Estimation of atmospheric optical turbulence strength in realistic airborne environments.

In this paper, atmospheric optical turbulence strength is estimated for realistic airborne environments using a modified phase-variance approach, as well as a modified slope-discrepancy approach. Realistic airborne environments are generated using wave-optics simulations of a plane wave propagating through increasing strengths of homogeneous atmospheric optical turbulence, both with and without aero-optical contamination (from in-flight wavefront sensor data) and additive-measurement noise. In comparison to the modified phase-variance approach, the results show that the modified slope-discrepancy approach more accurately estimates atmospheric optical turbulence strength over a wide range of conditions.

In-flight measurement of atmospheric-imposed tilt: experimental results and analysis.

The work presented here experimentally measures the tilt imposed on a laser beam by the atmosphere from Shack-Hartmann wavefront sensor measurements collected in-flight. Tip/tilt is imposed on the laser beam by propagating through optical turbulent structures larger than or of the order of the size of the beam diameter. This tip/tilt causes a dynamic, net deflection of the beam in the far field, referred to as jitter, which poses a serious problem for tracking in directed energy applications.

Neoadjuvant chemoradiotherapy for locally advanced rectal cancer with peritumoral abscesses and fistulas.

Purpose: Rectal cancer patients who present with peritumoral abscesses and fistulas at the time of diagnosis may be denied chemoradiotherapy (CRT) as the safety is unknown. The aim of this study was to investigate the safety of preoperative CRT in this patient group.

Methods: We performed a retrospective nested case-control study to compare outcomes between patients with locally advanced rectal cancer with peritumoral abscesses and fistulas (study group) and patients with T4 locally advanced rectal cancer with no evidence of abscesses and fistulas (control group).

Quality assurance guidelines for interstitial hyperthermia.

Quality assurance (QA) guidelines are essential to provide uniform execution of clinical hyperthermia treatments and trials. This document outlines the clinical and technical consequences of the specific properties of interstitial heat delivery and specifies recommendations for hyperthermia administration with interstitial techniques. Interstitial hyperthermia aims at tumor temperatures in the 40-44 °C range as an adjunct to radiation or chemotherapy.

Shock-related effects on aero-optical environment for hemisphere-on-cylinder turrets at transonic speeds.

The aero-optical environment around a hemisphere-on-cylinder turret with both flat and conformal windows was studied experimentally in flight using the Airborne Aero-Optical Laboratory-Transonic for a range of subsonic and transonic Mach numbers between 0.5 and 0.8.