135 research outputs found

    El Bronce Final prefenicio en Huelva según el registro arqueológico del Cabezo de San Pedro. Una revisión cuarenta años después

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    Hace casi cuatro décadas, como importante hito en la investigación histórico-arqueológica de la protohistoria peninsular, miles de fragmentos cerámicos localizados en unos trabajos de desmonte que se realizaban en el Cabezo de San Pedro en Huelva, demostraron la existencia en ese lugar de dos períodos principales del Bronce Final occidental, ambos anteriores a la presencia fenicia. En esos momentos de finales de la década de los años sesenta, un somero estudio de la evolución de las cerámicas locales decoradas con motivos bruñidos y con diseños pintados, permitía establecer la particular evolución del sitio y el contexto de su gradual incorporación al proceso orientalizante primero y posteriormente a la romanización a través del I Milenio a.C. El desarrollo de la investigación en los últimos años facilita ahora puntualizar muchos de los planteamientos que se establecieron en esos momentos, rechazar vías explicativas obsoletas y abrir otras nuevas que deberán contribuir con mayor objetividad a la mejor interpretación de los datos arqueológicos que desde entonces se han obtenido en el conjunto del Suroeste peninsular, para reescribir su Historia.Almost fourty years ago, thousands of pottery sherds discovered in Cabezo de San Pedro in Huelva demonstrated the existence of two historial periods belonging to the Late Bronze Age in this archaeological site, both of which developed well before the arrival of the Phoenicians to the Western Atlantic. In the late 1960s, a preliminary study of the evolution of local pottery decorated with stroke burnished and red painted patterns made it possible to assess the local evolution of the site throughout the first millenium B.C., including the Orientalizing and Romanization processes. Research developments over the last years allow us to qualify previous approaches, rejecting outdated explanations and opening other lines of interpretation that may contribute, with a higher degree of objectivity, to understand the archeological data of the southwest of the Iberian Peninsula in order to rewrite its history

    High-Luminance QD-LED Device With Digital and Dynamic Lighting Functions for Efficient Automotive Systems

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    The work of F. M. Gomez-Campos and S. Rodriguez-Bolivar was supported by the Spanish Junta de Andalucia under Project P18-RT-3303.Thiswork reports the design of a 60-segment photoluminescence quantum dot light emitting device (QD-LED) for automotive lighting systems. The QD-LED device was fabricated using a quantum dot film (QDF), incorporating two kinds of quantum dots (QDs) synthesized to emit at 531 nm (green) and 624 nm (red). When the QDF is excited with blue wavelength at 465 nm, a white color output is obtained. Likewise, by using different color filters, all the automotive lighting functions (interior and exterior) can be achieved. In addition, an electronic control module, based on the state-of-the-art multichannel automotive lighting emitting diode (LED) drivers, was specifically designed to control each segment individually to enable the possibility of external digital communication with the vehicle surroundings. That is key to develop the autonomous vehicle by incorporating what is known as car-to-X communication, used to transmit information to other vehicles and road users through light. Furthermore, this work is remarkable due to the low power consumption of the QD-LED device designed, which implies a high electrical efficiency, something critical for the electrical vehicle development. Besides, figures ofmerit and performance indicators are measured, offering promising values to use this nanotechnology in the next future of the vehicle transportation lighting systems.Junta de Andalucia P18-RT-330

    El poblamiento de la edad del cobre en la tierra llana de Huelva

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    Se presentan en este trabajo los resultados del Proyecto Tierra Llana de Huelva referidos a la ocupación de la Edad del Cobre. Proponemos una permanencia del sistema del poblamiento durante el Calcolítico y Bronce Pleno, y su ruptura hacia el Bronce Final, periodo en el que se estructura el territorio en turno a centros hegemónicos.____________________________They are presented in this work the results of the project Flat Earth of Huelva referred to the occupation of the Copper Age. We propose a permanency of the system of the settlement during the Calcolithic time and Middle-Bronze Age, and their rupture toward the Final Bronze Age, in the one that the territory appears structured to hegemonic centers

    Optical Absorption in N-Dimensional Colloidal Quantum Dot Arrays: Influence of Stoichiometry and Applications in Intermediate Band Solar Cells

