Slow Fetal Heart Rate before Miscarriage in the Early First Trimester Predicts Fetal Aneuploidy in Women with Recurrent Pregnancy Loss

Establishing whether miscarriages result from fetal aneuploidy or other factors is important for treating recurrent pregnancy loss. We examined the relationship between fetal heart rate (FHR) before miscarriage in the early first trimester and fetal karyotype, analyzing 223 pregnant women with recurrent pregnancy loss. Among the pregnancies, 110 resulted in live births regarded as normal karyotype (the Norm-group). The other 113 pregnancies ended in miscarriage, and we categorized them into groups based on fetal karyotype, determined by chorionic villus sampling: the Misc-NK (normal karyotype) group, n=35 euploid cases; the Misc-CA1 (chromosomal abnormality) group, n=18 cases of aneuploidy with trisomies 13/18/21, Turner’s syndrome, or Klinefelter’s syndrome; and the Misc-CA2 subgroup, n=60 cases of other aneuploidies excluding those in the Misc-CA1 group. We compared the groups’ regression line slopes and intercepts for FHR by an analysis of covariance. The FHRs of the Norm, Misc-NK and Misc-CA1 groups increased from 36 to 49 days after fertilization, but did not significantly differ across these groups. The Misc-CA2 group’s FHR did not increase and significantly differed from the other three groups (p<0.01). These results suggest that the absence of an increase in FHR in early pregnancy may indicate the presence of chromosomal abnormalities causing miscarriage

Strong atomic ordering in Gd-doped GaN

Gd-doped GaN (Ga 1-xGd xN) thin films were grown on a GaN(001) template by radio frequency plasma-assisted molecular beam epitaxy and characterized by means of x-ray diffraction (XRD) and transmission electron microscopy (TEM). Three samples with a different Gd composition were prepared in this study: x = 0.02, 0.05, and 0.08. XRD and TEM results revealed that the low Gd concentration GaN possesses the wurtzite structure. On the other hand, it was found that an ordered phase with a quadruple-periodicity along the [001] direction in the wurtzite structure is formed throughout the film with x = 0.08. We proposed the atomistic model for the superlattice structure observed here. © 2012 American Institute of Physics.Manabu Ishimaru, Kotaro Higashi, Shigehiko Hasegawa, Hajime Asahi, Kazuhisa Sato, and Toyohiko J. Konno, "Strong atomic ordering in Gd-doped GaN", Appl. Phys. Lett. 101, 101912 (2012) https://doi.org/10.1063/1.4751245

Warm and Dense Molecular Gas in the N159 Region: 12CO J=4-3 and 13CO J=3-2 Observations with NANTEN2 and ASTE

New 12CO J=4-3 and 13CO J=3-2 observations of the N159 region in the Large Magellanic Cloud have been made. The 12CO J=4-3 distribution is separated into three clumps. These new measurements toward the three clumps are used in coupled calculations of molecular rotational excitation and line radiation transfer, along with other transitions of the 12CO as well as the isotope transitions of 13CO. The temperatures and densities are determined to be ~70-80K and ~3x10^3 cm-3 in N159W and N159E and ~30K and ~1.6x10^3 cm-3 in N159S. These results are compared with the star formation activity. The N159E clump is associated with embedded cluster(s) as observed at 24 micron and the derived high temperature is explained as due to the heating by these sources. The N159E clump is likely responsible for a dark lane in a large HII region by the dust extinction. The N159W clump is associated with embedded clusters mainly toward the eastern edge of the clump only. These clusters show offsets of 20"-40" from the 12CO J=4-3 peak and are probably responsible for heating indicated by the derived high temperature. The N159W clump exhibits no sign of star formation toward the 12CO J=4-3 peak position and its western region. We suggest that the N159W peak represents a pre-star-cluster core of ~105M_sol which deserves further detailed studies. Note that recent star formation took place between N159W and N159E as indicated by several star clusters and HII regions, while the natal molecular gas toward the stars have already been dissipated by the ionization and stellar winds of the OB stars. The N159S clump shows little sign of star formation as is consistent with the lower temperature and somewhat lower density. The N159S clump is also a candidate for future star formation

Evolution of Developmental Programs for the Midline Structures in Chordates: Insights From Gene Regulation in the Floor Plate and Hypochord Homologues of Ciona Embryos

In vertebrate embryos, dorsal midline tissues, including the notochord, the prechordal plate, and the floor plate, play important roles in patterning of the central nervous system, somites, and endodermal tissues by producing extracellular signaling molecules, such as Sonic hedgehog (Shh). In Ciona, hedgehog.b, one of the two hedgehog genes, is expressed in the floor plate of the embryonic neural tube, while none of the hedgehog genes are expressed in the notochord. We have identified a cis-regulatory region of hedgehog.b that was sufficient to drive a reporter gene expression in the floor plate. The hedgehog.b cis-regulatory region also drove ectopic expression of the reporter gene in the endodermal strand, suggesting that the floor plate and the endodermal strand share a part of their gene regulatory programs. The endodermal strand occupies the same topographic position of the embryo as does the vertebrate hypochord, which consists of a row of single cells lined up immediately ventral to the notochord. The hypochord shares expression of several genes with the floor plate, including Shh and FoxA, and play a role in dorsal aorta development. Whole-embryo single-cell transcriptome analysis identified a number of genes specifically expressed in both the floor plate and the endodermal strand in Ciona tailbud embryos. A Ciona FoxA ortholog FoxA.a is shown to be a candidate transcriptional activator for the midline gene battery. The present findings suggest an ancient evolutionary origin of a common developmental program for the midline structures in Olfactores