102,475 research outputs found
The diameter of cortical axons depends both on the area of origin and target
No full textIn primates, different cortical areas send axons of different diameters into comparable tracts, notably the corpus callosum (Tomasi S, Caminiti R, Innocenti GM. 2012. Areal differences in diameter and length of corticofugal projections. Cereb Cortex. 22:1463-1472). We now explored if an area also sends axons of different diameters to different targets. We find that the parietal area PEc sends thicker axons to area 4 and 6, and thinner ones to the cingulate region (area 24). Areas 4 and 9, each sends axons of different diameters to the nucleus caudatus, to different levels of the internal capsule, and to the thalamus. The internal capsule receives the thickest axon, followed by thalamus and nucleus caudatus. The 2 areas (4 and 9) differ in the diameter and length of axons to corresponding targets. We calculated how diameter determines conduction velocity of the axons and together with pathway length determines transmission delays between different brain sites. We propose that projections from and within the cerebral cortex consist of a complex system of lines of communication with different geometrical and time computing properties. © The Author 2013
Local dependency dynamic programming in the presence of memory faults
No full textWe investigate the design of dynamic programming algorithms in unreliable memories, i.e., in the presence of faults that may arbitrarily corrupt memory locations during the algorithm execution. As a main result, we devise a general resilient framework that can be applied to all local dependency dynamic programming problems, where updates to entries in the auxiliary table are determined by the contents of neighboring cells. Consider, as an example, the computation of the edit distance between two strings of length n and m. We prove that, for any arbitrarily small constant ε ∈ (0,1] and n > m, this problem can be solved correctly with high probability in O (nm + αδ1+ε) worst-case time and O(nm + nδ) space, when up to δ memory faults can be inserted by an adversary with unbounded computational power and α < δ is the actual number of faults occurring during the computation. We also show that an optimal edit sequence can be constructed in additional time O (nδ + αδ 1+ε). It follows that our resilient algorithms match the running time and space usage of the standard non-resilient implementations while tolerating almost linearly-many faults. © S. Caminiti, I. Finocchi, E. G. Fusco
ON THE STRUCTURES OF POLYNUCLEAR HYDROLYSIS COMPLEXES OF INDIUM(III) IN AQUEOUS-SOLUTION
No full textAn X-ray diffraction study on the structure of the aqua Indium(II)ion in the sulphate solution.
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