Selection of Optimal Computing Platforms through the Suitability Measure a

Selection of spaceborne computing platforms requires balance among several competing factors. Traditional performance analysis techniques are illsuited for this purpose due to their overriding concern with runtime. The suitability measure is a new approach that quantifies the match between a computing platform and a program. It analyzes a program at the opcode and control flow levels, and compares this to a machine's capability to support the unique characteristics of the program. In this paper we develop the suitability measure and a series of program analysis methods. Experimental results confirm that machines that provide a better match to the program yield a higher suitability score. We prove that loops provide the only contribution to the suitability value, and also that the number of loop iterations is irrelevant, leading to the conclusion that a single pass through a loop is sufficient to derive a suitability value

A new species of Diplostephium (Asteraceae, Astereae) from the Atacama Desert, Chile

A new species, Diplostephium paposanum S.T.Ibáñez & Muñoz-Schick, sp. nov., is described for Chile, extending the southern distribution of the genus. Its position within the genus was confirmed by morphological and molecular data, discussed here. The new species was found in a coastal environment, new to the genus, and is geographically far removed from the other Chilean species, which are from the Andes. The formation where it occurs, known as lomas, acts as a biodiversity refuge in hyperarid environments. The presence of D. paposanum in this environment contributes to the evidence of a floristic connection between the Atacama Desert and the Neotropical Andes

Variability in phylogenetic diversity (PD) estimates illustrated with plant data for the high Andes of South America

Phylogenetic diversity (PD) is commonly calculated by adding together the branch lengths or ages of a subset of taxa present in an area, using a single phylogeny as a backbone. However, a phylogenetic hypothesis is the consensus of a range of equally likely trees, inherently variable in branch lengths and sometimes in topology. This study incorporates confidence intervals into PD calculations in order to account for such variability. Using the genera of Fabaceae and Solanaceae present in the high Andes, we calculated PD for three macro-zones (Puna, Paramo and Southern Andean Steppe) and studied its correlation with generic richness for these areas. We found a similar pattern between PD and richness in the Fabaceae, but not in the Solanaceae. Variability proved useful in interpreting the results, especially in the Solanaceae which showed alternative topologies. Further studies are needed to address the possible effects of this variability on the PD index. © 2012 The Royal Society of Ne