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NIMBioS Tuesday Seminar Series

Species montage. In conjunction with the interdisciplinary activities of the National Institute for Mathematical and Biological Synthesis (NIMBioS), a seminar series on topics in mathematical biology will be hosted at NIMBioS every other Tuesday at 3:30 p.m. (unless otherwise noted) in Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd. Seminar speakers will focus on their research initiatives at the interface of mathematics and many areas of the life sciences. Light refreshments will be served in Room 206 beginning 30 minutes before each talk. Faculty and students from across the UT community are welcome to join us. The schedule will be supplemented as additional speakers are added.

NIMBioS Interdisciplinary Seminars will resume in August 2016.

Video Archive of NIMBioS Seminars
Archived Seminar Calendars:   2016   2015   2014   2013   2012   2011   2010   2009

Date Speaker
Topic
  August 2016
Aug 23 Sergei Tarasov, NIMBioS postdoctoral fellow Systematics of dung beetles and ontology-informed models for phenotypic evolution
  September 2016
Sep 6 Nourridine Siewe, NIMBioS postdoctoral fellow Granuloma formation in leishmaniasis: A mathematical model
Sep 20 Sarah Flanagan, NIMBioS postdoctoral fellow Identifying signatures of selection on the genome: Case studies using pipefish
  October 2016
Oct 4 Lauren Smith-Ramesh, NIMBioS postdoctoral fellow (Oct 2016) Placing species invasions in a food web context: A new twist on old invasion hypotheses
Oct 11 Mark Moffett, National Museum of Natural History How a shift in social identity made enormous societies possible: An overlooked turning point in human evolution
Oct 18 Jay M. Ver Hoef*, National Marine Mammal Laboratory, NOAA-NMFS Alaska Fisheries Science Center Modern spatial statistics: Basis functions, convolutions, and big data
  January 2017
Jan 17 Andrew Rominger, NIMBioS postdoctoral fellow (Jan 2017) TBA
Jan 31 Oyita Udiani, NIMBioS postdoctoral fellow (Jan 2017) TBA
  February 2017
Feb 14 Klaus Schulten*, Beckman Institute, Univ. of Illinois, Urbana TBA
*NIMBioS Postdoctoral Fellows Invited Distinguished Visitor

Seminar Abstracts


J. Hoef photo. Time/Date: 3:30 Tuesday, October 18
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Jay Ver Hoef, National Marine Mammal Laboratory, NOAA-NMFS Alaska Fisheries Science Center; NIMBioS Postdoctoral Fellows Invited Distinguished Visitor
Topic: Modern spatial statistics: Basis functions, convolutions, and big data
Abstract: Since inception, spatial statistics has been plagued by computational constraints. The central problem is inversion of the covariance matrix, which is an n-cubed problem, which is only compounded by the increased interest in Bayesian hierarchical models that use Markov chain Monte Carlo methods. I will describe a popular trend lately to reparameterize spatial models as linear mixed models where the random-effects design matrix is reduced rank and composed of basis functions. There are interesting connections to spline models and moving average approaches (convolutions) that integrate kernels over white noise. The spatial basis approach allows implementation of models for large data sets and for developing dependence structures for complex topologies. I recount how these approaches became popular from early developments by Barry and Ver Hoef (1996), Higdon (1998), and Wikle and Cressie (1999). I illustrate the new methods with two cases: developing spatial abundance models for count data, and novel spatial models for data collected from stream networks. Click here for more information.

M. Moffett photo. Time/Date: 3:30 Tuesday, October 11
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Mark W. Moffett, National Museum of Natural History
Topic: How a shift in social identity made enormous societies possible: An overlooked turning point in human evolution
Abstract: Human societies are examined as distinct and coherent groups. In the societies of most other vertebrates, each member must recognize every other member as an individual. This typically limits societies to 100 members, and never more than 200. Numerous and diverse identity labels substitute for such knowledge in humans, and were necessary before our societies could grow more populous. How did a capacity for using societal labels arise? The rule of parsimony indicates that, at least as far back as their divergence from the chimpanzee line, our ancestors would have never lived in strict family groups or in any other compact societies offering regular face-to-face interaction. Nor did they form open networks. They were fission-fusion species that evolved, by simple steps, from having societies bounded by the recognition of individuals to societies differentiated by labels. I propose that this transition, ignored before now, occurred well before language by a simple shift in signals resembling those employed by chimpanzees. Free from usual size limits, societies at first reached into the multiple hundreds. Agriculture would permit societies to grow larger still, in part through the improved stabilization of labels within settled communities. This lecture expands upon the author's review in the September 2013 issue of Human Nature: Human Identity and the Evolution of Societies. Click here for more information.

