45 research outputs found

    An automated methodology for optimisation with respect to vessel manoeuvring

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    Over the past two decades the marine industry has been facing ever more stringent and radical environmental aims. These are not only been defined by the International Maritime Organisation (IMO), but also by individual countries defining limitations to greenhouse gases emitted by vessels. To combat this the industry has turned towards the use of more complex fluid analysis tools, both model scale tests and computational simulations. This analysis has not only focused on hull design, but also on hull roughness, hull propeller rudder interaction and the marine environment. The focus of this PhD research is to develop methodologies that can be utilised within the industry to optimise vessel performance. With this research optimisation aimed towards improving vessel manoeuvring, with focus away from the traditional nondimensional methodologies. To do so, this research aims to lean heavily on the utilisation of Reynolds Averaged Navier Stokes (RANS) method within Computational Fluid Dynamics (CFD). Towing tests have been considered the primary means of evaluating designs, not only for resistance but also for vessel motions. This includes the analysis forces and motions from both waves and manoeuvring tests. These tests however can be time consuming and financially costly. Therefore, the industry has begun to utilise CFD analysis at the early design stage as a low-cost and fast alternative. Not only this, but in recent years CFD has begun to achieve a level of accuracy matching towing tank tests. Due to these factors this research has a focus on the use of such computational means to improve vessel performance, with extensive validation against multiple towing tank tests. The research has a focus on developing and understanding that can be used to quickly evaluate a potential ship design’s manoeuvring characteristics. The methodology for simulating a captive harmonic test is presented, which has been validated against towing tank data conducted for the SIMMAN 2014 conference. This methodology is used in conjunction with a fully parametric hull form, developed within this research, to create and evolve equations used for ranking the hull forms manoeuvring performance. These unique equations are used in two optimisations cycles, one on the NPL hull and a further one on a custom hull to improve the vessels performance and efficiency. The optimum NPL hull forms are evaluated through a virtual turning circle manoeuvring simulation in CFD to quantify the improvements made through optimisation. This research developed a novel methodology for ranking manoeuvring characteristics that significantly reduced the overall optimisation time, as well as producing manoeuvring gains over 20% when evaluated in a simulated turning circle manoeuvre. In addition, the research has also presented best practice approaches for developing such a scheme and how to create a parametric setup that enables quick and accurate CFD simulations for complex manoeuvring simulations. This has been extensively validated against benchmark studies of the DTMB hull form from the SIMMAN 14 towing tank data.Over the past two decades the marine industry has been facing ever more stringent and radical environmental aims. These are not only been defined by the International Maritime Organisation (IMO), but also by individual countries defining limitations to greenhouse gases emitted by vessels. To combat this the industry has turned towards the use of more complex fluid analysis tools, both model scale tests and computational simulations. This analysis has not only focused on hull design, but also on hull roughness, hull propeller rudder interaction and the marine environment. The focus of this PhD research is to develop methodologies that can be utilised within the industry to optimise vessel performance. With this research optimisation aimed towards improving vessel manoeuvring, with focus away from the traditional nondimensional methodologies. To do so, this research aims to lean heavily on the utilisation of Reynolds Averaged Navier Stokes (RANS) method within Computational Fluid Dynamics (CFD). Towing tests have been considered the primary means of evaluating designs, not only for resistance but also for vessel motions. This includes the analysis forces and motions from both waves and manoeuvring tests. These tests however can be time consuming and financially costly. Therefore, the industry has begun to utilise CFD analysis at the early design stage as a low-cost and fast alternative. Not only this, but in recent years CFD has begun to achieve a level of accuracy matching towing tank tests. Due to these factors this research has a focus on the use of such computational means to improve vessel performance, with extensive validation against multiple towing tank tests. The research has a focus on developing and understanding that can be used to quickly evaluate a potential ship design’s manoeuvring characteristics. The methodology for simulating a captive harmonic test is presented, which has been validated against towing tank data conducted for the SIMMAN 2014 conference. This methodology is used in conjunction with a fully parametric hull form, developed within this research, to create and evolve equations used for ranking the hull forms manoeuvring performance. These unique equations are used in two optimisations cycles, one on the NPL hull and a further one on a custom hull to improve the vessels performance and efficiency. The optimum NPL hull forms are evaluated through a virtual turning circle manoeuvring simulation in CFD to quantify the improvements made through optimisation. This research developed a novel methodology for ranking manoeuvring characteristics that significantly reduced the overall optimisation time, as well as producing manoeuvring gains over 20% when evaluated in a simulated turning circle manoeuvre. In addition, the research has also presented best practice approaches for developing such a scheme and how to create a parametric setup that enables quick and accurate CFD simulations for complex manoeuvring simulations. This has been extensively validated against benchmark studies of the DTMB hull form from the SIMMAN 14 towing tank data

    Persistence of Environmental DNA in Freshwater Ecosystems

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    The precise knowledge of species distribution is a key step in conservation biology. However, species detection can be extremely difficult in many environments, specific life stages and in populations at very low density. The aim of this study was to improve the knowledge on DNA persistence in water in order to confirm the presence of the focus species in freshwater ecosystems. Aquatic vertebrates (fish: Siberian sturgeon and amphibian: Bullfrog tadpoles) were used as target species. In control conditions (tanks) and in the field (ponds), the DNA detectability decreases with time after the removal of the species source of DNA. DNA was detectable for less than one month in both conditions. The density of individuals also influences the dynamics of DNA detectability in water samples. The dynamics of detectability reflects the persistence of DNA fragments in freshwater ecosystems. The short time persistence of detectable amounts of DNA opens perspectives in conservation biology, by allowing access to the presence or absence of species e.g. rare, secretive, potentially invasive, or at low density. This knowledge of DNA persistence will greatly influence planning of biodiversity inventories and biosecurity surveys

    Post-TB health and wellbeing

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    TB affects around 10.6 million people each year and there are now around 155 million TB survivors. TB and its treatments can lead to permanently impaired health and wellbeing. In 2019, representatives of TB affected communities attending the ‘1st International Post-Tuberculosis Symposium´ called for the development of clinical guidance on these issues. This clinical statement on post-TB health and wellbeing responds to this call and builds on the work of the symposium, which brought together TB survivors, healthcare professionals and researchers. Our document offers expert opinion and, where possible, evidence-based guidance to aid clinicians in the diagnosis and management of post-TB conditions and research in this field. It covers all aspects of post-TB, including economic, social and psychological wellbeing, post TB lung disease (PTLD), cardiovascular and pericardial disease, neurological disability, effects in adolescents and children, and future research needs

    Exploiting bacterial DNA gyrase as a drug target: current state and perspectives

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    DNA gyrase is a type II topoisomerase that can introduce negative supercoils into DNA at the expense of ATP hydrolysis. It is essential in all bacteria but absent from higher eukaryotes, making it an attractive target for antibacterials. The fluoroquinolones are examples of very successful gyrase-targeted drugs, but the rise in bacterial resistance to these agents means that we not only need to seek new compounds, but also new modes of inhibition of this enzyme. We review known gyrase-specific drugs and toxins and assess the prospects for developing new antibacterials targeted to this enzyme

    2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

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    Correction to: 2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales. Archives of Virology (2021) 166:3567–3579. https://doi.org/10.1007/s00705-021-05266-wIn March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.This work was supported in part through Laulima Government Solutions, LLC prime contract with the US National Institute of Allergy and Infectious Diseases (NIAID) under Contract No. HHSN272201800013C. J.H.K. performed this work as an employee of Tunnell Government Services (TGS), a subcontractor of Laulima Government Solutions, LLC under Contract No. HHSN272201800013C. This work was also supported in part with federal funds from the National Cancer Institute (NCI), National Institutes of Health (NIH), under Contract No. 75N91019D00024, Task Order No. 75N91019F00130 to I.C., who was supported by the Clinical Monitoring Research Program Directorate, Frederick National Lab for Cancer Research. This work was also funded in part by Contract No. HSHQDC-15-C-00064 awarded by DHS S&T for the management and operation of The National Biodefense Analysis and Countermeasures Center, a federally funded research and development center operated by the Battelle National Biodefense Institute (V.W.); and NIH contract HHSN272201000040I/HHSN27200004/D04 and grant R24AI120942 (N.V., R.B.T.). S.S. acknowledges partial support from the Special Research Initiative of Mississippi Agricultural and Forestry Experiment Station (MAFES), Mississippi State University, and the National Institute of Food and Agriculture, US Department of Agriculture, Hatch Project 1021494. Part of this work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (FC001030), the UK Medical Research Council (FC001030), and the Wellcome Trust (FC001030).S

    2020 taxonomic update for phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

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    In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV

    Annual (2023) taxonomic update of RNA-directed RNA polymerase-encoding negative-sense RNA viruses (realm Riboviria: kingdom Orthornavirae: phylum Negarnaviricota)

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    55 Pág.In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.This work was supported in part through the Laulima Government Solutions, LLC, prime contract with the U.S. National Institute of Allergy and Infec tious Diseases (NIAID) under Contract No. HHSN272201800013C. J.H.K. performed this work as an employee of Tunnell Government Services (TGS), a subcontractor of Laulima Government Solutions, LLC, under Contract No. HHSN272201800013C. U.J.B. was supported by the Division of Intramural Resarch, NIAID. This work was also funded in part by Contract No. HSHQDC15-C-00064 awarded by DHS S and T for the management and operation of The National Biodefense Analysis and Countermeasures Centre, a federally funded research and development centre operated by the Battelle National Biodefense Institute (V.W.); and NIH contract HHSN272201000040I/HHSN27200004/D04 and grant R24AI120942 (N.V., R.B.T.). S.S. acknowl edges support from the Mississippi Agricultural and Forestry Experiment Station (MAFES), USDA-ARS project 58-6066-9-033 and the National Institute of Food and Agriculture, U.S. Department of Agriculture, Hatch Project, under Accession Number 1021494. The funders had no role in the design of the study; in the collection, analysis, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of the Army, the U.S. Department of Defence, the U.S. Department of Health and Human Services, including the Centres for Disease Control and Prevention, the U.S. Department of Homeland Security (DHS) Science and Technology Directorate (S and T), or of the institutions and companies affiliated with the authors. In no event shall any of these entities have any responsibility or liability for any use, misuse, inability to use, or reliance upon the information contained herein. The U.S. departments do not endorse any products or commercial services mentioned in this publication. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S.Government retains a non-exclusive, paid up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes.Peer reviewe

    2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

    Get PDF
    In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV

    2021 taxonomic update for phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales

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    peer reviewedIn March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and mended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, yriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and ammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/ or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV

    2020 taxonomic update for phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales

    Full text link
    In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV. © 2020, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply
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