Reclassification of <i>Vibrio hollisae</i> as <i>Grimontia hollisae</i> gen. nov., comb. nov.

The taxonomic positions of three representative strains of Vibrio hollisae (LMG 17719T, LMG 21416 and LMG 21538) were investigated by means of 16S rDNA sequences and phenotypic data. V. hollisae strains (GenBank/EMBL accession nos AJ514909–AJ514911) shared 99·5 % 16S rDNA sequence similarity, but had only 94·6 % similarity to their closest phylogenetic neighbour, Enterovibrio norvegicus. 16S rDNA sequence similarity of V. hollisae and Vibrio cholerae was only 91 %. These results suggest that V. hollisae should be placed into a novel genus, for which the name Grimontia gen. nov. is proposed

A Novel Approach for Performance Characterization of IaaS Clouds

The ability to predict the energy consumption of an HPC task, varying the number of assigned nodes, can lead to the ability to assign the correct number of nodes to tasks, saving large amount of energy. In this paper we present LBM, a model capable of predicting the resource usage (applicable to different resources, such as completion time and energy consumption) of programs, following a black box approach, where only passive measures of the running program are used to build the prediction model, without requiring its source code, or static analysis of the binary. LBM builds the predicting model using other programs as benchmarks. We tested LBM predicting the energy consumption of pitzDaily, a case of the OpenFOAM CFD suite, using a very low number of benchmarks (3), obtaining extremely precise predictions

Use of <i>recA</i> as an alternative phylogenetic marker in the family <i>Vibrionaceae</i>

This study analysed the usefulness of recA gene sequences as an alternative phylogenetic and/or identification marker for vibrios. The recA sequences suggest that the genus Vibrio is polyphyletic. The high heterogeneity observed within vibrios was congruent with former polyphasic taxonomic studies on this group. Photobacterium species clustered together and apparently nested within vibrios, while Grimontia hollisae was apart from other vibrios. Within the vibrios, Vibrio cholerae and Vibrio mimicus clustered apart from the other genus members. Vibrio harveyi- and Vibrio splendidus-related species formed compact separated groups. On the other hand, species related to Vibrio tubiashii appeared scattered in the phylogenetic tree. The pairs Vibrio coralliilyticus and Vibrio neptunius, Vibrio nereis and Vibrio xuii and V. tubiashii and Vibrio brasiliensis clustered completely apart from each other. There was a correlation of 0·58 between recA and 16S rDNA pairwise similarities. Strains of the same species have at least 94 % recA sequence similarity. recA gene sequences are much more discriminatory than 16S rDNA. For 16S rDNA similarity values above 98 % there was a wide range of recA similarities, from 83 to 99 %

Homotopy on spatial graphs and generalized Sato-Levine invariants

Edge-homotopy and vertex-homotopy are equivalence relations on spatial graphs which are generalizations of Milnor's link-homotopy. Fleming and the author introduced some edge (resp. vertex)-homotopy invariants of spatial graphs by applying the Sato-Levine invariant for the constituent 2-component algebraically split links. In this paper, we construct some new edge (resp. vertex)-homotopy invariants of spatial graphs without any restriction of linking numbers of the constituent 2-component links by applying the generalized Sato-Levine invariant.Comment: 16 pages, 13 figure

Duurzame schaalvergroting : kansen en dilemma's voor de biologische landbouw

Belangrijkste uitkomsten van dit onderzoek zijn: schaalvergroting in de biologische landbouw kan bijdragen aan verduurzaming; grotere biologische bedrijven kennen wel een aantal aandachtspunten; dure grond remt de groei van biologische bedrijven

<i>Vibrio neptunius</i> sp. nov., <i>Vibrio brasiliensis</i> sp. nov. and <i>Vibrio xuii</i> sp. nov., isolated from the marine aquaculture environment (bivalves, fish, rotifers and shrimps)

The fluorescent amplified fragment length polymorphism (FAFLP) groups A5 (21 isolates), A8 (6 isolates) and A23 (3 isolates) distinguished in an earlier paper (Thompson et al., Syst Appl Microbiol 24, 520-538, 2001) were examined in more depth. These three groups were phylogenetically related to Vibrio tubiashii, but DNA-DNA hybridization experiments proved that the three AFLP groups are in fact novel species. Chemotaxonomic and phenotypic analyses further revealed several differences among the 30 isolates and known Vibrio species. It is proposed to accommodate these isolates in three novel species, namely Vibrio neptunius (type strain LMG 20536T; EMBL accession no. AJ316171; G + C content of the type strain 46·0 mol%), Vibrio brasiliensis (type strain LMG 20546T; EMBL accession no. AJ316172; G + C content of the type strain 45·9 mol%) and Vibrio xuii (type strain LMG 21346T; EMBL accession no. AJ316181; G + C content of the type strain 46·6 mol%). These species can be differentiated on the basis of phenotypic features, including fatty acid composition (particularly 14 : 0 iso, 14 : 0 iso 3-OH, 16 : 0 iso, 16 : 0, 17 : 0 and 17 : 1?8c), enzyme activities and utilization and fermentation of various carbon sources