Direct Observation of Nonequivalent Fermi-Arc States of Opposite Surfaces in Noncentrosymmetric Weyl Semimetal NbP

We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) on noncentrosymmetric Weyl semimetal candidate NbP, and determined the electronic states of both Nb- and P-terminated surfaces corresponding to the "opposite" surfaces of a polar crystal. We revealed a drastic difference in the Fermi-surface topology between the opposite surfaces, whereas the Fermi arcs on both surfaces are likely terminated at the surface projection of the same bulk Weyl nodes. Comparison of the ARPES data with our first-principles band calculations suggests notable difference in electronic structure at the Nb-terminated surface between theory and experiment. The present result opens a platform for realizing exotic quantum phenomena arising from unusual surface properties of Weyl semimetals.Comment: 5 pages, 4 figure

An EST-SSR Linkage Map of Raphanus sativus and Comparative Genomics of the Brassicaceae†

Raphanus sativus (2n = 2x = 18) is a widely cultivated member of the family Brassicaceae, for which genomic resources are available only to a limited extent in comparison to many other members of the family. To promote more genetic and genomic studies and to enhance breeding programmes of R. sativus, we have prepared genetic resources such as complementary DNA libraries, expressed sequences tags (ESTs), simple sequence repeat (SSR) markers and a genetic linkage map. A total of 26 606 ESTs have been collected from seedlings, roots, leaves, and flowers, and clustered into 10 381 unigenes. Similarities were observed between the expression patterns of transcripts from R. sativus and those from representative members of the genera Arabidopsis and Brassica, indicating their functional relatedness. The EST sequence data were used to design 3800 SSR markers and consequently 630 polymorphic SSR loci and 213 reported marker loci have been mapped onto nine linkage groups, covering 1129.2 cM with an average distance of 1.3 cM between loci. Comparison of the mapped EST-SSR marker positions in R. sativus with the genome sequence of A. thaliana indicated that the Brassicaceae members have evolved from a common ancestor. It appears that genomic fragments corresponding to those of A. thaliana have been doubled and tripled in R. sativus. The genetic map developed here is expected to provide a standard map for the genetics, genomics, and molecular breeding of R. sativus as well as of related species. The resources are available at http://marker.kazusa.or.jp/Daikon

The Extracellular Matrix and Blood Vessel Formation: Not Just a Scaffold

The extracellular matrix plays a number of important roles, among them providing structural support and information to cellular structures such as blood vessels imbedded within it. As more complex organisms have evolved, the matrix ability to direct signalling towards the vasculature and remodel in response to signalling from the vasculature has assumed progressively greater importance. This review will focus on the molecules of the extracellular matrix, specifically relating to vessel formation and their ability to signal to the surrounding cells to initiate or terminate processes involved in blood vessel formation

Effect of alloying elements on in-plane ordering and disordering of solute clusters in Mg-based long-period stacking ordered structures: A first-principles analysis

Using density functional theory, we characterized the in-plane binding between L12-type solute clusters in Mg-M-RE (M = Al, Zn; RE = Y, Gd) long-period stacking ordered (LPSO) structures. The difference between the Al and Zn concentrations within the clusters determines whether the intercluster interaction is attractive or repulsive. Incomplete in-plane ordering observed experimentally in Mg-Zn-Y LPSO structures was suggested to be caused by the unlinked nature of the clusters owing to their significant inward contraction. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved