Contribución al conocimiento de la secuencia arqueológica y el hábitat del Holoceno inicial en el Maestrazgo

Se presenta el estudio de un total de cinco yacimientos localizados en el tramo superior del Riu de les Coces (Alt Maestral, Castellón). Partiendo de los problemas derivados de la naturaleza de la información manejada se aborda su contextualización en el marco de la secuencia arqueológica y del hábitat del Holoceno inicial en el Maestrazgo y en el contexto regional. Los resultados obtenidos permiten por un lado, relativizar la idea de una secuencia local continua e ininterrumpida desde el Magdaleniense superior hasta el Mesolítico Reciente, y por otro. la sucesión de dos modelos diferentes de ocupación del territorio

Casa de Lara (Villena, Alicante): un yacimiento Mesolítico y Neolítico al aire libre

Realizamos una propuesta de interpretación del yacimiento de Casa de Lara basándonos en el estudio de su industria lítica. Se incide en la revisión de la secuencia del yacimiento, en la existencia de problemas tafonómicos y en el lugar que ocupa dentro del proceso de neolitización del substrato mesolítico en la vertiente mediterránea de la Península Ibérica.With the study of lithic industry we make a new interpretation of prehistoric sire of Casa de Lara, We give special attention to the sequence reconstitution, the taphonomics problems and its place inout neolitisation process of mesolithic substract on the mediterranean side of Iberic Peninsula

Reconstructing social networks of Late Glacial and Holocene hunter–gatherers to understand cultural evolution

Culture is increasingly being framed as a driver of human phenotypes and behaviour. Yet very little is known about variations in the patterns of past social interactions between humans in cultural evolution. The archaeological record, combined with modern evolutionary and analytical approaches, provides a unique opportunity to investigate broad-scale patterns of cultural change. Prompted by evidence that a population's social connectivity influences cultural variability, in this article, we revisit traditional approaches used to infer cultural evolutionary processes from the archaeological data. We then propose that frameworks considering multi-scalar interactions (from individuals to populations) over time and space have the potential to advance knowledge in cultural evolutionary theory. We describe how social network analysis can be applied to analyse diachronic structural changes and test cultural transmission hypotheses using the archaeological record (here specifically from the Marine Isotope Stage 3 ca 57–29 ka onwards). We argue that the reconstruction of prehistoric networks offers a timely opportunity to test the interplay between social connectivity and culture and ultimately helps to disentangle evolutionary mechanisms in the archaeological record. This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.This work was funded by the European Research Council (ref. ERC-CoG 2015) under the European Union's horizon 2020 research and innovation programme (grant agreement no. 683018). J.F.-L.d.P. was also supported by grant no. 2018/040 from the CIDEGENT Excellence programme of Generalitat Valenciana

Ocupaciones prehistóricas del barranco de Olula (Almansa, Albacete): Estudio de los registros líticos de superficie

La industria lítica proveniente de los registros de superficie localizados en el Barranco de Olula (Almansa), permite plantear en esta zona la existencia de ocupaciones al aire libre anteriores a la Edad de Bronce. Se presenta la documentación valorando de forma crítica los problemas del registro del que proceden. Por último, se contextualiza esta información en el marco del poblamiento de la Prehistoria Reciente del Corredor Almansa-Vinalopó y de otras áreas próximas

Las primeras comunidades agropecuarias del Río Vinalopó (Alicante)

Se sintetiza la documentación empírica disponible sobre el poblamiento neolítico en la cuenca del río Vinalopó (Alicante, España). Al mismo tiempo se propone una hipótesis de trabajo sobre el proceso histórico a escala regional.We synthesise the empirical information about Neolithic settlements in Vinalopó Valley (Alicante, Spain). At the same time, we propose a work hypothesis about historical development at regional scale

Reconstructing Mesolithic social networks on the Iberian Peninsula using ornaments

Archaeologists have been reconstructing interactions amongst hunter-gatherer populations for a long time. These exchanges are materialised in the movements of raw materials and symbolic objects which are found far from their original sources. Social network, i.e. the structure constituted by these interactions, is a well-established concept in archaeology that is used to address the connectivity of hunter-gatherer populations. The heuristic potential of formal network analysis, however, has been scarcely exploited in prehistoric hunter-gatherer archaeology. Here, social network analysis is used to analyse the interactions amongst hunter-gatherers on the Iberian Peninsula in the Early and Late Mesolithic (10,200 to 7600 cal BP). We used ornaments to explore social interaction and constructed one network per phase of the Iberian Mesolithic. We applied a three-steps analysis: First, we characterised the overall structure of the networks. Second, we performed centrality analysis to uncover the most relevant nodes. Finally, we conducted an exploratory analysis of the networks' spatial characteristics. No significant differences were found between the overall network topology of the Early and Late Mesolithic. This suggests that the interaction patterns amongst human groups did not change significantly at a peninsular scale. Moreover, the spatial analysis showed that most interactions between human groups took place over distances under 300 km, but that specific ornament types like Columbella rustica were distributed over more extensive distances. Our findings suggest that Iberian Mesolithic social networks were maintained through a period of environmental, demographic and cultural transformation and that interactions took place at different scales of social integration

