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NIMBioS Tuesday Seminar Series - Fall 2014

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.

Video Archive of NIMBioS Seminars

Date Speaker
Topic
  August 2014
Aug 7, 2pm
RM105 Claxton
Naveen K. Vaidya, Mathematics and Statistics, Univ. of Missouri, Kansas City Mathematical Modeling of the Within-Host HIV Dynamics
  September 2014
Sep 9 Elizabeth Hobson, NIMBioS postdoctoral fellow Video icon. Emergent Social Properties and the Evolution of Social Complexity
Sep 11
Thur
Dr. Katsuya Tanaka, Research Center for Sustainability and Environment, Shiga Univ., Japan Payment Mechanisms for Managing Ecosystem Services in Southeast Asia
Sep 18
CANCELED
Dr. Zhirong Bao, Developmental Biology, Sloan Kettering Institute The making of a worm: Every gene, every cell, every minute
Sep 23 Angela Peace, NIMBioS postdoctoral fellow Video icon. Stoichiometric Producer-Grazer Models Incorporating the Effects of Food Quality on Grazer Dynamics
  October 2014
Oct 7 Peter Smouse*, Ecology, Rutgers Univ. Correlated Biotic and Abiotic Patterns in Embothrium coccineum: Can Embothrium Survive Patagonian Climate Change?
Oct 21 Sandy Kawano, NIMBioS postdoctoral fellow Video icon. Towards a Unified Approach for Quantifying Phenotypic Selection
  November 2014
Nov 4 Jake Ferguson, NIMBioS postdoctoral fellow Stochastic Models of Populations in Fluctuating Environments
Nov 11 Hanna Kokko*, Institute of Evolutionary Biology and Environmental Studies, Univ. of Zurich Males Exist: Does It Matter?
Nov 18 Robert Boyd*, Biological Anthropology, Arizona State Univ. Does Reciprocity Explain Human Cooperation?
Nov 25 Steven Abel, Chemical and Biomolecular Engineering, Univ. of Tennessee, Knoxville Deconstructing Signal Transduction at the Cell Membrane
  December 2014
Dec 2 Ioannis Sagouralis, NIMBioS postdoctoral fellow TBA
  January 2015
Jan 13 Caroline Farrior, NIMBioS postdoctoral fellow TBA
  February 2015
Feb 10 Michael Lynch*, Biology, Indiana Univ., Bloomington TBA
  March 2015
Mar 10 Laurent Excoffier*, Population Genetics CMPG Lab, Institute of Ecology and Evolution, Univ. of Bern TBA
  April 2016
Apr 12 Michael Whitlock*, Zoology, Univ. of British Columbia, Vancouver TBA
*NIMBioS Postdoctoral Fellows Invited Distinguished Visitor

NIMBioS Seminar Abstracts:

S. Abel photo. Time/Date: 3:30 p.m., Tuesday, November 25
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Steven Abel, Chemical and Biomolecular Engineering, Univ. of Tennessee, Knoxville
Topic: Deconstructing Signal Transduction at the Cell Membrane
Abstract: Cells orchestrate responses to their environment by means of biochemical reaction networks that propagate molecular signals from the cell membrane to the interior of the cell. These signal transduction networks involve many components interacting in a noisy environment, and mathematical modeling is an essential tool for understanding how they collectively interact in space and time to generate reliable responses. Many key signaling reactions occur at the cell membrane, yet how the membrane environment influences the collective behavior of signaling networks remains poorly understood. In this talk, we use theoretical and computational methods rooted in statistical mechanics to investigate (i) how the membrane environment influences emergent properties of signaling networks, and (ii) what mechanisms control the spatial organization of membrane-associated molecules when cells are in contact. In the first part, we use stochastic methods to study signaling networks that exhibit bi-stability. We find that confining proteins to a membrane-like environment can markedly alter the emergent behavior by altering protein mobility, protein concentration, and spatiotemporal correlations between pairs of molecules. In the second part, we use field-theoretic methods to study the binding and subsequent spatial reorganization of complementary molecules on apposed cell membranes. When two or more molecular complexes with different natural lengths are present, the species segregate into distinct spatial regions, even in the limit of vanishing membrane surface tension and bending rigidity. This result is unexpected, as minimization of membrane bending energy is often suggested to be the driving force for molecular segregation. Click here for more information. Seminar flyer (pdf).

