BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:Ants: a decentralized micro chemical factory
DTSTART:20120508T113000
DTEND:20120508T123000
DTSTAMP:20260511T062106Z
UID:db472c2b4495781a1ee4643e4b103fd1dfecac6bf1f305a67d3e3fa5
CATEGORIES:Conferences - Seminars
DESCRIPTION:Jean-Louis Deneubourg\, Université Libre de Bruxelles\, Belgi
 um\nThe organization of complex societies requires constant information fl
 ow between individuals. Food sharing is vital for a large number of specie
 s and is of particular importance within highly integrated societies\, suc
 h as in colonial organisms and in social insects. There is no doubt that t
 he shape of the food web organizes itself according to the spatial distrib
 ution of the individuals and of the stocks and that these stocks influence
  the spatial distribution of the insects. Nevertheless\, the mechanisms an
 d information exchange between individuals that govern the distribution of
  food inside a complex organizational system such as an ant colony remain 
 largely unknown.\nIncorporating division of labour and complex communicati
 on pathways\, communities of social insects are a prime example of collect
 ive energy management. To identify the relations between food retrieval\, 
 the food exchange\, the division of labour and the spatio-temporal organiz
 ation of the food stock\, an approach coupling theoretical modelling and e
 xperiments is followed.\n\nTo quantify how the spatial organization of the
  food stocks changes with the colony needs\, we monitored the flow of radi
 olabeled sugar solution inside an ant nest at different degrees of starvat
 ion (sequential scintigraphy). The sugar is the major source of energy. Th
 e spatial dynamics of the food flow revealed stable patterns and fine-tuni
 ng regulation of the feeding process. At the scale of the colony\, the col
 lective regulatory stock management task can be reproduced by a simple mod
 el that integrates a positive and a negative feedback proportional to the 
 number of ants that already received food.\n\nSpatial analysis of the suga
 r distribution showed that energy is heterogeneously stocked among individ
 uals and also heterogeneously consumed. Furthermore\, a regular spatial st
 ructure emerges\, leading to centralization of the stocks: heavily loaded 
 individuals being at the center of the cluster and weakly loaded individua
 ls at its periphery. Mathematical modelling suggests that this aggregation
 -segregation seems to result from a trade-off between the individual speci
 alization and the inter attraction between individuals.\n\nThe centralizat
 ion of both resources and information in self-organized systems might be a
  widespread phenomenon that deserves further studies.\n\nBio:\nhttp://www.
 ulb.ac.be/sciences/use/deneubourg.html
LOCATION:GR A3 31 http://plan.epfl.ch/?zoom=20&recenter_y=5864234.10491&re
 center_x=731131.75195&layerNodes=fonds\,batiments\,labels\,information\,pa
 rkings_publics\,arrets_metro&floor=3&q=GR_A3%2031
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR