Scheduling of unit-length jobs with bipartite incompatibility graphs on four uniform machines

In the paper we consider the problem of scheduling $n$ identical jobs on 4 uniform machines with speeds $s_1 \geq s_2 \geq s_3 \geq s_4,$ respectively. Our aim is to find a schedule with a minimum possible length. We assume that jobs are subject to some kind of mutual exclusion constraints modeled by a bipartite incompatibility graph of degree $\Delta$, where two incompatible jobs cannot be processed on the same machine. We show that the problem is NP-hard even if $s_1=s_2=s_3$. If, however, $\Delta \leq 4$ and $s_1 \geq 12 s_2$, $s_2=s_3=s_4$, then the problem can be solved to optimality in time $O(n^{1.5})$. The same algorithm returns a solution of value at most 2 times optimal provided that $s_1 \geq 2s_2$. Finally, we study the case $s_1 \geq s_2 \geq s_3=s_4$ and give an $O(n^{1.5})$-time $32/15$-approximation algorithm in all such situations

Draft Genome Sequence of the Type Strain Pseudomonas jessenii DSM 17150

We present the draft genome sequence of Pseudomonas jessenii type strain DSM 17150. The assembly consists of 13 contigs, contains 6,537,206 bp, and has a GC content of 59.7%

Draft Genome Sequence of the Type Strain Pseudomonas umsongensis DSM 16611

Here, we report the draft genome sequence of Pseudomonas umsongensis type strain DSM 16611. The assembly consists of 14 contigs containing 6,701,403 bp with a GC content of 59.73%

Draft Genome Sequence of the Type Strain Sphingopyxis bauzanensis DSM 22271

We present here the draft genome sequence of Sphingopyxis bauzanensis DSM 22271. The assembly contains 4,258,005 bp in 28 scaffolds and has a GC content of 63.3%. A series of specific genes involved in the catabolism or transport of aromatic compounds was identified

Pseudomonas silesiensis sp. nov. strain A3 T isolated from a biological pesticide sewage treatment plant and analysis of the complete genome sequence

Microorganisms classified in to the Pseudomonas genus are a ubiquitous bacteria inhabiting variety of environmental niches and have been isolated from soil, sediment, water and different parts of higher organisms (plants and animals). Members of this genus are known for their metabolic versatility and are able to utilize different chemical compounds as a source of carbon, nitrogen or phosphorus, which makes them an interesting microorganism for bioremediation or bio-transformation. Moreover, Pseudomonas sp. has been described as a microorganism that can easily adapt to new environmental conditions due to its resistance to the presence of high concentrations of heavy metals or chemical pollution. Here we present the isolation and analysis of Pseudomonas silesiensis sp. nov. strain A3T isolated from peaty soil used in a biological wastewater treatment plant exploited by a pesticide packaging company. Phylogenetic MLSA analysis of 4 housekeeping genes (16S rRNA, gyrB, rpoD and rpoB), complete genome sequence comparison (ANIb, Tetranucleotide identity, digital DDH), FAME analysis, and other biochemical tests indicate the A3T strain (type strain PCM 2856T=DSM 103370T) differs significantly from the closest relative species and therefore represents a new species within the Pseudomonas genus. Moreover, bioinformatic analysis of the complete sequenced genome showed that it consists of 6,823,539bp with a 59.58mol% G+C content and does not contain any additional plasmids. Genome annotation predicted the presence of 6066 genes, of which 5875 are coding proteins and 96 are RNA genes

Influence of approaches in CFD Solvers on Performance Prediction in Screw Compressors

Computational Fluid Dynamics (CFD) offers insight into screw compressor designs beyond the capabilities of other conventional methods. It allows evaluation of local flow patterns which influence performance but are difficult or impossible to investigate experimentally. Implementation of CFD in these machines is challenging due to the physics of the flow, the properties of the working fluids and the complexity of flow passages which change size and position. This is additionally challenged by a lack of methodologies available to generate the meshes required for the full three dimensional transient simulations. Commercially available CFD solvers need to fully interact with customized grid generators to enable resolution of grid deformation during a flow solution. However, the factors that influence flow predictions are not only related to grids but also to the approach which CFD solvers use to calculate distribution of parameters such as pressure, velocities, temperatures, etc. In this paper, two approaches most commonly used in commercial CFD software are compared and analysed. The first is a segregated cell-centre based solver and the second is a coupled vertex-centre based solver. Both are pressure based finite volume solvers. Customized grid generation software is used for meshing of moving rotors and flow domains around the rotors in an oil free air screw compressor with ‘N’ rotor profile of 3/5 lobe combination. The deforming rotor grid is maintained as identical in both solvers. The performance predictions obtained by calculations with these two CFD models are compared with measurements obtained on the test compressor in the City University London test rig. The comparison includes pressure in the compressor chamber, mass flow rate, indicated power and the volumetric efficiency. The study reveals differences between the results obtained by two different solvers and the experimental results. Analysis presented in this paper provides a good basis for further consideration of differencing schemes and other characteristics and settings for different CFD solvers in order to achieve accurate predictions of flows in positive displacement machines

