Time filter

Source Type

Brockville, Canada

Pond G.T.,St Lawrence College | Brimberg J.,Royal Military College of Canada | Wang Y.,Royal Military College of Canada | Simms B.,Royal Military College of Canada
Journal of Defense Modeling and Simulation | Year: 2015

This paper presents some interesting results that compare three heuristics applied to the sensor deployment problem. These heuristics are the genetic algorithm (GA), differential evolution (DE), and vertex swap algorithm (VSA). In both of two test problems, solved independently hundreds of times, the VSA routinely demonstrates better performance in terms of the quality of the solution and in lower execution times. The VSA is also combined with both the GA and DE to produce hybrid metaheuristics. However, repeated tests demonstrated that this provides little to no improvement in the quality of the final solution. Thus, a simple local search may be all that is needed for certain types of problems. © 2014 The Society for Modeling. Source

Sears N.,St Lawrence College | Baker G.R.,University of Toronto | Barnsley J.,University of Toronto | Shortt S.,Canadian Medical Association
International Journal for Quality in Health Care | Year: 2013

Objective: Incidence of adverse events (AEs) among home care patients and preventability ratings were estimated. Risk factors, AE types and factors associated with AEs were identified. Design: This study used a stratified, randomized sample of home care patients discharged in the fiscal year 2004/05. Trained nurse reviewers completed retrospective chart abstractions; charts for cases that were positive for screening criteria suggesting the presence of AEs were reviewed by trained physicians to determine the presence of and preventability of AEs. Setting: Three publicly funded home care programs in Ontario, Canada. Main outcome measures: Prevalence and types of AEs; ratings of preventability. Results: At least one screening criterion was positively identified in 286 (66.5%) of 430 cases. Physician reviewers identified 61 AEs in 55 (19.2%) of the 286 (12.8% of the 430) cases. The AE rate was 13.2 per 100 home care cases [95% confidence interval (CI): 10.4-16.6%, standard error 1.6%]. 32.7% (20 of 61 AEs) of the AEs were rated as having >50% probability of preventability; 6 deaths (10.9% of patients with an AE; 1.4% of all patients) occurred in AE-positive patients. The most common AEs were falls and adverse drug events. Conclusions: Providing health care through home care programs creates unintended harm to patients. The incidence rate of AEs of 13.2% suggests a significant number of home care patients experience AEs, one-third of which were considered preventable. Improvements in patient and informal caregiver education, skill development and clinical planning may be useful interventions to reduce AEs. © The Author 2013. Source

Moon J.,St Lawrence College
Electronic Engineering Times | Year: 2011

The validation of safety claims for systems running on multicore processors, and some OS characteristics that can facilitate the migration to multicore, are discussed. Any medical device for which reliability and availability are requirements need a real-time OS, and RTOS need to support symmetric multiprocessing. To ensure system dependability, the RTOS should also support time partitioning, priority inheritance, and processor affinity. The multicore RTOS should be supported by a tool set that lets developers assess load balancing, identify bottlenecks, determine opportunities for concurrency, characterize and debug interactions between threads running on multiple CPUs. Testing, statistical analysis and design validation complement one another to validate a software system, whether it is running on one or multiple cores. Source

Rico Y.,Trent University | Morris-Pocock J.,Trent University | Morris-Pocock J.,St Lawrence College | Zigouris J.,Trent University | And 2 more authors.
PLoS ONE | Year: 2015

Elucidating the adaptive genetic potential of wildlife populations to environmental selective pressures is fundamental for species conservation. Genes of the major histocompatibility complex (MHC) are highly polymorphic, and play a key role in the adaptive immune response against pathogens. MHC polymorphism has been linked to balancing selection or heterogeneous selection promoting local adaptation. However, spatial patterns of MHC polymorphism are also influenced by gene flow and drift. Wolverines are highly vagile, inhabiting varied ecoregions that include boreal forest, taiga, tundra, and high alpine ecosystems. Here, we investigated the immunogenetic variation of wolverines in Canada as a surrogate for identifying local adaptation by contrasting the genetic structure at MHC relative to the structure at 11 neutral microsatellites to account for gene flow and drift. Evidence of historical positive selection was detected at MHC using maximum likelihood codonbased methods. Bayesian and multivariate cluster analyses revealed weaker population genetic differentiation at MHC relative to the increasing microsatellite genetic structure towards the eastern wolverine distribution. Mantel correlations of MHC against geographical distances showed no pattern of isolation by distance (IBD: r = -0.03, p = 0.9), whereas for microsatellites we found a relatively strong and significant IBD (r = 0.54, p = 0.01). Moreover, we found a significant correlation between microsatellite allelic richness and the mean number of MHC alleles, but we did not observe low MHC diversity in small populations. Overall these results suggest that MHC polymorphism has been influenced primarily by balancing selection and to a lesser extent by neutral processes such as genetic drift, with no clear evidence for local adaptation. This study contributes to our understanding of how vulnerable populations of wolverines may respond to selective pressures across their range. Copyright: © 2015 Rico et al. Source

Gupalo E.,Institute of Experimental Cardiology | Kuk C.,Princess Margaret Hospital | Qadura M.,McMaster University | Buriachkovskaia L.,Institute of Experimental Cardiology | And 2 more authors.
Platelets | Year: 2013

Platelets are involved in host defense via clearance of bacteria from the circulation, interaction with virus particles, and uptake of various size particulates. There is a growing interest in micro- and nanoparticles for drug delivery and there is evidence that the properties of these particles critically influence their interaction and uptake by various tissues and cells including platelets. Virus mediated gene therapy applications are still challenged by the resultant thrombocytopenia and the mechanism(s) of platelet-foreign particles interaction remains unclear. We studied the specifics of platelet interaction with an active biological agent (adenovirus) and inert latex microspheres (MS) and investigated the role of platelet proteins in this interaction. We show that activated and not resting platelets internalize MS, without influencing platelet aggregation. In contrast, adenovirus induces and potentiates ADP-induced platelet aggregation and results in rapid expression of P-selectin. Platelets then internalize adenovirus and viral particles appear inside the open canalicular system. Inhibition of platelet αIIbβ3, GPIbα, and P-selectin decreases both platelet aggregation and internalization of MS. Inhibition of αIIbβ3 and αVβ3 does not abolish adenovirus platelet internalization and adenovirus-induced platelet activation is maintained. Our study demonstrates that platelets react differentially with foreign particles and that αIIbβ3 is a key player in platelet engulfing of foreign particles but not in mediating adenovirus internalization. Other platelet candidate molecules remain to be investigated as potential targets for management of adenovirus-induced thrombocytopenia. © 2013 Informa UK Ltd. Source

Discover hidden collaborations