The chert from the Castelltallat Formation (south-central Pyrenees): archaeometric characterisation and archaeological implications

Chert from the limestones and marly limestones of Castelltallat Formation (Ebro Basin) was widely used throughout prehistoric times in north-eastern Iberia to produce stone tools due to its properties and accessibility. A rough estimate indicates that this rock¿either as raw material or as lithic products¿was distributed mainly to the north of the outcrops, over an area of 6000-8000 km2. However, other rocks in the area have similar characteristics which can lead to confusion in the interpretation of its prehistoric use and distribution. In order to establish useful archaeometric criteria for differentiating this chert from other similar, the Castelltallat chert is characterised in petrographic, mineralogical and geochemical terms. The chert nodules are found to be homogenous at the macroscopic and microscopic level, with a significant presence of bioclasts, thus indicating they might be formed in a freshwater lake environment by the early diagenetic replacement of carbonates in shallow waters. The mineralogical composition is homogeneously uniform and of a flint type, characterised by an almost exclusive predominance of quartz, without any opaline phases, and a variable proportion of moganite. The iron oxide content is very low, whereas its chemical composition is unusually high in uranium which correlates positively with carbonate content and negatively with silica. Archaeometrical parameters are provided to reach a proper identification of tools knapped with this chert. This way, chert from Castelltallat Formation turns out to be a valuable lithological marker to evaluate the range of mobility of the human groups who lived in the north-eastern Iberia and their contacts with neighbouring areas

La nécropole néolithique de la Feixa del Moro (Juberri, Andorre): Examen et nouvelles données

At the beginning of the 1980s, a series of archaeological interventions carried out by what was previously called the 'Servei d'Investigacions Arqueológiques del Patrimoni Artistic Nacional d'Andorra' in a Pyrenean valley in Andorra allowed the investigation of the Feixa del Moro site. In a high-altitude area below a series of abandoned terraces, several dwellings and burial structures were located, all of them with chronologies ranging between the Early and the Middle Neolithic (from the mid 5th millennium to the early 4th millennium cal. BC). The distinctiveness of this site does not only lie in its geographical location, nor in the kind of structures discovered, but also in the very good state of preservation of the human bone material recovered from the burials, making Feixa del Moro one of the reference sites for the Neolithic in the Pyrenees and, in general, the Western Mediterranean. So far, sites with a similar conservation of both bones and burial structures are really uncommon. Moreover, the concentration in so small an area, and in the same stratigraphic unit, of such a diversity of evidence, including burials, silos and hearths, is yet more unusual. There are no similar sites in Andorra, or even in the entire Pyrenees. The only other burial site of comparable chronology discovered in the area is the Segudet site, and only a few high-altitude Neolithic dwelling sites are known. Even if cist burials are quite common in the northeast of the Iberian Peninsula and in Southern France, Feixa del Moro is the first that has been found at high altitude. The archaeological work undertaken between 1983 and 1985 provided a picture of a farming community belonging to the so-called 'Sepulcros de fosa' Culture, established in the very heart of the Pyrenees and, thus, highlighted the complexity of Neolithic settlement patterns, even in mountainous zones. At the same time, several analyses of the archaeological materials were already carried out, making Feixa del Moro a reference site for archaeological research even now. Nevertheless, three decades later, new methodologies and the technical advances available are allowing archaeologists to refine old interpretations, to reopen old debates and to carry out new analyses that can improve our understanding of the past. In this respect, since 2011, within the research project 'Aproximación a las primeras comunidades neolíticas del NE peninsular a través de sus prácticas funerarias' (HAR2011-23149), funded by the Spanish Ministry for the Economy and Competitiveness, a group of interdisciplinary researchers have begun to study several Neolithic burial contexts in the northeast of the Iberian Peninsula, among which Feixa del Moro. Following this perspective, in this paper, we present the outcome of the new analyses carried out on the burial goods and of the biochemistry and radiocarbon analyses carried out on the human bone material from the three cist burials of Feixa del Moro, with the aim of better understanding the early farming communities who settled in the Pyrenees. Since the last archaeological work carried out in the 1990s, large quantities of data have been lost. This has produced a certain degree of confusion and misunderstanding that has been repeated in other studies undertaken a posteriori on the site by other scholars. Some of these interpretations need to be revised. That it is why, within the current research project, we are not only bringing in new analyses, but also re-examining all the old written and graphic information available, as well as the state of the conserved archaeological material. The data presented in this paper resume all the available information on the Feixa del Moro site, correcting old mistakes and bias, updating the 1980s archaeological registers and presenting new analyses as well. Our aim is to ensure that Feixa del Moro remains a reference site for the Pyrenean and Western Mediterranean Neolithic. At the same time, we wish to encourage other researchers to undertake new analyses and to embrace new perspectives in order to improve our understanding of Neolithic societies

