Comparative Genomic Analysis of Vibrio diabolicus and Six Taxonomic Synonyms: A First Look at the Distribution and Diversity of the Expanded Species

Vibrio is a diverse genus of Gammaproteobacteria autochthonous to marine environments worldwide. Vibrio diabolicus and V. antiquarius were originally isolated from deep-sea hydrothermal fields in the East Pacific Rise. These species are closely related to members of the Harveyi clade (e.g., V. alginolyticus and V. parahaemolyticus) that are commonly isolated from coastal systems. This study reports the discovery and draft genome sequence of a novel isolate (Vibrio sp. 939) cultured from Pacific oysters (Crassostrea gigas). Questions surrounding the identity of Vibrio sp. 939 motivated a genome-scale taxonomic analysis of the Harveyi clade. A 49-genome phylogeny based on 1,109 conserved coding sequences and a comparison of average nucleotide identity (ANI) values revealed a clear case of synonymy between Vibrio sp. 939, V. diabolicus Art-Gut C1 and CNCM I-1629, V. antiquarius EX25 and four V. alginolyticus strains (E0666, FF273, TS13, and V2). This discovery expands the V. diabolicus species and makes available six additional genomes for comparative genomic analyses. The distribution of the expanded species is thought to be global given the range of isolation sources (horse mackerel, seawater, sediment, dentex, oyster, artemia and polycheate) and origins (China, India, Greece, United States, East Pacific Rise, and Chile). A subsequent comparative genomic analysis of this new eight-genome subclade revealed a high degree of individual genome plasticity and a large repertoire of genes related to virulence and defense. These findings represent a significant revision to the understanding of V. diabolicus and V. antiquarius as both have long been regarded as distinct species. This first look at the expanded V. diabolicus subclade suggests that the distribution and diversity of this species mirrors that of other Harveyi clade species, which are notable for their ubiquity and diversity

Assessing the Effectiveness of Weighted Information Gap Decision Theory Integrated with Energy Management Systems for Isolated Microgrids

In the context of microgrid, renewable energy variations are still a major concern for operators, especially in industrial applications in which microgrids are typically located in remote areas and are operated autonomously. Information gap decision theory (IGDT) is a nonprobabilistic method utilized to appraise various levels of risk without the availability of statistical data, such as probability density functions of uncertain parameters. Despite such a rewarding feature, the IGDT in its current form is unable to obtain time-varying robustness bands, meaning that it does not take into consideration the system risk imposed by renewable energy injections at each individual time interval in a short-term operation horizon. To overcome this issue, this article presents a modified version of the IGDT named weighted IGDT (W-IGDT), yielding risk-based time-varying robustness bands rather than time-independent ones. This article also proposes a W-IGDT-based energy management system (EMS) based on a linked unit commitment-optimal power flow (UC-OPF) framework, which simultaneously incorporates the generating units on/off status as well as power flow limits into the optimization procedure. In order to illustrate the performance of the proposed EMS, a CIGRE microgrid benchmark is utilized, and the results indicate the effectiveness of the W-IGDT-based EMS in terms of optimal operation and addressing the intermittency of renewable energy sources

Numerical investigation of continuous, high density turbidity currents response, in the variation of fundamental flow controlling parameters

During floods, the density of river water usually increases due to the increase in the concentration of the suspended sediment that the river carries, causing the river to plunge underneath the free surface of a receiving water basin and form a turbidity current that continues to flow along the bottom. The study and understanding of such complex and rare phenomena is of great importance, as they constitute one of the major mechanisms for suspended sediment transport from rivers into the ocean, lakes or reservoirs. In the present paper a previously tested and verified numerical model[1]is applied in laboratory scale numerical experiments of continuous, high density turbidity currents. The turbidity currents are produced by the steady discharge of fresh water – suspended sediment mixtures, into an inclined channel which is connected at its downstream end to a wide horizontal tank. Both, channel and tank are initially filled with fresh water. This configuration serves as a simplified experimental analog of natural, hyperpycnal turbidity currents that are formed at river outflows in the sea, lakes or reservoirs and usually travel within subaqueous canyon-fan complexes. The main aim is to investigate the exact qualitative and quantitative effect of fundamental, flow controlling parameters in the hydrodynamic and depositional characteristics of continuous, high density turbidity currents. According to the authors’ best knowledge, the present paper constitutes the first attempt in the literature, where the isolated effects of each individual controlling parameter as well as their relative importance on the hydrodynamic characteristics of continuous, high-density turbidity currents are quantitatively evaluated in detail. The numerical model used, is based on a multiphase modification of the Reynolds Averaged Navier–Stokes equations (RANS). For turbulence closure the Renormalization-group (RNG) k–ε model is applied, which is an enhanced version of the widely used standard k–ε model