R. Boyd photo. Time/Date: 3:30 p.m., Tuesday, November 18
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Robert Boyd, Biological Anthropology, Arizona State Univ. and NIMBioS Postdoctoral Fellows Invited Distinguished Visitor
Topic: Does Reciprocity Explain Human Cooperation?
Abstract: Humans cooperate extensively with unrelated individuals. While there is some controversy about large-scale cooperation, most authors agree that small scale cooperation is sustained by reciprocity. However, the theoretical work that supports this conclusion is not consistent with observed behavior in other social vertebrates. I will argue that existing work underestimates the effect of uncertainty on the evolution of reciprocity, and present two models that suggest that taking uncertainty into account can help explain different patterns of cooperation in humans and other social vertebrates. Click here for more information. Seminar flyer (pdf).

H. Kokko photo. Time/Date: 3:30 p.m., Tuesday, November 11
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Hanna Kokko, Institute of Evolutionary Biology and Environmental Studies, Univ. of Zurich; NIMBioS Postdoctoral Fellows Invited Distinguished Visitor
Topic: Males exist. Does it matter?
Abstract: Natural selection is a shortsighted process: it acts far more strongly on the individual than the group, thus (to take species' long term persistence as an example of a group- or population-level benefit) selection is not expected to equip species with best possible long-term persistence or best possible population growth. Here I show that sexual reproduction in particular is prone to the ‘tragedy of the commons', predicting unwise use of essential resources for reproduction. I will draw examples from birds as well as fish, as well as from fundamental issues about male and female evolution: why do individuals specialize in producing sperm and eggs, and is this a 'wise' way to organize reproduction? Click here for more information.

J. Ferguson photo. Time/Date: 3:30 p.m., Tuesday, November 4
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Jake Ferguson, NIMBioS Postdoctoral Fellow
Topic: Stochastic Models of Populations in Fluctuating Environments
Abstract: All animal populations are in environments that fluctuate through time, however data on the processes generating these fluctuations is often not available. One approach to account for this complexity is to study the long-run probabilistic properties of the fluctuations generated by environmental interactions. We will examine what this approach can teach us about specific cases of population-environment interactions and some of the general stochastic properties generated by these interactions. The emphasis will be on how stochastic models can shed light on unobserved ecological interactions and on the fundamental limitations of the approach. We will conclude by examining why inferring the role of environmental covariates on population growth is so difficult, and how reformulating population dynamics using a more fundamental definition of the growth process may shed light on population-environment interactions. Click here for more information. Seminar flyer (pdf).

S. Kawano photo. Time/Date: 3:30 p.m., Tuesday, October 21
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Sandy Kawano, NIMBioS Postdoctoral Fellow
Topic: Towards a unified approach for quantifying phenotypic selection
Abstract: Phenotypic selection is a major driver of adaptive evolution, and plays an important role in generating biodiversity. Despite the multitude of studies on selection analyses and the achievement of various milestones in estimating selection, recent attempts to capture the complexity of selection have made it evident that there are a number of challenges that evolutionary biologists still face. In particular, synthetic analyses have determined that many studies may be overlooking the effects of selection on variances and covariances by omitting nonlinear selection analyses, and that unmeasured traits can change the strength of selection in measured traits. There can be substantial barriers to conducting nonlinear selection analyses due to mathematical and analytical limitations, and some argue that the solution may compromise biological interpretations. A number of new methods have been developed to address some of these issues, but a consensus is yet to be reached. Also, it is currently unknown how changing different modeling parameters affect measures of phenotypic selection. In this talk, I describe the general framework applied to quantify phenotypic selection, existing challenges, and proposed methods for developing a more systematic approach to measure phenotypic selection. Click here for more information. Seminar flyer (pdf).
Video icon.Watch seminar online.

