ALBERT

Description: 1H 0707–495 is the most convincing example of a supermassive black hole with an X-ray spectrum being dominated by extremely smeared, relativistic reflection, with the additional requirement of strongly supersolar iron abundance. However, here we show that the iron features in its 2–10 keV spectrum are rather similar to the archetypal wind dominated source, PDS 456. We fit all the 2–10 keV spectra from 1H 0707–495 using the same wind model as used for PDS 456, but viewed at higher inclination so that the iron absorption line is broader but not so blueshifted. This gives a good overall fit to the data from 1H 0707–495, and an extrapolation of this model to higher energies also gives a good match to the NuSTAR data. Small remaining residuals indicate that the iron line emission is stronger than in PDS 456. This is consistent with the wider angle wind expected from a continuum-driven wind from the super-Eddington mass accretion rate in 1H 0707–495, and/or the presence of residual reflection from the underlying disc though the presence of the absorption line in the model removes the requirement for highly relativistic smearing, and highly supersolar iron abundance. We suggest that the spectrum of 1H 0707–495 is sculpted more by absorption in a wind than by extreme relativistic effects in strong gravity.

Description: To investigate the nature and origin of across-arc geochemical variations over time in mantle wedge derived magmas, we have carried out a geochemical study of basalts in the NE Japan arc spanning an age range from 35 Ma to the present. Back-arc basalts erupted at 24–18 Ma, 10–8 Ma, 6–3 Ma and 2·5–0 Ma have higher concentrations of both high field strength elements (HFSE) and rare earth elements (REE) [particularly light REE (LREE) and middle REE (MREE)], and higher incompatible trace element ratios compared with frontal-arc basalts at any given time. Geochemical modeling of Nb/Yb versus Nb shows that the frontal-arc and back-arc compositional differences are independent of subduction modification and can, in many cases, be explained by different degrees of melting (higher degrees of melting for frontal-arc magmas and lower degrees of melting for back-arc magmas) of a nearly homogeneous depleted mid-ocean ridge basalt (MORB) mantle (DMM)-like source, although there are several exceptions. These include some Pliocene frontal-arc basalts that may originate from a source that is slightly more depleted than DMM, several 35–32 Ma and 24–18 Ma back-arc basalts derived from a lithospheric mantle source that is enriched in HFSE compared with DMM, and a rare 16–12 Ma basalt that was erupted in the back-arc but was produced by a similar degree of melting to frontal-arc basalts erupted at the same time. Variations in ratios of fluid-mobile and -immobile elements and those of melt-mobile and -immobile elements for the 35–0 Ma NE Japan basalts indicate that the principal subduction component added to the source mantle prior to generation of these basalt magmas is a sediment-derived melt. Comparison of Sr and Nd isotopic compositions for Pacific Ocean MORB, the NE Japan basalts and subducting sediments suggests that the isotopic compositions of most post-16 Ma more depleted back-arc basalts can be explained by the addition of 〈2% bulk sediment; the most enriched isotope compositions of the subcontinental lithosphere-derived magmas can be accounted for by addition of a maximum 5–7% Japan Trench Sediment (JTS), if the original Sr and Nd compositions of the lithosphere approximated that of DMM. The Sr and Nd isotope composition of the frontal-arc basalts can be accounted for by the addition of 1–5% JTS. A depleted asthenospheric mantle (DMM-like) upwelling model with interaction between asthenospheric mantle-derived magmas and overlying lithospheric mantle can account for the geochemical characteristics of the 35–0 Ma NE Japan basalts. The frontal-arc magmas were generally generated by higher degrees of melting of the shallower part of the asthenospheric mantle, whereas the back-arc magmas resulted from lower degrees of melting of the deeper part of asthenospheric mantle. These latter magmas underwent interaction with the lithospheric mantle, resulting in more enriched Sr and Nd isotopic signatures for the pre-18 Ma back-arc basalts and post-22 Ma frontal-arc basalts, but less interaction, resulting in more depleted Sr and Nd isotopic signatures, for most of the back-arc basalts younger than 16 Ma.

Description: In an X-ray reflection spectrum, a tail-like spectral feature generated via Compton downscattering, known as a Compton shoulder (CS), appears at the low-energy side of the iron Kα line. Despite its great diagnostic potential, its use as a spectral probe of the reflector has been seriously limited due to observational difficulties and modelling complexities. We revisit the basic nature of the CS by systematic investigation into its dependence on spatial and temporal parameters. The calculations are performed by Monte Carlo simulations for sphere and slab geometries. The dependence is obtained in a two-dimensional space of column density and metal abundance, demonstrating that the CS solves parameter degeneration between them which was seen in conventional spectral analysis using photoelectric absorption and fluorescence lines. Unlike the iron line, the CS does not suffer from any observational dependence on the spectral hardness. The CS profile is highly dependent on the inclination angle of the slab geometry unless the slab is Compton-thick, and the time evolution of the CS is shown to be useful to constrain temporal information on the source if the intrinsic radiation is variable. We also discuss how atomic binding of the scattering electrons in cold matter blurs the CS profile, finding that the effect is practically similar to thermal broadening in a plasma with a moderate temperature of ~5 eV. Spectral diagnostics using the CS is demonstrated with grating data of X-ray binary GX 301–2, and will be available in future with high-resolution spectra of active galactic nuclei obtained by microcalorimeters.

