New objects in old structures: The Iron Age hoard of the Palacio III megalithic funerary complex (Almadén de la Plata, Seville, Spain)

Cultural contact, exchange and interaction feature high in the list of challenging topics of current research on European Prehistory. Not far off is the issue of the changing role of monuments in the making and maintaining of key cultural devices such as memory and identity. Addressing both these highly-debated issues from a science-based perspective, in this paper we look at an unusual case study set in southern Iberia and illustrate how these archaeological questions can benefit from robust materials-science approaches.We present the contextual, morphological and analytical study of an exceptional Early Iron Age hoard composed of a number of different (and mostly exotic) materials such as amber, quartz, silver and ceramic. This hoard, found under the fallen orthostat of a megalithic structure built at least 2000 years earlier, throws new light on long-distance exchange networks and the effect they could have had on the cultural identities and social relations of local Iberian Early Iron Age communities. Moreover, the archaeometric study reveals how diverse and distant the sources of these item are (Northern Europe to Eastern and Western Mediterranean raw materials, as well as local and eastern technologies), therefore raising questions concerning the social mechanisms used to establish change and resistance in contexts of colonial encounter

Ferromagnetism below the Stoner limit in La-doped SrB_6

Spin-polarized band calculations for LaSr_7B_{48} show a weak ferro-magnetic state. This is despite a low density-of-states (DOS) and a low Stoner factor. The reason for the magnetic state is found to be associated with a gain in potential energy in addition to the exchange energy, as a spin-splitting is imposed. An impurity like La DOS is essential for this effect. It makes a correction to the Stoner factor, and provides an explanation of the recently observed weak ferro-magnetism in doped hexaborides.Comment: 6 pages, 2 tables, 1 figur

The Composition of the São Brás Copper Hoard in Relation to the Bell Beaker Metallurgy in the South-western Iberian Peninsula

A large ceramic vessel was discovered at São Brás (southern Portugal) containing a metallic hoard from the Chalcolithic/Early Bronze Age period. These weapons and tools were characterized by microanalytical techniques as being composed of copper with varying arsenic contents (2.2± 1.6 wt%) and minor amounts of lead, bismuth and iron. The collection shows a clear association between daggers and copper with a higher arsenic content, which can be explained by the high status of these silvery alloys. Finally, the compositional distribution of the hoard was compared with the metallurgy of the Bell Beaker and non–Bell Beaker communities inhabiting the south-western Iberian Peninsula.info:eu-repo/semantics/acceptedVersio

Procedencia de las puntas de jabalina del “Dolmen de la Pastora” (Valencina de la Concepción, Sevilla)

In this article, along with an updated bibliographical revision, a new archaeometric approach to La Pastora javelin tip type is presented. New results of XRF and Lead Isotopes analyses of metal objects of this type from the “Dolmen de la Pastora” (Valencina de la Concepción, Sevilla, Spain) and the site of La Pijotilla (Badajoz, Spain) are included, incorporating data from Outeiro de São Bernardo (Moura, Portugal). The evidence related with the interpretation of the archaeological context of these three sites allow to propose a date for these javelins that would stand in the centuries of transition between the 3rd and 2nd millennium BC. The confrontation of compositional and isotopic data from the javelin tips with other metallic elements of the region and with the isotopically characterized mineralization in the southwest of the Iberian Peninsula, in addition to mineralizations and metals of the eastern Mediterranean, support their ‘local’ production in the peninsular southwest, although with regional typological variations and from diversified mineral sources.Este artículo combina una revisión bibliográfica actualizada y una nueva aproximación arqueométrica a las puntas de jabalina tipo La Pastora. Se incluyen recientes resultados del análisis por FRX e isótopos de plomo de ejemplares de este tipo metálico procedentes del “Dolmen de La Pastora” (Valencina de la Concepción, Sevilla) y del yacimiento de La Pijotilla (Badajoz), incorporando los datos de Outeiro de São Bernardo (Moura, Portugal). Las evidencias relacionadas con la interpretación arqueológica contextual de estos tres yacimientos permiten sugerir una fecha para las jabalinas tipo La Pastora en los siglos de transición entre el III y el II milenio a.C. Se confrontan los datos compositivos e isotópicos de las puntas de jabalina con otros elementos metálicos del ámbito regional y con las mineralizaciones caracterizadas isotópicamente en el suroeste de la Península Ibérica, además de con mineralizaciones y elementos metálicos del Mediterráneo oriental. Ello permite defender la producción ‘local’ de estas jabalinas en el suroeste peninsular, aunque con variaciones tipológicas regionales y a partir de fuentes minerales diversificadas

