Tue, 02 Mar 2021

14:00 - 15:00
Virtual

Connectome‐Based Propagation Model in Amyotrophic Lateral Sclerosis

Jil Meier
(Charité Berlin)
Abstract

How can a random walker on a network be helpful for patients suffering from amyotrophic lateral sclerosis (ALS)? Clinical trials in ALS continue to rely on survival or clinical functional scales as endpoints, since anatomical patterns of disease spread in ALS are poorly characterized in vivo. In this study, we generated individual brain networks of patients and controls based on cerebral magnetic resonance imaging (MRI) data. Then, we applied a computational model with a random walker to the brain MRI scan of patients to simulate this progressive network degeneration. We observe that computer‐simulated aggregation levels of the random walker mimic true disease patterns in ALS patients. Our results demonstrate the utility of computational network models in ALS to predict disease progression and underscore their potential as a prognostic biomarker.

After presenting this study on characterizing the structural changes in neurodegenerative diseases with network science, I will give an outlook on my new work on characterizing the dynamic changes in brain networks for Parkinson’s disease and counteracting these with (simulated) deep brain stimulation using the neuroinformatics platform The Virtual Brain (www.thevirtualbrain.org) .

Article link: https://onlinelibrary.wiley.com/doi/full/10.1002/ana.25706

Mon, 08 Feb 2021

16:00 - 17:00

Finance and Statistics: Trading Analogies for Sequential Learning

MARTIN LARSSON
(Carnegie Mellon University)
Abstract


The goal of sequential learning is to draw inference from data that is gathered gradually through time. This is a typical situation in many applications, including finance. A sequential inference procedure is `anytime-valid’ if the decision to stop or continue an experiment can depend on anything that has been observed so far, without compromising statistical error guarantees. A recent approach to anytime-valid inference views a test statistic as a bet against the null hypothesis. These bets are constrained to be supermartingales - hence unprofitable - under the null, but designed to be profitable under the relevant alternative hypotheses. This perspective opens the door to tools from financial mathematics. In this talk I will discuss how notions such as supermartingale measures, log-optimality, and the optional decomposition theorem shed new light on anytime-valid sequential learning. (This talk is based on joint work with Wouter Koolen (CWI), Aaditya Ramdas (CMU) and Johannes Ruf (LSE).)
 

Wed, 24 Feb 2021

16:00 - 17:30
Virtual

The decomposability conjecture

Andrew Marks
(UCLA)
Abstract

We characterize which Borel functions are decomposable into
a countable union of functions which are piecewise continuous on
$\Pi^0_n$ domains, assuming projective determinacy. One ingredient of
our proof is a new characterization of what Borel sets are $\Sigma^0_n$
complete. Another important ingredient is a theorem of Harrington that
there is no projective sequence of length $\omega_1$ of distinct Borel
sets of bounded rank, assuming projective determinacy. This is joint
work with Adam Day.

Oxford Mathematics Online Public Lecture in Partnership with Wadham College celebrating Roger Penrose's Nobel Prize

Spacetime Singularities - Roger Penrose, Dennis Lehmkuhl and Melvyn Bragg
Tuesday 16 February 2021
5.00-6.30pm

Dennis Lehmkuhl: From Schwarzschild’s singularity and Hadamard’s catastrophe to Penrose’s trapped surfaces
Roger Penrose: Spacetime singularities - to be or not to be?
Roger Penrose & Melvyn Bragg: In conversation

Wed, 10 Mar 2021

10:30 - 12:30
Virtual

Introduction on Nonlinear Wave Equations (Lecture 4 of 4)

Professor Qian Wang
(Oxford University)
Abstract

The course covers the standard material on nonlinear wave equations, including local existence, breakdown criterion, global existence for small data for semi-linear equations, and Strichartz estimate if time allows.

Wed, 24 Feb 2021

10:30 - 12:30
Virtual

Introduction on Nonlinear Wave Equations (Lecture 3 of 4)

Professor Qian Wang
(Oxford University)
Abstract

The course covers the standard material on nonlinear wave equations, including local existence, breakdown criterion, global existence for small data for semi-linear equations, and Strichartz estimate if time allows.

Wed, 10 Feb 2021

10:30 - 12:30
Virtual

Introduction on Nonlinear Wave Equations (Lecture 2 of 4)

Professor Qian Wang
((Oxford University))
Abstract

The course covers the standard material on nonlinear wave equations, including local existence, breakdown criterion, global existence for small data for semi-linear equations, and Strichartz estimate if time allows.

Wed, 27 Jan 2021

10:30 - 12:30
Virtual

Introduction on Nonlinear Wave Equations (Lecture 1 of 4)

Professor Qian Wang
((Oxford University))
Abstract


The course covers the standard material on nonlinear wave equations, including local existence, breakdown criterion, global existence for small data for semi-linear equations, and Strichartz estimate if time allows.  

 

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