La metalurgia de aleaciones de base cobre en la Península ibérica durante la Edad del Bronce Final: una revisión del sítio de Siriguarach (Alcañiz, Teruel)

Since the 1970s, several exploration works revealed the potential of the Siriguarach final Bronze Age settlement. Two significant facts were noticed: all the moulds were discovered in the same construction. Three of these moulds are affiliated to the Atlantic typology, which is typical of the western regions of France and Iberian Peninsula. So far, the investigations managed to set Siriguarach into the Ebro Valley metallurgical context. Several productive behaviours were identified and all reflect a technical mastery comparable to similar population of the End of the European Bronze Age: some being rudimentary when others are identified as more sophisticated. The typology of the moulds leads us to study internal relationships between the Atlantic regions and the Mediterranean ones. The current investigation shows that not only goods circulated from one area to another, but so did men, techniques, and ideas. Nowadays, Siriguarach is still under study. This site has not revealed its full potential. Thanks to the richness of this settlement, it should be possible to discover more information about the structure and the role assigned to the metallurgical activitiesDifférents travaux de prospections réalisés depuis les années 1970 ont révélé le potentiel du site d’habitat de l’âge du Bronze et du début de l’âge du Fer de Siriguarach. Deux informations ont retenu notre attention : la découverte d’un lot de moules dans une même construction ; l’appartenance de trois de ces moules à la typologie dite atlantique, caractéristique des régions de l’ouest de la péninsule Ibérique et de la France. Les recherches menées jusque-là ont permis de situer Siriguarach dans le contexte de la vallée de l’Ebre et de caractériser sa métallurgie par rapport à celle de ses voisins. Il a été possible d’identifier et de comparer plusieurs comportements productifs, certains très rudimentaires et d’autres plus évolués, mais qui dans tous les cas reflétaient une maîtrise technique comparable au reste de l’Europe du Bronze final. L’étude des relations internes, entre l’Atlantique et la Méditerranée, démontre non seulement la circulation des biens mais également des techniques, des idées et des hommes. Mais le site n’a pas fini de révéler son potentiel. Cette contribution porte sur une réévaluation des matériels qui permet de poser de nouveaux jalons chronologiques et d’établir de nouvelles problématiques concernant l’organisation de l’espace et des activités métallurgique

Large-Scale Asymmetries in the Transitional Disks of SAO 206462 and SR 21

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations in the dust continuum (690 GHz, 0.45 mm) and 12CO J=6-5 spectral line emission, of the transitional disks surrounding the stars SAO 206462 and SR 21. These ALMA observations resolve the dust-depleted disk cavities and extended gaseous disks, revealing large-scale asymmetries in the dust emission of both disks. We modeled these disks structures with a ring and an azimuthal gaussian, where the azimuthal gaussian is motivated by the steady-state vortex solution from Lyra & Lin (2013). Compared to recent observations of HD 142527, Oph IRS 48, and LkHa 330, these are low-contrast (< 2) asymmetries. Nevertheless, a ring alone is not a good fit, and the addition of a vortex prescription describes these data much better. The asymmetric component encompasses 15% and 28% of the total disk emission in SAO 206462 and SR 21 respectively, which corresponds to a lower limit of 2 MJup of material within the asymmetry for both disks. Although the contrast in the dust asymmetry is low, we find that the turbulent velocity inside it must be large (~20% of the sound speed) in order to drive these azimuthally wide and radially narrow vortex-like structures. We obtain residuals from the ring and vortex fitting that are still significant, tracing non-axisymmetric emission in both disks. We compared these submillimeter observations with recently published H-band scattered light observations. For SR 21 the scattered light emission is distributed quite differently from the submillimeter continuum emission, while for SAO 206462 the submillimeter residuals are suggestive of spiral-like structure similar to the near-IR emission.Comment: ApJL, in press. 6 pages, 3 figures, 2 table

Self-assembly of Fmoc-tetrapeptides based on the RGDS cell adhesion motif

Self-assembly in aqueous solution has been investigated for two Fmoc [Fmoc ¼ N-(fluorenyl)-9-methoxycarbonyl] tetrapeptides comprising the RGDS cell adhesion motif from fibronectin or the scrambled sequence GRDS. The hydrophobic Fmoc unit confers amphiphilicity on the molecules, and introduces aromatic stacking interactions. Circular dichroism and FTIR spectroscopy show that the self-assembly of both peptides at low concentration is dominated by interactions among Fmoc units, although Fmoc-GRDS shows b-sheet features, at lower concentration than Fmoc-RGDS. Fibre X-ray diffraction indicates b-sheet formation by both peptides at sufficiently high concentration. Strong alignment effects are revealed by linear dichroism experiments for Fmoc-GRDS. Cryo-TEM and smallangle X-ray scattering (SAXS) reveal that both samples form fibrils with a diameter of approximately 10 nm. Both Fmoc-tetrapeptides form self-supporting hydrogels at sufficiently high concentration. Dynamic shear rheometry enabled measurements of the moduli for the Fmoc-GRDS hydrogel, however syneresis was observed for the Fmoc-RGDS hydrogel which was significantly less stable to shear. Molecular dynamics computer simulations were carried out considering parallel and antiparallel b-sheet configurations of systems containing 7 and 21 molecules of Fmoc-RGDS or Fmoc-GRDS, the results being analyzed in terms of both intermolecular structural parameters and energy contributions

Calcium-sensing receptor antagonism or lithium treatment ameliorates aminoglycoside-induced cell death in renal epithelial cells

AbstractThe aminoglycoside antibiotic gentamicin elicits proximal tubular toxicity and cell death. In calcium-sensing receptor (CaR)-transfected HEK-293 (CaR-HEK) cells and CaR-expressing proximal tubule-derived opossum kidney (OK) cells, chronic gentamicin treatment elicits dose-dependent, caspase-mediated apoptotic cell death. Here we investigated whether the renal cell toxicity of the CaR agonist gentamicin could be prevented by CaR antagonism or by lithium cotreatment which may interfere with receptor-mediated signalling. Chronic treatment of OK and CaR-HEK cells with low concentrations of gentamicin elicited cell death, an effect that was ameliorated by cotreatment with the CaR negative allosteric modulator (calcilytic) NPS-89636. This calcilytic also attenuated CaR agonist-induced ERK activation in these cells. In addition, 1 mM LiCl, equivalent to its therapeutic plasma concentration, also inhibited gentamicin-induced toxicity in both cell types. This protective effect of lithium was not due to the disruption of phosphatidylinositol-mediated gentamicin uptake as the cellular entry of Texas red-conjugated gentamicin into OK and CaR-HEK cells was unchanged by lithium treatment. However, the protective effect of lithium was mimicked by glycogen synthase 3β inhibition. Together, these data implicate CaR activation and a lithium-inhibitable signalling pathway in the induction of cell death by gentamicin in renal epithelial cells in culture

Microscale coiling in bis-imidazolium supramolecular hydrogel fibres induced by release of a cationic serine protease inhibitor

Gels formed by a gemini dicationic amphiphile incorporate a serine protease inhibitor, which could be used in a new approach to the treatment of Rosacea, within the fibres as well as in the space between them, affecting a number of gel properties but most importantly inducing remarkable fibre coiling at the microscopic level as a result of drug release from the gel. Drug release and skin permeation experiments show its potential for topical administration

