Constraints on the black hole spin in the quasar SDSS J094533.99+100950.1

The spin of the black hole is an important parameter which may be responsible for the properties of the inflow and outflow of the material surrounding a black hole. Broad band IR/optical/UV spectrum of the quasar SDSS J094533.99+100950.1 is clearly disk-dominated, with the spectrum peaking up in the observed frequency range. Therefore, disk fitting method usually used for Galactic black holes can be used in this object to determine the black hole spin. We develop the numerical code for computing disk properties, including radius-dependent hardening factor, and we apply the ray-tracing method to incorporate all general relativity effects in light propagation. We show that the simple multicolor disk model gives a good fit, without any other component required, and the disk extends down to the marginally stable orbit. The best fit accretion rate is 0.13, well below the Eddington limit, and the black hole spin is moderate, 0.3. The contour error for the fit combined with the constraints for the black hole mass and the disk inclination gives a constraint that the spin is lower than 0.8. We discuss the sources of possible systematic errors in the parameter determinations

Surgical treatment of head and neck port-wine stains by means of a staged zonal approach

BACKGROUND: The majority of patients with capillary malformations (port-wine stains) develop soft-tissue and bony hypertrophy leading to gross facial asymmetry and functional deficits in vision, breathing, speech, and feeding. The authors describe and illustrate a surgical approach for the treatment of these malformations with restoration of facial symmetry and contour based on facial subunits. METHODS: The authors conducted a retrospective case series of patients from 2004 to 2011 presenting for primary evaluation and treatment to a tertiary referral center specializing in vascular anomalies. The medical records and photographs of patients with facial capillary malformations and soft-tissue hypertrophy were reviewed. RESULTS: Of the 160 patients who presented with the diagnosis of facial capillary malformation/port-wine stain, 96 (60 percent) had soft-tissue hypertrophy in one or more dermatomes resulting in facial asymmetry. Only 4.4 percent of patients had solely V1 involvement, 38.8 percent had V2 involvement, and 15.6 percent had V3 involvement. The technique and incisions used for each facial zone are described in detail. In all cases, incisions were placed along existing boundaries of facial subunits. Serial pulsed-dye laser treatments were also performed. CONCLUSIONS: Sixty percent of patients with facial capillary malformation experience soft-tissue hypertrophy with or without bony remodeling, and surgical correction is required. The authors describe a staged surgical treatment for these patients based on a subunit and zonal approach to the face. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV

A Biomechanical Evaluation of Auricular Cartilage Autografts in Orbital Floor Defect Repair

OBJECTIVE: Auricular cartilage is used as a surgical implant in the management of orbital floor fractures. However, no specific parameters exist regarding the use/limitations of this potential graft. In order to determine the mechanical efficacy of adult auricular cartilage grafts, a mechanical model was developed and studied for structural threshold size limits. METHODS: Thirty-seven cadaveric auricular cartilage specimens were tested in a laboratory. A plexiglass baseplate was created with four different sized holes, defined as 1.0x, 1.2x, 1.4x, and 1.6x the mean minor axis of the specimens. Each specimen was used to bridge one hole under increasing loads until mechanical failure. Structural stiffness at three different loading stages, structural failure strength, and percent failure of the entire system for each defect size was calculated. RESULTS: Specimens tested on 1.0x, 1.2x, 1.4x and 1.6x defects demonstrated 0%, 0%, 20%, and 60% system failure rates, respectively. Structural stiffness curves showed a similar trend, with ANOVA demonstrating a significant difference in mechanical properties between defect sizes (p = 0.03). The curve representing 1.6 x defect size demonstrated significantly reduced structural stiffness relative to 1.0x, 1.2x, and 1.4x curves. There was no statistical difference between 1.2x and 1.4x testing sets (p = 0.09). CONCLUSION: A clinically significant biomechanical and functional threshold exists between 1.2xand 1.4x defect sizes. Given a mean minor axis of 2.06 cm, orbital blow-out defects2.4 cm may require a more rigid material. Cartilage grafts that allow failure, however, may better protect the globe in subsequent injury