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A fully automated laboratory-based measurement system for characterization of coil system parameters is presented. This method uses an inexpensive personal computer (PC)-controlled stepper motor positioning system in conjunction with a network/spectrum analyzer and an analog-to-digital converter (A/D) board that allows high resolution data acquisition in an unattended manner. A graphical interface was created for complete control of stepper motor movement, measurement, and data acquisition. The system is capable of performing a wide range of measurements that can, either individually or combined, characterize radiofrequency (RF) and gradient coils used in MRI. Measurement methods, theory, and results for conductor and shield current distributions, mutual impedance, and magnetic fields are given. Comparisons with theoretical calculations are included to validate the accuracy and utility of the system.

We report on the serendipitous discovery of an unresolved, evolving, sub-km-radius object with a semimajor axis < 10 km inside that of the edge of Saturn's main rings. The object has been detectable in Cassini images since at least May 2012 and its changing orbit shows evidence of a possible disruption in early 2013.

Background The outcomes literature on proximal phalanx fractures in children is sparse. The purpose of this study is to report the complications and outcomes of displaced proximal phalanx fractures after treatment with closed reduction and percutaneous pinning. Methods A retrospective chart review identified 105 patients treated with closed reduction and percutaneous pinning of displaced proximal phalanx fractures. Specific complications were recorded for all patients. Thirty-one of these patients returned more than 1 year after surgery for assessment including visual analog scales of pain level, functional ability, and aesthetics. Objective measurements included range of motion, grip and pinch strength, and finger deformity. Radiographs were taken to assess deformity. Results Five of the 105 patients (4.8%) had a complication including infection, pin site complication, or malunion. Thirty- six had stiffness and 31 ultimately underwent hand therapy to regain motion. Subcondylar fractures were associated with a greater likelihood of stiffness. In the 31 patients returning for assessment, the median visual analog scale score was 0 for pain (none), function (full), and aesthetics (perfect). Range of motion, grip, and pinch strength were equivalent to the contralateral side. Seven of the 31 patients (22.6%) had a measureable coronal plane deviation averaging 5° (range 3°-13°) on radiographs. Deviation was associated with subcondylar fractures and a worse aesthetic VAS. Deviation was not associated with worse outcomes overall. Conclusions Pediatric patients with a displaced proximal phalanx fracture treated with closed reduction and percutaneous pinning have an initial notable complication rate related to stiffness; subcondylar proximal phalanx fractures are more commonly affected. At greater than 1 year follow up, patients had full motion, no pain, and were happy with both function and appearance despite minor deformity in some. These complication data may help better inform patients and families prior to surgical intervention.

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A method is presented which rapidly characterizes the mutual impedance between elements in array coils for MR imaging as a function of offset distances between elements, These "coupling surfaces" allow the designer to quickly determine the overlap distances which minimize coupling between array elements.The method allows arbitrary element geometries and a layered, planar media. Additionally, because the Green's functions and current distributions are stored in Fourier space, the transverse fleld distributions are easily obtained, allowing the weighting coefficients form image combination to be determined.

Plant development is affected by physical stresses of all kinds. The most sensitive time is during anthesis and early fruit growth, when reproductive structures may fail to develop or embryos may abort. Water limitation can cause both effects, and explanatory theories are based on turgor, photosynthate availability, or hormonal relationships. Data will be presented for maize to show that failure of the female flower accounts for reproductive sensitivity to limited water. There is a correlation between sensitivity and the availability of reserve photosynthate that overrides the effects of turgor. The failure of the female flower is attributable partly to inhibited silk growth and partly to arrested development of the entire seed after fertilization takes place.