bluuebunny/crossref_metadata_2025 huggingface dataset:
Full-Scale Reynolds Number VIV Testing of Tri-Helically Grooved Drill Riser Buoyancy Module
Authors: Gaskill Collin , Wu Jie , Yin Decao
Published: September 2018

A newly developed Tri-Helically Grooved drilling riser buoyancy module design was tested in the towing tank of SINTEF Ocean in June 2017. This new design aims to reduce riser drag loading and suppress vortex-induced vibrations (VIV). Objectives of the test program were two-fold: to assess the hydrodynamic performance of the design allowing for validation of previous computational fluid dynamics (CFD) studies through empirical measurements, and, to develop a hydrodynamic force coefficient database to be used in numerical simulations to evaluate drilling riser deformation due to drag loading and fatigue lives when subjected to VIV.

This paper provides the parameters of the testing program and a discussion of the results from the various testing configurations assessed.

Tests were performed using large scale, rigid cylinder test models at Reynolds numbers in the super-critical flow regime, defined as starting at a Reynolds number of Re = 3.5 × 105 – 5.0 × 105 (depending on various literatures) and continuing until Re = 3 × 106. Towing tests, with fixed and freely oscillating test models, were completed with both a bare test cylinder and a test cylinder with the Tri-Helical Groove design. Additional forced motion tests were performed on the helically grooved model to calculate lift and added mass coefficients at various amplitudes and frequencies of oscillation for the generation of a hydrodynamic force coefficient database for VIV prediction software.

Significant differences were observed in the hydrodynamic performance of the bare and helically grooved test models considering both in-line (IL) drag and cross-flow (CF) cylinder excitation and oscillation amplitude. For the helically grooved model, measured static drag shows a strong independence from Reynolds number and elimination of the drag crisis region with an average drag coefficient of 0.63.

Effective elimination of VIV and subsequent drag amplification was observed at relatively higher reduced velocities, where the bare test model shows a significant dynamic response. A small level of expected response for the helically grooved model was seen across the lower range of reduced velocities. However, disruption of vortex correlation still occurs in this range and non-sinusoidal and highly amplitude-modulated responses were observed.
Risk Analysis for FPSO Vapor Cloud Explosion Considering Domino Effect
Authors: Wang Mian , Sun Liping , Li Mingxin
Published: September 2018

Floating Production Storage and Offloading (FPSO), a significant offshore oil-gas production system, faces a variety of risks in the process of operation. Vapor cloud explosion (VCE) caused by combustible gas leakage is likely to occur on the topside of FPSO. As an initial accident, VCE has an effect on surrounding devices, leading to subsequent consequences and ampliative scale of the accident. The process, known as the domino effect, can result in severe consequences, indicating that it is necessary to analyze characteristics and impacts of the domino effect on FPSO. In this study, the most risky equipment is determined. VCE overpressure on device surfaces caused by gas leakage of this most risky equipment is calculated, and the results are used for analyzing the domino effect based on Bayesian network.
Station-Keeping Trials in Ice: Ice and Metocean Conditions
Authors: Teigen Sigurd Henrik , Lindvall Joakim K. , Samardzija Ilija , Hansen Roar I.
Published: September 2018

In March 2017, Statoil performed station-keeping trials in drifting ice in the Bay of Bothnia with the two anchor handling tug supply vessels Magne Viking and Tor Viking. During the trials observations of ice and metocean conditions were performed via a range of platforms and techniques. The purpose of the observations was to document the main physical parameters affecting the station-keeping vessel and ice management vessel, as well as giving tactical information on ice conditions and input to simultaneous numerical simulations. Measurements of meteorological parameters (wind speed, wind direction, air temperature, etc.) were done from the two vessels and supplemented with manual observations. Ice drift was independently measured by drifting ice trackers and ADCPs (also measuring ocean current) moored on the sea bed. Measurements of ice thickness were carried out with moored Ice Profiling Sensors (IPSs) and manual ice core samples, which were also analyzed for salinity and temperature profiles. The IPS ice thickness data was later processed together with the ice drift to provide 2D spatial data. The deepest ice ridge keels ranged from 5.4 m at the site with the most benign ice conditions to 10.9 m at the most severe site. Ridge frequency also increased from 2 ridges km−1 to 16 ridges km−1 at the most severe site (given a keel threshold of 3 m). In the present study, statistical summaries of the different time series collected at the sites of the station-keeping trials are presented, highlighting the variability in the ice conditions. Using the vessel tracks and overall drift of the broken channels, ice thickness and drift measurements are classified as being inside or outside the managed ice zone.
Background and New Revision of DNVGL-RP-F108
Authors: Lindberg Bjerke Steinar , Tronskar Jens P. , Chong Steven , Venås Asle
Published: September 2018

DNV-RP-F108 [1] was first issued in 2006. The Recommended Practice was developed to provide guidance on testing and analyses for fracture control of pipeline girth welds subjected to cyclic plastic deformation, e.g. during installation by the reeling method, but also for other situations where pipelines may be subjected to large plastic strains. The Recommended Practice was based upon a Project Guideline developed within the Joint Industry Project “Fracture Control for Installation Methods Introducing Cyclic Plastic Strain - Development of Guidelines for Reeling of Pipelines”.

The new revision is based on the extensive experience and knowledge gained over the years use of the previous versions, as well as new knowledge from recent R&D projects.

The main content of Appendix A of DNV-OS-F101 (now DNVGL-ST-F101) [2] have been transferred to DNVGL-RP-F108. Only the requirements relative to ECA and testing have been retained in DNVGL-ST-F101 [2].

The new revision has got a new number and new title, i.e. DNVGL-RP-F108, “Assessment of Flaws in Pipeline and Riser Girth Welds”.

This paper lists the fundamental changes made in the new RP from the old Appendix A of the previous DNV-OS-F101 and discusses some of the changes, although within this paper it is not possible to cover all changes. The focus is on clarification of use of S-N versus the fracture mechanics approach for fatigue life computation, classification of fatigue sensitive welds, calculations of more accurate crack driving force by re-introduction of the plate solution, for which a new Lr,max (plastic collapse) calculation and a modified way to account for residual stresses have been specified. The RP presents new assessment procedures pertaining to use of finite element analyses for fracture mechanics assessments. A unique feature of the new RP is the guidance on sour service testing and assessments included in the Appendix C of the document to support pipeline/riser ECAs to develop flaw acceptance criteria for NDT.
Lifting Wind Turbine Components From a Floating Vessel: A Review on Current Solutions and Open Problems
Authors: Haselsteiner Andreas F. , Ohlendorf Jan-Hendrik , Oelker Stephan , Ströer Lena , Thoben Klaus-Dieter , Wiedemann Katharina , De Ridder Emmanuel , Lehmann Sven
Published: September 2018

Offshore wind energy is experiencing rapid development and is expected to make up an even bigger part of the worlds future energy mix. New installation concepts for offshore wind farms involve lifting operations of wind turbine components from floating vessels. These installation concepts will only be economic if the lifting operations are performed safely at sea states with high significant wave heights. In this paper, we give an overview of current technical solutions, which could be used to lift the components tower, nacelle, hub and rotor blade from a floating vessel. We classify and analyze solutions found in patents and the academic literature and point out open problems, which need to be addressed to enable lifting operations at higher sea states than what is currently feasible. While enhancements on the vessel and crane can help to achieve this goal as well, this paper only deals with technical solutions concerning the interface between the vessel and the component as well as the interface between the component and the crane. Consequently, we analyze, classify and discuss solutions for the seafastening, the lifting gear as well as motion compensation systems. We find that there exists a large number of solutions, which are specific for a single component, but few solutions, which are applicable to all components without adaptations. Additionally, we miss hydraulic seafastening mechanisms, which are remotely controlled and synchronized with the lifting operation. Consequently, we argue that standardized interfaces between the component and the crane as well as remotely controlled and synchronized seafastening mechanisms are best suited to enhance the lifting process.
A Flexible Connector Design for Multi-Modular Floating Structures
Authors: Zhao Huai , Xu Daolin , Zhang Haicheng , Shi Qijia
Published: September 2018

The paper aims to provide a novel flexible connector model for the connection of a multi-modular floating platform. The structural model of the connector is presented. To evaluate connector loads, the governing equation for a modularized floating platform is established using the Rigid Module Flexible Connector (RMFC) model. The dynamic analysis for a two-module floating platform is carried out by using the frequency domain approach in random waves and the extreme loads of the flexible connector are estimated. The finite element method is applied for strength and stiffness analysis to assess the performance of the connector.
Numerical and Experimental Research on the Ultimate Strength for a Stiffened Titanium Cylinder
Authors: Yuan Siming , Chen Qiang
Published: September 2018

Titanium alloys are widely used in naval ships due to its high strength, low density, no magnetism, corrosion resistance and so on. However, the material nonlinearity brings new challenges to the ultimate strength evaluation on the Titanium structure. This work is to evaluate the ultimate strength for a stiffened titanium cylinder with consideration of material nonlinearity by numerical analysis and scaled model experiment. Firstly, a series of titanium alloy stiffened cylinder pressure hulls are analyzed for their ultimate strength by non-linear Finite Element Method (FEM). Secondly, model tests are carried out for the above titanium cylinders to obtain their ultimate carrying capacity. Thirdly, the good agreement between experiment and numerical results verify that the numerical simulation method is suitable for ultimate strength evaluation. Finally, some influential factors on the ultimate capacity of the stiffened titanium cylinder are investigated, including stiffeners arrangement, thickness of cylinder hulls, inside diameter. The research work can map the limitations of the current rules and to support the development of ultimate strength assessment guidelines for titanium cylinder pressure hulls.
Integrity of Sour Gas Pipeline Despite Local Hard Zones
Authors: Salama Mamdouh M. , Rincon Hernan , Wilson Stuart
Published: September 2018

The recent premature failure of TMCP steel pipes handling sour gas was attributed to the presence of local hard spots. This raised concern regarding the suitability of the Thermo-Mechanically Controlled Process (TMCP) steel for sour service. The paper discusses the impact of hard spots on pipeline fracture resistance in sour service, proposes a basis for steel specification to avoid the formation of hard spots and presents a recommended qualification program to ensure the integrity of the steel pipelines despite the presence of hard spots.
Structural Configuration Selection and Optimization of 7th Generation Semi-Submersible Drilling Unit
Authors: Li De-Jiang , Fu Qiang , Du Zhi-Fu , Xiao Yuan , Han Rong-Gui , