO2 and Propane-CO2
No full textThis paper investigates the feasibility of using inexpensive techniques to enhance the coefficient of performance (COP) of the refrigeration cycle used in the liquefaction of natural gas. The effect of mixing the propane refrigerant with ammonia, sulfur dioxide and carbon dioxide on the performance and the work of the compressor is studied. It is shown that the mixture of ammonia-propane and sulfur dioxide-propane enhances the overall COP by 7% and 9%, respectively. The addition of ammonia and sulfur dioxide to the propane refrigerant reduces the overall compressor work by reducing the overall mass flowrate required to absorb a constant heat from the natural gas. On the other hand, the mixture of carbon dioxide-propane degrades the overall COP by 70%. The addition of carbon dioxide increases the overall mass flowrate required to absorb a constant heat from the natural gas. Interestingly, the proposed method requires small capital and running costs
Repeated application of a novel creatine cream improves muscular peak and average power in male subjects
No full textUsing a multicenter, randomized controlled trial, (N = 123, age 23 [+ or -] 4 years) we sought to determine whether administration of a novel, topical creatine supplement could improve muscular performance after acute and repeated (7-day) exposure. To study the acute performance enhancing effects of the supplement, subjects completed 5 sets of 15 maximal concentric single-leg knee extensions with and without the application of a low- (low dose [LD]-3.5 ml) or high-dose (high dose [HD]-7 ml) topical creatine cream. After a wash-out period, subjects had one leg randomized to receive either the creatine or placebo cream, with further randomization into an oral creatine or placebo supplement group. Subjects completed 5 sets of 15 maximal concentric single leg knee extensions before and after the supplementation protocol. After acute application, no significant differences in peak power (LD: 252 [+ or -] 93 W, HD: 261 [+ or -] 100 W, p = 0.21), average power (LD: 172 [+ or -] 65 W, HD: 177 [+ or -] 69 W, p = 0.78), or fatigue index (LD: 13.4 [+ or -] 10.6%, HD: 14 [+ or -] 11.9%, p = 0.79) were observed between experimental and placebo creams (peak power: LD: 244 [+ or -] 76 W, HD: 267 [+ or -] 109 W; average power: LD: 168 [+ or -] 57 W, HD: 177 [+ or -] 67 W; fatigue index: LD: 12.4 [+ or -] 9.6%, HD: 12.8 [+ or -] 10.6%) or when controlling for sex. After the 7-day supplementation protocol, a significant increase in average power (creatine: 203 [+ or -] 61-220 [+ or -] 65 W, placebo: 224 [+ or -] 61-214 [+ or -] 61 W) and peak power (creatine: 264 [+ or -] 73-281 [+ or -] 80 W, placebo: 286 [+ or -] 79-271 [+ or -] 73 W) in the leg receiving creatine cream was observed in male subjects. No differences were observed in female subjects. The topical creatine cream did not enhance measures of muscle performance after acute application, but was able to improve peak and average power in male subjects after 7 consecutive days of application
Application of biochar for efficient municipal wastewater treatment
No full textA more circular and therefore more sustainable economy requires us to value our waste. Something like wastewater can be an unconventional source of nutrients, energy, and water. Thus, far from being something to discard or ignore, wastewater can be a resource option. Similarly, biochar is the solid by-product of pyrolysis and its cascading use can offset the cost of the process. A wide variety of research on biochar has highlighted its ability to absorb/adsorb nutrients, metals, and complex compounds; filter suspended solids; enhance microorganisms’ growth; retain water and nutrients as well as increase
carbon content of soil. The thesis analyzes the effect of biochar in two biological treatment processes, activated sludge for municipal wastewater and anaerobic digestion for sludge at Charlottetown Pollution Control Plant located in the province of Prince Edward Island, Canada. The analysis is carried out using Response Surface Methodology for varied size and dose of two types of carbon, namely biochar from wood pallets and non-treated activated carbon (AC) sourced from Sigma Aldrich Inc. A higher COD removal efficiency of above 80%, 82% and 88% in the retention time of 1, 4 and 24 hours respectively is achieved in the region of lower size and higher dose for AC. Whereas, for similar condition and variations the reactor fed with biochar achieved COD removal efficiency of 60, 78 and 69 for hydraulic retention time (HRT) of 1, 4 and 24 hours, respectively. The study showed that the addition of AC and biochar improves the settleability of the sludge. However, the improvement was found to depend on carbon size and dose, irrespective of the carbon type use. A sludge volume index (SVI) as low as 37.33 was obtained with biochar. The response surface analysis showed that minimum SVI could be achieved with small size and higher dose of carbon material. It was also found that the use of carbon in anaerobic digestion has significant effect on the biogas yield and the quality of the biosolids. However, the study can only be a qualitative indication of AC and biochar effect in anaerobic digestion. There are far too many
interaction and lurking effects caused due to addition of biochar and AC which in return effects the biogas yield and nutrient content of bio-solids. Moreover, biochar addition was found to be better than AC in anaerobic systems. This study has showed that types of biochar has significant impact on the biological systems in the wastewater treatment process and could be a viable way for valorization of wastewater. In addition, sustainable biochar systems are an attractive approach for carbon sequestration and total waste management cycle
Projections of daily mean surface temperature over the Beijing-Tianjin-Hebei region through a stepwise cluster downscaling method
No full textA stepwise cluster analysis (SCA) method is developed to downscale the daily mean surface temperature of 23 meteorological stations over the Beijing-Tianjin-Hebei (BTH) region in North China. Through comparisons of three evaluation indicators, including correction coefficients (CORRs), root mean square errors (RMSEs), and mean relative errors (MREs), between model simulations and observations, the SCA is proven to be capable of simulating the daily mean temperature in the baseline period (1961–2005). The projections of mean surface temperature under RCP4.5 and RCP8.5 scenarios are then developed using the SCA model. The results show that the mean surface temperature at most stations would keep increasing in future throughout the twenty-first century. The largest magnitude and rate of temperature increase are reported in the northwest mountains of the BTH region (especially obvious in winter), suggesting that the response to climate change in highland regions is more sensitive than that in low elevations. It is also reported that the projected changes in mean surface temperature in coastal regions are smaller than those in plain areas. This could be due to ocean’s moderating influence in the HadGEM2-ES. In terms of seasonal changes in surface temperature, the smallest magnitude of warming is expected in summer while the highest is likely to occur in winter, especially under RCP8.5 emission scenarios. Furthermore, the annual cycle analysis for temperature changes suggests that the highest amplitude of warming is expected in cold months (i.e., February or December) while the smallest is likely to occur in warm months (i.e., July or August)
Increasing the COP of a refrigeration cycle in natural gas liquefaction process using refrigerant blends of Propane-NH3, Propane-SO2 and Propane-CO2
No full textThis paper investigates the feasibility of using inexpensive techniques to enhance the coefficient of performance (COP) of the refrigeration cycle used in the liquefaction of natural gas. The effect of mixing the propane refrigerant with ammonia, sulfur dioxide and carbon dioxide on the performance and the work of the compressor is studied. It is shown that the mixture of ammonia-propane and sulfur dioxide-propane enhances the overall COP by 7% and 9%, respectively. The addition of ammonia and sulfur dioxide to the propane refrigerant reduces the overall compressor work by reducing the overall mass flowrate required to absorb a constant heat from the natural gas. On the other hand, the mixture of carbon dioxide-propane degrades the overall COP by 70%. The addition of carbon dioxide increases the overall mass flowrate required to absorb a constant heat from the natural gas. Interestingly, the proposed method requires small capital and running costs