A positive feedback loop between germ cells and gonads induces and maintains sexual reproduction in a cnidarian.

The fertile gonad includes cells of two distinct developmental origins: the somatic mesoderm and the germ line. How somatic and germ cells interact to develop and maintain fertility is not well understood. Here, using grafting experiments and transgenic reporter animals, we find that a specific part of the gonad-the germinal zone-acts as a sexual organizer to induce and maintain de novo germ cells and somatic gonads in the cnidarian .

miRNA-target complementarity in cnidarians resembles its counterpart in plants.

microRNAs (miRNAs) are important post-transcriptional regulators that activate silencing mechanisms by annealing to mRNA transcripts. While plant miRNAs match their targets with nearly-full complementarity leading to mRNA cleavage, miRNAs in most animals require only a short sequence called 'seed' to inhibit target translation. Recent findings showed that miRNAs in cnidarians, early-branching metazoans, act similarly to plant miRNAs, by exhibiting full complementarity and target cleavage; however, it remained unknown if seed-based regulation was possible in cnidarians.

Improving apparent diffusion coefficient accuracy on a compact 3T MRI scanner using gradient nonlinearity correction.

Background: Gradient nonlinearity (GNL) leads to biased apparent diffusion coefficients (ADCs) in diffusion-weighted imaging. A gradient nonlinearity correction (GNLC) method has been developed for whole body systems, but is yet to be tested for the new compact 3T (C3T) scanner, which exhibits more complex GNL due to its asymmetrical design.

Purpose: To assess the improvement of ADC quantification with GNLC for the C3T scanner.

Lightweight, compact, and high-performance 3T MR system for imaging the brain and extremities.

Purpose: To build and evaluate a small-footprint, lightweight, high-performance 3T MRI scanner for advanced brain imaging with image quality that is equal to or better than conventional whole-body clinical 3T MRI scanners, while achieving substantial reductions in installation costs.

Methods: A conduction-cooled magnet was developed that uses less than 12 liters of liquid helium in a gas-charged sealed system, and standard NbTi wire, and weighs approximately 2000 kg. A 42-cm inner-diameter gradient coil with asymmetric transverse axes was developed to provide patient access for head and extremity exams, while minimizing magnet-gradient interactions that adversely affect image quality.

Technical Aspects of Contrast-enhanced MR Angiography: Current Status and New Applications.

This article is based on a presentation at the meeting of the Japanese Society of Magnetic Resonance in Medicine in September 2016. The purpose is to review the technical developments which have contributed to the current status of contrast-enhanced magnetic resonance angiography (CE-MRA) and to indicate related emerging areas of study. Technical developments include MRI physics-based innovations as well as improvements in MRI engineering.