Late Glacial and Early Holocene human demographic responses to climatic and environmental change in Atlantic Iberia

Successive generations of hunter-gatherers of the Late Glacial and Early Holocene in Iberia had to contend with rapidly changing environments and climatic conditions. This constrained their economic resources and capacity for demographic growth. The Atlantic façade of Iberia was occupied throughout these times and witnessed very significant environmental transformations. Archaeology offers a perspective on how past human population ecologies changed in response to this scenario. Archaeological radiocarbon data are used here to reconstruct demographics of the region over the long term. We introduce various quantitative methods that allow us to develop palaeodemographic and spatio-temporal models of population growth and density, and compare our results to independent records of palaeoenvironmental and palaeodietary change, and growth rates derived from skeletal data. Our results demonstrate that late glacial population growth was stifled by the Younger Dryas stadial, but populations grew in size and density during the Early to Middle Holocene transition. This growth was fuelled in part by an increased dependence on marine and estuarine food sources, demonstrating how the environment was linked to demographic change via the resource base, and ultimately the carrying capacity of the environment. This article is part of the theme issue 'Cross-disciplinary approaches to prehistoric demography'.FCT: DL 57/2016/CP1361/CT0026info:eu-repo/semantics/publishedVersio

Silver nanoparticle chains for ultra-long-range plasmonic waveguides for Nd3+ fluorescence

Plasmonic waveguides have been shown to be a promising approach to confine and transport electromagnetic energy beyond the diffraction limit. However, ohmic losses generally prevent their integration at micrometric or millimetric scales. Here, we present a gain-compensated plasmonic waveguide based on the integration of linear chains of Ag nanoparticles on an optically active Nd3+-doped solid-state gain medium. By means of dual confocal fluorescence microscopy, we demonstrate long-range optical energy propagation due to the near-field coupling between the plasmonic nanostructures and the Nd3+ ions. The subwavelength fluorescence guiding is monitored at distances of around 100 µm from the excitation source for two different emission ranges centered at around 900 nm and 1080 nm. In both cases, the guided fluorescence exhibits a strong polarization dependence, consistent with the polarization behavior of the plasmon resonance supported by the chain. The experimental results are interpreted through numerical simulations in quasi-infinite long chains, which corroborate the propagation features of the Ag nanoparticle chains at both excitation (λexc = 590 nm) and emission wavelengths. The obtained results exceed by an order of magnitude that of previous reports on electromagnetic energy transport using linear plasmonic chains. The work points out the potential of combining Ag nanoparticle chains with a small interparticle distance (~2 nm) with rare-earth-based optical gain media as ultra-long-range waveguides with extreme light confinement. The results offer new perspectives for the design of integrated hybrid plasmonic–photonic circuits based on rare-earth-activated solid-state platformsThis research has been funded by the Spanish State Research Agency under contracts PID2019-108257GB-I00 and RTI2018-098452-B-100, Comunidad de Madrid under contract CAM (SI1/PJI/2019-00105) and the María de Maeztu “Programme for Units of Excellence in R&D” CEX2018-000805-

On the effects of cutting-edge angle on high-feed turning of Inconel 718© superalloy

Machining processes on heat-resistant superalloys—i.e., turbine cases, rings, or shafts—are challenging tasks. The high-added value of such parts makes cycle times be longer than expected. Recently, high-feed turning technique has attracted the attention of practitioners due to its high material removal rate capability. PrimeTurning™ tool unifies the concepts of high-feed and multidirectional turning using multiple active cutting edges. It should be capable of reducing machine downtimes in that kind of parts. However, to avoid early tool replacement and rejects on high added value parts, a deeper knowledge on the high-feed turning process is necessary. Here, inserts specifically designed for high-feed turning in heat resistant Inconel 718© alloy were tested using three cutting-edge angles. The results showed that when chip thickness is more relevant, a cutting-edge angle of 30° reduces the likelihood of notches. Even if force components are high, surface roughness is improved and the risk of fractures is minimized, together with a high evacuation volume. On the other hand, increasing the cutting-edge angle (45° and 60°) without compensating the feed rate, tends to produce tool fractures due to chip overload. Besides, experimental tests showed that long tool-to-workpiece contact times, tend to shorten tool life, due to excessive heat accumulation and poor chip control.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Funding MCIN/AEI/https://doi.org/10.13039/501100011033 and "FSE invierte en tu futuro", from the Ministry of Science and Innovation of the Government of Spain, in the IB-RELIABLE project (DPI2016-74845-R). UPV/EHU for the financial aid for the pre-doctoral grants PIF 19/96