IslandScholar
Not a member yet
16367 research outputs found
Sort by
Nexus between nitrous oxide emissions and agricultural land use in Agrarian economy: An ARDL bounds testing approach
No full textThis paper analyses the relationship between Nitrous Oxide emissions, agricultural land use, and economic growth in Pakistan. Agriculture largely contributes to Nitrous Oxide emissions. Hence, models of agriculture induced Nitrous Oxide emissions are estimated in addition to models of total Nitrous Oxide emissions. Estimated models accommodate more flexible forms of relationship between economic growth and emissions than those of the widely adopted models in testing the Environmental Kuznets Curve. The Auto-Regressive Distributed Lag (ARDL) bounds testing approach to co-integration and the vector error correction model approach is applied to test the Environmental Kuznets’s Curve hypothesis for Pakistan and to detect the directions of causality among variables using the time series data for the period 1971 to 2012. Results indicate that an N-shaped rather than an inverted U-shaped relationship exists in the case of Pakistan. The tipping values for total Nitrous Oxide emissions and agriculturally induced Nitrous Oxide emissions indicate that Pakistan passes through a phase of increasing environmental degradation. Increases in agricultural land use and per capita energy use will increase the level of Nitrous Oxide emissions. However, controlling Nitrous Oxide emissions from agricultural land use and per capita, energy use without adversely affecting economic development will be a serious policy challenge for Pakistan
Prevalence of anthelmintic resistant cyathostomins in Prince Edward Island, Canada
No full textCyathostomins are the most common parasites of adult horses worldwide. Currently, the three classes of anthelmintics used to treat cyathostomin infections includes
benzimidazoles, pyrimidines and macrocyclic lactones. However, due to widespread overuse, cyathostomins have developed varying degrees of resistance to all
classes of anthelmintics. Fecal egg count reduction tests (FECRT) are currently used to determine the presence of anthelmintic resistance (AR), while egg reap-
pearance periods (ERP) are used to investigate early macrocyclic lactone resistance. The objective of this study was to investigate the prevalence of cyathostomin
pyrantel pamoate and ivermectin resistance, and to determine ERP at Prince Edward Island (PEI), Canada horse farms. In addition, fecal cultures and larval
identification were performed to evaluate the prevalence of small and large strongyle egg shedding in PEI. Fecal egg counts (FEC) were performed on 270 horses on
14 horse farms across PEI. Horses with≥ 200 eggs per gram (EPG) met the inclusion criteria and were enrolled in the study (n = 101). The median (range) horses per
farm was 7.5 (4–11) and 6.0 (4–8) for pyrantel pamoate and ivermectin groups, respectively. Horses were initially treated with 6.6 mg/kg of pyrantel pamoate orally
(n = 101). Fecal egg counts were conducted every two weeks for 8 weeks post treatment. Once individual FEC were ≥ 200 EPG, horses were dewormed with 0.2 mg/
kg of ivermectin orally (n = 80), and FEC were performed every 2–3 weeks for seven weeks. In this study the ERP was defined as the week the mean FECR were 10%
below the initial mean two-week post treatment FECR. Fecal egg count reduction tests and ERP were used to evaluate the efficacy of each anthelmintic. Fecal culture
was performed to confirm the shedding of cyathostomin eggs. Fecal egg count reduction tests detected pyrantel pamoate resistance on 5/14 farms. No signs of
ivermectin AR were detected, while reappearance of eggs occurred at 4–6 weeks and 7–9 weeks for pyrantel pamoate and ivermectin, respectively. Fecal culture
detected large strongyles on 5/14 farms, which accounted for 0.3% of strongyle type eggs cultured. The prevalence of Strongylus vulgaris among individual horses in
this study was 2.8% and was detected on 2/14 farms. These findings will allow us to educate owners and veterinarians on appropriate anthelmintic protocols in PEI
and can be used as a baseline for continued monitoring of ERP and anthelmintic resistance in this region.Sir James Dunn Animal Welfare Centr
An efficient navigation system for autonomous mobile robots in dynamic social environments
No full textIn this paper, we propose an efficient navigation framework for autonomous mobile robots in dynamic social environments. The main idea of the proposed enhanced dynamic window approach (EDWA) model is to combine the advantages of the dynamic window approach (DWA) technique and the hybrid reciprocal velocity obstacles (HRVO) technique by taking into account the output velocity vector of the HRVO method into the objective function of the conventional DWA model. The proposed EDWA model’s output is the efficient control command for the mobile robots. To validate the effectiveness of the proposed EDWA model, we conduct a series of experiments in both simulated and real-world environments. The results illustrate that our proposed EDWA model enables the robots to proactively and safely avoid dynamic obstacles in its vicinity
Applications of gold nanoparticles in ELISA, PCR, and immuno-PCR assays: A review
