Servicing the federation : the case for metadata harvesting

The paper presents a comparative analysis of data harvesting and distributed computing as complementary models of service delivery within large-scale federated digital libraries. Informed by requirements of flexibility and scalability of federated services, the analysis focuses on the identification and assessment of model invariants. In particular, it abstracts over application domains, services, and protocol implementations. The analytical evidence produced shows that the harvesting model offers stronger guarantees of satisfying the identified requirements. In addition, it suggests a first characterisation of services based on their suitability to either model and thus indicates how they could be integrated in the context of a single federated digital library

El Dret català durant els segles XVI i XVII

El text consta d'una descripció i un estudi de les institucions jurídiques i de govern de Catalunya vigents durant els segles XVI i XVIII, sobretot en l'àmbit públic, i d'una prèvia i breu introducció historicojurídica. L'article se centra en les fonts del dret català, i a l'entorn d'aquest tema va reconstruint també la història política i social del país, tot referint els seus òrgans de govern, legislatius i judicials, i les seves vicissituds des del regnat de Ferran el Catòlic fins a la promulgació del Decret de Nova Planta de 1716.Description and study of Catalonias legal and executive institutions in the 16th and 17th centuries, especially in the public sphere, preceded by a brief introduction to its legal history. The article focuses on the sources of Catalan law and, within this context, also reviews Catalonias political and social history in terms of its executive, legislative and judicial bodies and their vicissitudes, from the reign of Ferdinand the Catholic to the passing of the Decree of Nueva Planta in 1716.El texto consta de una descripción y un estudio de las instituciones jurídicas y de gobierno de Catalunya vigentes en los siglos XVI y XVII, sobre todo en el ámbito público, y de una previa y breve introducción histórico-jurídica. El artículo se centra en las fuentes del derecho catalán, y al filo de este tema va reconstruyendo también la historia política y social del país, refiriendo sus órganos de gobierno, legislativos y judiciales, y sus vicisitudes desde el reinado de Fernando el Católico hasta la promulgación del Decreto de Nueva Planta de 1716

Amplituhedron meets Jeffrey-Kirwan Residue

The tree amplituhedra A^(m)_n,k are mathematical objects generalising the notion of polytopes into the Grassmannian. Proposed for m=4 as a geometric construction encoding tree-level scattering amplitudes in planar N=4 super Yang-Mills theory, they are mathematically interesting for any m. In this paper we strengthen the relation between scattering amplitudes and geometry by linking the amplituhedron to the Jeffrey-Kirwan residue, a powerful concept in symplectic and algebraic geometry. We focus on a particular class of amplituhedra in any dimension, namely cyclic polytopes, and their even-dimensional conjugates. We show how the Jeffrey-Kirwan residue prescription allows to extract the correct amplituhedron volume functions in all these cases. Notably, this also naturally exposes the rich combinatorial and geometric structures of amplituhedra, such as their regular triangulations.Peer reviewedFinal Accepted Versio