BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Namur Institute For Complex Systems - ECPv6.15.14//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-ORIGINAL-URL:https://www.naxys.be
X-WR-CALDESC:Events for Namur Institute For Complex Systems
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Europe/Paris
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20160327T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20161030T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20170326T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20171029T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20180325T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20181028T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20170523T130000
DTEND;TZID=Europe/Paris:20170523T140000
DTSTAMP:20260409T072050
CREATED:20170318T163007Z
LAST-MODIFIED:20170514T143251Z
UID:161-1495544400-1495548000@www.naxys.be
SUMMARY:Stefano Berti (University of Lille)
DESCRIPTION:Title: Reaction-transport systems in heterogeneous environments and population dynamics \nAbstract: Understanding the conditions ensuring the persistence of a population or determining the efficiency of its invasion into a new territory are issues of primary importance in population biology. A convenient conceptual framework to study these problems from a theoretical point of view is offered by reaction-transport equations. Taking this modeling approach\, in the first part of the talk I present a study on the evolution of a population in a heterogeneous environment in the presence of advection. The habitat consists of a periodic alternation of favorable and unfavorable patches where the population grows according to logistic dynamics and dies at a fixed rate\, respectively. I show that the population can survive and invade the habitat only above a critical size of the favorable patches and below a critical velocity of the medium. I characterize the survival/extinction transition\, and I present some analytical and numerical results on the invasion speed. Then\, I discuss some limitations of this description\, extending the analysis to a model with a growth term accounting for decreased reproductive power at low population densities. The phenomenology of this model is found to be richer when varying the advection intensity.\nIn the second part of the talk I discuss some effects of discreteness and demographic stochasticity on the extinction dynamics of a population confined in a favorable patch (an oasis) surrounded by a deadly environment. For this purpose\, I introduce an individual-based reaction-diffusion model and investigate its behavior focusing on the average time to extinction and on the quasistationary distribution of the number of individuals that sets in for large enough patch sizes.
URL:https://www.naxys.be/event/stefano-berti/
LOCATION:Seminar room\, Rempart de la Vierge 8\, Namur\, 1170
CATEGORIES:NAXYS Seminar
END:VEVENT
END:VCALENDAR