Zonal Velocity Bands and the Solar Activity Cycle

We compare the zonal flow pattern in subsurface layers of the Sun with the distribution of surface magnetic features like sunspots and polar faculae. We demonstrate that in the activity belt, the butterfly pattern of sunspots coincides with the fast stream of zonal flows, although part of the sunspot distribution does spill over to the slow stream. At high latitudes, the polar faculae and zonal flow bands have similar distributions in the spatial and temporal domains.Comment: To appear in Solar Physic

The 35S U5 snRNP is generated from the activated spliceosome during In vitro splicing

Primary gene transcripts of eukaryotes contain introns, which are removed during processing by splicing machinery. Biochemical studies In vitro have identified a specific pathway in which introns are recognised and spliced out. This occurs by progressive formation of spliceosomal complexes designated as E, A, B, and C. The composition and structure of these spliceosomal conformations have been characterised in many detail. In contrast, transitions between the complexes and the intermediates of these reactions are currently less clear. We have previously isolated a novel 35S U5 snRNP from HeLa nuclear extracts. The protein composition of this particle differed from the canonical 20S U5 snRNPs but was remarkably similar to the activated B* spliceosomes. Based on this observation we have proposed a hypothesis that 35S U5 snRNPs represent a dissociation product of the spliceosome after both transesterification reactions are completed. Here we provide experimental evidence that 35S U5 snRNPs are generated from the activated B* spliceosomes during In vitro splicing

Fingerprints of Spin-Orbital Physics in Crystalline O2_2

The alkali hyperoxide KO$_2$ is a molecular analog of strongly-correlated systems, comprising of orbitally degenerate magnetic O$_2^-$ ions. Using first-principles electronic structure calculations, we set up an effective spin-orbital model for the low-energy \textit{molecular} orbitals and argue that many anomalous properties of KO$_2$ replicate the status of its orbital system in various temperature regimes.Comment: 4 pages, 2 figures, 1 tabl

Spin States of Cobalt Ions in the Bulk and on the Surface of LaCoO3 Probed by X-ray Absorption, Emission, and Photoelectron Spectra

We present X-ray photoelectron, Co L2,3 and O K X-ray absorption, as well as Co Kβ1,3 X-ray emission spectroscopy results of studies of the spin states of trivalent cobalt ions in single-crystal cobaltite LaCoO3. We show that at room temperature, in the bulk of a LaCoO3 single crystal, Co3+ ions are in the low-spin state, while high-spin Co2+, high-spin Co3+, low-spin Co3+ , and probably also intermediate-spin Co3+ ions are localated on the surface

Localized States at Zigzag Edges of Multilayer Graphene and Graphite Steps

We report the existence of zero energy surface states localized at zigzag edges of $N$-layer graphene. Working within the tight-binding approximation, and using the simplest nearest-neighbor model, we derive the analytic solution for the wavefunctions of these peculiar surface states. It is shown that zero energy edge states in multilayer graphene can be divided into three families: (i) states living only on a single plane, equivalent to surface states in monolayer graphene; (ii) states with finite amplitude over the two last, or the two first layers of the stack, equivalent to surface states in bilayer graphene; (iii) states with finite amplitude over three consecutive layers. Multilayer graphene edge states are shown to be robust to the inclusion of the next nearest-neighbor interlayer hopping. We generalize the edge state solution to the case of graphite steps with zigzag edges, and show that edge states measured through scanning tunneling microscopy and spectroscopy of graphite steps belong to family (i) or (ii) mentioned above, depending on the way the top layer is cut.Comment: 6 pages, 4 figure

Higher Fano manifolds

In this paper we address Fano manifolds with positive higher Chern characters. They are expected to enjoy stronger versions of several of the nice properties of Fano manifolds. For instance, they should be covered by higher dimensional rational varieties, and families of higher Fano manifolds over higher dimensional bases should admit meromorphic sections (modulo the Brauer obstruction). Aiming at finding new examples of higher Fano manifolds, we investigate positivity of higher Chern characters of rational homogeneous spaces. We determine which rational homogeneous spaces of Picard rank $1$ have positive second Chern character, and show that the only rational homogeneous spaces of Picard rank $1$ having positive second and third Chern characters are projective spaces and quadric hypersurfaces. We also classify Fano manifolds of large index having positive second and third Chern characters. We conclude by discussing conjectural characterizations of projective spaces and complete intersections in terms of these higher Fano conditions

Rapid generation of endogenously driven transcriptional reporters in cells through CRISPR/Cas9

