On the microstructure, growth pattern and original porosity of belemnite rostra: insights from calcitic Jurassic belemnites

Calcitic belemnite rostra are usually employed to perform paleoenvironmental studies based on geochemical data. However, several questions, such as their original porosity and microstructure, remain open, despite they are essential to make accurate interpretations based on geochemical analyses.This paper revisits and enlightens some of these questions. Petrographic data demonstrate that calcite crystals of the rostrum solidum of belemnites grow from spherulites that successively develop along the apical line, resulting in a “regular spherulithic prismatic” microstructure. Radially arranged calcite crystals emerge and diverge from the spherulites: towards the apex, crystals grow until a new spherulite is formed; towards the external walls of the rostrum, the crystals become progressively bigger and prismatic. Adjacent crystals slightly vary in their c-axis orientation, resulting in undulose extinction. Concentric growth layering develops at different scales and is superimposed and traversed by a radial pattern, which results in the micro-fibrous texture that is observed in the calcite crystals in the rostra.Petrographic data demonstrate that single calcite crystals in the rostra have a composite nature, which strongly suggests that the belemnite rostra were originally porous. Single crystals consistently comprise two distinct zones or sectors in optical continuity: 1) the inner zone is fluorescent, has relatively low optical relief under transmitted light (TL) microscopy, a dark-grey color under backscatter electron microscopy (BSEM), a commonly triangular shape, a “patchy” appearance and relatively high Mg and Na contents; 2) the outer sector is non-fluorescent, has relatively high optical relief under TL, a light-grey color under BSEM and low Mg and Na contents. The inner and fluorescent sectors are interpreted to have formed first as a product of biologically controlled mineralization during belemnite skeletal growth and the non-fluorescent outer sectors as overgrowths of the former, filling the intra- and inter-crystalline porosity. This question has important implications for making paleoenvironmental and/or paleoclimatic interpretations based on geochemical analyses of belemnite rostra.Finally, the petrographic features of composite calcite crystals in the rostra also suggest the non-classical crystallization of belemnite rostra, as previously suggested by other authors.

Józef Wittlin y el exilio europeo

El presente estudio realiza un recorrido por el exilio del autor polaco Józef Wittlin, situándolo en el contexto del exilio europeo que comenzó con la toma de poder del partido nacionalsocialista en Alemania en 1933. Se hará hincapié en la relación y colaboración de Wittlin con otros exiliados europeos, especialmente autores de lengua alemana, así como en los principales lugares de confluencia de exiliados y en los problemas que afrontaron los escritores en ese momento.

Ventajas de aplicar la triangulación empresarial entre España, China y América Latina. Una relación win-win para todos los polos

España tiene la oportunidad de desempeñar un papel importante en el proceso de internacionalización de las empresas chinas hacia Europa y América Latina gracias a la histórica experiencia de las multinacionales españolas en estas regiones. Puesto que las relaciones diplomáticas entre España y China gozan de buena sintonía, si España aprovecha la posición de privilegio respecto al resto de economías europeas, el gigante asiático podría estar interesado en el apoyo de España en América Latina, propiciando así la implantación de iniciativas de cooperación entre los tres polos. Los puntos clave para construir una relación win-win en clave triangular es la importancia de un socio local para profundizar en su despliegue internacional en América Latina, que las empresas chinas requieren, además del expertise y know-how necesarios en los procesos operativos, siendo en estos ámbitos las empresas españolas las mejor posicionadas.

Unraveling EU Policies: the ““Common Basic Principles”” and the ““European Integration Fund”” as a technology of government

this paper is about EU “soft policies” on immigrant integration. It analyzes the “Common Basic Principles” (CBPs) and the “European Integration Fund” (EIF), two devices that have been recently established within this framework. It adopts the theoretical perspective of the “anthropology of policy” and “governmentality studies”. It shows the context of birth of the aforementioned devices, as well as their functioning and the assessment done by the actors implied in the elaboration/implementation/evaluation of the related policies. It is based both on documentary research as well as direct observation and interviews done to the actors implied. It concludes that the PBC and the EIF should be considered as a “technology of government”, that strives to align the conduct of the actors with the governmental aims, as well as it produces specific practices and knowledge. It also underlines an intrinsic feature of many policies: their “congenital failure”, since they are (often) disputed and resignified by situated actors, who are embedded in asymmetrical power relations.