Theoretical study of the HS (v',,j' = 1) + O2;(v''=0,j''=1) reaction

We report a theoretical study of the title four-atom reaction for a wide range of translational energies, considering the reactants in the ground vibrational state and also in some vibrationally excited levels of the HS radical. All calculations have employed the quasi-classical trajectory (QCT) method and a reported double many-body expansion potential energy surface for ground electronic state of HSO2. Cross sections as well as specific rate constants for HS elimination are reported and compared with literature data for such processes. To account the zero-point energy problem in QCT calculations, an internal energy quantum mechanics threshold (IEQMT) criteria is used. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 200

Chandra observations of the planetary nebula IC 4593

The ACIS-S camera on board the Chandra X-ray Observatory has been used to discover a hot bubble in the planetary nebula (PN) IC4593, the most distant PN detected by Chandra so far. The data are used to study the distribution of the X-ray-emitting gas in IC 4593 and to estimate its physical properties. The hot bubble has a radius of ~2$^{\prime\prime}$ and is found to be confined inside the optically-bright innermost cavity of IC 4593. The X-ray emission is mostly consistent with that of an optically-thin plasma with temperature $kT\approx0.15$ keV (or $T_\mathrm{X}\approx1.7\times10^{6}$ K), electron density $n_\mathrm{e}\approx15$ cm$^{-3}$, and intrinsic X-ray luminosity in the 0.3-1.5 keV energy range $L_\mathrm{X}=3.4\times10^{30}$ erg s$^{-1}$. A careful analysis of the distribution of hard ($E>$0.8 keV) photons in IC 4593 suggests the presence of X-ray emission from a point source likely associated with its central star (CSPN). If this were the case, its estimated X-ray luminosity would be $L_\mathrm{X,CSPN}=7\times10^{29}$ erg s$^{-1}$, fulfilling the log$(L_\mathrm{X,CSPN}/L_\mathrm{bol})\approx-7$ relation for self-shocking winds in hot stars. The X-ray detection of the CSPN helps explain the presence of high-ionisation species detected in the UV spectra as predicted by stellar atmosphere models.Comment: 6 pages, 4 figures; Accepted to MNRA

Electronic structure near the 1/8-anomaly in La-based cuprates

We report an angle resolved photoemission study of the electronic structure of the pseudogap state in \NdLSCO ($T_c<7$ K). Two opposite dispersing Fermi arcs are the main result of this study. The several scenarios that can explain this observation are discussed.Comment: A high-resolution version can be found at http://lns.web.psi.ch/lns/download/Pockets/arXiv.pd

de Sitter Thick Brane Solution in Weyl Geometry

In this paper, we consider a de Sitter thick brane model in a pure geometric Weyl integrable five-dimensional space-time, which is a generalization of Riemann geometry and is invariant under a so-called Weyl rescaling. We find a solution of this model via performing a conformal transformation to map the Weylian structure into a familiar Riemannian one with a conformal metric. The metric perturbations of the model are discussed. For gravitational perturbation, we get the effective modified P$\ddot{\text{o}}$schl-Teller potential in corresponding Schr$\ddot{\text{o}}$dinger equation for Kaluza-Klein (KK) modes of the graviton. There is only one bound state, which is a normalizable massless zero mode and represents a stable 4-dimensional graviton. Furthermore, there exists a mass gap between the massless mode and continuous KK modes. We also find that the model is stable under the scalar perturbation in the metric. The correction to the Newtonian potential on the brane is proportional to $e^{-3 r \beta/2}/r^2$, where $\beta$ is the de Sitter parameter of the brane. This is very different from the correction caused by a volcano-like effective potential.Comment: 24 pages, 13 figures, published versio

Spectroscopic evidence for preformed Cooper pairs in the pseudogap phase of cuprates

Angle-resolved photoemission on underdoped La$_{1.895}$Sr$_{0.105}$CuO$_4$ reveals that in the pseudogap phase, the dispersion has two branches located above and below the Fermi level with a minimum at the Fermi momentum. This is characteristic of the Bogoliubov dispersion in the superconducting state. We also observe that the superconducting and pseudogaps have the same d-wave form with the same amplitude. Our observations provide direct evidence for preformed Cooper pairs, implying that the pseudogap phase is a precursor to superconductivity

Ubicación de la secuencia repetitiva PFCOL692 en fragmentos genómicos de Plasmodíum falciparum

