Publications

Analysis of the Human Pineal Proteome by Mass Spectrometry
Mariette Matondo
Guillaume Dumas
Erik Maronde
2022-09-30
Melatonin (published)
doi.org
Evaluation of Real-life Use of Point-of-care Rapid Antigen Testing for SARS-CoV-2 in Schools (EPOCRATES): a cohort study
Ana C. Blanchard MD MSc
Marc Desforges PhD
Annie-Claude Labbé MD
Cat Tuong Nguyen MD PhD
Yves Petit MSc
Dominic Besner BEd
Kate Zinszer PhD
Olivier Séguin PhD
Zineb Laghdir MSc
Kelsey Adams MScPH
Marie-Ève Benoit MSc
Geneviève Leduc
Jean Longtin MD
Jiannis Ragoussis PhD
David L. Buckeridge MD PhD
Caroline Quach MD MSc
SARS-CoV-2 transmission has an impact on education. In this study, we assessed the performance of rapid antigen detection tests (RADTs) vers… (see more)us polymerase chain reaction (PCR) for the diagnosis of SARS-CoV-2 infection in school settings, and RADT use for monitoring exposed contacts. In this real-world, prospective observational cohort study, high-school students and staff were recruited from 2 high schools in Montréal, Canada, and followed from Jan. 25 to June 10, 2021. Twenty-five percent of asymptomatic participants were tested weekly by RADT (nasal) and PCR (gargle). Class contacts of cases were tested. Symptomatic participants were tested by RADT (nasal) and PCR (nasal and gargle). The number of cases and outbreaks were compared with those of other high schools in the same area. Overall, 2099 students and 286 school staff members consented to participate. The overall specificity of RADTs varied from 99.8% to 100%, with a lower sensitivity, varying from 28.6% in asymptomatic to 83.3% in symptomatic participants. Secondary cases were identified in 10 of 35 classes. Returning students to school after a 7-day quarantine, with a negative PCR result on days 6–7 after exposure, did not lead to subsequent outbreaks. Of cases for whom the source was known, 37 of 51 (72.5%) were secondary to household transmission, 13 (25.5%) to intraschool transmission, and 1 to community contacts between students in the same school. Rapid antigen detection tests did not perform well compared with PCR in asymptomatic individuals. Reinforcing policies for symptom screening when entering schools and testing symptomatic individuals with RADTs on the spot may avoid subsequent substantial exposures in class. Preprint: medRxiv — doi.org/10.1101/2021.10.13.21264960
2022-09-30
CMAJ Open (published)
doi.org
Finger-STS: Combined Proximity and Tactile Sensing for Robotic Manipulation
Francois R. Hogan
Jean-François Tremblay
Bobak H. Baghi
Michael Jenkin
Kaleem Siddiqi
Gregory Dudek
This paper introduces and develops novel touch sensing technologies that enable robots to better sense and react to to intermittent contact … (see more)interactions. We present Finger-STS, a robotic finger embodiment of the See-Through-your-Skin (STS) sensor that can capture 1) an “in the hand” visual perspective of an object that is being manipulated and 2) a high resolution tactile imprint of the contact geometry. We demonstrate the value of the sensor on a Bead Maze task. Here the multimodal feedback provided by the Finger-STS is leveraged by a robot to locate a bead visually and to guide it across a wire in response to tactile cues, with no additional sensing or planning required. To achieve this, we introduce a set of relevant visuotactile operations using computer vision-based algorithms. In particular, we sense the proximity of the object relative to the sensor as well as the nature of contact as a high resolution stick/slip vector field tracking the object motion in the finger.
