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We developed a web-based tool to provide students with access to old exam problems and solutions. By controlling the order in which students saw the problems, as well as their access to solutions, we obtained data about student learning by studying old exam problems. Our data suggest that in general students learn from doing old exam problems, and that having access to the problem solutions increases their learning. However, the data also suggest the depth of learning may be relatively shallow. In addition, the data show that doing old exam problems provides important formative assessment about the student's overall preparedness for the exam and their particular areas of strength and weakness. (Contains 1 table and 6 figures.)

Unconventional natural gas along with deepwater and subsalt offshore gas is expected to contribute heavily in the overall gas supply in the United States. The demand for gas supply is expected to increase as natural gas consumption increases.

A digital x-ray imaging system was designed for small-animal studies. This system is a fiber-optics taper-coupled imaging system with two CCD arrays uniquely jointed. The x-ray source of the system has a small focal spot of 20 [micro]m. This digital imaging system contains specially designed shelves to provide magnification levels, ranging from 1.5x to 5x. The system is characterized in terms of its properties of spatial resolution. An observer-based spatial resolution measurement was conducted with a line-pair target and a sector test pattern. The modulation transfer function of the system, with different magnifications, was studied by use of a 10-[micro]m lead slit. The average resolutions at 50% and 5% modulations at 1x magnification were measured as 3.9 and 8.4 lp/mm, respectively, where lp indicates line pairs. With 5x magnification, the 50% and the 5% modulations provided 13.2- and 29.9-lp/mm, respectively, average spatial resolutions. The measurements showed consistency between the two individual CCD arrays; the difference in resolution between the two CCDs is less than 1%, even at high magnifications. OCIS codes: 110.7440, 040.0040, 330.6130, 110.4100.

Recent discoveries of basement-hosted uranium deposits in the Patterson Lake corridor in the southwestern Athabasca Basin of Canada have brought vigorous exploration interest to the region. New lithostratigraphic constraints, geochronology and airborne geophysical surveys have dramatically improved the understanding of the host basement geology, warranting a re-examination of the remote predictive mapping and geophysical responses of the buried basement rocks. This study took a two-step approach to examine the regional basement geology and architecture. First, a mosaic of the long-wavelength response of potential field (gravity and magnetic) datasets was examined to divide the basement into regional domains based on bulk physical property variations. The interpretive geological model was then refined using textural and lineament analysis of new airborne gravity and magnetic datasets, geological drill hole logs and magnetic susceptibility measurements. The new basement map identifies and updates major features including a crustal-scale structure that separates the southern Tantato Domain from the newly defined eastern Taltson Domain. This structure may have played a role in localizing fluid flow in the Patterson Lake corridor, defining the spatial extents of structurally controlled buried felsic intrusions, and redefines the boundaries of the Taltson, Clearwater and Tantato Domains. In addition, the potential field enhancements delineated significant regional faults that controlled the geometry of Paleoproterozoic cover sequences and have implications for understanding the crustal architecture of the southern Rae Province. These new interpretations shed light on the tectonic history of the region to support on-going exploration activities and delineate regionally prospective areas in this understudied area of the Canadian Shield. Thematic collection: This article is part of the Uranium Fluid Pathways collection available at: https://www.lyellcollection.org/cc/uranium-fluid-pathways [ABSTRACT FROM AUTHOR]

Background: A radial incision with radial plate fixation for distal radius fracture has historically been avoided due to its risk to the superficial branch of the radial nerve (SBRN). With careful technique, it is possible to avoid injury to the SBRN, thereby minimizing the soft tissue injury associated with other approaches. We compare subjective and objective functional outcomes of radial plate fixation surgeries that we performed with those of dorsal and volar plate fixation in current literature. Methods: Patients at a single center who underwent radial plate fixation for an AO type A or AO type B distal radius fracture between December 2006 and December 2014 were enrolled in the study. Postoperative grip strength and 3-digit pinch strength were measured systematically in the injured and uninjured wrists. Patients also completed a Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire to assess subjective outcomes. Results: Thirty-six patients met our inclusion criteria and had available medical records. Postoperative grip strength in the injured wrist was significantly lowered—68% compared with the uninjured wrist. After subgroup analysis of dominant and nondominant wrist injuries, there was no significant difference in grip strength between injured and uninjured wrists. There was no significant decrease in postoperative 3-digit pinch strength in the injured wrist—89% compared with the uninjured wrist. The mean QuickDASH score for our study participants was 20.9. Conclusions: Radial plate fixation is an effective approach for distal radius fractures. Objective and subjective outcomes are noninferior to those of a dorsal or volar approach. [ABSTRACT FROM AUTHOR]