Pressure dependence of the spin dynamics around a quantum critical point : An inelastic neutron scattering study of Ce0.87La0.13Ru2Si2

Inelastic neutron scattering experiments performed on a single crystal of the antiferromagnetic compound Ce$_{0.87}$La$_{0.13}$Ru$_{2}$Si$_{2}$ under applied pressures of up to 5 kbar are reported. A quantum critical point is reached at around 2.6 kbar where long-range magnetic order disappears. The variation of the characteristic energy scales with respect to temperature and pressure is followed and found to saturate in the ordered phase.Comment: 14 pages (6 figures

Identification and characterization of an oocyte factor required for development of porcine nuclear transfer embryos.

Nuclear reprogramming of differentiated cells can be induced by oocyte factors. Despite numerous attempts, these factors and mechanisms responsible for successful reprogramming remain elusive. Here, we identify one such factor, necessary for the development of nuclear transfer embryos, using porcine oocyte extracts in which some reprogramming events are recapitulated. After incubating somatic nuclei in oocyte extracts from the metaphase II stage, the oocyte proteins that were specifically and abundantly incorporated into the nuclei were identified by mass spectrometry. Among 25 identified proteins, we especially focused on a multifunctional protein, DJ-1. DJ-1 is present at a high concentration in oocytes from the germinal vesicle stage until embryos at the four-cell stage. Inhibition of DJ-1 function compromises the development of nuclear transfer embryos but not that of fertilized embryos. Microarray analysis of nuclear transfer embryos in which DJ-1 function is inhibited shows perturbed expression of P53 pathway components. In addition, embryonic arrest of nuclear transfer embryos injected with anti-DJ-1 antibody is rescued by P53 inhibition. We conclude that DJ-1 is an oocyte factor that is required for development of nuclear transfer embryos. This study presents a means for identifying natural reprogramming factors in mammalian oocytes and a unique insight into the mechanisms underlying reprogramming by nuclear transfer

Internal lipid synthesis and vesicle growth as a step toward self-reproduction of the minimal cell

One of the major properties of the semi-synthetic minimal cell, as a model for early living cells, is the ability to self-reproduce itself, and the reproduction of the boundary layer or vesicle compartment is part of this process. A minimal bio-molecular mechanism based on the activity of one single enzyme, the FAS-B (Fatty Acid Synthase) Type I enzyme from Brevibacterium ammoniagenes, is encapsulated in 1-palmitoyl-2oleoyl-sn-glycero-3-phosphatidylcholine (POPC) liposomes to control lipid synthesis. Consequently molecules of palmitic acid released from the FAS catalysis, within the internal lumen, move toward the membrane compartment and become incorporated into the phospholipid bilayer. As a result the vesicle membranes change in lipid composition and liposome growth can be monitored. Here we report the first experiments showing vesicles growth by catalysis of one enzyme only that produces cell boundary from within. This is the prototype of the simplest autopoietic minimal cell

Germline Transgenic Pigs by Sleeping Beauty Transposition in Porcine Zygotes and Targeted Integration in the Pig Genome

Genetic engineering can expand the utility of pigs for modeling human diseases, and for developing advanced therapeutic approaches. However, the inefficient production of transgenic pigs represents a technological bottleneck. Here, we assessed the hyperactive Sleeping Beauty (SB100X) transposon system for enzyme-catalyzed transgene integration into the embryonic porcine genome. The components of the transposon vector system were microinjected as circular plasmids into the cytoplasm of porcine zygotes, resulting in high frequencies of transgenic fetuses and piglets. The transgenic animals showed normal development and persistent reporter gene expression for >12 months. Molecular hallmarks of transposition were confirmed by analysis of 25 genomic insertion sites. We demonstrate germ-line transmission, segregation of individual transposons, and continued, copy number-dependent transgene expression in F1-offspring. In addition, we demonstrate target-selected gene insertion into transposon-tagged genomic loci by Cre-loxP-based cassette exchange in somatic cells followed by nuclear transfer. Transposase-catalyzed transgenesis in a large mammalian species expands the arsenal of transgenic technologies for use in domestic animals and will facilitate the development of large animal models for human diseases

Characterization of dendritic growth in Fe-C system using time-resolved X-ray tomography and physics-based filtering

Joint 5th International Conference on Advances in Solidification Processes (ICASP-5) & 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining (CSSCR-5), 17–21 June 2019, Salzburg, AustriaTime-resolved in situ tomography of dendritic growth in Fe–0.45 mass% C carbon steel was performed using synchrotron radiation X-rays at SPring-8 synchrotron radiation facility (Japan) with improvement of the image quality using a physics-based filter. The voxel size of the reconstructed image was approximately 6.5 μm × 6.5 μm × 6.5 μm, and the time resolution (duration of 360° rotation) was 4 s (0.25 rps). Three-dimensional images of the dendrites were reconstructed even without image processing; however, the low contrast resolution in Fe–C alloys led to poor image quality. Consequently, it was impossible to precisely track the solid/liquid interface or evaluate the average curvature. To improve the image quality, a physics-based filter (a PF filter) was developed using a phase-field model. In the PF filter, images were retrieved in terms of interface curvature. The PF filter significantly improved the computed tomography image quality. As a result, dendritic growth was clearly observed even in Fe–C alloys. Moreover, the average curvature of the solid/liquid interface was evaluated as a function of solidification time (solid fraction). The ability to systematically characterize growing dendrites will be beneficial for modeling and simulation of solidification phenomena

An analysis of root biomass in a sapling cultivation experiment for afforestation on salt affected land

The purpose of this study is to analyze the data of root biomasses measured in a sapling cultivation experiment reported by Oda et al. (2009). In the experiment, Eucalyptus rudis × E. camaldulensis, E. camaldulensis and E. sargentii were cultivated in a glasshouse at Tsukuba, Japan, and those were watered with 0, 100 and 200 mmol-NaCl/L solution. The dry weight of the roots tended to decrease with increase of NaCl concentration. The significant relationship were observed between the tree height and the dry weight of the roots (r = 0.818-0.851, p < 0.001). These suggest that the root biomass of the tree species may be able to be estimated by the allometry equations. The biomass ratios of the root to the shoot did not increase with NaCl concentration despite that the reduction of shoot growth is generally much greater than the reduction of root growth under saline condition. The biomass ratio of the root to shoot of Eucalyptus saplings might not increase with NaCl concentration because same tendency was reported by Marcar (1993)

Improvement effect of semi-arid land afforestation on soil environment

Carbon fixation by afforestation in semi-arid land has been proposed as one of the most promising countermeasures against the global warming issue. Our demonstration area for carbon fixation suffered some serious problems, such as salinization and water logging, which we attempted to solve. We tried to reduce the groundwater level by taking advantage of the transpiration of planted trees. The two sites used were identified as D-low and D-high. In this study, the transpiration of planted trees, soil water change, and groundwater level were measured. E. sargentii and E. occidentalis were considered to be optimum. From the analyses of the groundwater and soil water contents, water was found to gather at the D-low site. However, analysis of the Neutron Moisture Meter (NMM) data indicated that the volumetric water content did not rise. Through the transpiration of planted trees, groundwater was absorbed via tree roots located in deep soil. Thus, the groundwater level was expected to decrease, but this decrease was prevented by the collected water. On the other hand, due to afforestation at the D-high site, where it was difficult for water to gather, a decreasing tendency in the amount of groundwater was clearly shown by the volumetric water content. Furthermore, the precipitation water trickled down through the soil surface layer, which was expected to mitigate the salt accumulation in topsoil. Soil improvement effects by afforestation, i.e., desalination and the prevention of water logging through the transpiration of planted trees, were confirmed in our research area