La comunicación en el aula de sétimo año

Reflections on communication in the learning process at the level of the seventh year of secondary education based on the methodological and pedagogical approaches, considered in research of a multidisciplinary team of the CIDE of UNA (National University), with the aim of building the “teaching performance profile for the seventh year of Costa Rican education”. It demonstrates the role of teachers to ensure favorable communication links to the learning process, not only to capture the attention and interest of students through varied and systematic motivations, but also by the honesty, openness, personal example and involvement in the task, problems and aspirations of students.Recibido 31 de julio de 2009 • Aceptado 14 de setiembre de 2009 • Corregido 17 de junio de 2010 &nbsp; &nbsp; &nbsp; Reflexiones sobre la comunicación en el proceso de aprendizaje en el nivel del sétimo año de la educación secundaria, con base en los abordajes metodológico y pedagógico, apreciados en investigación de un equipo interdisciplinario del CIDE de la UNA, con el objetivo de construir el “Perfil de desempeño docente para el 7mo año de la educación costarricense”. Se evidencia el protagonismo del cuerpo docente para lograr vínculos comunicativos favorables al proceso de aprendizaje, donde no bastaba con captar la atención y el interés del estudiantado a través de variadas y sistemáticas motivaciones, sino también la honestidad, receptividad, ejemplo personal e involucramiento en el quehacer, problemáticas y aspiraciones del estudiantado

Characterization of endogenous Kv1.3 channel isoforms in T cells

Producción CientíficaVoltage-dependent potassium channel Kv1.3 plays a key role on T-cell activation; however, lack of reliable antibodies has prevented its accurate detection under endogenous circumstances. To overcome this limitation, we created a Jurkat T-cell line with endogenous Kv1.3 channel tagged, to determine the expression, location, and changes upon activation of the native Kv1.3 channels. CRISPR-Cas9 technique was used to insert a Flag-Myc peptide at the C terminus of the KCNA3 gene. Basal or activated channel expression was studied using western blot analysis and imaging techniques. We identified two isoforms of Kv1.3 other than the canonical channel (54 KDa) differing on their N terminus: a longer isoform (70 KDa) and a truncated isoform (43 KDa). All three isoforms were upregulated after T-cell activation. We focused on the functional characterization of the truncated isoform (short form, SF), because it has not been previously described and could be present in the available Kv1.3−/− mice models. Overexpression of SF in HEK cells elicited small amplitude Kv1.3-like currents, which, contrary to canonical Kv1.3, did not induce HEK proliferation. To explore the role of endogenous SF isoform in a native system, we generated both a knockout Jurkat clone and a clone expressing only the SF isoform. Although the canonical isoform (long form) localizes mainly at the plasma membrane, SF remains intracellular, accumulating perinuclearly. Accordingly, SF Jurkat cells did not show Kv1.3 currents and exhibited depolarized resting membrane potential (VM), decreased Ca2+ influx, and a reduction in the [Ca2+]i increase upon stimulation. Functional characterization of these Kv1.3 channel isoforms showed their differential contribution to signaling pathways involved in formation of the immunological synapse. We conclude that alternative translation initiation generates at least three endogenous Kv1.3 channel isoforms in T cells that exhibit different functional roles. For some of these functions, Kv1.3 proteins do not need to form functional plasma membrane channels.Ministerio de Economía y Competitividad (grant PID 2020‐118517RB‐I00)Junta de Castilla y León (grants VA172P20) and (CLU-2019-02)Funds from Institut Curie, INSERM,Agence Nationale de la Recherche RetroTact (ANR‐20CE15‐0009‐01,ANR‐10‐IDEX‐0001‐02 PSL*, and ANR‐11‐LABX‐0043)Fondation pour la Recherche Médicale FRM (EQU202003010280

Spiral Density Waves in a Young Protoplanetary Disk

Gravitational forces are expected to excite spiral density waves in protoplanetary disks, disks of gas and dust orbiting young stars. However, previous observations that showed spiral structure were not able to probe disk midplanes, where most of the mass is concentrated and where planet formation takes place. Using the Atacama Large Millimeter/submillimeter Array we detected a pair of trailing symmetric spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. The arms extend to the disk outer regions and can be traced down to the midplane. These millimeter-wave observations also reveal an emission gap closer to the star than the spiral arms. We argue that the observed spirals trace shocks of spiral density waves in the midplane of this young disk.Comment: This is our own version of the manuscript, the definitive version was published in Science (DOI: 10.1126/science.aaf8296) on September 30, 2016. Posted to the arxiv for non-commercial us