Clot Formation in the Sipunculid Worm Themiste petricola: A Haemostatic and Immune Cellular Response

Clot formation in the sipunculid Themiste petricola, a coelomate nonsegmented marine worm without a circulatory system, is a cellular response that creates a haemostatic mass upon activation with sea water. The mass with sealing properties is brought about by homotypic aggregation of granular leukocytes present in the coelomic fluid that undergo a rapid process of fusion and cell death forming a homogenous clot or mass. The clot structure appears to be stabilized by abundant F-actin that creates a fibrous scaffold retaining cell-derived components. Since preservation of fluid within the coelom is vital for the worm, clotting contributes to rapidly seal the body wall and entrap pathogens upon injury, creating a matrix where wound healing can take place in a second stage. During formation of the clot, microbes or small particles are entrapped. Phagocytosis of self and non-self particles shed from the clot occurs at the clot neighbourhood, demonstrating that clotting is the initial phase of a well-orchestrated dual haemostatic and immune cellular response

Valentí Almirall and Francisco Pi y Margall. Agreements and disagreements

RESUMEN: Valentí Almirall y Francisco Pi y Margall pueden ser considerados como los dos autores más influyentes del federalismo pactista español y, sin embargo, nunca se ha realizado un trabajo dedicado específicamente al estudio comparado ni de sus propuestas teóricas, ni de sus trayectorias políticas. Hasta el momento, la mayoría de los trabajos que han prestado atención a las relaciones entre ambos autores se han centrado en su ruptura política y en el catalanismo de Almirall como principal factor diferencial. Tan solo Jorge Cagiao ha abordado con minuciosidad las diferencias teóricas entre el federalismo pimargaliano y el almiraliano, aunque la comparación entre el pensamiento de Pi y el de Almirall no es el único objetivo de su obra1. En este estudio se tratará de poner la comparación en el centro, intentando resolver pormenorizadamente qué elementos distancian su pensamiento y qué relación se puede encontrar entre esos elementos y sus diferentes trayectorias políticas. ¿Es el catalanismo el verdadero factor distanciador o existen otros factores con mayor peso? ¿Permiten sus obras explicar sus distintas carreras políticas o deben buscarse explicaciones en el marco estratégico desde el que operaron como políticos?ABSTRACT: Valentí Almirall and Francisco Pi y Margall can be considered as the two most influential authors of spanish pactist federalism and yet, there has never been done an essay specifically focused neither to the comparative study of their theoretical proposals, neither to their political careers. So far, most of the studies that have paid attention to the relations between both authors have been focused on their political breakup and to the almiralian catalanism as the main differentiating factor. Only Jorge Cagiao has approached the theoretical differences between pimargalian and almiralian federalism in detail. However, the comparison between the thought of Pi and Almirall wasn’t the only aim of his work2. In this study comparison will be the central element, trying to resolve in detail what elements distance their thoughts and what relation can be found between those elements and their different political careers. Is catalanism the true spacer element or are there other factors with more importance in the distancing between both authors? Can their theoretical works explain their very diferent political careers or do we have to look for explanations on the strategic framework from where they operated as politicians?Máster en Historia Contemporáne