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.<br><br>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

Regulation of carotenoid biosynthesis in photosynthetic organs

A substantial proportion of the dazzling diversity of colors displayed by living organisms throughout the tree of life is determined by the presence of carotenoids, which most often provide distinctive yellow, orange and red hues. These metabolites play fundamental roles in nature that extend far beyond their importance as pigments. In photosynthetic lineages, carotenoids are essential to sustain life, since they have been exploited to maximize light harvesting and protect the photosynthetic machinery from photooxidative stress. Consequently, photosynthetic organisms have evolved several mechanisms that adjust the carotenoid metabolism to efficiently cope with constantly fluctuating light environments. This chapter will focus on the current knowledge concerning the regulation of the carotenoid biosynthetic pathway in leaves, which are the primary photosynthetic organs of most land plants.My research is mainly funded by the EC Marie Curie research project CarotenActors (FP7-PEOPLE-2011-IIF 300862) and the MINECO Postdoctoral Grant (FPDI-2013-018882). I also acknowledge the support from grants from MINECO (BIO2011-23680) and CYTED (Ibercarot-112RT0445).Peer reviewe