Description: We have measured the linear polarization of hard X-ray emission from the Crab in a previously unexplored energy interval, 20–120 keV. The introduction of two new observational parameters, the polarization fraction and angle stands to disentangle geometrical and physical effects, thereby providing information on the pulsar wind geometry and magnetic field environment. Measurements are conducted using the PoGOLite Pathfinder – a balloon-borne polarimeter. Polarization is determined by measuring the azimuthal Compton scattering angle of incident X-rays in an array of plastic scintillators housed in an anticoincidence well. The polarimetric response has been characterized prior to flight using both polarized and unpolarized calibration sources. We address possible systematic effects through observations of a background field. The measured polarization fraction for the integrated Crab light curve is $18.4^{+9.8}_{-10.6}$  per cent, corresponding to an upper limit (99 per cent credibility) of 42.4 per cent, for a polarization angle of (149.2 ± 16.0)°.

Description: Cation mixing in positive electrode materials for rechargeable lithium ion batteries, LiNi x Mn 2– x O 4 ( x = 0, 0.2, 0.5) and Li 0.21 Ni 0.7 Mn 1.64 O 4– (denoted as x = 0.7), is analyzed by high-angular-resolution electron-channeling X-ray/electron spectroscopy (HARECXS/HARECES) techniques, using energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy. Mixing between the tetrahedral lithium sites and the octahedral transition metal sites is quantified, and the site-dependent valence states of the transition metals are examined. In the non-doped ( x = 0) sample, Mn was found to occupy only octahedral sites as either Mn 3+ or Mn 4+ . For x = 0.2–0.7, some of the nickel ions (6–13% depending on x ) occupy tetrahedral anti-sites. All the nickel ions are in the divalent state, regardless of the occupation site. For x = 0.2 and 0.7, manganese ions occupy both octahedral and tetrahedral sites; those in the octahedral sites are tetravalent, while the tetrahedral sites contain a mixture of divalent and trivalent ions. For x = 0.5, manganese occupies only the octahedral sites, with all ions determined to be in the tetravalent state (within experimental accuracy). All the samples substantially satisfied the local charge neutrality conditions. This study demonstrates the feasibility of using HARECXS/HARECES for quantitative analysis of the atomic configuration and valence states in lithium manganese oxide spinel materials.

Description: Frontonasal dysplasia (FND) refers to a class of midline facial malformations caused by abnormal development of the facial primordia. The term encompasses a spectrum of severities but characteristic features include combinations of ocular hypertelorism, malformations of the nose and forehead and clefting of the facial midline. Several recent studies have drawn attention to the importance of Alx homeobox transcription factors during craniofacial development. Most notably, loss of Alx1 has devastating consequences resulting in severe orofacial clefting and extreme microphthalmia. In contrast, mutations of Alx3 or Alx4 cause milder forms of FND. Whilst Alx1 , Alx3 and Alx4 are all known to be expressed in the facial mesenchyme of vertebrate embryos, little is known about the function of these proteins during development. Here, we report the establishment of a zebrafish model of Alx -related FND. Morpholino knock-down of zebrafish alx1 expression causes a profound craniofacial phenotype including loss of the facial cartilages and defective ocular development. We demonstrate for the first time that Alx1 plays a crucial role in regulating the migration of cranial neural crest (CNC) cells into the frontonasal primordia. Abnormal neural crest migration is coincident with aberrant expression of foxd3 and sox10 , two genes previously suggested to play key roles during neural crest development, including migration, differentiation and the maintenance of progenitor cells. This novel function is specific to Alx1, and likely explains the marked clinical severity of Alx1 mutation within the spectrum of Alx -related FND.

Description: Sulfatide (HSO 3 -3-galactosylceramide), which enriched in lipid rafts of plasma membranes in various epithelial cell lines, is a critical component of host cells for effective production of influenza A virus. However, the function of sulfatide in other virus infections targeting epithelial cells remains unknown. In this study, the effect of sulfatide on infection of human parainfluenza virus type 3 (hPIV3) was demonstrated by using genetically produced sulfatide-enriched cells and by treatment of hPIV3-infected cells with anti-sulfatide monoclonal antibody (GS-5) as well as by addition of sulfatide to the cells. hPIV3 was found to bind to sulfatide in a virus overlay assay and a solid-phase binding assay. Genetic expression of sulfatide in COS-7 cells defective in sulfatide suppressed initial hPIV3 infection and formation of multinucleate virus-infected cells. Treatment of virus-infected LLC-MK2 cells with GS-5 promoted formation of multinucleate cells. In contrast, exogenous addition of sulfatide to hPIV3-infected COS-7 cells and cells expressing the hPIV3- hemagglutinin-neuraminidase ( HN ) gene and fusion ( F ) gene conspicuously reduced the formation of multinucleate cells. The results suggest that sulfatide negatively regulates the fusion process of hPIV3, possibly through interaction with HN or F glycoprotein on the cell surface.

