Tensor correlation in 4He with the tensor-optimized shell model

We study the characteristics of the tensor correlation in $^4$He using a shell model type method. We treat the tensor force explicitly by performing a configuration-mixing calculation in the $2p2h$ basis and include single-particle states up to intermediately high angular momenta. We adopt the Gaussian expansion method for the quantitative description of the spatial shrinkage of the single-particle states to optimize the tensor correlation. We are able to describe the full strength of the tensor correlation for $^4$He in the shell model type method by realizing convergence. We call this model the tensor-optimized shell model. It is found that in $^4$He, three specific $2p2h$ configurations are strongly coupled with the $(0s)^4$ configuration due to the characteristic features of the tensor operator.Comment: 18 pages, 8 figures, Changed content, To be Published in Prog. Theor. Phys. 117(2007

NaCl-dependent formation of the highly crystalline phase in sufficiently hydrated dimyristoylphosphatidylglycerol bilayers

We investigated the low-temperature phase behavior of dimyristoylphosphatidylglycerol (DMPG) bilayers in the presence of high concentration of NaCl (≥100 mM). Differential scanning calorimetry showed that the highly crystalline (HC) phase grew after an initial delay period when DMPG bilayers were sufficiently hydrated and incubated at 1˚C in the presence of more than 100 mM NaCl. The HC phase formation reached a plateau, the level of which depended on NaCl concentration; all the lipids were unable to be in the HC phase at the plateau stage without a quite high concentration of NaCl. Since electron microscopic observations suggested that the HC phase formed coexists with the precursor phases in a closed vesicle, elastic constrain and/or shortage of free sodium ions in the inside of the closed vesicle may prevent the complete transition into the HC phase

Tracing Monopoles and Anti-monopoles in a Magnetic Hedgehog Lattice

The magnetic hedgehog lattice (HL), which was recently discovered in the $B$20-type chiral magnet MnSi$_{1-x}$Ge$_x$, is a topological spin texture with a periodic array of magnetic monopoles and anti-monopoles. Within the continuum approximation, the monopoles and anti-monopoles are predicted to move, collide, and pair annihilate in an applied magnetic field, but it remains unclear how the lattice discretization affects their motions. Here, we study the trajectories of monopoles and anti-monopoles in a lattice system by simulated annealing with field sweep. We show that the monopoles and anti-monopoles move and repel before pair annihilations. We also clarify that their motions are closely related with the field dependence of the scalar spin chirality.Comment: 6 pages, 5 figure

Relationship between quantity of IFNT estimated by IFN-stimulated gene expression in peripheral blood mononuclear cells and bovine embryonic mortality after AI or ET

<p>Abstract</p> <p>Background</p> <p>Interferon tau (IFNT), which is secreted into the uterine cavity during the maternal recognition period (MRP), is a key factor for establishment of pregnancy. The present study aims to clarify the relationship between the ability of a bovine conceptus to produce IFNT during the MRP and the conceptus's ability to establish pregnancy.</p> <p>Methods</p> <p>In the first experiment, IFNT (0, 500, or 1000 micrograms) was administered into the uterine horn ipsilateral to the CL 16 or 17 d after standing estrus, and mRNA levels of IFN-stimulated gene 15-kDa protein (<it>ISG15</it>) and <it>Mx2 </it>in peripheral blood mononuclear cells (PBMCs) were determined. In the second experiment, we investigated <it>ISG15 </it>mRNA expression in PBMCs during the MRP in cattle after either artificial insemination (AI) or embryo transfer (ET).</p> <p>Results</p> <p>Intrauterine administration of IFNT stimulated <it>ISG15 </it>and <it>Mx2 </it>gene expressions in PBMCs in cattle, and there was a positive correlation between the expressions of peripheral markers and the quantity of IFNT administered. In pregnant and normal interestrous interval (< 25 d) cattle (nIEI cattle), expression levels of the <it>ISG15 </it>gene showed similar patterns after AI and ET, and <it>ISG15 </it>mRNA expression was increased in pregnant cattle but unchanged in nIEI cattle. In contrast, <it>ISG15 </it>gene expression in extended interestrous interval (greater than or equal to 25 d) cattle (eIEI cattle) differed after ET compared with AI. In eIEI cattle after ET, <it>ISG15 </it>gene expression increased, such that the value on day 18 was intermediate between those of pregnant and nIEI cattle. In eIEI cattle after AI, <it>ISG15 </it>gene expression did not increase throughout the observation period.</p> <p>Conclusions</p> <p>The results of the current study indicate that the quantity of conceptus-derived IFNT can be estimated by measuring <it>ISG15 </it>mRNA levels in PBMCs from cattle. Using this approach, we demonstrate that <it>ISG15 </it>gene expression during the MRP in eIEI cattle differed after ET compared with AI. In addition, the modest increase in <it>ISG15 </it>gene expression in eIEI cattle after ET suggests that late embryo losses were due to delayed or insufficient growth of the conceptus during the MRP in cattle.</p