P. Smouse photo. Time/Date: 3:30 p.m., Tuesday, October 7
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Peter Smouse, Ecology, Rutgers University; NIMBioS Postdoctoral Fellows Invited Distinguished Visitor
Topic: Correlated Biotic and Abiotic Patterns in Embothrium coccineum: Can Embothrium Survive Patagonian Climate Change?
Abstract: Adaptive radiation and reproductive isolation can determine the biogeographic structure of any species. Embothrium coccineum (Proteaceae) is a South American tree species that dates to the Oligocene, and now spans 200 of latitude and 1500m of elevation on both slopes of the Andes. It is both morphologically and genetically highly variable, as is typical of species spanning such vast geographical regions in both hemispheres. We have deployed hyper-dimensional PCA and CCA methods to explore the correspondence between biotic pattern and current geographic and climatic gradients for 34 populations (934 individuals). Smaller, rounder leaves and particular alleles typify the colder-drier parts of the range, while larger, lanceolate leaves and alternative alleles typify warmer-moister areas. The climate of South America is changing, so we "forward mapped" those patterns onto a future climatic landscape, based on a projected doubling of CO2 for South America. Our analytic approach can be extended to analysis of biotic/abiotic co- patterns in other species facing climatic challenge. Species with sufficient geographic and adaptive substrate, and with sufficient dispersal potential, should be able to "keep up" with the pace of spatial climatic shift. The tolerable climatic regime Embotthrium will clearly shift a bit geographically, but this lineage has survived repeated and dramatic climatic shifts since the Oligocene, and it should also be able to move and adapt quickly enough to meet the present challenge. On balance, it seems clear that Embothrium is here to stay. Click here for more information. Seminar flyer (pdf).

A. Peace photo. Time/Date: 3:30 p.m., Tuesday, September 23
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Angela Peace, NIMBioS Postdoctoral Fellow
Topic: Stoichiometric Producer-Grazer Models Incorporating the Effects of Food Quality on Grazer Dynamics
Abstract: There has been important progress in understanding ecological dynamics through the development of the theory of ecological stoichiometry. By considering the balance of multiple chemical elements in ecological interactions, this fast growing theory provides new constraints and mechanisms that can be formulated into mathematical models. Stoichiometric models incorporate the effects of both food quantity and food quality into a single framework that produce rich dynamics. Here we present producer-grazer Lotka-Volterra type models to investigate the growth response of Daphnia to algae of varying phosphorus:carbon ratios. We incorporate the consequences of both phosphorus limitation as well as phosphorus excess on grazer's growth. These modeling efforts provide insight on the effects of varying nutrient content on grazer dynamics and deepen our understanding of the effects of stoichiometry on the mechanisms governing population dynamics and the interactions between trophic levels. Click here for more information. Seminar flyer (pdf).
Video icon.Watch seminar online.

photo. Canceled
Time/Date: 3:30 p.m., Thursday, September 18
Join us for refreshments at 3:15 p.m
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Dr. Zhirong Bao, Developmental Biology, Sloan Kettering Institute
Topic: The Making of a Worm: Every Gene, Every Cell, Every Minute
Abstract: The nematode C. elegans, a.k.a the worm, is a major model organism for biomedical research. Its size and transparency make in toto imaging a powerful approach to tackle its biology and achieve synergy with genetics and systems biology. We study C. elegans embryogenesis by combining these approaches. I will discuss our efforts on the following fronts: (1) optical microscopy for long-term live imaging through embryogenesis at single-cell resolution; (2) image analysis for automated cell lineage tracing; (3) genome-wide analysis of the phenotypic landscape and mechanistic models of development; and (4) construction of an interactive 4D atlas of neural development for the entire nervous system.
Click here for more information. Seminar flyer (pdf).

