Model-free Consensus Maximization for Non-Rigid Shapes

Many computer vision methods use consensus maximization to relate measurements containing outliers with the correct transformation model. In the context of rigid shapes, this is typically done using Random Sampling and Consensus (RANSAC) by estimating an analytical model that agrees with the largest number of measurements (inliers). However, small parameter models may not be always available. In this paper, we formulate the model-free consensus maximization as an Integer Program in a graph using `rules' on measurements. We then provide a method to solve it optimally using the Branch and Bound (BnB) paradigm. We focus its application on non-rigid shapes, where we apply the method to remove outlier 3D correspondences and achieve performance superior to the state of the art. Our method works with outlier ratio as high as 80\%. We further derive a similar formulation for 3D template to image matching, achieving similar or better performance compared to the state of the art.Comment: ECCV1

The Sea Squirt as a Model Organism For Biophysics

Botryllus schlosseri is a sessile marine invertebrate found in the Pacific coastal waters of the US. As a chordate, it is our nearest invertebrate relative and therefore shares many of our important biochemical pathways. By treating its water with clinical drugs, we can inhibit mechano-transductive pathways, tuning the stiffness of the extracellular matrix and causing a global vascular regression. Since the summer of 2016, we have hosted a breeding colony on the Boise State University campus. In the future we intend to use the sea squirt as a model system for investigation of chemical and mechanical circuits in a living organism. Keeping these animals alive in land-locked environments presents a unique challenge as they require precisely controlled saltwater tank conditions. Essential information about the life cycle of the organism is presented with reasonable conditions for simulating an ocean environment. We found success in relatively long term husbandry of the sea squirts through a combination of monitoring chemistry, changing tank water regularly, dosing the tank with a food several times daily, and by brushing free accumulated algae on the animals themselves roughly weekly. Optimized techniques are presented to facilitate husbandry and microscopy of sea squirts for future scientific research

Deconstructing the Cell’s Mechanical Circuits by 3D Orbital Tracking Microrheology

We seek to address a critical question in physical cell biology: is it possible to develop an ‘inventory’ of mechanical or force-sensing modules of cell and tissue behavior in analogy to the modules in biochemical signaling networks? To discover these mechanical modules we focus on a specific system of broad interest - cell extrusion in epithelial sheets. We will measure how chemical perturbations affect the mechanics and rheology of both the cytoplasm and the extracellular matrix of living cells. To measure intracellular viscoelasticity we will track a fluorescent particle or organelle using high-resolution 3D orbital tracking and high speed video microscopy. The mean squared displacement of the particle vs. time provides a measure of the frequency-dependent complex viscoelastic modulus. Finally we will monitor the regression of vasculature during pathway inhibition to deconstruct the chemical-mechanical circuits that regulate the vessel growth and retraction known as anoikis