Statistical Learning in Wasserstein Space

We seek a generalization of regression and principle component analysis (PCA) in a metric space where data points are distributions metrized by the Wasserstein metric. We recast these analyses as multimarginal optimal transport problems. The particular formulation allows efficient computation, ensures existence of optimal solutions, and admits a probabilistic interpretation over the space of paths (line segments). Application of the theory to the interpolation of empirical distributions, images, power spectra, as well as assessing uncertainty in experimental designs, is envisioned

Escape through a time-dependent hole in the doubling map

We investigate the escape dynamics of the doubling map with a time-periodic hole. We use Ulam's method to calculate the escape rate as a function of the control parameters. We consider two cases, oscillating or breathing holes, where the sides of the hole are moving in or out of phase respectively. We find out that the escape rate is well described by the overlap of the hole with its images, for holes centred at periodic orbits.Comment: 9 pages, 7 figures. To appear in Physical Review E in 201

An Engineered Protease that Cleaves Specifically after Sulfated Tyrosine

The bacterial protease OmpT has been engineered to cleave after sulfotyrosine residues in peptide substrates but not after phosphotyrosine (see scheme). A selection/counterselection screen was used to identify OmpT variants with the desired specificity and high levels of overall catalytic activity

Impact of boundaries on fully connected random geometric networks

Many complex networks exhibit a percolation transition involving a macroscopic connected component, with universal features largely independent of the microscopic model and the macroscopic domain geometry. In contrast, we show that the transition to full connectivity is strongly influenced by details of the boundary, but observe an alternative form of universality. Our approach correctly distinguishes connectivity properties of networks in domains with equal bulk contributions. It also facilitates system design to promote or avoid full connectivity for diverse geometries in arbitrary dimension.Comment: 6 pages, 3 figure

Six-Quark Amplitudes from Fermionic MHV Vertices

The fermionic extension of the CSW approach to perturbative gauge theory coupled with fermions is used to compute the six-quark QCD amplitudes. We find complete agreement with the results obtained by using the usual Feynman rules.Comment: Latex file, 16 pages, 4 figure

In vitro scanning saturation mutagenesis of proteins

The present invention combines PCR.TM. mutagenesis with in vitro transcription/translation and ELISA for the rapid generation and characterization of protein mutants. The PCR.TM. products are used directly as the template for the in vitro transcription/translation reactions and because no cloning steps are required, the in vitro saturation mutagenesis of one residue can be completed in duplicate within a week by a single investigator. This high throughput enables the saturation mutagenesis of numerous residues of interest, a process that can be described as in vitro scanning saturation mutagenesis. Compositions and methods of use of such a process are described herein.Board of Regents, University of Texas Syste

Antibodies with increased affinities for anthrax antigens

The invention overcomes the deficiencies of the prior art by providing antibody compositions having improved affinities for Bacillus anthracis antigens. The compositions have important thereapeutic and diagnostic applications, including treatment or detection of infection by Bacillus anthracis.Board of Regents, University of Texas Syste

Antibodies with increased affinities for anthrax antigens

The invention overcomes the deficiencies of the prior art by providing antibody compositions having improved affinities for Bacillus anthracis antigens. The compositions have important thereapeutic and diagnostic applications, including treatment or detection of infection by Bacillus anthracis.Board of Regents, University of Texas Syste

The role of perceived source location in auditory stream segregation: separation affects sound organization, common fate does not

The human auditory system is capable of grouping sounds originating from different sound sources into coherent auditory streams, a process termed auditory stream segregation. Several cues can influence auditory stream segregation, but the full set of cues and the way in which they are integrated is still unknown. In the current study, we tested whether auditory motion can serve as a cue for segregating sequences of tones. Our hypothesis was that, following the principle of common fate, sounds emitted by sources moving together in space along similar trajectories will be more likely to be grouped into a single auditory stream, while sounds emitted by independently moving sources will more often be heard as two streams. Stimuli were derived from sound recordings in which the sound source motion was induced by walking humans. Although the results showed a clear effect of spatial separation, auditory motion had a negligible influence on stream segregation. Hence, auditory motion may not be used as a primitive cue in auditory stream segregation