Single molecule FRET experiments are important for studying processes that happen on the molecular scale. By using pulsed illumination and collecting single photons, it is possible to use information gained from the fluorescence lifetime of the chromophores in the FRET pair to gain more accurate estimates of the underlying FRET rate which is used to determine information about the distance between the chromophores of the FRET pair. In this paper, we outline a method that utilizes Bayesian inference to learn parameter values for a model informed by the physics of a immobilized single-molecule FRET experiment. This method is unique in that it combines a rigorous look at the photophysics of the FRET pair and a nonparametric treatment of the molecular conformational statespace, allowing the method to learn not just relevant photophysical rates (such as relaxation rates and FRET rates), but also the number of molecular conformational states.

Optometry is an important field in medicine as it allows people a chance to have their vision corrected and it serves as a health screening opportunity for those who receive a dilated eye examination. One of the largest barriers to receiving a dilated eye exam is insurance coverage. Most health insurance policies have limited optometric coverage. By expanding health insurance plans to be more inclusive of optometric care, people who use these health insurance plans will have a better access of care.

The reionization of the Universe is thought to have completed by redshift z~5.5. To probe this era, galaxy observations in the Subaru Deep Field (SDF) have identified more than 100 galaxies at z~6, many spectroscopically confirmed through follow-up observations. Using available optical/IR data, we model with CIGALE the spectral energy distributions (SEDs) of 43 SDF galaxies, including newly acquired data from the UKIRT WFCAM K-band for seven previously studied objects. In particular, modeling deep IR photometry is sensitive to the galaxy's Lyman continuum (LyC) escape fraction (fesc). We find the median implied fesc value as ~0.4+/-0.1 (mean error). Significant uncertainties in data and fitting result in a large range of fesc for individual objects, but analysis suggests that fesc is likely high enough for galaxies to finish reionization by z~6. More importantly, we find trends between the CIGALE UV slope b, fesc, and dust extinction E(B-V): for a given E(B-V), b appear steeper by ~0.4 than at z=0. Lower fesc values appear to be associated with bluer b and lower E(B-V), but only weakly. This suggests that LyC could have escaped through holes with sufficiently wide opening angles surrounding the ISM from outflows of supernovae and/or weak AGN to escape, but resulting in a large range of implied fesc values depending on the orientation of each galaxy. The current HST, Spitzer and ground-based photometric and model errors for the 43 galaxies are large, so IR spectroscopic observations with the James Webb Space Telescope are needed to better constrain this possibility.

The purpose of this paper is to provide an analysis of entanglement and the particular problems it poses for some physicists. In addition to looking at the history of entanglement and non-locality, this paper will use the Bell Test as a means for demonstrating how entanglement works, which measures the behavior of electrons whose combined internal angular momentum is zero. This paper will go over Dr. Bell's famous inequality, which shows why the process of entanglement cannot be explained by traditional means of local processes. Entanglement will be viewed initially through the Copenhagen Interpretation, but this paper will also look at two particular models of quantum mechanics, de-Broglie Bohm theory and Everett's Many-Worlds Interpretation, and observe how they explain the behavior of spin and entangled particles compared to the Copenhagen Interpretation.

X-ray free electron lasers are used in measuring diffraction patterns from nanocrystals in the 'diffract-before-destroy' mode by outrunning radiation damage. The finite-sized nanocrystals provide an opportunity to recover intensity between Bragg spots by removing the modulating function that depends on crystal shape, i.e. the transform of the crystal shape. This shape-transform dividing-out scheme for solving the phase problem has been tested using simulated examples with cubic crystals. It provides a phasing method which does not require atomic resolution data, chemical modification to the sample, or modelling based on the protein databases. It is common to find multiple structural units (e.g. molecules, in symmetry-related positions) within a single unit cell, therefore incomplete unit cells (e.g. one additional molecule) can be observed at surface layers of crystals. In this work, the effects of such incomplete unit cells on the 'dividing-out' phasing algorithm are investigated using 2D crystals within the projection approximation. It is found that the incomplete unit cells do not hinder the recovery of the scattering pattern from a single unit cell (after dividing out the shape transforms from data merged from many nanocrystals of different sizes), assuming that certain unit-cell types are preferred. The results also suggest that the dynamic range of the data is a critical issue to be resolved in order to apply the shape transform method practically.

Serial femtosecond crystallography requires reliable and efficient delivery of fresh crystals across the beam of an X-ray free-electron laser over the course of an experiment. We introduce a double-flow focusing nozzle to meet this challenge, with significantly reduced sample consumption, while improving jet stability over previous generations of nozzles. We demonstrate its use to determine the first room-temperature structure of RNA polymerase II at high resolution, revealing new structural details. Moreover, the double flow-focusing nozzles were successfully tested with three other protein samples and the first room temperature structure of an extradiol ring-cleaving dioxygenase was solved by utilizing the improved operation and characteristics of these devices.

X-ray free-electron lasers provide novel opportunities to conduct single particle analysis on nanoscale particles. Coherent diffractive imaging experiments were performed at the Linac Coherent Light Source (LCLS), SLAC National Laboratory, exposing single inorganic core-shell nanoparticles to femtosecond hard-X-ray pulses. Each facetted nanoparticle consisted of a crystalline gold core and a differently shaped palladium shell. Scattered intensities were observed up to about 7 nm resolution. Analysis of the scattering patterns revealed the size distribution of the samples, which is consistent with that obtained from direct real-space imaging by electron microscopy. Scattering patterns resulting from single particles were selected and compiled into a dataset which can be valuable for algorithm developments in single particle scattering research.