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    We present a theoretical atomistic study of the optical properties of non-toxic InX (X = P, As, Sb) colloidal quantum dot arrays for application in photovoltaics. We focus on the electronic structure and optical absorption and on their dependence on array dimensionality and surface stoichiometry motivated by the rapid development of experimental techniques to achieve high periodicity and colloidal quantum dot characteristics. The homogeneous response of colloidal quantum dot arrays to different light polarizations is also investigated. Our results shed light on the optical behaviour of these novel multi-dimensional nanomaterials and identify some of them as ideal building blocks for intermediate band solar cells.Junta de Andalucia P18-RT-3303School of Electronic and Electrical Engineering, University of LeedsUK Research & Innovation (UKRI)Engineering & Physical Sciences Research Council (EPSRC)Junta de Andaluci

    Band-like transport in “green” quantum dot films: The effect of composition and stoichiometry

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    ACKNOWLEDGMENTS This work was undertaken on ARC3, part of the High Performance Computing Facilities at the University of Leeds, UK. P.R. gratefully acknowledges financial support from EPSRC through a Doctoral Training Grant. F.M.G.C., S.R.B., and E.S.S.-G. received financial support from Project No. P18-RT-3303 from the Spanish Junta de Andalucia. M.C. is thankful to the School of Electronic and Electrical Engineering, University of Leeds, for financial support.SUPPLEMENTARY MATERIAL https://www.scitation.org/doi/suppl/10.1063/5.0078375 See the supplementary material for the mobility calculations for the rest of the materials considered here. The lowermost conduction miniband visualization in the reciprocal space is also included, along with the tables of flight times and fitting parameters.Two-dimensional quantum dot (QD) arrays are considered as promising candidates for a wide range of applications that heavily rely on their transport properties. Existing QD films, however, are mainly made of either toxic or heavy-metal-based materials, limiting their applications and the commercialization of devices. In this theoretical study, we provide a detailed analysis of the transport properties of “green” colloidal QD films (In-based and Ga-based), identifying possible alternatives to their currently used toxic counterparts. We show how changing the composition, stoichiometry, and the distance between the QDs in the array affects the resulting carrier mobility for different operating temperatures. We find that InAs QD films exhibit high carrier mobilities, even higher compared to previously modeled CdSe (zb) QD films. We also provide the first insights into the transport properties of properly passivated InP and GaSb QD films and envisage how realistic systems could benefit from those properties. Ideally passivated InP QD films can exhibit mobilities an order of magnitude larger compared to what is presently achievable experimentally, which show the smallest variation with (i) increasing temperature when the QDs in the array are very close and (ii) an increasing interdot distance at low operating temperatures (70 K), among the materials considered here, making InP a potentially ideal replacement for PbS. Finally, we show that by engineering the QD stoichiometry, it is possible to enhance the film’s transport properties, paving the way for the synthesis of higher performance devices.Spanish Junta de AndaluciaEngineering and Physical Sciences Research Council P18-RT-330

    Antioxidant responses related to temozolomide resistance in glioblastoma

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    Ministerio de Ciencia, Innovación y Universidades; Universidad de Málaga CBUA.Glioblastoma remains one of the most challenging and devastating cancers, with only a very small proportion of patients achieving 5-year survival. The current standard of care consists of surgery, followed by radiation therapy with concurrent and maintenance chemotherapy with the alkylating agent temozolomide. To date, this drug is the only one that provides a significant survival benefit, albeit modest, as patients end up acquiring resistance to this drug. As a result, tumor progression and recurrence inevitably occur, leading to death. Several factors have been proposed to explain this resistance, including an upregulated antioxidant system to keep the elevated intracellular ROS levels, a hallmark of cancer cells, under control. In this review, we discuss the mechanisms of chemoresistance -including the important role of glioblastoma stem cells-with emphasis on antioxidant defenses and how agents that impair redox balance (i.e.: sulfasalazine, erastin, CB-839, withaferin, resveratrol, curcumin, chloroquine, and hydroxychloroquine) might be advantageous in combined therapies against this type of cancer.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Hippocampal pallium and map-like memories through vertebrate evolution

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    The hippocampus in humans and other mammals is essential for episodic and relational memories. Comparative evidence indicates that a hippocampal pallium homologue is present in birds, reptiles, amphibians, ray-finned fishes, cartilaginous fishes and agnathans. Some of their characteristics, such as the topological position and the pattern of connectivity, appear remarkably well conserved. We review here substantial data showing that in all the vertebrate groups studied up to date, from fish to mammals, the hippocampus plays a fundamental role in spatial memory. In these vertebrates groups, the hippocampal pallium homologue is involved in the use of map-like, relational representations of the objective space that provide stable allocentric frames of reference, thus allowing flexible navigation. These similarities suggest a common evolutionary ancestry and indicate that the functional properties of the hippocampus appear early in the vertebrate phylogenesis and are retained through the independent evolution of the vertebrate lineages.Ministerio de Economía y Competitividad de España PSI2011-2748