In this paper we established the subtelomeric localization of the repetitive sequence PFCOL692 of Plasmodium falciparum by the characterization of four clones from a hEMBL41 PFCOL692 genomic library, which contains 15-23Kbp long inserts of parasite genomic DNA. Characterization was made by restriction analysis and the PFCOL692 localization in the genome was explored using specific probes for telomeric (pTB4.1) and subtelomeric regions (pRep20) of P falciparum chromosomes. We proposed a possible organization for the parasite chromosomes ends, where the copies of PFCOL692 are clusters in the subtelomeric region and their localization is conserved with respect to the pRep20 sequence. In addition, we established that PFCOL692 is not located next to the telomere.Las secuencias repetitivas son componentes estructurales de los genomas eucariotes. Se desconoce la función de la mayoría de ellas, pero, al parecer, no son simplemente ADN egoísta sino que intervienen en procesos de recombinación y regulación génica. En este estudio se estableció la localización subtelomérica dela secuencia repetitiva PFCOL692 en los cromosomas de Plasmodium falciparum, a través de la caracterización de cuatro clones de la genoteca ?EMBL4/PFCOL692, que contenían insertos entre 15 y 23Kb de ADN genómico del parásito; esta caracterización se hizo mediante análisis de restricción y la posible ubicación de PFCOL692 en el genoma se exploró utilizando sondas específicas para las regiones telomérica (pTB4.1) y subtelomérica (pRep20) de los cromosomas de P. falciparum. El análisis de los mapas de restricción obtenidos permitió plantear una posible ubicación de PFCOL692 en el extremo de los cromosomas del parásito, donde las copias de esta secuencia se encuentran agrupadas en un segmento del subtelómero y con una posición conservada con respecto a la secuencia pRep20 Se sugiere, además, que PFCOL692 no se encuentra en el limite entre el subtelómero y el telómero

Situación actual y perspectivas de futuro de los productos lacteos vinculados a la raza Payoya

Los productos lácteos derivados de las cabras de raza Payoya, autóctona de suroeste andaluz, presentan potencialidades comerciales debido a sus características organolépticas y a otras características ligadas a su procedencia u origen y al sistema de manejo. En este estudio se analiza la situación actual de estos productos desde los puntos de vista estructural y comercial y se presentan algunos resultados empíricos que demuestran las preferencias de los consumidores andaluces por los quesos de esta raza caprina. Para la promoción de los productos, los ganaderos pueden establecer estrategias como la diferenciación de los productos en cuanto a la excelencia de calidad sensorial objetiva y la puesta en relieve de sus aspectos diferenciales intangibles

Cricetidae (Rodentia, Mammalia) from the oligocene of the valley of Lakes (Mongolia): the genera Aralocricetodon, Eocricetodon, Bagacricetodon, Witenia and Paracricetodon

We describe the remains of Aralocricetodon Bendukidze, 1993; Bagacricetodon Gomes Rodrigues et al., 2012; Eocricetodon Wang, 2007; Witenia de Bruijn et al., 2003 and Paracricetodon Schaub, 1925 (Cricetidae, Rodentia, Mammalia) from the Taatsiin Gol and Taatsiin Tsagaan Nuur areas (Mongolia). The studied material (comprising 128 teeth) stems from 9 localities and 23 fossil layers spanning a time interval from ∼33 to ∼24 Ma (early to late Oligocene) and covering the biozones from A to C1. The general dental pattern between the species from the early and late Oligocene differed. The occlusal pattern of the molars was more complicated and the crowns were lower during the early versus late Oligocene. This indicates a change in diet towards more abrasive plants. Several of the studied species were common in both Europe and Asia Minor during the early Oligocene. The species collected from the late Oligocene have also been recorded in Kazakhstan and China. This indicates an interesting biogeographical pattern that merits future study

Domain wall brane in squared curvature gravity

We suggest a thick braneworld model in the squared curvature gravity theory. Despite the appearance of higher order derivatives, the localization of gravity and various bulk matter fields is shown to be possible. The existence of the normalizable gravitational zero mode indicates that our four-dimensional gravity is reproduced. In order to localize the chiral fermions on the brane, two types of coupling between the fermions and the brane forming scalar is introduced. The first coupling leads us to a Schr\"odinger equation with a volcano potential, and the other a P\"oschl-Teller potential. In both cases, the zero mode exists only for the left-hand fermions. Several massive KK states of the fermions can be trapped on the brane, either as resonant states or as bound states.Comment: 18 pages, 5 figures and 1 table, references added, improved version to be published in JHE

DNA-based Self-Assembly of Chiral Plasmonic Nanostructures with Tailored Optical Response

Surface plasmon resonances generated in metallic nanostructures can be utilized to tailor electromagnetic fields. The precise spatial arrangement of such structures can result in surprising optical properties that are not found in any naturally occurring material. Here, the designed activity emerges from collective effects of singular components equipped with limited individual functionality. Top-down fabrication of plasmonic materials with a predesigned optical response in the visible range by conventional lithographic methods has remained challenging due to their limited resolution, the complexity of scaling, and the difficulty to extend these techniques to three-dimensional architectures. Molecular self-assembly provides an alternative route to create such materials which is not bound by the above limitations. We demonstrate how the DNA origami method can be used to produce plasmonic materials with a tailored optical response at visible wavelengths. Harnessing the assembly power of 3D DNA origami, we arranged metal nanoparticles with a spatial accuracy of 2 nm into nanoscale helices. The helical structures assemble in solution in a massively parallel fashion and with near quantitative yields. As a designed optical response, we generated giant circular dichroism and optical rotary dispersion in the visible range that originates from the collective plasmon-plasmon interactions within the nanohelices. We also show that the optical response can be tuned through the visible spectrum by changing the composition of the metal nanoparticles. The observed effects are independent of the direction of the incident light and can be switched by design between left- and right-handed orientation. Our work demonstrates the production of complex bulk materials from precisely designed nanoscopic assemblies and highlights the potential of DNA self-assembly for the fabrication of plasmonic nanostructures.Comment: 5 pages, 4 figure