No full textDevelopment of state-of-the-art assays for sensitive and specific detection of disease biomarkers has received significant interest for early detection and prevention of various diseases. Enzyme Linked Immunosorbent assays (ELISA) and Polymerase Chain Reaction (PCR) are two examples of proteins and nucleic acid detection assays respectively, which have been widely used for the sensitive detection of target analytes in biological fluids. Recently, immuno-PCR has emerged as a sensitive detection method, where high specificity of sandwich ELISA assays is combined with high sensitivity of PCR for trace detection of biomarkers. However, inherent disadvantages of immuno-PCR assays limit their application as rapid and sensitive detection method in clinical settings. With advances in nanomaterials, nanoparticles-based immunoassays have been widely used to improve the sensitivity and simplicity of traditional immunoassays. Owing to facile synthesis, surface functionalization, and superior optical and electronic properties, gold nanoparticles have been at the forefront of sensing and detection technologies and have been extensively studied to improve the efficacies of immunoassays. This review provides a brief history of immuno-PCR assays and specifically focuses on the role of gold nanoparticles to improve the sensitivity and specificity of ELISA, PCR and immuno-PCR assays
Adamantane carboxylic acids demonstrate mitochondrial toxicity consistent with oil sands-derived naphthenic acids
No full textNaphthenic acids (NAs) are thought to be a primary cause of toxicity of oil sands process-affected water (OSPW). The purpose of this study was to determine if commercially available adamantane carboxylic acids act by mitrochondrial mechanisms similar to NAs found in OSPW. Mitochondria isolated from rainbow trout (Oncorhynchus mykiss) liver were exposed to commercially available adamantane acids, 3-hydroxyadamantane-1-carboxylic acid (CAS 42711-75-1) and 3,5-dimethyladamantane-1-carboxylic acid (CAS 14670-94-1), or to NAs extracted and purified from OSPW. The effects of these compounds on state 3 and 4 respiration, mitochondrial membrane potential, and mitochondrial reactive oxygen species (ROS; H2O2 production) were quantified. The compound 3-hydroxyadamantane-1-carboxylic acid only inhibited state 3 respiration at the highest concentration (2560 mg/L) and showed a concentration-dependent reduction in H2O2 production. Consistent with extracted OSPW NAs, 3,5-dimethyladamantane-1-carboxylic acid inhibited state 3 respiration and increased H2O2 production, but with a two-fold greater EC50 than the NA mixture extracted from OSPW. All three compounds uncoupled mitochondrial membrane potential and increased state 4 respiration. Based on these results, the adamantane 3,5-dimethyladamantane-1-carboxylic NAs may act via similar mitrochondrial mechanisms as NAs extracted from OSPW and could be used to further explore toxic mechanisms.Natural Sciences and Engineering Research CouncilCanada Research Chair
A quality improvement project on pain management at a tertiary pediatric hospital
No full textTo assess and improve pain management practices for hospitalized children in an urban tertiary pediatric teaching hospital. Methods: Health Quality Ontario Quality Improvement (QI) framework informed this study. A pre (T1) –post (T2) intervention assessment included chart reviews and children/caregiver surveys to ascertain pain management practices. Information on self-reported pain intensity, painful procedures, pain treatment and satisfaction were obtained from children/caregivers. Documented pain assessment, pain scores, and pharmacological/non-pharmacological pain treatments were collected by chart review. T1 data was fed back to pediatric units to inform their decisions and pain management targets. Results: At T1, 51 (58% of eligible participants) children/caregivers participated. At T2, 86 (97%) chart reviews and 51 (54%) children/caregivers surveys were completed. Most children/caregivers at T1 (78%) and T2 (80%) reported moderate to severe pain during their hospitalization. A mean of 2.6 painful procedures were documented in the previous 24 h, with the most common being needle-related procedures at both T1 and T2. Pain management strategies were infrequently used during needle-related procedures at both time points. Conclusion: No improvements in pain management as measured by the T1 and T2 data occurred. Findings informed further pain management initiatives in the participating hospital
Dynamics of a diffusive vaccination model with therapeutic impact and non-linear incidence in epidemiology
No full textIn this paper, we study a more general diffusive spatially dependent vaccination model for infectious disease. In our diffusive vaccination model, we consider both therapeutic impact and nonlinear incidence rate. Also, in this model, the number of compartments of susceptible, vaccinated and infectious individuals are considered to be functions of both time and location, where the set of locations (equivalently, spatial habitats) is a subset of Rn with a smooth boundary. Both local and global stability of the model are studied. Our study shows that if the threshold level R0≤1, the disease-free equilibrium E0 is globally asymptotically stable. On the other hand, if R0>1 then there exists a unique stable disease equilibrium E∗. The existence of solutions of the model and uniform persistence results are studied. Finally, using finite difference scheme, we present a number of numerical examples to verify our analytical results. Our results indicate that the global dynamics of the model are completely determined by the threshold value R0
