Kalogeiton V.,Calvin University |
Ferrari V.,Calvin University |
Schmid C.,French Institute for Research in Computer Science and Automation
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2016
Object detection is one of the most important challenges in computer vision. Object detectors are usually trained on bounding-boxes from still images. Recently, video has been used as an alternative source of data. Yet, for a given test domain (image or video), the performance of the detector depends on the domain it was trained on. In this paper, we examine the reasons behind this performance gap. We define and evaluate different domain shift factors: spatial location accuracy, appearance diversity, image quality and aspect distribution. We examine the impact of these factors by comparing performance before and after factoring them out. The results show that all four factors affect the performance of the detectors and their combined effect explains nearly the whole performance gap. © 2016 IEEE.
Mcclure-Warnier J.-A.,University of Calgary |
Conly J.M.,University of Calgary |
Conly J.M.,Calvin University |
Zhang K.,University of Calgary |
Zhang K.,Calvin University
Journal of Visualized Experiments | Year: 2013
Staphylococcal Cassette Chromosome mec (SCCmec) typing is a very important molecular tool for understanding the epidemiology and clonal strain relatedness of methicillin-resistant Staphylococcus aureus (MRSA), particularly with the emerging outbreaks of community-associated MRSA (CA-MRSA) occurring on a worldwide basis. Traditional PCR typing schemes classify SCCmec by targeting and identifying the individual mec and ccr gene complex types, but require the use of many primer sets and multiple individual PCR experiments. We designed and published a simple multiplex PCR assay for quick-screening of major SCCmec types and subtypes I to V, and later updated it as new sequence information became available. This simple assay targets individual SCCmec types in a single reaction, is easy to interpret and has been extensively used worldwide. However, due to the sophisticated nature of the assay and the large number of primers present in the reaction, there is the potential for difficulties while adapting this assay to individual laboratories. To facilitate the process of establishing a MRSA SCCmec assay, here we demonstrate how to set up our multiplex PCR assay, and discuss some of the vital steps and procedural nuances that make it successful.
PubMed | Calvin University
Type: Journal Article | Journal: Blood | Year: 2011
The endothelium actively participates in neutrophil migration out of the vasculature via dynamic, cytoskeleton-dependent rearrangements leading to the formation of transmigratory cups in vitro, and to domes that completely surround the leukocyte in vivo. Leukocyte-specific protein 1 (LSP1), an F-actin-binding protein recently shown to be in the endothelium, is critical for effective transmigration, although the mechanism has remained elusive. Herein we show that endothelial LSP1 is expressed in the nucleus and cytosol of resting endothelial cells and associates with the cytoskeleton upon endothelial activation. Two-photon microscopy revealed that endothelial LSP1 was crucial for the formation of endothelial domes in vivo in response to neutrophil chemokine keratinocyte-derived chemokine (KC) as well as in response to endogenously produced chemokines stimulated by cytokines (tumor necrosis factor [TNF] or interleukin-1 [IL-1]). Endothelial domes were significantly reduced in Lsp1(-/-) compared with wild-type (WT) mice. Lsp1(-/-) animals not only showed impaired neutrophil emigration after KC and TNF stimulation, but also had disproportionate increases in vascular permeability. We demonstrate that endothelial LSP1 is recruited to the cytoskeleton in inflammation and plays an important role in forming endothelial domes thereby regulating neutrophil transendothelial migration. The permeability data may underscore the physiologic relevance of domes and the role for LSP1 in endothelial barrier integrity.
PubMed | Calvin University
Type: Journal Article | Journal: Annals of surgery | Year: 2015
To determine whether active negative pressure peritoneal therapy with the ABThera temporary abdominal closure device reduces systemic inflammation after abbreviated laparotomy.Excessive systemic inflammation after abdominal injury or intra-abdominal sepsis is associated with poor outcomes.We conducted a single-center, randomized controlled trial. Forty-five adults with abdominal injury (46.7%) or intra-abdominal sepsis (52.3%) were randomly allocated to the ABThera (n = 23) or Barkers vacuum pack (n = 22). On study days 1, 2, 3, 7, and 28, blood and peritoneal fluid were collected. The primary endpoint was the difference in the plasma concentration of interleukin-6 (IL-6) 24 and 48 hours after temporary abdominal closure application.There was a significantly lower peritoneal fluid drainage from the ABThera at 48 hours after randomization. Despite this, there was no difference in plasma concentration of IL-6 at baseline versus 24 (P = 0.52) or 48 hours (P = 0.82) between the groups. There was also no significant intergroup difference in the plasma concentrations of IL-1, -8, -10, or -12 p70 or tumor necrosis factor between these time points. The cumulative incidence of primary fascial closure at 90 days was similar between groups (hazard ratio, 1.6; 95% confidence interval, 0.82-3.0; P = 0.17). However, 90-day mortality was improved in the ABThera group (hazard ratio, 0.32; 95% confidence interval, 0.11-0.93; P = 0.04).This trial observed a survival difference between patients randomized to the ABThera versus Barkers vacuum pack that did not seem to be mediated by an improvement in peritoneal fluid drainage, fascial closure rates, or markers of systemic inflammation.ClinicalTrials.gov identifier NCT01355094.
Patrick Schenck L.,Calvin University |
Beck P.,Calvin University |
Waterhouse C.,Calvin University
Journal of Leukocyte Biology | Year: 2015
Despite progress in understanding enteric inflammation, current therapies, although effective in many patients with inflammatory bowel disease (IBD), have significant sideeffects, and, in many patients, it is refractory to treatment. The Src kinase Fyn mediated IFN-γ-induced increased permeability in model epithelia, and so we hypothesized that inhibition of Fyn kinase would be anti-colitic. Mice [B6.129SF2/J wild-type (WT), Fyn KO, or chimeras] received 2.5% dextran sodium sulfate (DSS) or normal water for 10 d and were necropsied immediately or 3 d later. Gut permeability was assessed by FITC-dextran flux, colitis by macroscopic and histologic parameters, and immune cell status by cytokine production and CD4+ T cell Foxp3 expression. Fyn KO mice consistently displayed significantly worse DSS-induced disease than WT, correlating with decreased IL-10 and increased IL-17 in splenocytes and the gut; Fyn KOmice failed to thrive after removal of the DSS water. Analysis of chimeric mice indicated that the increased sensitivity to DSS was due to the lack of Fyn kinase in hematopoietic, but not stromal, cells, in accordance with Fyn+ T cell increases inWTmice exposed to DSS and Fyn KO mice having a reduced number of CD4+ Foxp3+ cells in baseline or colitic conditions and a reduced capacity to induce Foxp3 expression in vitro. Other experiments suggest that the colonic microbiota in Fyn KO mice is not preferentially colitogenic. Contrary to our expectation, the absence of Fyn kinase resulted in greater DSS-induced disease, and analysis of chimeric mice indicated that leukocyte Fyn kinase is beneficial in limiting colitis. © 2015 Federation of American Societies for Experimental Biology. All rights reserved.