Draft Genome Sequence of the Type Strain Sphingopyxis witflariensis DSM 14551

Here, we present the draft genome sequence of Sphingopyxis witflariensis strain DSM 14551. The assembly consists of 38 contigs and contains 4,306,761 bp, with a GC content of 63.3%

A tabu search heuristic for the Equitable Coloring Problem

The Equitable Coloring Problem is a variant of the Graph Coloring Problem where the sizes of two arbitrary color classes differ in at most one unit. This additional condition, called equity constraints, arises naturally in several applications. Due to the hardness of the problem, current exact algorithms can not solve large-sized instances. Such instances must be addressed only via heuristic methods. In this paper we present a tabu search heuristic for the Equitable Coloring Problem. This algorithm is an adaptation of the dynamic TabuCol version of Galinier and Hao. In order to satisfy equity constraints, new local search criteria are given. Computational experiments are carried out in order to find the best combination of parameters involved in the dynamic tenure of the heuristic. Finally, we show the good performance of our heuristic over known benchmark instances

Isolation and Characterization of Pseudomonas spp. Strains That Efficiently Decompose Sodium Dodecyl Sulfate

Due to their particular properties, detergents are widely used in household cleaning products, cosmetics, pharmaceuticals, and in agriculture as adjuvants tailoring the features of pesticides or other crop protection agents. The continuously growing use of these various products means that water soluble detergents have become one of the most problematic groups of pollutants for the aquatic and terrestrial environments. Thus it is important to identify bacteria having the ability to survive in the presence of large quantities of detergent and efficiently decompose it to non-surface active compounds. In this study, we used peaty soil sampled from a surface flow constructed wetland in a wastewater treatment plant to isolate bacteria that degrade sodium dodecyl sulfate (SDS). We identified and initially characterized 36 Pseudomonas spp. strains that varied significantly in their ability to use SDS as their sole carbon source. Five isolates having the closest taxonomic relationship to the Pseudomonas jessenii subgroup appeared to be the most efficient SDS degraders, decomposing from 80 to 100% of the SDS present in an initial concentration 1 g/L in less than 24 h. These isolates exhibited significant differences in degree of SDS degradation, their resistance to high detergent concentration (ranging from 2.5 g/L up to 10 g/L or higher), and in chemotaxis toward SDS on a plate test. Mass spectrometry revealed several SDS degradation products, 1-dodecanol being dominant; however, traces of dodecanal, 2-dodecanol, and 3-dodecanol were also observed, but no dodecanoic acid. Native polyacrylamide gel electrophoresis zymography revealed that all of the selected isolates possessed alkylsulfatase-like activity. Three isolates, AP3_10, AP3_20, and AP3_22, showed a single band on native PAGE zymography, that could be the result of alkylsulfatase activity, whereas for isolates AP3_16 and AP3_19 two bands were observed. Moreover, the AP3_22 strain exhibited a band in presence of both glucose and SDS, whereas in other isolates, the band was visible solely in presence of detergent in the culture medium. This suggests that these microorganisms isolated from peaty soil exhibit exceptional capabilities to survive in, and break down SDS, and they should be considered as a valuable source of biotechnological tools for future bioremediation and industrial applications

On bipartization of cubic graphs by removal of an independent set

We study a new problem for cubic graphs: bipartization of a cubic graph Q by deleting sufficiently large independent set I. It can be expressed as follows: Given a connected n-vertex tripartite cubic graph Q = (V, E) with independence number α(Q), does Q contain an independent set I of size k such that Q − I is bipartite? We are interested for which value of k the answer to this question is affirmative. We prove constructively that if α(Q) ≥ 4n/10, then the answer is positive for each k fulfilling ⌊(n − α(Q))/2⌋ ≤ k ≤ α(Q). It remains an open question if a similar construction is possible for cubic graphs with α(Q) \u3c 4n/10. Next, we show that this problem with α(Q) ≥ 4n/10 and k fulfilling inequalities ⌊n/3⌋ ≤ k ≤ α(Q) can be related to semi-equitable graph 3-coloring, where one color class is of size k, and the subgraph induced by the remaining vertices is equitably 2-colored. This means that Q has a coloring of type (k, ⌈(n − k)/2⌉, ⌊(n − k)/2⌋)