Multiplicity fluctuations in the string clustering approach

We present our results on multiplicity fluctuations in the framework of the string clustering approach. We compare our results --with and without clustering formation-- with CERN SPS NA49 data. We find a non-monotonic behaviour of these fluctuations as a function of the collision centrality, which has the same origin as the observed fluctuations of transverse momentum: the correlations between the produced particles due to the cluster formation.Comment: 16 pages, 4 figures, revte

Transverse momentum distributions and their forward- backward correlations in the percolating colour string approach

The forward-backward correlations in the $p_T$ distributions, which present a clear signature of non-linear effects in particle production, are studied in the model of percolating colour strings. Quantitative predictions are given for these correlations at SPS, RHIC and LHC energies. Interaction of strings also naturally explains the flattening of $p_T$ distributions and increase of $$ with energy and atomic number for nuclear collisionsComment: 6 pages in LaTex, 3 figures in Postscrip

Transverse momentum fluctuations and percolation of strings

The behaviour of the transverse momentum fluctuations with the centrality of the collision shown by the Relativistic Heavy Ion Collider data is naturally explained by the clustering of color sources. In this framework, elementary color sources --strings-- overlap forming clusters, so the number of effective sources is modified. These clusters decay into particles with mean transverse momentum that depends on the number of elementary sources that conform each cluster, and the area occupied by the cluster. The transverse momentum fluctuations in this approach correspond to the fluctuations of the transverse momentum of these clusters, and they behave essentially as the number of effective sources.Comment: 16 pages, RevTex, 4 postscript figures. Enhanced version. New figure

Recuperación de agrosistemas degradados en la cuenca del lago de Cuitzeo (Michoagán, México): II. Control de Cárcavas.

II SIMPOSIO NACIONAL SOBRE CONTROL DE LA DEGRADACIÓN DE SUELOS. Universidad Autónoma de Madrid.{ESP}Con la participación de instituciones de investigación europeas y mejicanas concurrentes en el Proyecto REVOLSO/INCO (, se evaluó durante 3 años consecutivos, en la cuenca del Lago de Cuitzeo (Michoacán, Méjico), la construcción de pequeñas represas con neumáticos de desecho para la retención de azolves y control de cárcavas, producto del efecto erosivo del escurrimiento del agua de escorrentía producida por la compactación del suelo. La estabilización de taludes se realizó con veza (Vicia villosa), janamargo (V. sativa), pasto llorón (Eragrostis curvula), acacia (Acacia retinoides) y garrapata (Desmodium grahamii). Como resultados de estas medidas (basadas en el conocimiento de procesos de recuperación de suelos) se contribuye al mejoramiento de áreas productivas y se diminuye la erosión de las cárcavas, con lo cual se reduce el aporte de sedimentos a los cuerpos de agua y, en suma, se mejora el ambiente, aportándose soluciones de bajo costo que pueden romper el círculo vicioso erosión-pobreza.{ENG}Different European and Mexican institutions are collaborating in an international Project (named REVOLSO, INCO Program) working at the Cuitzeo Basin (Michoacán, Mexico). During 3 years the efficience of small dams built with tyres for the erosion control of gullies was assessed. Plant species tested for gullies stabilization were: Vicia villosa, V. sativa, Eragrostis curvula, Acacia retinoides, and Desmodium grahamii. Results are promising, because a deacreasing of erosion process was evident to a low cost. In this way, this actions could improve the soil conservation, diminishing the amount of sediments arriving to the big dams and broken the feedback circle soil erosion-poverty.Universidad Autónoma de Madrid Consejería de Economía e Innovación Tecnológic

Percolation of strings and the first RHIC data on multiplicity and tranverse momentum distributions

The dependence of the multiplicity on the number of collisions and the transverse momentum distribution for central and peripheral Au-Au collisions are studied in the model of percolation of strings relative to the experimental conditions at RHIC. The comparison with the first RHIC data shows a good agreement.Comment: RevTeX, 11 pages, 4 eps figures included using epsfi

Characterization of microsatellite loci in Erysimum mediohispanicum (Brassicaceae) and cross-amplification in related species

• Premise of the study : We have developed and optimized microsatellite loci from a genomic library of Erysimum mediohispanicum. Microsatellites were also tested for cross-amplifi cation in 31 other Erysimum species. • Methods and Results : A total of 10 microsatellite loci were successfully amplifi ed. They were polymorphic for 81 E. mediohispanicum individuals from two locations in Sierra Nevada (southeastern Spain), which showed similar patterns of genetic diversity. On average, microsatellites had 8.6 alleles per locus and an expected heterozygosity of 0.69. Only one locus signifi cantly departed from Hardy – Weinberg equilibrium in both locations. Most of the markers successfully amplifi ed in other Erysimum species. • Conclusions : The genetic attributes of microsatellite loci will allow their application to population genetic studies in Erysimum , such as genetic differentiation and structure, gene fl ow, pollinator-mediated speciation, and hybridization studies.&nbsp

Production of Secondaries in High Energy d+Au Collisions

In the framework of Quark-Gluon String Model we calculate the inclusive spectra of secondaries produced in d+Au collisions at intermediate (CERN SPS) and at much higher (RHIC) energies. The results of numerical calculations at intermediate energies are in reasonable agreement with the data. At RHIC energies numerically large inelastic screening corrections (percolation effects) should be accounted for in calculations. We extract these effects from the existing RHIC experimental data on minimum bias and central d+Au collisions. The predictions for p+Au interactions at LHC energy are also given.Comment: 18 pages and 10 figure