L. Smith-Ramesh photo. Time/Date: 3:30 Tuesday, October 4
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Lauren Smith-Ramesh, NIMBioS postdoctoral fellow
Topic: Placing species invasions in a food web context: A new twist on old invasion hypotheses
Abstract: A core goal of invasion ecology is to identify the factors that drive species invasions. A few dominant hypotheses have surfaced to explain why invaders succeed, including the 'enemy escape hypothesis,' which purports that invaders suffer reduced damage from natural enemies relative to natives. However, empirical support for enemy escape is mixed. Placing our study of invasion in a more complete food web context (beyond two trophic levels) may help to explain why this hypothesis often fails. Through theoretical and empirical case studies of invasive plants in Eastern deciduous forests of the United States, I consider how food web context can inform our understanding of species invasions. Then, I present a global synthesis that examines how food web complexity interacts with invasion success across habitats. By considering invasion in the context of broader food-web interactions, we can explain why common hypotheses such as enemy escape often fail, while gaining new power to explain global patterns of species invasions. Click here for more information.

S. Flanagan photo. Time/Date: 3:30 Tuesday, September 20
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Sarah Flanagan, NIMBioS postdoctoral fellow
Topic: Identifying signatures of selection on the genome: case studies using pipefish
Abstract: Understanding the genetic basis of complex traits is one of the major goals of evolutionary biology. Population genetics, which focuses on genetic variation within and among populations, is one way to approach understanding the genetic basis of evolutionarily relevant traits by differentiating between signatures of neutral processes (e.g. migration and drift) and selective pressures. In this talk, I will discuss various approaches to identifying signatures of selection in the context of next-generation sequencing studies, as well as some of their challenges and constraints when applied to actual datasets. Specifically, I will focus on traditional population genetics approaches to identifying signatures of selection among populations, such as FST outlier scans, as well as selection components analysis, a method that compares allele frequencies among individuals within a single population to identify signatures of selection. Throughout the talk, I will include results from empirical studies of natural populations of the Gulf pipefish, a marine fish characterized by male pregnancy and sex-role-reversal. Click here for more information. Seminar flyer (pdf).
Video icon.Watch seminar online.

N. Siewe photo. Time/Date: 3:30 Tuesday, September 6
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Nourridine Siewe, NIMBioS postdoctoral fellow
Topic: Granuloma formation in leishmaniasis: A mathematical model
Abstract: Leishmaniasis is a disease caused by protozoan parasites of the genus Leishmania. The two common forms of leishmaniasis are cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). VL is the more severe of the two and, if untreated, may become fatal. The hallmark of VL is the formation of granuloma in the liver or the spleen. In this talk, I present a mathematical model of the evolution of granuloma in the liver. The model is represented by a system of partial differential equations and it includes immigration of cells from the adaptive immune system into the granuloma; the rate of the influx is determined by the strength of the immune response of the infected individual. It is shown that parasite load decreases as the strength of the immune system increases. Furthermore, the efficacy of a commonly used drug, which increases T cell proliferation, increases in a person with stronger immune response. The model also provides an explanation of why, in contrast to humans, mice recover naturally from VL in the liver. Click here for more information. Seminar flyer (pdf).

S. Tarasov photo. Time/Date: 3:30 Tuesday, August 23
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Sergei Tarasov, NIMBioS postdoctoral fellow
Topic: Systematics of dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) and ontology-informed models for phenotypic evolution
Abstract: The first and main part of my talk will be focused on the systematics and phylogenetics of dung beetles. Dung beetles are a globally distributed group of insects that comprises ˜6200 species feeding mainly on mammalian excrements. Additionally, dung beetles are popular model organisms in ecology and evo-devo; for the last two decades they have experienced a systematics renaissance with the adoption of modern phylogenetic approaches. Numerous studies produced contradictory trees leading to the lack of consensus on their evolutionary history. In my research, I revisit the phylogenetics and attempt to revise the classification of dung beetles through the acquisition of global morphological and molecular datasets. To improve phylogenetic inference, I employ novel approaches that use Bayesian posterior prediction for selecting data partitions in molecular analysis and partitioning of morphological matrices using anatomy ontologies. Both the molecular and morphological datasets yield generally consistent results, which provide new insight into relationships and suggest a new classification for dung beetles. The second part of my talk will be devoted to my ongoing postdoctoral project focused on modeling phenotypic evolution. The dependencies among body parts in organisms evolve during the course of evolution, yet the current comparative phylogenetic methods generally operating with a single character ignore them. These anatomical dependencies can be represented as a tree graph, which is allowed to evolve over phylogenetic tree as a single complex unit. The application of such framework enables mapping evolution of the entire phenotype and addressing questions on the evolutionary novelties and adaptive dynamics of morphology. Since this project is in initial stage, I will mainly explore underlying concepts and its potential application.
Click here for more information. Seminar flyer (pdf).
Video icon.Watch seminar online.