La explotación tartésica de la casiterita entre los ríos Tajo y Guadiana: San Cristóbal de Logrosán (Cáceres)

The objective of this work is to offer a synthesis of the archaeological and archaeo-mining investigation carried out in recent years (1998 and 2000-2002) in the Cerro de San Cristobal site, Logrosán (Cáceres). The results allow us to propose a chaîne opératoire for the cassiterite treatment and use in Cerro de San Cristóbal during the transition from the Late Bronze Age to the Orientalizing period. The management and role of this mineral in the Tajo-Guadiana relations and in the Atlantic- Mediterranean circuits meeting in the Southwest of the Iberian Peninsula, together with other factors, seems to justify the early integration of the territory of Extremadura in Tartessos. The investigation in Logrosán and the archaeology of tin were suddenly interrupted by the unexpected death of its main promoter, Dr. Craig Merideth. The continuation of this project is now to be channelled through the recent declaration of the Cerro de San Cristobal as a ‘geosite’ in the ‘Ibores-Villuercas- Jara Geopark’ and through the National Research, Development and Innovation Scheme’s project El tiempo del tesoro de Aliseda, among whose actions is the archaeomining survey from the West of the peneplain of Cáceres made in 2011.El objetivo de este trabajo es ofrecer una síntesis de la investigación arqueológica y arqueominera realizada entre 1998 y 2000-2002 en el Cerro de San Cristóbal de Logrosán (Cáceres). Esta permite proponer una probable ‘cadena operativa’ del beneficio de la casiterita en este lugar durante el tránsito Bronce Final-Periodo Orientalizante. La gestión e imbricación del mineral en las relaciones Tajo-Guadiana y en los circuitos atlántico-mediterráneos confluyentes en el Suroeste de la Península Ibérica parecen justificar, entre otras razones, la temprana integración del actual territorio extremeño en Tartessos. La investigación en Logrosán y la arqueología del estaño se vieron bruscamente interrumpidas por el inesperado fallecimiento de su principal impulsor, Craig Merideth. Su continuidad pretende canalizarse a través de la reciente declaración del Cerro de San Cristóbal como “geositio” del Geoparque “Ibores-Villuercas-Jara” y del proyecto del Plan Nacional I+D+i El tiempo del tesoro de Aliseda, entre cuyas acciones se encuentra la prospección arqueominera del oeste de la penillanura cacereña realizada en 2011

Soil water content effects on net ecosystem CO2 exchange and actual evapotranspiration in a Mediterranean semiarid savanna of Central Chile

Biosphere-atmosphere water and carbon fluxes depend on ecosystem structure, and their magnitudes and seasonal behavior are driven by environmental and biological factors. We studied the seasonal behavior of net ecosystem CO2 exchange (NEE), Gross Primary Productivity (GPP), Ecosystem Respiration (RE), and actual evapotranspiration (ETa) obtained by eddy covariance measurements during two years in a Mediterranean Acacia savanna ecosystem (Acacia caven) in Central Chile. The annual carbon balance was −53 g C m−2 in 2011 and −111 g C m−2 in 2012, showing that the ecosystem acts as a net sink of CO2, notwithstanding water limitations on photosynthesis observed in this particularly dry period. Total annual ETa was of 128 mm in 2011 and 139 mm in 2012. Both NEE and ETa exhibited strong seasonality with peak values recorded in the winter season (July to September), as a result of ecosystem phenology, soil water content and rainfall occurrence. Consequently, the maximum carbon assimilation rate occurred in wintertime. Results show that soil water content is a major driver of GPP and RE, defining their seasonal patterns and the annual carbon assimilation capacity of the ecosystem, and also modulating the effect that solar radiation and air temperature have on NEE components at shorter time scales.This work was funded by FONDECYT projects 1120713 and 1170429, a grant from the Inter-American Institute for Global Change Research (IAI) [grant number CRN3056], which is supported by the US National Science Foundation [grant number GEO-1128040], and the Spanish Ministry of Economy and Competitiveness project GEI Spain (CGL2014-52838-C2-1-R), including ERDF founds. F. Bravo-Martínez is grateful to CONICYT for the grants “Formación de Capital Humano Avanzado-2009′′, “Beca de Apoyo al término de la tesis doctoral-2012′′, and CORFO INNOVA Grant N° 09CN14-5704. We thank to Enrique Pérez Sanchez-Cañete and Borja Ruíz- Reverter for technical support. We also thank “CODELCO–División Andina” for use of the site. C. Montes acknowledges the NASA Postdoctoral Program and to Universities Space Research Association

