Experimental comparison of control architectures

Most control systems of flexible production cells have a hierarchical structure. They become very complicated and difficult to maintain and modify when the underlying production cells grow in size and complexity. Moreover, they are characterised by a relatively high sensitivity to failures. As opposed to that, heterarchical control systems are flexible, modular, easy to modify, and to some extent, fault-tolerant. The performance of two control systems, with a hierarchical and a heterarchical structure, based on an exemplary flexible production cell is evaluated by means of simulation experiments. Under ideal circumstances, both control systems perform equally wel

Experimental comparison of control architectures

Most control systems of flexible production cells have a hierarchical structure. They become very complicated and difficult to maintain and modify when the underlying production cells grow in size and complexity. Moreover, they are characterised by a relatively high sensitivity to failures. As opposed to that, heterarchical control systems are flexible, modular, easy to modify, and to some extent, fault-tolerant. The performance of two control systems, with a hierarchical and a heterarchical structure, based on an exemplary flexible production cell is evaluated by means of simulation experiments. Under ideal circumstances, both control systems perform equally wel

Insect pathogenicity in plant-beneficial pseudomonads: phylogenetic distribution and comparative genomics.

Bacteria of the genus Pseudomonas occupy diverse environments. The Pseudomonas fluorescens group is particularly well-known for its plant-beneficial properties including pathogen suppression. Recent observations that some strains of this group also cause lethal infections in insect larvae, however, point to a more versatile ecology of these bacteria. We show that 26 P. fluorescens group strains, isolated from three continents and covering three phylogenetically distinct sub-clades, exhibited different activities toward lepidopteran larvae, ranging from lethal to avirulent. All strains of sub-clade 1, which includes Pseudomonas chlororaphis and Pseudomonas protegens, were highly insecticidal regardless of their origin (animals, plants). Comparative genomics revealed that strains in this sub-clade possess specific traits allowing a switch between plant- and insect-associated lifestyles. We identified 90 genes unique to all highly insecticidal strains (sub-clade 1) and 117 genes common to all strains of sub-clade 1 and present in some moderately insecticidal strains of sub-clade 3. Mutational analysis of selected genes revealed the importance of chitinase C and phospholipase C in insect pathogenicity. The study provides insight into the genetic basis and phylogenetic distribution of traits defining insecticidal activity in plant-beneficial pseudomonads. Strains with potent dual activity against plant pathogens and herbivorous insects have great potential for use in integrated pest management for crops