K. Tanaka photo. Time/Date: 3:30 p.m., Thursday, September 11
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Katsuya Tanaka, Research Center for Sustainability and Environment, Shiga Univ., Japan
Topic: Payment mechanisms for managing ecosystem services in Southeast Asia
Abstract: This talk introduces two empirical applications of payment mechanisms for managing ecosystem services through agroforestry practices.The first application is payment for ecosystem services (PES) in the Philippines. Our survey based on hypothetical PES shows that farmers have significant willingness to adopt agroforestry practices under payment schemes. Because of heterogeneity among farmers, the flexible payment outperforms the fixed payment. The second application is eco-certifications in Indonesia. Our results from the propensity score matching show that eco-certification of agroforestry coffee production has a potential to contribute to increasing farmers' income and reducing environmental impact in West Sumatra. Click here for more information.

photo. Time/Date: 3:30 p.m., Tuesday, September 9
Join us for refreshments at 3:00 p.m
Location: Hallam Auditorium, Room 206, Claxton Building, 1122 Volunteer Blvd.
Speaker: Elizabeth Hobson, NIMBioS postdoctoral fellow
Topic: Emergent Social Properties and the Evolution of Social Complexity
Abstract: Group-level properties, such as dominance hierarchies, emerge from the outcomes of individual-level events. Although individuals can gain critical benefits from their position in the hierarchy, we have a limited understanding how real-world hierarchies form or what signals and decision rules individuals use to construct and maintain them in complex groups. A study of aggression in two groups of captive monk parakeets (Myiopsitta monachus) found that a transition to large-scale ordered aggression occurred in newly-formed groups after one week, with individuals thereafter preferring to direct aggression against those nearby in rank. Network motifs in the form of chains of aggression among individuals provided information about relative rank and were highly predictive of behavioral preferences. I present a new theory, the "knowledge-behavior feedback loop," which links an individual's knowledge of rank with its consequent behavior. I use this framework to explain the transition from unstructured to strategic aggression and the formation and persistence of dominance hierarchies in groups capable of both social memory and social inference. I will discuss how this work provides insight into the social and cognitive complexity of the monk parakeet and how this approach could be used more broadly to understand the evolution of social complexity in other species. Click here for more information, Seminar flyer (pdf).
Video icon.Watch seminar online.

photo. Time/Date: 2:00 p.m., Thursday, August 7
Join us for refreshments at 1:45 p.m
Location: Franklin Classroom, Room 105, Claxton Building, 1122 Volunteer Blvd.
Speaker: Naveen K. Vaidya, Mathematics and Statistics, Univ. of Missouri, Kansas City
Topic: Mathematical Modeling of the Within-Host HIV Dynamics
Abstract: The most challenging issues of managing HIV infection within a host are establishment of latently infected cells, emergence of drug resistance, and opioid dependence. In this talk, I will demonstrate how mathematical models that are consistent with experimental data can help address these issues. First, I will show that latently infected cells are largely generated before the initiation of antiretroviral therapy (ART) during early infection and that the density of latently infected cells often decays during initial ART. These results suggest that the latent infection can be limited by early ART during acute HIV infection. Second, I will show that although administration of ART cannot suppress viral load in many patients due to the emergence of resistance, it can alter the viral fitness resulting in an increase of CD4+ T cell count, which should yield clinical benefits. This benefit depends on the cell proliferation rate, which, in some situations, produces sustained T-cell oscillations. Third, I will discuss how opioid dependence can alter viral dynamics, steady state viral load, and basic reproduction number.
For more information, click here.

NIMBioS Seminar Archive

  2014
  2013
  2012
  2011
  2010
  2009