71 research outputs found

    On identifying Palaeolithic single occupation episodes: archaeostratigraphic and technological approaches to the Neanderthal lithic record of stratigraphic unit xa of El Salt (Alcoi, eastern Iberia)

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    Within the framework of archaeological palimpsest dissection, stratigraphic association of lithic remains with hearths and other archaeological materials in undisturbed Neanderthal contexts allows us to seek patterns in lithic and faunal assemblage composition, assess the degree of time averaging within assemblages and investigate the spatial distribution of archaeological remains. So far, the European Neanderthal record shows variability in such spatial parameters, not only among different geographic regions but also across time. This approach has been employed to draw conclusions about the main features of Neanderthal occupations from in situ archaeological contexts within individual site sequences. As contribution to this topic, we present new results from our ongoing archaeostratigraphic investigation of stratigraphic unit xa from El Salt (Alcoi, Alacant, eastern Iberia). Our previous study, based on stratigraphic analysis of the lithic record consisting of raw material units, yielded several micropalimpsests within unit xa. Here, we carry out further technological and spatial analysis of the micropalimpsest units. The results obtained from it suggest that we may be able, in specific cases, to recognise indicators of diachrony within the context of these archaeostratigraphic units. This confirms the existence of a micropalimpsest, and suggests that we have the chance to find analytical frames that are even closer to the human temporal scale than the AU. This should be the target of future interdisciplinary behavioural study of El Salt unit xa. This work illustrates the potential of a spatial and archaeostratigraphic approach to stone tool technology and brings to light the importance of archaeological palimpsest dissection as a first step for behavioural analysis in Palaeolithic research.Archaeological excavations at El Salt rockshelter are funded by the Spanish central government through the project called Neandertales en la montaña alicantina: un enfoque multianalítico (MEC-FEDER HAR2015-68321-P), and by the Valencian autonomous government through public research funding (DOGV P-0300900-H). One of the authors (AM) is also funded by Universitat d’Alacant through a university faculty formation grant (UAFPU 2018-049)

    Optimization of the Multi-Spectral Euclidean Distance Calculation for FPGA-based Spaceborne Systems

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    Due to the high quantity of operations that spaceborne processing systems must carry out in space, new methodologies and techniques are being presented as good alternatives in order to free the main processor from work and improve the overall performance. These include the development of ancillary dedicated hardware circuits that carry out the more redundant and computationally expensive operations in a faster way, leaving the main processor free to carry out other tasks while waiting for the result. One of these devices is SpaceCube, a FPGA-based system designed by NASA. The opportunity to use FPGA reconfigurable architectures in space allows not only the optimization of the mission operations with hardware-level solutions, but also the ability to create new and improved versions of the circuits, including error corrections, once the satellite is already in orbit. In this work, we propose the optimization of a common operation in remote sensing: the Multi-Spectral Euclidean Distance calculation. For that, two different hardware architectures have been designed and implemented in a Xilinx Virtex-5 FPGA, the same model of FPGAs used by SpaceCube. Previous results have shown that the communications between the embedded processor and the circuit create a bottleneck that affects the overall performance in a negative way. In order to avoid this, advanced methods including memory sharing, Native Port Interface (NPI) connections and Data Burst Transfers have been used

    Evaluación de los productos de la reducción de un concentrado cromífero en la obtención de recubrimientos difusivos de carburos de cromo