2022-09-30
IEEE Robotics and Automation Letters (published)
doi.org
In-Processing Fairness Improvement Methods for Regression Data-Driven Building Models: Achieving Uniform Energy Prediction
Ying Sun
Benjamin C. M. Fung
Fariborz Haghighat
2022-09-30
Energy and Buildings (published)
doi.org
Interpolated Adversarial Training: Achieving Robust Neural Networks Without Sacrificing Too Much Accuracy
Alex Lamb
Vikas Verma
Kenji Kawaguchi
Juho Kannala
Alexander Matyasko
Yoshua Bengio
Savya Khosla
Adversarial robustness has become a central goal in deep learning, both in theory and in practice. However, successful methods to improve th… (see more)e adversarial robustness (such as adversarial training) greatly hurt generalization performance on the unperturbed data. This could have a major impact on how achieving adversarial robustness affects real world systems (i.e. many may opt to forego robustness if it can improve accuracy on the unperturbed data). We propose Interpolated Adversarial Training, which employs recently proposed interpolation based training methods in the framework of adversarial training. On CIFAR-10, adversarial training increases the standard test error (when there is no adversary) from 4.43% to 12.32%, whereas with our Interpolated adversarial training we retain adversarial robustness while achieving a standard test error of only 6.45%. With our technique, the relative increase in the standard error for the robust model is reduced from 178.1% to just 45.5%.
2022-09-30
Neural Networks (published)
doi.org
arxiv.org
Lifelong Topological Visual Navigation
Rey Reza Wiyatno
Anqi Xu
Liam Paull
Commonly, learning-based topological navigation approaches produce a local policy while preserving some loose connectivity of the space thro… (see more)ugh a topological map. Nevertheless, spurious or missing edges in the topological graph often lead to navigation failure. In this work, we propose a sampling-based graph building method, which results in sparser graphs yet with higher navigation performance compared to baseline methods. We also propose graph maintenance strategies that eliminate spurious edges and expand the graph as needed, which improves lifelong navigation performance. Unlike controllers that learn from fixed training environments, we show that our model can be fine-tuned using only a small number of collected trajectory images from a real-world environment where the agent is deployed. We demonstrate successful navigation after fine-tuning on real-world environments, and notably show significant navigation improvements over time by applying our lifelong graph maintenance strategies.
2022-09-30
IEEE Robotics and Automation Letters (published)
doi.org
arxiv.org
MixEHR-Guided: A guided multi-modal topic modeling approach for large-scale automatic phenotyping using the electronic health record
Yuri Ahuja
Yuesong Zou
Aman Verma
David L Buckeridge
Yuemei Li
2022-09-30
Journal of Biomedical Informatics (published)
doi.org
Processing visual ambiguity in fractal patterns: Pareidolia as a sign of creativity
Antoine Bellemare-Pepin
Yann Harel
Jordan O'Byrne
Geneviève Mageau
Arne Dietrich
Karim Jerbi

Creativity is a highly sought after and multifaceted skill. Unfortunately, we only have a loose grasp on its cognitive underpinnings. Emp… (see more)irical research typically probes creativity by estimating the potential for problem solving and novel idea generation, a process known as “divergent thinking”. Here, by contrast, we examine creativity through the lens of perceptual abilities. In particular, we ask whether creative individuals are better at perceiving recognizable forms in noisy or ambiguous stimuli, a phenomenon known as pareidolia. To this end, we designed a visual perception task in which 50 participants, with various levels of creativity, were presented with ambiguous stimuli and asked to identify as many recognizable forms as possible. The stimuli consisted of cloud-like images with various levels of complexity, which we controlled by manipulating fractal dimension (FD) and contrast level. We found that pareidolic perceptions arise more often and more rapidly in individuals that are more creative. Furthermore, the emergence of pareidolia in individuals with lower creativity scores was more restricted to images with a narrow range of FD values, suggesting a wider repertoire for perceptual abilities in creative individuals. Our findings suggest that pareidolia may be used as a perceptual proxy of idea generation abilities, a key component of creative behavior. In sum, we extend the established body of work on divergent thinking, by introducing divergent perception as a complementary manifestation of the creative mind. These findings expand our understanding of the perception-creation link and open new paths in studying creative behavior in humans.

2022-09-30
iScience (published)
doi.org
Smart Futures Based Resource Trading and Coalition Formation for Real-Time Mobile Data Processing
Ruitao Chen
Xianbin Wang
Xue Liu
Collaboration among mobile devices (MDs) is becoming more important, as it could augment computing capacity at the network edge through peer… (see more)-to-peer service provisioning, and directly enhance real-time computational performance in smart Internet-of-Things applications. As an important aspect of collaboration mechanism, conventional resource trading (RT) among MDs relies on an onsite interaction process, i.e., price negotiation between service providers and requesters, which, however, inevitably incurs excessive latency and degrades RT efficiency. To overcome this challenge, this article adopts the concept of futures contract (FC) used in financial market, and proposes a smart futures for low latency RT. This new technique enables MDs to form trading coalitions and negotiate multilateral forward contracts applied to a collaboration term in the future. To maximize the benefits of self-interested MDs, the negotiation process of FC is modelled as a coalition formation game comprised of three components executed in an iterative manner, i.e., futures resource allocation, revenue sharing and payment allocation, and distributed decision-making of individual MD. Additionally, a FC enforcement scheme is implemented to efficiently manage the onsite resource sharing via recording resource balances of different task-types and MDs. Simulation results prove the superiority of smart futures in RT latency reduction and trading fairness provisioning.
2022-09-30
IEEE Transactions on Services Computing (published)
doi.org
The tumor-specific antigen landscape of acute myeloid leukemia
Gregory Ehx
Krystel Vincent
Jean-David Larouche
Chantal Durette
Jean-Philippe Laverdure
Joël Lanoix
Éric Bonneil
Marie-Pierre Hardy
Caroline Coté
Nandita Noronha
Leslie Hesnard
Qingchuan Zhao
Céline M Laumont
Sébastien Lemieux
Pierre Thibault
Claude Perreault
2022-09-30
Molecular Immunology (published)
doi.org
Work-in-Progress: SuperNAS: Fast Multi-Objective SuperNet Architecture Search for Semantic Segmentation
Marihan Amein
Zhuoran Xiong
Olivier Therrien
Brett H. Meyer
Warren J. Gross
We present SuperNAS, a fast multi-objective neural architecture search framework for semantic segmentation. SuperNAS subsamples the structur… (see more)e and pre-trained parameters of DeepLabV3+, without fine-tuning, dramatically reducing training time during search. To further reduce candidate evaluation time, we use a subset of the validation dataset during search. Only the final, Pareto-dominant, candidates are ultimately fine-tuned using the complete training set. We evaluate SuperNAS by searching for models that effectively trade accuracy and computational cost on the PASCAL VOC 2012 dataset. SuperNAS finds competitive designs quickly, e.g., taking just 0.5 GPU days to discover a DeepLabV3+ variant that reduces FLOPs and parameters by 10% and 20% respectively, for less than 3% increased error.
2022-09-30
Conference on Compilers, Architecture, and Synthesis for Embedded Systems (published)
doi.org
Evolution of cell size control is canalized towards adders or sizers by cell cycle structure and selective pressures
Felix Proulx-Giraldeau
Jan M Skotheim
Paul François
Cell size is controlled to be within a specific range to support physiological function. To control their size, cells use diverse mechanisms… (see more) ranging from ‘sizers’, in which differences in cell size are compensated for in a single cell division cycle, to ‘adders’, in which a constant amount of cell growth occurs in each cell cycle. This diversity raises the question why a particular cell would implement one rather than another mechanism? To address this question, we performed a series of simulations evolving cell size control networks. The size control mechanism that evolved was influenced by both cell cycle structure and specific selection pressures. Moreover, evolved networks recapitulated known size control properties of naturally occurring networks. If the mechanism is based on a G1 size control and an S/G2/M timer, as found for budding yeast and some human cells, adders likely evolve. But, if the G1 phase is significantly longer than the S/G2/M phase, as is often the case in mammalian cells in vivo, sizers become more likely. Sizers also evolve when the cell cycle structure is inverted so that G1 is a timer, while S/G2/M performs size control, as is the case for the fission yeast S. pombe. For some size control networks, cell size consistently decreases in each cycle until a burst of cell cycle inhibitor drives an extended G1 phase much like the cell division cycle of the green algae Chlamydomonas. That these size control networks evolved such self-organized criticality shows how the evolution of complex systems can drive the emergence of critical processes.
2022-09-29
eLife (published)
doi.org