Factor decomposition of spatial disparities: The case of the European regions

This note examines the evolution and origin of regional disparities in per capita GDP in the European Union. To this end, we propose a new methodology that allows us to analze the role played in explaining the variability of per capita GDP across the European regions by spatial differences in labour productivity, employment rate and the ratio of active to total population.

Thread-spawning schemes for speculative multithreading

Speculative multithreading has been recently proposed to boost performance by means of exploiting thread-level parallelism in applications difficult to parallelize. The performance of these processors heavily depends on the partitioning policy used to split the program into threads. Previous work uses heuristics to spawn speculative threads based on easily-detectable program constructs such as loops or subroutines. In this work we propose a profile-based mechanism to divide programs into threads by searching for those parts of the code that have certain features that could benefit from potential thread-level parallelism. Our profile-based spawning scheme is evaluated on a Clustered Speculative Multithreaded Processor and results show large performance benefits. When the proposed spawning scheme is compared with traditional heuristics, we outperform them by almost 20%. When a realistic value predictor and a 8-cycle thread initialization penalty is considered, the performance difference between them is maintained. The speed-up over a single thread execution is higher than 5x for a 16-thread-unit processor and close to 2x for a 4-thread-unit processor.Peer ReviewedPostprint (published version

Mobility as movement: A measuring proposal based on transition matrices

In this note we introduce a family of functions that various theoretical results have revealed as useful mobility measures. These functions have enabled us to circumvent an impossibility result obtained by Shorrocks (1978), by adapting one of his axioms to the context of mobility as movement. A particular case belonging to this family is the Bartholomew index, which is widely used in the empirical literature.

Regional Productive Specialisation and Inequality in the European Union

This paper examines productive specialization in the regions of the European Union over the period 1977 to 1999 using the information provided by various methodological instruments. The results obtained reveal a process of convergence in regional productive structures during the twenty-three years considered. This has been due to the behavior of regions with high levels of specialization at the start of the period, whose productive structures have tended to shift to wards the European average overtime. The analysis carried out also high lights the major role played by regional size, level of development and geographical location in explaining specialization in the European context. Finally, the empirical evidence provided suggests that changes in regional productive structures are closely linked to the evolution of the spatial distribution of per capita income in the European Union. Keywords: Specialization, economic activity, regions, European Union. JEL Code: F15, R11, R12.

VHDL Implementation, Verification and Logic Synthesis of Memory Bus Arbiters for Multi-Processor System

Projecte final de carrera fet en col.laboració amb Leibniz Universität Hannover. Institut für Mikroelektronische System

Patterns of geographic variation of thermal adapted candidate genes in Drosophila subobscura sex chromosome arrangements

Background The role of chromosomal arrangements in adaptation is supported by the repeatable clinal variation in inversion frequencies across continents in colonizing species such as Drosophila subobscura. However, there is a lack of knowledge on the genetic variation in genes within inversions, possibly targets of climatic selection, across a geographic latitudinal gradient. In the present study we analysed four candidate loci for thermal adaptation, located close to the breakpoints, in two chromosomal arrangements of the sex (A) chromosome of Drosophila subobscura with different thermal preferences. Individual chromosomes with A2 (the inverted arrangement considered warm adapted) or AST (the standard ancestral arrangement considered cold adapted) were sequenced across four European localities at varying latitudes, up to ~ 2500 Kms apart. Results Importantly, we found very low differentiation for each specific arrangement across populations as well as no clinal patterns of genomic variation. This suggests wide gene exchange along the cline. Differentiation between the sex chromosome arrangements was significant in the two more proximal regions relative to the AST orientation but not in the distal ones, independently of their location inside or outside the inversion. This can be possibly due to variation in the levels of gene flux and/or selection acting in these regions. Conclusions Gene flow appears to have homogenized the genetic content within-arrangement at a wide geographical scale, despite the expected diverse selective pressures in the specific natural environments of the different populations sampled. It is thus likely that the inversion frequency clines in this species are being maintained by local adaptation in face of gene flow. The differences between arrangements at non-coding regions might be associated with the previously observed differential gene expression in different thermal regimes. Higher resolution genomic scans for individual chromosomal arrangements performed over a large environmental gradient are needed to find the targets of selection and further elucidate the adaptive mechanisms maintaining chromosomal inversion polymorphisms

El Consejo Superior de Investigaciones Científicas está envejecido

Don José Antonio Martin Pereda es vicerrector de Investigación y Relaciones Exteriores de la Universidad Politécnica de Madrid y catedrático de laboratorio de electrónica y componentes de -la Escuela Técnica Superior de Ingenieros de Telecomunicación. A través de su conversación se entra en el panorama del momento científico actual

La investigación en 1984

Entrevista a D. José Antonio Martín Pereda en la que el investigador expresa sus opiniones sobre el estado de la investigación en la década de los 80 y la falta de juventud de los miembros que constituyen el Instituto de Investigaciones Científicas