Contact tracing is associated with treatment success of index tuberculosis cases in Uganda.

Objective: To determine the effect of contact tracing on the treatment outcomes of index tuberculosis (TB) cases in Uganda.

Methods: We evaluated TB cases registered at an urban public health facility in Uganda in 2015-2020. We extracted data from the unit's TB and contact tracing registers.

Water-Window X-Ray Pulses from a Laser-Plasma Driven Undulator.

Femtosecond (fs) x-ray pulses are a key tool to study the structure and dynamics of matter on its natural length and time scale. To complement radio-frequency accelerator-based large-scale facilities, novel laser-based mechanisms hold promise for compact laboratory-scale x-ray sources. Laser-plasma driven undulator radiation in particular offers high peak-brightness, optically synchronized few-fs pulses reaching into the few-nanometer (nm) regime.

Probing polar molecules with high harmonic spectroscopy.

We bring the methodology of orienting polar molecules together with the phase sensitivity of high harmonic spectroscopy to experimentally compare the phase difference of attosecond bursts of radiation emitted upon electron recollision from different ends of a polar molecule. This phase difference has an impact on harmonics from aligned polar molecules, suppressing emission from the molecules parallel to the driving laser field while favoring the perpendicular ones. For oriented molecules, we measure the amplitude ratio of even to odd harmonics produced when intense light irradiates CO molecules and determine the degree of orientation and the phase difference of attosecond bursts using molecular frame ionization and recombination amplitudes.

Oriented rotational wave-packet dynamics studies via high harmonic generation.

We produce oriented rotational wave packets in CO and measure their characteristics via high harmonic generation. The wave packet is created using an intense, femtosecond laser pulse and its second harmonic. A delayed 800 nm pulse probes the wave packet, generating even-order high harmonics that arise from the broken symmetry induced by the orientation dynamics.

Wavelength scaling of high harmonic generation efficiency.

Using longer wavelength laser drivers for high harmonic generation is desirable because the highest extreme ultraviolet frequency scales as the square of the wavelength. Recent numerical studies predict that high harmonic efficiency falls dramatically with increasing wavelength, with a very unfavorable lambda(-(5-6)) scaling. We performed an experimental study of the high harmonic yield over a wavelength range of 800-1850 nm.