Behavioral and histopathological consequences of transient ischemic stroke in the Flinders Sensitive Line rat, a genetic animal model of depression
No full textPatients with depression have an increased risk for stroke, higher mortality rates following stroke and worse functional outcomes among survivors. Preclinical studies may help to better understand the underlying mechanisms linking these two diseases, but only a few animal studies have investigated the effects of prestroke depression. The present study investigates whether Flinders Sensitive Line (FSL) rats, a genetic depression model, respond differently to focal ischemic stroke compared to control strains (Flinders Resistant Line [FRL] and Sprague-Dawley [SD]). Male adult FSL, FRL and SD rats received a unilateral injection of either vehicle or Endothelin-1 (ET-1) adjacent to the middle cerebral artery (MCA). Motor function was assessed at 48 h followed by euthanasia and infarct volume measurement using 2,3,5-triphenyltetrazolium chloride (TTC) staining and image analysis. In a separate cohort behavior was assessed using standard tests for motor function, locomotor activity, cognition, anxiety- and depression-like behavior beginning at 10 days post-injection followed by infarct quantification. We found that ET-1-induced MCA occlusion produced significant infarcts in all three strains. Stroke animals had slightly impaired motor function, but there was no clear interaction effects between strain and stroke surgery on behavioral outcomes. We conclude that FSL rats show no increased susceptibility to brain damage or behavioral deficits following ET-1-induced focal ischemic stroke compared to controls
The assessment of emerging data-intelligence technologies for modeling Mg+2 and SO4−2 surface water quality
No full textThe concentration of soluble salts in surface water and rivers such as sodium, sulfate, chloride, magnesium ions, etc., plays an important role in the water salinity. Therefore, accurate determination of the distribution pattern of these ions can improve better management of drinking water resources and human health. The main goal of this research is to establish two novel wavelet-complementary intelligence paradigms so-called wavelet least square support vector machine coupled with improved simulated annealing (W-LSSVM-ISA) and the wavelet extended Kalman filter integrated with artificial neural network (W-EKF- ANN) for accurate forecasting of the monthly), magnesium (Mg+2), and sulfate (SO4−2) indices at Maroon River, in Southwest of Iran. The monthly River flow (Q), electrical conductivity (EC), Mg+2, and SO4−2 data recorded at Tange-Takab station for the period 1980–2016. Some preprocessing procedures consisting of specifying the number of lag times and decomposition of the existing original signals into multi-resolution sub-series using three mother wavelets were performed to develop predictive models. In addition, the best subset regression analysis was designed to separately assess the best selective combinations for Mg+2 and SO4−2. The statistical metrics and authoritative validation approaches showed that both complementary paradigms yielded promising accuracy compared with standalone artificial intelligence (AI) models. Furthermore, the results demonstrated that W-LSSVM-ISA-C1 (correlation coefficient (R) = 0.9521, root mean square error (RMSE) = 0.2637 mg/l, and Kling-Gupta efficiency (KGE) = 0.9361) and W-LSSVM-ISA-C4 (R = 0.9673, RMSE = 0.5534 mg/l and KGE = 0.9437), using Dmey mother that outperformed the W-EKF-ANN for predicting Mg+2 and SO4−2, respectively
Natural attachment and size of cultured oysters limit mortality from a non‐indigenous predator
No full textOyster recruitment to spat collectors can result in the clumping of two or more individuals, whereby they naturally cement to each other's shells. On‐bottom oyster farmers typically separate these oysters and re‐deploy them on the seafloor, potentially exposing them to predators. This raises the question of whether refraining from separating these oysters might provide an advantage against predation. We addressed this question using eastern oysters (Crassostrea virginica) and the non‐indigenous European green crab (Carcinus maenas) from part of their invaded range in Atlantic Canada. We assessed the influence of oyster arrangement (single vs. paired) and oyster size (small‐ vs. mid‐size) on mortality caused by two sizes of this invasive predator. Mortality rates were assessed with 24 h trials in which 30 oysters of a given size and arrangement were exposed to green crab predation. We found a significant influence of oyster arrangement (paired<single) and size (mid<small size) on mortality rates, without a significant interaction between these factors. A consistent predation tactic was used by the green crabs to attack and feed on the oysters, but the natural pairing of oysters seemed to delay or limit the ability of the crabs to break the shells. Our results suggest avoiding or delaying the separation of oysters until they reach a refuge size, particularly in oyster‐suitable habitats invaded or likely to be invaded by green crabs