Upcoming Seminars home talks

Upcoming Seminars


MONDAY, November 5, 2007


        APPLIED ANALYSIS AND PDE READING SEMINAR     PSA 304   1:40 p.m.
        Moderators: Slim Ibrahim, Svetlana Roudenko, Sergei Suslov,
                    Department of Mathematics and Statistics
          "Local and Global Analysis of Nonlinear Dispersive Equations"
        ABSTRACT: We study in details modern approaches in Analysis and
        Nonlinear PDEs based on the book from CBMS series by Terence
        Tao (Field's Medalist 2006). Graduate students and postdocs are
        especially welcome.

TUESDAY, November 6, 2007


        GRADUATE STUDENT RESEARCH SEMINAR           PSA 206   12:00 p.m.
        Kevin Flores, Department of Mathematics and Statistics
          "A Mathematical Model to Correlate the Importance of Gene
          Specific Mutations and Tumor Development"
        ABSTRACT: Understanding the correlation of gene specific
        mutations and tumor development has important implications in
        cancer therapy. Recent empirical data have elucidated the
        candidate cancer genes responsible for carcinogenesis through
        mutation and expression analysis. This work has revealed the
        heterogeneities in genotype that encode cancers of the same
        malignancy grade, providing evidence for the existence of
        multiple mutational paths that a population of cancer cells can
        take to manifest itself as a disease. The cell genotypes that
        are present in a tumor affect the malignancy grade through
        their effect on the phenotypes of individual cells that the
        tumor is comprised of. In this talk I will discuss recently
        developed methods others have used to analyze protein networks
        with a graph theoretical approach to connect the gene
        expression and mutation data to cell phenotype.
          For this project, we have constructed a gene regulatory
        network from the KEGG pathway database. This network includes
        most accurately and completely the relevant pathways that
        contain the known cancer genes, which in turn encode distinct
        cell phenotypes. We are analyzing the network to predict the
        sensitivity of cell signaling pathways that control cell growth
        and death to alterations caused by gene mutations. The
        prevalence of gene mutations show no correlation to the
        betweenness - centrality of their respective nodes in the
        network and a low correlation with the number of paths that
        affect proteins whose expression are known to cause different
        cell phenotypes.
          Because of the lack of necessary reaction rate data to model
        any of the interactions, we turn to a network boolean dynamics
        model. With synchronous updating we find that the phenotypic
        output resulting from the deterministic network dynamics are
        insensitive to the candidate gene mutations.
          With asynchronous updating we find that the state space of
        the dynamics becomes too large to sample using random initial
        conditions. I will discuss an implementation of the Wang-Landau
        monte carlo algorithm to sample the asynchronous progression of
        the network states.
          Bagels, coffee and tea will be served in PSA 206 at 11:50 a.m.

WEDNESDAY, November 7, 2007


        NUMBER THEORY SEMINAR                       PSH 552   10:40 a.m.
        Dong Quan Nguyen, Department of Mathematics and Statistics
          "Algebraic Points on Cubic Hypersurfaces II"
        ABSTRACT: We prove the Cassels Swinnerton-Dyer conjecture for
        the case n=3 following a paper of Coray.

        ANALYSIS / PDE SEMINAR                       PSA 306   1:30 p.m.
        Horst Heck, Technical University Darmstadt, Germany
          "Muckenhoupt Weights and Maximal Regularity for Parabolic
          Problems"
        ABSTRACT: We describe the connection between maximal
        L^{p}-L^{q} regularity for parabolic problems and estimates for
        the resolvent of the associated operator in weighted L^p
        spaces. The weights used are exactly the Muckenhoupt class A_p.

        ANALYSIS / PDE SEMINAR                       PSA 306   2:00 p.m.
        Matthias Geissert, Technical University Darmstadt, Germany
          "The Navier-Stokes Flow in the Exterior of a Rotating
          Obstacle"
        ABSTRACT: We show the existence of local solutions to the
        Navier-Stokes flow in exterior rotating domains. In order to do
        so, we first transform the set of equations to a fixed domain.
        In this talk we present two different transformations leading
        to different problems and different notions of solutions (mild
        and strong solutions). Finally, we discuss whether the
        solutions coincide.

        ECOSYSTEMS ENGINEERING SEMINAR &
        ENVIRONMENTAL FLUID DYNAMICS SEMINAR       ISTB2 299   4:40 p.m.
        Kristina Katsaros, University of Miami
          "Atmosphere-Ocean Research during the Space Age"
        ABSTRACT: My scientific interests began with air-sea
        interaction studies on the small scale, because infrared
        satellite instruments observe the uppermost fractions of a
        millimeter of the air-sea interface. One has to understand
        waves, the effect of rain, currents and surfactants. Over the
        past 50 years (since Sputnik and the establishment of NASA) the
        satellite instruments employed almost all of the wavelengths of
        the electro-magnetic spectrum where the atmosphere provides a
        window or interesting emissions, reflections or radar returns.
        The backcatter provided by short gravity waves on the sea has
        allowed observation of surface winds, which in themselves do
        not have an electromagnetic emission. Microwave radiometers and
        radars map storms over the global ocean revealing their
        internal structure and evolution in amazing ways.
          Participating in these developments has been a privilege that
        eventually lead to management positions with a French
        Department of Oceanography from Space and a NOAA research
        laboratory in Miami. I will take you on a ride through these
        developments and exciting times and share some of the
        scientific results and experiences that may be of general
        interest.

