Spatial-temporal-covariance-based modeling, analysis, and simulation of aero-optics wavefront aberrations.

We introduce a framework for modeling, analysis, and simulation of aero-optics wavefront aberrations that is based on spatial-temporal covariance matrices extracted from wavefront sensor measurements. Within this framework, we present a quasi-homogeneous structure function to analyze nonhomogeneous, mildly anisotropic spatial random processes, and we use this structure function to show that phase aberrations arising in aero-optics are, for an important range of operating parameters, locally Kolmogorov. This strongly suggests that the d5/3 power law for adaptive optics (AO) deformable mirror fitting error, where d denotes actuator separation, holds for certain important aero-optics scenarios.

Head and neck malignant fibrous histiocytomas.

Malignant fibrous histiocytoma of the head and neck is a rare tumor with less than 50 total cases reported in the literature. Its rarity and complex histopathology combine to make it a difficult diagnosis. Two cases are described.

Cervical epidural anesthesia for head and neck surgery.

Patients with head and neck cancer frequently suffer from chronic obstructive pulmonary disease and arteriosclerotic cardiovascular disease, making them poor risks for anesthesia. Arrhythmogenic inhalation anesthetics along with assisted ventilation used in general anesthesia further complicate the intraoperative, as well as the postoperative, course. Cervical epidural anesthesia has been employed in a number of cases of breast and upper thoracic surgery at Walter Reed Army Medical Center with remarkable success.

Adenotonsillar hypertrophy and upper airway obstruction in evolutionary perspective.

Primary care physicians have become increasingly reluctant to refer children for tonsillectomy and adenoidectomy (T and A) during the past years while antimicrobial therapy for pharyngotonsillitis and otitis media has become more common. Consequently, more children retain tonsils and adenoids throughout the childhood years. Airway compromise from adenotonsillar hypertrophy is reported in 11 cases-8 with insidious onset, 3 with acute onset.