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    Las materias primas tradicionalmente utilizadas como fuentes portadoras de cromo (ferrocromo, cromo en polvo y óxido de cromo) en procesos de cromado difusivo presentan un elevado costo y en el caso del ferrocromo, dificultades para su trituración. En el trabajo se realiza una evaluación del efecto que posee el uso de los productos de la reducción aluminotérmica de un concentrado cromífero sobre las características y propiedades de recubrimientos difusivos de carburos complejos de cromo. Para evaluar los recubrimientos se utilizaron ensayos de Microscopia Óptica, Microdurometría, Difracción de Rayos X y Energía Dispersiva de Rayos X. Se determinó que la aplicación de tratamientos difusivos empleando un régimen de tratamiento de 1 000 oC – 4 h permite obtener recubrimientos de carburos complejos de cromo en los tres sustratos investigados (acero AISI 1055, acero para herramientas W108 y un hierro fundido gris). Las capas obtenidas no difieren por su morfología de las reportadas en trabajos precedentes y se caracterizan por poseer similar microdureza, así como espesores análogos o superiores a los alcanzados empleando fuentes portadoras de cromo convencionales en los procesos de cromado difusivo. Los recubrimientos también se destacan por sus elevados contenidos de cromo (entre 65 y 71 % en el caso del acero AISI 1055). Además, se comprobó que las mezclas elaboradas con los productos de la reducción del concentrado cromífero poseen la capacidad de aportar el cromo necesario para el normal desarrollo del proceso difusivo y que tienen una durabilidad, en las condiciones experimentales utilizada

    An instance of Neanderthal mobility dynamics: a lithological approach to the flint assemblage from stratigraphic unit VIII of El Salt rockshelter (Alcoi, eastern Iberia)

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    The relationship between hunter-gatherer group mobility and lithic raw material procurement strategies is central to the study of Neanderthal productive behaviours. In this framework, determination of flint procurement sources through lithological analysis is key to infer Neanderthal group mobility patterns. El Salt rockshelter (Alcoi, Alacant, eastern Iberia) features different nearby flint sources, including primary outcrops and secondary deposits containing flint. In this study, we sourced the stratigraphic unit viii archaeological flint assemblage based on identification of geogenic and postgenetic lithological traits. Our results indicate that flint procurement at El Salt during the stratigraphic unit viii Neanderthal occupations was mainly linked to Pleistocene secondary deposits along the upper and middle courses of Serpis river. The artefacts were made predominantly on alluvially reworked nodules of different flint types. Connecting these procurement areas with their corresponding knapping products reveals a direct relationship between flint-source distance and degree of technical intervention, and defines a hypothetically unidirectional series of rivershore itineraries of procurement.This work has been accomplished during the valid period of the research project titled Clima e interacciones humanas en el Mediterráneo central ibérico durante el MIS 4 (IBEMIS4), granted by the Spanish central government (PID2019-107113RB-I00). The first author (AM) is funded by Universitat d’Alacant through a university faculty formation grant (UAFPU2018-049). The second (SSR) and the fourth (LP) are funded by the Valencian autonomous government through a predoctoral research-staff contracting grant (ACIF/2021/407) and a postdoctoral research-staff contracting grant (APOSTD/2020/202), respectively

    Multidisciplinary evidence of an isolated Neanderthal occupation in Abric del Pastor (Alcoi, Iberian Peninsula)

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    Testing Neanderthal behavioural hypotheses requires a spatial–temporal resolution to the level of a human single occupation episode. Yet, most of the behavioural data on Neanderthals has been obtained from coarsely dated, time-averaged contexts affected by the archaeological palimpsest effect and a diversity of postdepositional processes. This implies that time-resolved Neanderthal behaviour remains largely unknown. In this study, we performed archaeostratigraphic analysis on stratigraphic units ive, ivf, ivg, va, vb and vc from Abric del Pastor (Alcoi, Iberian Peninsula). Further, we isolated the archaeological remains associated with the resulting archaeostratigraphic unit and applied raw material, technological, use-wear, archaeozoological and spatial analyses. Our results show a low-density accumulation of remains from flintknapping, flint tool-use and animal processing around a hearth. These data provide a time-resolved human dimension to previous high-resolution environmental and pyrotechnological data on the same hearth, representing the first comprehensive characterisation of a Neanderthal single occupation episode. Our integrated, multidisciplinary method also contributes to advance our understanding of archaeological record formation processes.This paper has been developed during the research project Clima e interacciones humanas en el Mediterráneo central ibérico durante el MIS 4 (IBEMIS4) funded by the Spanish Government (PID2019-107113RB-I00). This paper is part of SSR’s PhD thesis and all authors agree. Several authors developed their work within different research groups/projects/contrats: SSR by the Generalitat Valenciana through a predoctoral research-staff contracting Grant (ACIF/2021/407); AM by Universitat d’Alacant through a university faculty formation Grant (UAFPU2018-049); MB by the Spanish central government through a university faculty formation Grant (FPU17/02885); LP is beneficiary on postdoctoral research Grant (APOSTD/2020/202) funded by the Generalitat Valenciana and European Social Fund. CMH, BG and CM are part of the research group SCRP (Sociedades cazadoras recolectoras paleolíticas), MB and LP are part of the research group PREMEDOC (GIUV2015-213), CM is part of the research group MBA (Micromorfología y Biomarcadores arqueológicos), and MV is a part of the ‘Neanderthal behaviour and paleoecology in Mediterranean ecosystems’ project (PID2019-103987GB-C31)