CRISPR/Cas9 technologies have been employed for genome editing to achieve gene knockouts and knock-ins in somatic cells. Similarly, certain endogenous genes have been tagged with fluorescent proteins. Often, the detection of tagged proteins requires high expression and sophisticated tools such as confocal microscopy and flow cytometry. Therefore, a simple, sensitive and robust transcriptional reporter system driven by endogenous promoter for studies into transcriptional regulation is desirable. We report a CRISPR/Cas9-based methodology for rapidly integrating a firefly luciferase gene in somatic cells under the control of endogenous promoter, using the TGFβ-responsive gene PAI-1. Our strategy employed a polycistronic cassette containing a non-fused GFP protein to ensure the detection of transgene delivery and rapid isolation of positive clones. We demonstrate that firefly luciferase cDNA can be efficiently delivered downstream of the promoter of the TGFβ-responsive gene PAI-1. Using chemical and genetic regulators of TGFβ signalling, we show that it mimics the transcriptional regulation of endogenous PAI-1 expression. Our unique approach has the potential to expedite studies on transcription of any gene in the context of its native chromatin landscape in somatic cells, allowing for robust high-throughput chemical and genetic screens

Arquivar atividades em termos de autenticidade de documentos eletrônicos e variação do número de cópias

The article is devoted to the problems of archive activity during the digital era, which are conditioned from the authors' point of view by the introduction of electronic documents that have changed the content of paperwork and archiving key categories - authenticity and copy number variation, as well as related originality and authenticity. The technologies of work in the archive, always considered as a unique system of originals are based on the traditional understanding of these categories. Using the method of expert assessments during the determination of key category content, the authors conclude that the current activity of the archives is aimed at copy production activity increase, their management and the provision of authenticity, reliability, integrity and suitability for use. Nowadays the issue of document archiving requires the consolidation of state and non-state structure efforts to develop a new attitude to the authenticity of electronic documents, to change the usual nature of archival institution interaction with users and interested citizens, state authorities and administration, law enforcement and judicial system.El artículo está dedicado a los problemas de la actividad de archivo durante la era digital, que están condicionados desde el punto de vista de los autores por la introducción de documentos electrónicos que han cambiado el contenido del papeleo y las categorías clave de archivo: autenticidad y variación del número de copias, como así como la originalidad y autenticidad relacionadas. Las tecnologías de trabajo en el archivo, siempre consideradas como un sistema único de originales, se basan en el entendimiento tradicional de estas categorías. Usando el método de evaluaciones de expertos durante la determinación del contenido de la categoría clave, los autores concluyen que la actividad actual de los archivos está dirigida a aumentar la actividad de producción de copias, su gestión y la provisión de autenticidad, confiabilidad, integridad y adecuación para su uso. Hoy en día, el tema del archivo de documentos requiere la consolidación de los esfuerzos de la estructura estatal y no estatal para desarrollar una nueva actitud hacia la autenticidad de los documentos electrónicos, para cambiar la naturaleza habitual de la interacción de la institución archivística con los usuarios y ciudadanos interesados, las autoridades estatales, la administración y la ley.O artigo é dedicado aos problemas da atividade de arquivo durante a era digital, eles são condicionados a partir do ponto de vista dos autores para a introdução de documentos eletrônicos que mudaram o conteúdo de documentos e categorias de arquivos-chave: autenticidade e variação do número de cópias, bem como a originalidade e autenticidade relacionadas. Tecnologias de trabalho no arquivo, sempre considerado como um único sistema original, com base no entendimento tradicional destas categorias. Usando o método de avaliações de peritos para a determinação da categoria-chave, os autores concluem que a atividade de arquivos atual visa aumentar cópias atividade de produção, gestão e prestação de autenticidade, confiabilidade, integridade e adequação para uso. Hoje, a questão do arquivamento de documentos requer a consolidação dos esforços de estruturas estatais e não-estatais para desenvolver uma nova atitude em relação à autenticidade dos documentos eletrônicos, para mudar a natureza habitual da interação da instituição de arquivo utilizadores e cidadãos interessados, autoridades estatais, administração e direito

Interaction Between Superconducting and Ferromagnetic Order Parameters in Graphite-Sulfur Composites

The superconductivity of graphite-sulfur composites is highly anisotropic and associated with the graphite planes. The superconducting state coexists with the ferromagnetism of pure graphite, and a continuous crossover from superconducting to ferromagnetic-like behavior could be achieved by increasing the magnetic field or the temperature. The angular dependence of the magnetic moment m(alpha) provides evidence for an interaction between the ferromagnetic and the superconducting order parameters.Comment: 11 pages, 4 figures, to be published in Phys. Rev.

Magnetic properties of carbon phases synthesized using high pressure-high temperature treatment

Two sets of samples were synthesized at 3.5 GPa near the point of C60 cage collapse at different annealing times. A clear structural transformation from mixture of C60 polymeric phases to graphite-like hard carbon phase was confirmed by X-ray diffraction and Raman spectroscopy. Magnetic force microscopy and superconducting quantum interference device were used to characterize the magnetic properties of the synthesized samples. We found that the sample preparation conditions used in this study are not suitable to produce bulk magnetic carbon.Comment: 26 pages, 7 figure