The double-deficit hypothesis acknowledges both phonological processing deficits and serial naming speed deficits as two dimensions associated with reading disabilities. The purpose of this study was to examine these two dimensions of reading as they were related to the reading skills of 29 Spanish average readers and poor readers (mean age 9 years 7 months) who met the criteria for either single phonological deficit (PD), double deficit (DD), or no deficit. DD children were the slowest readers and had the weakest orthography processing skills. No significant differences were found between PD and DD groups on word and pseudoword reading. Word reading and reading comprehension skills were average or above average in the three studied groups. As in previous studies in transparent orthographies, word reading was not a salient problem for Spanish poor readers, whereas for the DD group, reading speed and orthographic recognition skills were significantly affected.

Abstract. We introduce in this paper a notion of continuity in digital spaces which extends the usual notion of digital continuity. Our approach uses multivalued maps. We show how the multivalued approach provides a better framework to define topological notions, like retractions, in a far more realistic way than by using just single-valued digitally continuous functions. In particular, we characterize the deletion of simple points, one of the most important processing operations in digital topology, as a particular kind of retraction.

We consider an infinite Hermitian positive definite matrix M which is the moment matrix associated with a measure μ with infinite and compact support on the complex plane.We prove that if the polynomials are dense in L 2 (μ) then the smallest eigenvalue λ n of the truncated matrix M n of M of size (n + 1) × (n + 1) tends to zero when n tends to infinity. In the case of measures in the closed unit disk we obtain some related results.

In a recent paper (Escribano et al. in Discrete Geometry for Computer Imagery 2008. Lecture Notes in Computer Science, vol. 4992, pp. 81-92, 2008 we have introduced a notion of continuity in digital spaces which extends the usual notion of digital continuity. Our approach, which uses multivalued functions, provides a better framework to define topological notions, like retractions, in a far more realistic way than by using just single-valued digitally continuous functions.In this work we develop properties of this family of continuous functions, now concentrating on morphological operations and thinning algorithms. We show that our notion of continuity provides a suitable framework for the basic operations in mathematical morphology: erosion, dilation, closing, and opening. On the other hand, concerning thinning algorithms, we give conditions under which the existence of a retraction F : X -> X\D guarantees that D is deletable. The converse is not true, in general, although it is in certain particular important cases which are at the basis of many thinning algorithms.

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