FRIDAY, November 9, 2007


        TENURE TRACK FACULTY MEETING                 PSA 206   1:40 p.m.
        AGENDA: Discussion of Fall 2008 course scheduling, particularly
        calculus courses.

        COLLOQUIUM                                   PSA 206   2:40 p.m.
        Imbi Traat, University of Tartu, Estonia
          "Optimal Domain Estimation under Summation Restriction"
        ABSTRACT: The talk is based on the Ph.D. Thesis and on a joint
        unpublished paper with Kaja Sõstra.
          The users of official statistics usually require consistent
        estimates. In domains' case the simplest requirement is that
        estimated domain totals sum up to the estimated population
        total. In fact, this relationship, naturally holding for the
        true population parameters, is a kind of auxiliary information,
        which should be incorporated into estimation process with the
        aim to improve estimates.
          Recently, Knottnerus (2003) has proposed a new estimator,
        called General Restriction (GR) estimator that estimates a
        parameter vector so that the restrictions are satisfied for the
        estimates. The new estimator is optimal in the class of all
        estimators satisfying the same restrictions and using the same
        initial estimators in its construction.
          Sõstra (2003) has developed these ideas for domain estimation
        under summation restriction. Several good properties are
        fulfilled for new domain estimators - they satisfy
        restrictions, they are optimal, they are usually more precise
        than the initial domain estimators.
          In the presentation, the cases with estimated, fixed and
        conditionally fixed population total are considered. The
        restricted domain estimators are elaborated for initial ratio
        estimators. It appears that the covariance structure of domain
        ratio estimators is simple for some designs (the design-based
        approach is used). Simple covariance structure of initial
        estimators simplifies respective restriction estimators, so
        that they can be easily calculated. In addition to the
        formulae, illustrative simulation results under two sampling
        designs are given.

          References:
        Knottnerus, P. (2003). Sample Survey Theory: Some Pythagorean
          Perspectives. New-York: Springer.
        Sõstra, K. (2007). Restriction Estimator for Domains. Ph.D.
          Thesis, University of Tartu.
        Traat, I., Ilves, M. (2007). The Hypergeometric Sampling
          design, Theory and Practice. Acta Appl Math 97(1-3), 311-321.

                Refreshments will be served in PSA 206 at 3:30 p.m.

        MATH BIOLOGY SEMINAR                         PSA 102   3:40 p.m.
        Rongsong Liu, Purdue University, West Lafayette
          "Plant-Herbivore Interactions Mediated by Plant Toxicity"
        ABSTRACT: We explore the impact of plant toxicity on the
        dynamics of a plant-herbivore interaction, such as that of a
        mammalian browser and its plant forage species, by studying a
        mathematical model that includes a toxin-determined functional
        response. In this functional response, the traditional Holling
        Type 2 response is modified to include the negative effect of
        toxin on herbivore growth, which can overwhelm the positive
        effect of biomass ingestion at sufficiently high plant toxicant
        concentrations. Two types of consumption decisions of the
        herbivore are considered.

                            UPCOMING EVENT
        Monday, November 19, 2007
        NONLINEAR DYNAMICS AND PDE MINI-CONFERENCE
                                                     PSA 206   8:00 a.m.
        Abstracts available at
                  http://math.asu.edu/conferences/ndpc-index.html

        8 a.m.   Welcome Reception
        8:40-9:30 a.m.   Igor Kukavica,
                         University of Southern California
          "Decay Properties of Solutions of the Navier-Stokes Equations"
        9:40-10:30 a.m.  Luan Thach Hoang,
                         University of Minnesota
          "Navier-Stokes Equations: The Normalization Map, Statistical
          Solutions and Fluid Dynamics"
        10:30-11 a.m.    Coffee Break
        11 a.m.-12 p.m.  Pablo Padilla, University of Mexico
          "A Variational Approach to Study Invariant Sets In Dynamical
           Systems"
        12-1:40 p.m.     Lunch
        1:40-2:30 p.m.   Edriss Titi, University of California, Irvine,
                         Weizmann Institute of Science
          "Global Regularity for Three-dimensional Navier-Stokes
           Equations and Other Relevant Geophysical Models"
        3:00 p.m.        Refreshments
        3:40-4:30 p.m.   Alp Eden, Bogazici University (Turkey)
          "Davey-Stewartson Equation Generalized: Global Existence vs.
          Blow-Up of Solutions"
        5:30 p.m.        Dinner
        8:00 p.m.        Reception at department chair's house