3D printing and high tibial osteotomy

High tibial osteotomy (HTO) is a relatively conservative surgical option in the management of medial knee pain. Thus far, the outcomes have been variable, and apparently worse than the arthroplasty alternatives when judged using conventional metrics, owing in large part to uncer - tainty around the extent of the correction planned and achieved. This review paper introduces the concept of detailed 3D planning of the procedure, and describes the 3D printing technology that enables the plan to be performed. The different ways that the osteotomy can be undertaken, and the varying guide designs that enable accurate regis - tration are discussed and described. The system accuracy is reported. In keeping with other assistive technologies, 3D printing enables the surgeon to achieve a preoperative plan with a degree of accuracy that is not possible using conventional instruments. With the advent of low dose CT, it has been possible to confirm that the procedure has been under - taken accurately too. HTO is the ‘ultimate’ personal intervention: the amount of correction needed for optimal offloading is not yet com - pletely understood. For the athletic person with early medial joint line over - load who still runs and enjoys life, HTO using 3D printing is an attractive option. The clinical effectiveness remains unproven

External quality assessment of urinary methylmalonic acid quantification - results of a pilot study

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work noncommercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http:// creativecommons.org/licenses/by-nc/3.0

A Drosophila Circuit Feels the (Sleep) Pressure

How sleep is homeostatically regulated remains a mystery. In this issue of Neuron, Donlea et al. (2014) provide evidence in Drosophila that a set of sleep-inducing neurons require Crossveinless-c, a specific Rho-GTPase-activating protein (Rho-Gap), to alter their membrane excitability in response to sleep deprivation

Single Cable Transmission for Multi-Channel MRI using Frequency Division Multiplexing

Parallel imaging and RF array coils require a great quantity of MRI channels, which can produce ghosting and interference to decrease imaging SNR. In this work, we make use of a frequency division multiplexing (FDM) technique to combine several channel signals and transmit them in single cable. At present the PCB board is prototyped and tested with the signal generator. We propose to build the completed circuit with coil array on board to recover the multichannel FID signals.published_or_final_versio

On the k-Boundedness for Existential Rules

The chase is a fundamental tool for existential rules. Several chase variants are known, which differ on how they handle redundancies possibly caused by the introduction of nulls. Given a chase variant, the halting problem takes as input a set of existential rules and asks if this set of rules ensures the termination of the chase for any factbase. It is well-known that this problem is undecidable for all known chase variants. The related problem of boundedness asks if a given set of existential rules is bounded, i.e., whether there is a predefined upper bound on the number of (breadth-first) steps of the chase, independently from any factbase. This problem is already undecidable in the specific case of datalog rules. However, knowing that a set of rules is bounded for some chase variant does not help much in practice if the bound is unknown. Hence, in this paper, we investigate the decidability of the k-boundedness problem, which asks whether a given set of rules is bounded by an integer k. We prove that k-boundedness is decidable for three chase variants, namely the oblivious, semi-oblivious and restricted chase.Comment: 20 pages, revised version of the paper published at RuleML+RR 201

Comparison of Optical Modulation Methods for RF Coil Interlinks

Optical modulation method is one of the key factors in the optical link design for MRI RF coil interlinks. In this work, link performances of direct modulation by laser diode and external modulation by Mach Zehnder Interferometer are compared in the aspects of power gain, modulation bandwidth, noise figure and dynamic range. An external optical link can achieve better performance by the use of a low noise and high power laser. However, a direct optical link shows advantages in link structure, compact size and low cost. It is more feasible in engineering for large coil array interlinks.published_or_final_versio

Night Thoughts: George Gaylord Simpson’s Reflections on Leaving the American Museum of Natural History

George Gaylord Simpson (1902-1984) was a leader in twentieth century vertebrate palaeontology, and he contributed to making the American Museum of Natural History a powerhouse in the field. In 1959, Simpson left his job at the museum in a bitter dispute with its management. Simpson never published a rationale for his resignation, but he secretly wrote one. After his first day unemployed, Simpson penned a long account of the circumstances surrounding his decision to leave. This STS Occasional Paper presents a complete transcription of Simpson’s “Night Thoughts,” with brief introductory notes. Simpson was scathing of the museum’s Director, Albert Parr, and his once-close colleague, Edwin Colbert. This STS Occasional Paper also gives Colbert a voice, allowing him a counterbalance via correspondence with the editor about his reaction to Simpson’s essay. The biographer will find key insights into a turning point in Simpson’s career. They also will find a rare glimpse into the American Museum’s management during Parr’s directorship. Loyalties were tested to their breaking point. Some loyalties broke

Array with multiple loops for vertical field system

For vertical field MRI applications, the structure of the loop array is quite different from those in a horizontal-magnetic-field system. The conventional decoupling techniques are hard to be extended to vertical MRI system. Therefore, the loops for vertical MRI system are quite difficult to decouple. So far the coil array with up to two loop coils have been investigated on open low-field MRI, the array with more than three loop coils is sparsely reported. In this study, we present a decoupling technique using inductors for vertical-field loop coils. A four-channel array consisted of 3 loops and a saddle coil has been built for human knee at 0.5T vertical MRI system.published_or_final_versio