ORCID Profile
0000-0001-7528-697X
Current Organisations
Université Laval
,
Centre de recherche de l'Institut universitaire en santé mentale de Québec
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Publisher: arXiv
Date: 2022
Publisher: arXiv
Date: 2022
Publisher: American Physical Society (APS)
Date: 19-06-2017
Publisher: American Physical Society (APS)
Date: 24-03-2015
Publisher: Elsevier BV
Date: 06-2007
Publisher: Springer Science and Business Media LLC
Date: 11-2004
Publisher: SIGMA (Symmetry, Integrability and Geometry: Methods and Application)
Date: 03-08-2012
Publisher: Springer Science and Business Media LLC
Date: 29-08-2013
Publisher: arXiv
Date: 2022
Publisher: SPIE-Intl Soc Optical Eng
Date: 07-04-2022
Publisher: Elsevier BV
Date: 06-2008
Publisher: Elsevier BV
Date: 12-2003
Publisher: Springer Science and Business Media LLC
Date: 28-10-2015
Publisher: AIP Publishing
Date: 12-2010
DOI: 10.1063/1.3430564
Abstract: We study integrals over Hermitian supermatrices of arbitrary size p + q, which are parametrized by an external field X and a source Y of respective sizes m + n and p + q. We show that these integrals exhibit a simple topological expansion in powers of a formal parameter ℏ, which can be identified with 1/(p − q). The loop equation and the associated spectral curve are also obtained. The solutions to the loop equation are given in terms of the symplectic invariants introduced by Eynard and Orantin [Commun. Number Theory Phys. 1, 347 (2007)]. The symmetry property of the latter objects allows us to prove a duality that relates supermatrix models in which the role of X and Y are interchanged.
Publisher: Oxford University Press (OUP)
Date: 31-03-2015
DOI: 10.1093/IMRN/RNU039
Publisher: Cold Spring Harbor Laboratory
Date: 02-2022
DOI: 10.1101/2022.01.31.477297
Abstract: Despite an increasing number of studies highlighting the impacts of climate change on boreal species, the main factors that will drive changes in species assemblages remain ambiguous. We quantify two climate-induced pathways based on direct and indirect effects on species occupancy and assemblage dis-similarity under different harvest management scenarios. The direct climate effects illustrate the impact of climate variables while the indirect effects are reflected through the changes in land cover composition. To understand the main causes in assemblage dissimilarity, we analyze the regional and the latitudinal species assemblage dissimilarity by decomposing it into balanced variation in species occupancy and occurrence and occupancy and occurrence gradient . We develop empirical models to predict the distribution of more than 100 bird and beetle species in the Côte-Nord region of Québec over the next century. Our results show that the two pathways are complementary and alter bio ersity, mainly caused by balanced variation in species occupancy and occurrence. At the regional scale, both effects have an impact on decreasing the number of winning species. Yet, responses are much larger in magnitude under mixed climate effects (a mixture of direct and indirect effects). Regional assemblage dissimilarity reached 0.77 and 0.69 under mixed effects versus 0.09 and 0.10 under indirect effects for beetles and birds, respectively, between RCP8.5 and baseline climate scenarios when considering harvesting. Therefore, inclusion of climatic variables considers aspects other than just those related to forest landscapes, such as life cycles of animal species. Latitudinally, assemblage dissimilarity increased following the climate conditions pattern. Our analysis contributes to the understanding of how climate change alters bio ersity by reshaping community composition and highlights the importance of climate variables in bio ersity prediction.
