Genome-wide Integrative Analysis of Zika-Virus-Infected Neuronal Stem Cells Reveals Roles for MicroRNAs in Cell Cycle and Stemness.

Zika virus (ZIKV) infection is implicated in severe fetal developmental disorders, including microcephaly. MicroRNAs (miRNAs) post-transcriptionally regulate numerous processes associated with viral infection and neurodegeneration, but their contribution to ZIKV pathogenesis is unclear. We analyzed the mRNA and miRNA transcriptomes of human neuronal stem cells (hNSCs) during infection with ZIKV MR766 and Paraiba strains. Integration of the miRNA and mRNA expression data into regulatory interaction networks showed that ZIKV infection resulted in miRNA-mediated repression of genes regulating the cell cycle, stem cell maintenance, and neurogenesis. Bioinformatics analysis of Argonaute-bound RNAs in ZIKV-infected hNSCs identified a number of miRNAs with predicted involvement in microcephaly, including miR-124-3p, which dysregulates NSC maintenance through repression of the transferrin receptor (TFRC). Consistent with this, ZIKV infection upregulated miR-124-3p and downregulated TFRC mRNA in ZIKV-infected hNSCs and mouse brain tissue. These data provide insights into the roles of miRNAs in ZIKV pathogenesis, particularly the microcephaly phenotype

Kcne4 deletion sex- and age-specifically impairs cardiac repolarization in mice.

Myocardial repolarization capacity varies with sex, age, and pathology; the molecular basis for this variation is incompletely understood. Here, we show that the transcript for KCNE4, a voltage-gated potassium (Kv) channel β subunit associated with human atrial fibrillation, was 8-fold more highly expressed in the male left ventricle compared with females in young adult C57BL/6 mice (P < 0.05). Similarly, Kv current density was 25% greater in ventricular myocytes from young adult males (P < 0.05). Germ-line Kcne4 deletion eliminated the sex-specific Kv current disparity by diminishing ventricular fast transient outward current (Ito,f) and slowly activating K(+) current (IK,slow1). Kcne4 deletion also reduced Kv currents in male mouse atrial myocytes, by >45% (P < 0.001). As we previously found for Kv4.2 (which generates mouse Ito,f), heterologously expressed KCNE4 functionally regulated Kv1.5 (the Kv α subunit that generates IKslow1 in mice). Of note, in postmenopausal female mice, ventricular repolarization was impaired by Kcne4 deletion, and ventricular Kcne4 expression increased to match that of males. Moreover, castration diminished male ventricular Kcne4 expression 2.8-fold, whereas 5α-dihydrotestosterone (DHT) implants in castrated mice increased Kcne4 expression >3-fold (P = 0.01) to match noncastrated levels. KCNE4 is thereby shown to be a DHT-regulated determinant of cardiac excitability and a molecular substrate for sex- and age-dependent cardiac arrhythmogenesis

Analysis of the EMBRACE aperture array antenna by the characteristic Basis Function Method

This paper describes the use of the Characteristic Basis Function Method for the simulation of large phased array antennas for radio astronomy. It will be shown how the antenna effective area and the receiver noise temperature depend on array size. Also the receiving sensitivity Aeff /T sys normalised with respect to the physical area of the array will be shown for different array sizes and scan angles

Polar phonons and spin-phonon coupling in HgCr2S4 and CdCr2S4

Polar phonons of HgCr2S4 and CdCr2S4 are studied by far-infrared spectroscopy as a function of temperature and external magnetic field. Eigenfrequencies, damping constants, effective plasma frequencies and Lyddane-Sachs-Teller relations, and effective charges are determined. Ferromagnetic CdCr2S4 and antiferromagnetic HgCr2S4 behave rather similar. Both compounds are dominated by ferromagnetic exchange and although HgCr2S4 is an antiferromagnet, no phonon splitting can be observed at the magnetic phase transition. Temperature and magnetic field dependence of the eigenfrequencies show no anomalies indicating displacive polar soft mode behavior. However, significant effects are detected in the temperature dependence of the plasma frequencies indicating changes in the nature of the bonds and significant charge transfer. In HgCr2S4 we provide experimental evidence that the magnetic field dependence of specific polar modes reveal shifts exactly correlated with the magnetization showing significant magneto-dielectric effects even at infrared frequencies.Comment: 8 pages, 8 figure

β\beta-Stars or On Extending a Drawing of a Connected Subgraph

We consider the problem of extending the drawing of a subgraph of a given plane graph to a drawing of the entire graph using straight-line and polyline edges. We define the notion of star complexity of a polygon and show that a drawing $\Gamma_H$ of an induced connected subgraph $H$ can be extended with at most $\min\{ h/2, \beta + \log_2(h) + 1\}$ bends per edge, where $\beta$ is the largest star complexity of a face of $\Gamma_H$ and $h$ is the size of the largest face of $H$. This result significantly improves the previously known upper bound of $72|V(H)|$ [5] for the case where $H$ is connected. We also show that our bound is worst case optimal up to a small additive constant. Additionally, we provide an indication of complexity of the problem of testing whether a star-shaped inner face can be extended to a straight-line drawing of the graph; this is in contrast to the fact that the same problem is solvable in linear time for the case of star-shaped outer face [9] and convex inner face [13].Comment: Appears in the Proceedings of the 26th International Symposium on Graph Drawing and Network Visualization (GD 2018