Just got this (very late) announcement of a highly interesting seminar next week(!), Monday 3rd Dec., 10:30, Lunch room, Floor 2, SciLifeLab Stockholm. [Message from Francesco Vezzi 2012-Nov-30] "Dear all, next week there will be two SBC seminars: Monday (Decembers the 3rd) Megan Owen will present us her recent work in a seminar titled "Statistics in the Space of Phylogenetic Trees". Megan
Owen is a researcher at David R. Cheriton School of Computer Science at
the University of Waterloo in Canada. Megan's current research focuses
on using geometric spaces to represent, study, and analyze phylogenetic
trees and networks, as well as tree-shaped data arising from medical
imaging. She is also interested in mathematical and statistical problems
related to understanding these spaces. Tuesday (December the 4th) Emil Kölbeck will present us her her master thesis work (supervisor Erik Sonnhammer) in a seminar titled "Protein domain versatility scoring methods". Both seminars will take place at 10.30 in the Lunch Room floor 2 at SciLifeLab Stockholm. Megan Owen's Abstract: We
introduce new notions of mean and variance for a set or distribution of
phylogenetic trees. These definitions of mean and variance are
analogous to those for a weighted set of points in Euclidean space, but
with the underlying space being the space of phylogenetic trees
constructed by Billera, Holmes, and Vogtmann (2001). A property of this
space (non-positive curvature) ensures there is a unique shortest path
between any two trees. Furthermore, this path can be computed in
polynomial time, leading to a practical algorithm for computing the mean
and variance. I will compare the mean and variance to existing
consensus tree and summary methods, as well as present applications to
such biological problems as the reconstruction of phylogenetic trees and
the automatic labeling of lung airway scans. "/JN |
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