Temporal bone volumetric image deblurring in spiral computed tomography scanning

RATIONALE AND OBJECTIVES: We developed a method for volumetric image deblurring in spiral (helical) computed tomography (CT) scanning with a three-dimensional (3D) Gaussian point spread function (PSF) to improve the quality of temporal bone spiral CT images for assessing the position of cochlear implants electrodes. METHODS: A patient was scanned after cochlear implantation, and the temporal bone was reconstructed into a volume with 128 voxels per dimension, 0.1 mm per voxel side, and x 10 gray-scale expansion. The 3D PSF in spiral CT imaging was assumed to be Gaussian separable transversely and longitudinally. Standard deviations of the PSF were derived and subjectively adjusted. The image was then deconvolved using Wiener filtering and maximum-likelihood deconvolution methods. Image quality was assessed both visually and quantitatively using cross-sectional area at half of the maximum (CAHM) of the implanted array as the figure of merit. RESULTS: Substantial image deblurring was achieved via deconvolution. Subjectively, anatomic structures were more clearly shown. Deconvolution reduced the CAHM by approximately one third, on average. Three-dimensional deconvolution had better image quality than two-dimensional deconvolution. The maximum-likelihood method produced superior image quality but took longer to process relative to Wiener filtering. CONCLUSION: Volumetric image deblurring is practical with a Gaussian PSF. The maximum-likelihood method is preferred if time permits. Deconvolution facilitates the study of fine details of the temporal bone and cochlear implant.     

Metastatic malignant melanoma: an unusual case presentation

Secondary involvement of the genitourinary tract with malignant melanoma is a common autopsy finding, but rarely evident clinically. We report a rare case involving a previously asymptomatic patient presenting with gross hematuria and a large renal mass, which was found to be metastatic melanoma. We propose that metastatic melanoma to the kidney, although rare, be considered in the differential diagnosis of disease processes causing hematuria.     

Accreditation of doctoral psychology training programs: Results of a nationwide survey.

A survey of all applied psychology doctoral training programs listed in Graduate Study in Psychology and Associated Fields (American Psychological Association [APA], 1990) examining the experiences of directors of training with APA's process of accreditation found an overall positive view by training directors. However, some accreditation components were identified as troublesome. Recommendations are offered to address these concerns and to improve some problem areas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Advanced analysis of metal distributions in human hair

A variety of techniques (secondary electron microscopy with energy dispersive X-ray analysis, time-of-flight--secondary ion mass spectrometry, and synchrotron X-ray fluorescence) were utilized to distinguish metal contamination occurring in hair arising from endogenous uptake from an individual exposed to a polluted environment, in this case a lead smelter. Evidence was sought for elements less affected by contamination and potentially indicative of biogenic activity. The unique combination of surface sensitivity, spatial resolution, and detection limits used here has provided new insight regarding hair analysis. Metals such as Ca, Fe, and Pb appeared to have little representative value of endogenous uptake and were mainly due to contamination. Cu and Zn, however, demonstrate behaviors worthy of further investigation into relating hair concentrations to endogenous function.     

Technology: Planning for capital investment in regulated energy markets

Building the business case for capital investment decisions is often thought of and analyzed from the perspective of revenue potential and retained earnings. Net present value techniques are employed to evaluate investment choices and arrive at go or no-go decisions. The focus on revenue potential is especially effective for deregulated industries, but less so for regulated companies.     

Technology: Full value of generator—ROI and safety—From demand response

US energy policy is a mix of federal, state, and local directives. Nevertheless, the convergence of smart technology, environmental regulation, renewable energy sources, and market prices are combining to reshape the electric energy industry.     

Performance evaluation of the SX‐6 vector architecture for scientific computations

The growing gap between sustained and peak performance for scientific applications is a well‐known problem in high‐performance computing. The recent development of parallel vector systems offers the potential to reduce this gap for many computational science codes and deliver a substantial increase in computing capabilities. This paper examines the intranode performance of the NEC SX‐6 vector processor, and compares it against the cache‐based IBM Power3 and Power4 superscalar architectures, across a number of key scientific computing areas. First, we present the performance of a microbenchmark suite that examines many low‐level machine characteristics. Next, we study the behavior of the NAS Parallel Benchmarks. Finally, we evaluate the performance of several scientific computing codes. Overall results demonstrate that the SX‐6 achieves high performance on a large fraction of our application suite and often significantly outperforms the cache‐based architectures. However, certain classes of applications are not easily amenable to vectorization and would require extensive algorithm and implementation reengineering to utilize the SX‐6 effectively. Copyright © 2005 John Wiley & Sons, Ltd.     

Note: He puff system for dust detector upgrade

Local detection of surface dust is needed for the safe operation of next-step magnetic fusion devices such as ITER. An electrostatic dust detector, based on a grid of interlocking circuit traces biased to 50 V, has been developed to detect dust on remote surfaces and was successfully tested for the first time on the National Spherical Torus Experiment. In this note, we report a helium puff system that clears residual dust from this detector and any incident debris or fibers that might cause a permanent short circuit. Two consecutive helium puffs delivered by three 0.45 mm nozzles at an angle of 30° cleared the entire 5 cm × 5 cm surface of the detector.