<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data

Protohistoric mining in the Extremadura: The case of in the Cerro de San Cristóbal de Logrosán (Cáceres)

Este artículo resume los trabajos realizados en el Cerro de San Cristóbal (Logrosán, Cáceres) entre  1998  y 2002.  Dichos  trabajos,  impulsados  por  el Dr.  Craig  Merideth  hasta  su muerte en 2005,  permitieron  reconocer  un asentamiento  minero-metalúrgico especializado  en el be- nef icio de la casiterita. Pese a estar muy alterado por las explotaciones de los años cincuenta del siglo XX, se pudieron  documentar  restos de cabañas,  trazas de labores  antiguas  y ciertos aspectos de la “cadena operativa” de la explotación y uso del estaño en este enclave. Todo ello  se enmarca  en un contexto  crono-cultural  de los  siglos  IX/VIII-VII/VI  a.C.,  durante  el cual el actual territorio extremeño se conformó como periferia tartésica. Por otra parte, se avanzan los resultados metalúrgicos preliminares de las nuevas actuaciones llevadas a cabo en 2013 en el Cerro de San Cristóbal  tras su declaración  como “geositio”  dentro del Geoparque “Villuercas-Ibores-Jara”.In this paper the archaeological work carried out in Cerro de San Cristóbal (Logrosán, Cáceres) during the period 1998 to 2002 is summarized. The work, led by Dr. Craig Merideth until his  death  in 2005, allowed  to document  what was interpreted  as a mining-metallurgical site specialized  in the  treatment  of cassiterite.  Despite  being  the prehistoric  layers  disturbed by  contemporary,  1950´s,  mining  works,  it  was  possible  to  document  traces  of  prehistoric mining,  remains  of  elliptical  huts  and  some  of  the  steps  of  the  proposed  operational  chain for the mining and processing of tin in the site. The chronological/cultural context for the archaeological register was placed between the 9th-8th/7th-6th  centuries B.C., during which the present-day Extremadura territory was conformed as a Tartesian periphery. Also, the preliminary metallurgical results of the recent (summer 2013, after its declaration as a “Geosite” within the “Villuercas-Ibores-Jara” Geopark) archaeological  excavation in Cerro de San Cristóbal are presented

Class-modeling analysis reveals T-cell homeostasis disturbances involved in loss of immune control in elite controllers

Despite long-lasting HIV replication control, a significant proportion of elite controller (EC) patients may experience CD4 T-cell loss. Discovering perturbations in immunological parameters could help our understanding of the mechanisms that may be operating in those patients experiencing loss of immunological control. Methods A case–control study was performed to evaluate if alterations in different T-cell homeostatic parameters can predict CD4 T-cell loss in ECs by comparing data from EC patients showing significant CD4 decline (cases) and EC patients showing stable CD4 counts (controls). The partial least-squares–class modeling (PLS-CM) statistical methodology was employed to discriminate between the two groups of patients, and as a predictive model. Results Herein, we show that among T-cell homeostatic alterations, lower levels of naïve and recent thymic emigrant subsets of CD8 cells and higher levels of effector and senescent subsets of CD8 cells as well as higher levels of exhaustion of CD4 cells, measured prior to CD4 T-cell loss, predict the loss of immunological control. Conclusions These data indicate that the parameters of T-cell homeostasis may identify those EC patients with a higher proclivity to CD4 T-cell loss. Our results may open new avenues for understanding the mechanisms underlying immunological progression despite HIV replication control, and eventually, for finding a functional cure through immune-based clinical trials.projects RD12/0017/0031, RD16/0025/ 0013, and SAF2015-66193-R as part of the Health Research and Development Strategy, State Plan for Scientific and Technical Research and Innovation (2008– 2011 and 2013–2016) and cofinanced by the Institute of Health Carlos III (ISCIII), Sub-Directorate General for Research Assessment and Promotion and European Regional Development Fund. NR is a Miguel Servet investigator from the ISCIII (CP14/00198), Madrid, Spain. C Restrepo was funded by project RD12/0017/ 0031 and is currently funded by project RD16/0025/0013. M García is a predoctoral student co-funded by grant CP14/00198 and an Intramural Research Scholarship from Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD)