Structural variants (SVs) are an important source of human genetic diversity, but their contribution to traits, disease and gene regulation remains unclear. We mapped cis expression quantitative ...trait loci (eQTLs) in 13 tissues via joint analysis of SVs, single-nucleotide variants (SNVs) and short insertion/deletion (indel) variants from deep whole-genome sequencing (WGS). We estimated that SVs are causal at 3.5-6.8% of eQTLs-a substantially higher fraction than prior estimates-and that expression-altering SVs have larger effect sizes than do SNVs and indels. We identified 789 putative causal SVs predicted to directly alter gene expression: most (88.3%) were noncoding variants enriched at enhancers and other regulatory elements, and 52 were linked to genome-wide association study loci. We observed a notable abundance of rare high-impact SVs associated with aberrant expression of nearby genes. These results suggest that comprehensive WGS-based SV analyses will increase the power of common- and rare-variant association studies.
Transcriptome-wide association studies integrate gene expression data with common risk variation to identify gene-trait associations. By incorporating epigenome data to estimate the functional ...importance of genetic variation on gene expression, we generate a small but significant improvement in the accuracy of transcriptome prediction and increase the power to detect significant expression-trait associations. Joint analysis of 14 large-scale transcriptome datasets and 58 traits identify 13,724 significant expression-trait associations that converge on biological processes and relevant phenotypes in human and mouse phenotype databases. We perform drug repurposing analysis and identify compounds that mimic, or reverse, trait-specific changes. We identify genes that exhibit agonistic pleiotropy for genetically correlated traits that converge on shared biological pathways and elucidate distinct processes in disease etiopathogenesis. Overall, this comprehensive analysis provides insight into the specificity and convergence of gene expression on susceptibility to complex traits.
Global quantitative analysis of genetic interactions is a powerful approach for deciphering the roles of genes and mapping functional relationships among pathways. Using colony size as a proxy for ...fitness, we developed a method for measuring fitness-based genetic interactions from high-density arrays of yeast double mutants generated by synthetic genetic array (SGA) analysis. We identified several experimental sources of systematic variation and developed normalization strategies to obtain accurate single- and double-mutant fitness measurements, which rival the accuracy of other high-resolution studies. We applied the SGA score to examine the relationship between physical and genetic interaction networks, and we found that positive genetic interactions connect across functionally distinct protein complexes revealing a network of genetic suppression among loss-of-function alleles.
A flux pump is a kind of power source that energizes superconducting magnets usually embedded in the cryogenic system. Therefore, heat loss through current leads is eliminated, allowing for more ...efficient cooling design. A winding technique, the so-called "wind-and-flip," had been proposed by the authors to realize a jointless HTS coil for a perfect resistanceless closed loop, which may enable to induce a persistent current in an HTS coil wound with second-generation HTS tape. In this paper, we investigated charging/discharging characteristics and a possibility of persistent current operation of a jointless HTS coil with a flux pump. Results are discussed with regard to current capacity and temporal stability with a prototype jointless HTS coil.
We had proposed a winding method, the so-called "wind-and-flip," which enables a persistent current-mode operation of a high-temperature superconducting (HTS) pancake coil. Two pancake coils had been ...fabricated using this method and tested in a liquid nitrogen bath with an external magnetic field. The result showed that the time stability was not good enough to use for magnetic resonance imaging or nuclear magnetic resonance when they were magnetized by field cooling at 77 K. In this paper, the test results of a stacked HTS pancake coil for a center magnetic field of 1 T are presented. The coils were cooled to 20 K by conduction cooling using a Gifford-McMahon cryocooler. We measured the time stability of the persistent current-mode operation at 20 K, which shows a strong possibility of a high-field HTS magnet using this method.
A large bore magnet coil wound without turn to turn insulation was fabricated and cooled down to 10 K by conduction cooling. The coil has room temperature bore of 102 mm in diameter and consists of ...22 double pancakes wound with 2G HTS conductor on aluminium alloy bobbin. Tests for 22 double pancake coils were performed at 77 K for individual single DPC, coupled 2 DPCs, 4 DPCs, 8 DPCs and 22 DPCs. Tested DPCs were connected by splice joint and assembled coil structure was installed to the vacuum cryostat with radiation shield and cooled down to 10 K for 28 h. The coil generate 4.1 T when operating current ramped to 200 A by 0.1 A/s without quench. Test results agreed well with the designed performance showing field homogeneity of 0.021% for radial axis and 0.056% for vertical axis in 10 mm DSV at 4.1073T. The magnet showed quench at 210A when ramping rate was 0.15 A/s at 10K. The results showed that without turn to turn insulation winding method is a possible option for making compact magnet coil with sufficient structural integrity, thermal and electrical stability at the same time.
