Altered Cortical Microarchitecture and Bone Metabolism in Patients with Monoclonal Gammopathy of Undetermined Significance

Patients with monoclonal gammopathy of undetermined significance (MGUS) are at increased fracture risk, and we have previously shown that MGUS patients have altered trabecular bone microarchitecture compared with controls. However, there are no data on whether the porosity of cortical bone, which may play a greater role in bone strength and the occurrence of fractures, is increased in MGUS. Thus, we studied cortical porosity and bone strength (apparent modulus) using high-resolution peripheral quantitative computed tomography imaging of the distal radius in 50 MGUS patients and 100 age-, gender-, and body mass index–matched controls. Compared with controls, MGUS patients had both significantly higher cortical porosity (+16.8%; P < .05) and lower apparent modulus (–8.9%; P < .05). Despite their larger radial bone size, MGUS patients have significantly increased cortical bone porosity and reduced bone strength relative to controls. This increased cortical porosity may explain the increased fracture risk seen in MGUS patients

The 74MHz System on the Very Large Array

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and resolution (~25 arcsec) for low-frequency observations. We review the hardware, the calibration and imaging strategies, comparing them to those at higher frequencies, including aspects of interference excision and wide-field imaging. Ionospheric phase fluctuations pose the major difficulty in calibrating the array. Over restricted fields of view or at times of extremely quiescent ionospheric ``weather'', an angle-invariant calibration strategy can be used. In this approach a single phase correction is devised for each antenna, typically via self-calibration. Over larger fields of view or at times of more normal ionospheric ``weather'' when the ionospheric isoplanatic patch size is smaller than the field of view, we adopt a field-based strategy in which the phase correction depends upon location within the field of view. This second calibration strategy was implemented by modeling the ionosphere above the array using Zernike polynomials. Images of 3C sources of moderate strength are provided as examples of routine, angle-invariant calibration and imaging. Flux density measurements indicate that the 74 MHz flux scale at the VLA is stable to a few percent, and tied to the Baars et al. value of Cygnus A at the 5 percent level. We also present an example of a wide-field image, devoid of bright objects and containing hundreds of weaker sources, constructed from the field-based calibration. We close with a summary of lessons the 74 MHz system offers as a model for new and developing low-frequency telescopes. (Abridged)Comment: 73 pages, 46 jpeg figures, to appear in ApJ

Probing Cation Antisite Disorder in Gd2Ti2O7 Pyrochlore by Site-specific NEXAFS and XPS

Disorder in Gd2Ti2O7 is investigated by near-edge x-ray-absorption fine structure (NEXAFS) and x-ray photoelectron spectroscopy (XPS). NEXAFS shows Ti4+ ions occupy octahedral sites with a tetragonal distortion induced by vacant oxygen sites. O 1s XPS spectra obtained with a charge neutralization system from Gd2Ti2O7(100) and the Gd2Ti2O7 pyrochlore used by Chen et al. [Phys. Rev. Lett. 88, 105901 (2002)], both yielded a single peak, unlike the previous result on the latter that found two peaks. The current results give no evidence for an anisotropic distribution of Ti and O. The extra features reported in the aforementioned communication resulted from charging effects and incomplete surface cleaning. Thus, a result confirming the direct observation of simultaneous cation-anion antisite disordering and lending credence to the split vacancy model has been clarified

Ionospheric Challenges of the International Polar Year

Fifty years ago, the first International Geophysical Year (lGY) generated a huge step function increase in observations of ionospheric variability associated with the almost continuous geomagnetic activity experienced during the largest solar maximum of the past 100 years. In turn, these observations fueled more than a decade of theoretical advancement of magnetospheric-ionospheric electrodynamics and geomagnetic storm physics

Polycyclic aromatic hydrocarbons (PAHs) and estrogenic compounds in experimental flue gas streams

The importance of combustion processes as a source of substances with estrogenic activity in the environment was investigated. Wood (nontreated and treated with wood preservatives), barbecue charcoal, meat, and kitchen waste were combusted in a laboratory-scale incinerator. Flue gas emissions (particulates and gaseous pollutants) were trapped in polyurethane foam cartridges. The cartridges were subjected to Soxhlet extraction and part of the extracts redissolved in dimethylsulfoxide (DMSO) for analyses of estrogenic activity by means of the yeast-based human estrogen receptor (hER) bioassay. A synthetic estrogen, 17-alpha-ethinylestradiol (EE2), was used as the reference estrogenic compound. Part of the extracts was analyzed for the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs). Estrogenic compounds in the flue gas (wood) were as high as 234 +/- 25 ng m(-3) EE2 equivalent compared with 27 to 81 ng m(-3) EE2 equivalent in flue gas from combustion of barbecue charcoal. Concentrations of polycyclic aromatic hydrocarbons in both flue gas streams were in the range of 21000 +/- 2000 and 240 +/- 110 ng m(-3), respectively. In general, the concentrations of EE2 equivalent in the flue gas samples were at least a factor of 1000 lower than total PAH concentration. The EE2 levels were not related to the concentration of PAHs in any flue gas sample

Duke Surgery Patient Safety: an open-source application for anonymous reporting of adverse and near-miss surgical events

BACKGROUND: Studies have shown that 4% of hospitalized patients suffer from an adverse event caused by the medical treatment administered. Some institutions have created systems to encourage medical workers to report these adverse events. However, these systems often prove to be inadequate and/or ineffective for reviewing the data collected and improving the outcomes in patient safety. OBJECTIVE: To describe the Web-application Duke Surgery Patient Safety, designed for the anonymous reporting of adverse and near-miss events as well as scheduled reporting to surgeons and hospital administration. SOFTWARE ARCHITECTURE: DSPS was developed primarily using Java language running on a Tomcat server and with MySQL database as its backend. RESULTS: Formal and field usability tests were used to aid in development of DSPS. Extensive experience with DSPS at our institution indicate that DSPS is easy to learn and use, has good speed, provides needed functionality, and is well received by both adverse-event reporters and administrators. DISCUSSION: This is the first description of an open-source application for reporting patient safety, which allows the distribution of the application to other institutions in addition for its ability to adapt to the needs of different departments. DSPS provides a mechanism for anonymous reporting of adverse events and helps to administer Patient Safety initiatives. CONCLUSION: The modifiable framework of DSPS allows adherence to evolving national data standards. The open-source design of DSPS permits surgical departments with existing reporting mechanisms to integrate them with DSPS. The DSPS application is distributed under the GNU General Public License