    The technological study of Palaeolithic lithic assemblages from the human occupation episode perspective: the cases of El Salt and El Pastor (Alcoi, Alacant)

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    El objetivo de este artículo es la puesta en valor de las diferencias interpretativas entre el análisis de los conjuntos líticos desde marcos analíticos de baja resolución temporal hacia aquellos con una escala temporal menor vinculados a lo que podrían ser ocupaciones singulares. Para ello, se ofrece una síntesis de los resultados de estudios tecnológicos realizados sobre conjuntos líticos de las unidades estratigráficas xa de El Salt y iv de El Pastor.L’objectiu d’aquest article és la posada en valor de les diferències interpretatives entre l’anàlisi dels conjunts lítics des de marcs analítics de baixa resolució temporal cap a aquells amb una escala temporal menor vinculats al que podrien ser ocupacions singulars. Per això, s’hi oferix una síntesi dels resultats d’estudis tecnològics realitzats sobre conjunts lítics de les unitats estratigràfiques xa d’El Salt i iv d’El Pastor.The goal of this paper is to put in value the interpretative differences between the analysis of lithic assemblages from low-temporal resolution analytical frames towards those counting on a lower time-scale, which are linked to what could be single occupations. For doing that, it is offered a synthesis of results from technological studies carried out on lithic assemblages from the stratigraphic units xa of El Salt and iv of El Pastor

    Fabricación de PLC utilizando microcontroladores para uso didáctico con características industriales

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    Definición o planteamiento del problema.-Marco teórico de la investigación.-Introducción a los PLC.-Arquitectura Harvard.-Software libre de programación de PLC con microcontroladores.-Software (Waltech Ladder Maker).-Metodología de la investigación.-Alcances y análisis de resultados.Trabajo de graduación para optar al grado de Ingeniero en Mecatrónica

    A novel biallelic loss-of-function variant in DAND5 causes heterotaxy syndrome

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    Funding J.A.B. acknowledges funding from iNOVA4Health-UID/Multi/04462/2013, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência through national funds and cofunded by Fundo Europeu de Desenvolvimento Regional (FEDER) under the PT2020 Partnership Agreement.The majority of heterotaxy cases do not obtain a molecular diagnosis, although pathogenic variants in more than 50 genes are known to cause heterotaxy. A heterozygous missense variant in DAND5, a nodal inhibitor, which functions in early development for establishment of right-left patterning, has been implicated in heterotaxy. Recently, the first case was reported of a DAND5 biallelic loss-of-function (LoF) variant in an individual with heterotaxy. Here, we describe a second unrelated individual with heterotaxy syndrome and a homozygous frameshift variant in DAND5 (NM_152654.2:c.197del [p.Leu66ArgfsTer22]). Using an in vitro assay, we demonstrate that the DAND5 c.197del variant is unable to inhibit nodal signaling when compared with the wild-type expression construct. This work strengthens the genetic and functional evidence for biallelic LoF variants in DAND5 causing an autosomal recessive heterotaxy syndrome.publishersversionpublishe
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