    Wearable System for Biosignal Acquisition and Monitoring Based on Reconfigurable Technologies

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    Wearable monitoring devices are now a usual commodity in the market, especially for the monitoring of sports and physical activity. However, specialized wearable devices remain an open field for high-risk professionals, such as military personnel, fire and rescue, law enforcement, etc. In this work, a prototype wearable instrument, based on reconfigurable technologies and capable of monitoring electrocardiogram, oxygen saturation, and motion, is presented. This reconfigurable device allows a wide range of applications in conjunction with mobile devices. As a proof-of-concept, the reconfigurable instrument was been integrated into ad hoc glasses, in order to illustrate the non-invasive monitoring of the user. The performance of the presented prototype was validated against a commercial pulse oximeter, while several alternatives for QRS-complex detection were tested. For this type of scenario, clustering-based classification was found to be a very robust option.This work was funded by Banco Santander and Centro Mixto UGR-MADOC through project SIMMA (code 2/16). The contribution of Víctor Toral was funded by the University of Granada through a grant from the “Iniciación a la investigación 2016” program. The contribution of Antonio García was partially funded by Spain’s Ministerio de Educación, Cultura y Deporte (Programa Estatal de Promoción del Talento y su Empleabilidad en I+D+i, Subprograma Estatal de Movilidad, within Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016) under a “Salvador de Madariaga” grant (PRX17/00287). The contribution of Francisco J. Romero was funded by Spain’s Ministerio de Educación, Cultura y Deporte under a FPU grant (FPU16/01451). The contribution of Francisco M. Gómez-Campos was funded by Spain’s Ministerio de Economía, Industria y Competitividad under Project ENE2016_80944_R

    Metabolic Adjustments following Glutaminase Inhibition by CB-839 in Glioblastoma Cell Lines

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    Glioblastoma multiforme is the most common primary brain tumor. Unfortunately, it is also one of the cancer types that has the worst morbidity and mortality ratios, so new targets and treatments need to be found. The metabolism of glutamine is fundamental for the proliferation of many tumor cells, including glioblastomas. Glutaminase isoenzyme GLS is one of the responsible enzymes for the pro-oncogenic pathways that induce metabolic reprogramming and leads to altered levels of some amino acids and other key intermediary metabolites in glioblastoma. Using the clinically approved GLS inhibitor CB-839 (Telaglenastat), we found significant changes in glutamine metabolism, including both the oxidative and reductive fates of Gln-derived alpha-ketoglutarate in the tricarboxylic acid cycle, in three glioblastoma cell lines. One of them, the T98G glioblastoma cell line, showed the greatest modification of metabolite levels involved in the de novo biosynthetic pathways for nucleotides, as well as a higher content of methylated and acetylated metabolites.This research was funded by Ministerio de Ciencia y Tecnología of Spain, grant number RTI2018-096866-B-I00 (to J.M.M. and J.M.) and Junta de Andalucía, Grant UMA18-FEDERJA-082 (to J.M.). R.J.D. is supported by the Howard Hughes Medical Institute, the National Cancer Institute (R35CA220444901), the Cancer Prevention and Research Institute of Texas, and the Moody Foundation. J.D.l.S.-J. is granted by FPU17/04084, Ministerio de Ciencia, Innovación y Universidades. Partial funding for open access charge: Universidad de Málag

    Natural and anthropic pollution episodes during the Late Holocene evolution of the Tinto River estuary (SW Spain)

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    This paper investigates the paleoenvironmental evolution of a core extracted in the middle sector of the Tinto River estuary, SW Spain, one of the most polluted areas in the world due to mining over thousands of years (>4 kyr BP) and recent industrial discharges. This evolution includes alluvial sands (>6.4 cal kyr BP), bioclastic sands and silts deposited in subtidal and intertidal channels during and after the Holocene transgression maximum (6.4-4.3 cal kyr BP), the sedimentation of clayey-sandy silts in low and high marshes during the last 2.4 kyr BP and a final anthropic filling. Three sharp peaks of pollution have been detected, representing a) a natural origin during the Holocene transgression; b) the impact of the first mining activities (~4.5 cal kyr BP); and c) the effect of industrial discharge and a new period of mining activity throughout the 19th and 20th centuries. Foraminifera, ostracods and molluscs disappeared during these last two peaks
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