We fabricated superconducting magnet using second-generation (2G) high-temperature superconducting wire by SuNAM. Magnetic field strength at the center is 4 T, and room temperature bore diameter is ...203 mm. The magnet consists of 30 double pancake coils (DPCs) with the inner diameter of 245 mm and outer diameter of 297 mm. All double pancakes were wound by no-insulation method and performance were tested separately before assemble. Tested DPCs were resistively connected by HTS tape(splice joint), and assembled coil was conduction cooled by a two-stage Gifford-McMahon cryo-cooler to the operating temperature of 8 K. The size of magnet is 452 mm in height. Current, voltage, and field strength were measured as a function of time with various ramping up and down conditions and results were compared with the simulated behavior. The coil generates 4 T when operating current ramped to 205 A by 0.03 A/s without quench. Initial cool down time was 72 h and the measure field homogeneity in 10 mm DSV was 0.015% and 0.012% in radial axis and vertical axis, respectively. The results showed that no-insulation winding method is a possible option for making compact magnet coil with sufficient structural integrity, thermal and electrical stability at the same time. The magnet showed quench at field strength of 4.49 T when ramped with 0.2 A/s to 235 A. The magnet showed same performance after recovery from quench.
It has been well known that a coated conductor (CC), 2G superconducting tape, shows a higher critical current and better performance than the 1G, BSCCO one. However, there has still been no way to ...make a superconducting joint with CC, so it has been almost impossible to build a CC superconducting magnet in persistent current mode. As a viable solution for this, we have proposed a special winding technology called the Wind-and-Flip method. It shows a new possibility for the generation of a persistent current mode in a magnet with CC. First, we partially cut a wide CC tape into two pieces along the tape except at both end parts like cutting the abdomen of a fish. Then we wind two pancake coils with the cut but connected CC tape. Finally, one of the two coils is turned over, and then the magnetic fields from both coils would have the same direction with each other. In this paper, we made two high-temperature superconducting double pancake windings by the Wind-and-Flip method. One has turn-to-turn insulation layers while the other does not. They both have oxygen-free copper bobbins for the conduction cooling. First, they were magnetized by field cooling within a fine background magnet, and operated in persistent current mode at 77 K. As a result of the experiment, we measured and compared temporal stabilities for both pancake windings to investigate the possible use of these windings for magnetic resonance imaging or nuclear magnetic resonance applications. We have future plans of measuring the temporal stabilities of similar windings under lower temperatures and confirm the possibility of a high-field high-temperature superconducting magnet, which will be fabricated by stacking these pancake coils with larger cold bore size.
We proposed an HTS wind power generator that has armature windings in the rotor. Field windings in the stator make a slightly higher magnetic field than the field windings in the rotor if both ...windings have same size of armature windings and field coils. In addition, we split the field windings into two and installed one of the split ones inside the armature, i.e., the so-called dual field windings. This structure is mechanically complex because the armature windings rotate between two stationary field windings. However, the output voltage of the 10-MW generator is 12% higher than that of the rotating field with this structural modification. We set up six different types of field winding arrangement and analyze the field magnitudes and field distributions in the armature and field windings of each one. Finally, the output voltages are calculated by a finite-element method at full load.
A conduction-cooled high-temperature superconducting magnet using 2nd generation HTS wire, which has a room-temperature bore 102 mm in diameter, has been developed and tested up to 3 T with the ...operating temperature of 20 K. The magnet consists of 22 double pancake coils (DPCs) with an inner diameter of 140 mm and outer diameter of 182 mm. Twenty-two double pancake coils were tested separately at 77 K for checking the IV -curve. Selected DPCs were resistively connected by HTS tape (Splice joint), and an assembled magnet coil with the size of 182.5 mm diameter and 242 mm in height was conduction cooled by a two-stage Gifford-McMahon cryo-cooler to 20 K. Current, voltage, and field strength were measured as a function of time with various ramping up and down conditions. The resulting performance data of the assembled magnet agreed well with the expectation from FEM simulation. The aimed field homogeneity of 0.1% in 10 mm diameter sphere volume was proved when operating current was 141.6 A at 20 K with central magnetic field intensity of 2.9975 T by hall sensor. The magnetic flux density at center showed nonlinear dependence with ramping current within the range of 0.05 A/sec ~0.15 A/sec because of charging delay. However, saturated magnetic flux density showed the same value of 2.9975 T regardless of ramping rate.
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