28 research outputs found
Stachorutes cabagnerensis sp. n., Collembola (Neanuridae) de la región central de España, y una aproximación preliminar a la filogenia del género
A new species of the genus Stachorutes, Stachorutes cabagnerensis n. sp., from central Spain is described. It is characterized by the presence of 6+6 eyes in the head, retinaculum 2+2 teeth, dentes with 5 hairs, and the absence of mucron. A phylogenetic analysis of this genus was attempted. Potential synapomorphies supporting the monophyly of Stachorutes are presented. One member of the genus (the Nearctic S. navajellus) appears as a basal form, phylogenetically distant from the remaining (Old World) species. There is evidence for a monophyletic infrageneric clade with the species S. dematteisi, S. jizuensis and S. sphagnophilus. However, more information is required for further phylogenetic resolution.Se describe una nueva especie del genero Stachorutes de la region central de España. Stachorutes cabagnerensis nov. sp. se caracteriza por la presencia de 6+6 ojos en la cabeza, retinaculum con 2+2 dientes y 5 sedas en cada rama del dentes; la furca carece de mucrĂłn. Se ha efectuado un análisis filogenĂ©tico. Las sinapomorfias potenciales establecen la monofilia del gĂ©nero. Una especie del mismo, S. navajellus, aparece como forma basal, filogenĂ©ticamente distante del resto de especies (Viejo Mundo). Se podrĂa establecer un clado infragenĂ©rico con las especies S. dematteisi, S. jizuensis y S. sphagnophilus. Sin embargo, se precisa de mayor informaciĂłn para poder confirmarlo
Computability and dynamical systems
In this paper we explore results that establish a link between dynamical
systems and computability theory (not numerical analysis). In the last few decades,
computers have increasingly been used as simulation tools for gaining insight into
dynamical behavior. However, due to the presence of errors inherent in such numerical
simulations, with few exceptions, computers have not been used for the
nobler task of proving mathematical results. Nevertheless, there have been some recent
developments in the latter direction. Here we introduce some of the ideas and
techniques used so far, and suggest some lines of research for further work on this
fascinating topic
GEANT4--a simulation toolkikt
Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics
On i-operators on real normed spaces
We gradually study i-operators on real vector spaces, on real topological vector spaces, and on real normed spaces. Among several things we prove the existence of real topological vector spaces (different from the James’ space) that are free of continuous i-operators. We also prove that every real normed space can be equivalently renormed to be free of norm i-operators. Examples of spaces of continuous functions not admitting norm i-operators and whose unit sphere is free of convex subsets with non-empty interior relative to it are also found. Finally, we also provide some results on a problem posed by Wenzel in [10].Keywords: i-operator, Cartesian