Imaging of Antiferroelectric Dark Modes in an Inverted Plasmonic Lattice [Dataset]

6 pages. -- S1. Transversal electric field distribution for the SLR at 1.57 eV. -- S2. Simulated electric field and charge distributions for a threesome of slits. -- S3. Simulated electric field and charge distributions for the simplest local dark mode of the inverted honeycomb lattice. -- S4. Profiles of the EELS signal and the simulated electric field along the slits for the antiferroelectric dark modes. -- S5. Array of the magnetic dipoles over the structure used to simulate antiferroelectric dark modes.Plasmonic lattice nanostructures are of technological interest because of their capacity to manipulate light below the diffraction limit. Here, we present a detailed study of dark and bright modes in the visible and near-infrared energy regime of an inverted plasmonic honeycomb lattice by a combination of Au+ focused ion beam lithography with nanometric resolution, optical and electron spectroscopy, and finite-difference time-domain simulations. The lattice consists of slits carved in a gold thin film, exhibiting hotspots and a set of bright and dark modes. We proposed that some of the dark modes detected by electron energy-loss spectroscopy are caused by antiferroelectric arrangements of the slit polarizations with two times the size of the hexagonal unit cell. The plasmonic resonances take place within the 0.5–2 eV energy range, indicating that they could be suitable for a synergistic coupling with excitons in two-dimensional transition metal dichalcogenides materials or for designing nanoscale sensing platforms based on near-field enhancement over a metallic surface.Peer reviewe

Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

Meiotic silencing and fragmentation of the male germline restricted chromosome in zebra finch

During male meiotic prophase in mammals, X and Y are in a largely unsynapsed configuration, which is thought to trigger meiotic sex chromosome inactivation (MSCI). In avian species, females are ZW, and males ZZ. Although Z and W in chicken oocytes show complete, largely heterologous synapsis, they too undergo MSCI, albeit only transiently. The W chromosome is already inactive in early meiotic prophase, and inactive chromatin marks may spread on to the Z upon synapsis. Mammalian MSCI is considered as a specialised form of the general meiotic silencing mechanism, named meiotic silencing of unsynapsed chromatin (MSUC). Herein, we studied the avian form of MSUC, by analysing the behaviour of the peculiar germline restricted chromosome (GRC) that is present as a single copy in zebra finch spermatocytes. In the female germline, this chromosome is present in two copies, which normally synapse and recombine. In contrast, during male meiosis, the single GRC is always eliminated. We found that the GRC in the male germline is silenced from early leptotene onwards, similar to the W chromosome in avian oocytes. The GRC remains largely unsynapsed throughout meiotic prophase I, although patches of SYCP1 staining indicate that part of the GRC may self-synapse. In addition, the GRC is largely devoid of meiotic double strand breaks. We observed a lack of the inner centromere protein INCENP on the GRC and elimination of the GRC following metaphase I. Subsequently, the GRC forms a micronucleus in which the DNA is fragmented. We conclude that in contrast to MSUC in mammals, meiotic silencing of this single chromosome in the avian germline occurs prior to, and independent of DNA double strand breaks and chromosome pairing, hence we have named this phenomenon meiotic silencing prior to synapsis (MSPS)

Releyendo el fenómeno de la neolitización en el Bajo Aragón a la luz de la excavación del Cingle de Valmayor XI (Mequinenza, Zaragoza)

Este trabajo presenta los resultados preliminares obtenidos en la excavación del Cingle de Valmayor XI, desarrollada dentro del proyecto de investigación ‘Los caminos del Neolítico’. A través del análisis de las dataciones radiocarbónicas y de una detallada lectura estratigráfica se han podido establecer tres horizontes de ocupación diferentes con cronologías que corresponden a distintos momentos del vi milenio cal bc. Se ofrece una descripción general de los eventos arqueológicos documentados en cada una de estas fases, así como de gran parte del material recuperado –cerámica, lítica, industria ósea, elementos de adorno, fauna y restos carpológicos–. Por otra parte, a la luz de las nuevas dataciones presentadas, se propone una revisión del fenómeno de la neolitización en la región del Bajo Aragón y, por extensión, en todo el valle del Ebro; también se cuestiona la identificación de contextos como propios de economías productoras simplemente a través de la presencia de ciertos elementos materiales considerados tradicionalmente como ‘marcadores neolíticos’, sin que existan variaciones con respecto a las estrategias subsistenciales o de explotación del territorio

The Neolithic expansion in the Western Mediterranean: Understanding a global phenomenon from regional perspectives

This volume sets out to offer the reader an overview of the neolithization process, the origin of the so-called Cardial Ware early Neolithic, in the Western Mediterranean between the last centuries of the seventh millennium and the mid-sixth millennium BC