Description: Late Oligocene to Middle Miocene adakitic andesites are found in the southern part of Okushiri Island, the northern Noto Peninsula and in the Toyama region in the present-day back-arc margin of the SW and NE Japan arcs. On Okushiri Island, adakitic andesite is accompanied by moderately alkaline basalt, whereas on the Noto Peninsula, adakitic andesite has been erupted along with high magnesian andesite (HMA), bronzite andesite and tholeiitic basalt. Adakitic andesites from all three locations are characterized by high Sr/Y and low Y, and have higher MgO contents than adakitic melts generated by experimental melting of metabasalt and amphibolite. They also have higher Ni and Cr contents than either Archaean tonalite–trondhjemite–granodiorite (TTG) suites or Early Cretaceous adakitic granites, which have been attributed to partial melting of subducted oceanic crust. The Noto Peninsula adakitic andesite has Sr and Nd isotopic compositions identical to normal mid-ocean ridge basalt (N-MORB), whereas the Okushiri Island and Toyama adakitic andesites are more isotopically primitive than N-MORB. The Noto Peninsula primary adakitic melt was derived from subducted oceanic N-MORB crust, whereas the Okushiri Island and Toyama primary adakites are interpreted as melts of subducted N-MORB and sediment that have subsequently interacted with the overlying mantle wedge peridotite. To explain the comagmatism of adakite, HMA and basalt, the following model is proposed. A hydrated adakitic diapir ascends from the subducting slab and is heated because it enters the overlying hot mantle wedge. The subsequent establishment of thermal and H 2 O gradients in the adakitic diapir and surrounding mantle wedge peridotite results in concurrent generation of adakitic andesite magma in the inner adakitic diapir region (low temperature and high H 2 O content), HMA and bronzite andesite magmas in the intermediate peridotite region (intermediate temperature and H 2 O content), and tholeiitic basalt magma in the outer peridotite region (high temperature and lower H 2 O content). Comagmatic adakite and mildly alkaline basalt are found in cooler and wetter adakitic diapirs and hotter and drier peridotite regions respectively. The most likely tectono-magmatic situation for the genesis of adakitic magmas in this example of a cool subduction zone involves upwelling of hot asthenosphere into the subcontinental lithosphere beneath the back-arc side of the NE Japan arc and northern end of the SW Japan arc, during the period spanning the pre-Japan Sea opening to syn-opening stages. The unusually high temperature conditions established in the mantle wedge owing to upwelling of hot asthenosphere caused partial melting of the relatively cool subducting Pacific plate, resulting in the generation of adakitic magmas.

Description: As our cyber society develops and expands, the importance of cybersecurity operations is growing in response to cybersecurity threats coming from beyond national borders. Efficient cybersecurity operations require information exchanges that go beyond organizational borders. Various industry specifications defining information schemata for such exchanges are thus emerging. These specifications, however, define their own schemata since their objectives and the types of information they deal with differ, and desirable schemata differ depending on the purposes. They need to be organized and orchestrated so that individual organizations can fully exchange information and collaborate with one another. To establish the foundations of such orchestration and facilitate information exchanges, this paper proposes a reference ontology for cybersecurity operational information. The ontology structures cybersecurity information and orchestrates industry specifications. We built it from the standpoint of cybersecurity operations in close collaboration with cybersecurity organizations including security operation centers handling actual cybersecurity operations in the USA, Japan and South Korea. This paper demonstrates its usability by discussing the coverage of industry specifications. It then defines an extensible information structure that collaborates with such specifications by using the ontology and describes a prototype cybersecurity knowledge base we constructed that facilitates cybersecurity information exchanges among various parties. Finally, it discusses the usage scenarios of the ontology and knowledge base in cybersecurity operations. Through this work, we wish to contribute to the advancement of cybersecurity information exchanges.

Description: Small interfering RNA (siRNA)-based RNA interference (RNAi) is widely used for target gene silencing in various organisms. We previously showed that 8-nt-long 5' proximal nucleotides, which include seed sequence (positions 2–8 from the 5' end of guide strand), and the complementary sequence of the passenger strand are capable of being simultaneously replaced with cognate deoxyribonucleotides without any substantial loss of gene silencing. In the present study, examination was made of RNA requirements in the non-seed region of siRNA. The non-seed region of siRNA was found to be subdivided into four domains, in which two nucleotide pairs (positions 13 and 14) were replaceable with cognate deoxyribonucleotides without reducing RNAi activity. However, RNA sequences at positions 9-12 and 15-18 were essential for effective gene silencing, and these two double-stranded RNA cores are required for binding of the trans -activation response RNA-binding protein (TRBP). The terminal RNA (positions 19–21) provided Argonaute protein binding sites. Argonaute binding was enhanced by the presence of RNAs at positions 15–18. Knockdown experiments showed that, unlike Argonaute and TRBP, Dicer was dispensable for RNAi. Based on these observations, we discuss possible RNA/protein and protein/protein interactions in RNA-induced silencing complex formation.