Publisher: IOP Publishing
Date: 23-12-2013
Publisher: Springer Science and Business Media LLC
Date: 02-2003
Publisher: Elsevier BV
Date: 05-2006
Publisher: Springer Science and Business Media LLC
Date: 20-01-2022
Publisher: American Physical Society (APS)
Date: 04-03-2019
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.CELREP.2018.04.065
Abstract: Primary afferents transduce environmental stimuli into electrical activity that is transmitted centrally to be decoded into corresponding sensations. However, it remains unknown how afferent populations encode different somatosensory inputs. To address this, we performed two-photon Ca
Publisher: IOP Publishing
Date: 09-01-2004
Publisher: American Physical Society (APS)
Date: 17-12-2019
Publisher: American Physical Society (APS)
Date: 24-09-2018
Publisher: Oxford University Press (OUP)
Date: 2006
Publisher: Springer Science and Business Media LLC
Date: 09-2012
Publisher: SPIE
Date: 26-04-2016
DOI: 10.1117/12.2212726
Publisher: Springer Science and Business Media LLC
Date: 08-01-2012
Publisher: International Press of Boston
Date: 2012
Publisher: American Mathematical Society
Date: 22-11-2004
DOI: 10.1090/CRMP/037/10
Publisher: Elsevier BV
Date: 07-2001
Publisher: Oxford University Press (OUP)
Date: 05-2023
DOI: 10.1093/PNASNEXUS/PGAD150
Abstract: Dimension reduction is a common strategy to study nonlinear dynamical systems composed by a large number of variables. The goal is to find a smaller version of the system whose time evolution is easier to predict while preserving some of the key dynamical features of the original system. Finding such a reduced representation for complex systems is, however, a difficult task. We address this problem for dynamics on weighted directed networks, with special emphasis on modular and heterogeneous networks. We propose a two-step dimension-reduction method that takes into account the properties of the adjacency matrix. First, units are partitioned into groups of similar connectivity profiles. Each group is associated to an observable that is a weighted average of the nodes’ activities within the group. Second, we derive a set of equations that must be fulfilled for these observables to properly represent the original system’s behavior, together with a method for approximately solving them. The result is a reduced adjacency matrix and an approximate system of ODEs for the observables’ evolution. We show that the reduced system can be used to predict some characteristic features of the complete dynamics for different types of connectivity structures, both synthetic and derived from real data, including neuronal, ecological, and social networks. Our formalism opens a way to a systematic comparison of the effect of various structural properties on the overall network dynamics. It can thus help to identify the main structural driving forces guiding the evolution of dynamical processes on networks.
Publisher: American Physical Society (APS)
Date: 11-11-2020
Publisher: Elsevier BV
Date: 08-2009
Publisher: Springer Science and Business Media LLC
Date: 08-2017
Publisher: Oxford University Press (OUP)
Date: 18-04-2023
DOI: 10.1093/PNASNEXUS/PGAD136
Abstract: Over the last decade, random hyperbolic graphs have proved successful in providing geometric explanations for many key properties of real-world networks, including strong clustering, high navigability, and heterogeneous degree distributions. These properties are ubiquitous in systems as varied as the internet, transportation, brain or epidemic networks, which are thus unified under the hyperbolic network interpretation on a surface of constant negative curvature. Although a few studies have shown that hyperbolic models can generate community structures, another salient feature observed in real networks, we argue that the current models are overlooking the choice of the latent space dimensionality that is required to adequately represent clustered networked data. We show that there is an important qualitative difference between the lowest-dimensional model and its higher-dimensional counterparts with respect to how similarity between nodes restricts connection probabilities. Since more dimensions also increase the number of nearest neighbors for angular clusters representing communities, considering only one more dimension allows us to generate more realistic and erse community structures.
Publisher: Oxford University Press (OUP)
Date: 15-12-2012
DOI: 10.1093/IMRN/RNR235
Publisher: Springer Science and Business Media LLC
Date: 11-07-2006
Publisher: Springer Science and Business Media LLC
Date: 05-09-2022
DOI: 10.1007/S00422-022-00941-W
Abstract: Fifty years ago, Wilson and Cowan developed a mathematical model to describe the activity of neural populations. In this seminal work, they ided the cells in three groups: active, sensitive and refractory, and obtained a dynamical system to describe the evolution of the average firing rates of the populations. In the present work, we investigate the impact of the often neglected refractory state and show that taking it into account can introduce new dynamics. Starting from a continuous-time Markov chain, we perform a rigorous derivation of a mean-field model that includes the refractory fractions of populations as dynamical variables. Then, we perform bifurcation analysis to explain the occurrence of periodic solutions in cases where the classical Wilson–Cowan does not predict oscillations. We also show that our mean-field model is able to predict chaotic behavior in the dynamics of networks with as little as two populations.
Publisher: World Scientific Pub Co Pte Lt
Date: 04-2015
DOI: 10.1142/S2010326315500070
Abstract: We study a new Selberg-type integral with n + m indeterminates, which turns out to be related to the deformed Calogero–Sutherland systems. We show that the integral satisfies a holonomic system of n + m non-symmetric linear partial differential equations. We also prove that a particular hypergeometric function defined in terms of super-Jack polynomials is the unique solution of the system. Some properties such as duality relations, integral formulas, Pfaff–Euler and Kummer transformations are also established. As a direct application, we evaluate the expectation value of ratios of characteristic polynomials in the classical β-ensembles of Random Matrix Theory.
Publisher: IOP Publishing
Date: 17-01-2014
Publisher: IOP Publishing
Date: 19-06-2006
Publisher: Springer Science and Business Media LLC
Date: 26-09-2003
Publisher: Springer Science and Business Media LLC
Date: 25-10-2012
Location: Canada
Start Date: 2005
End Date: 2006
Funder: Natural Sciences and Engineering Research Council
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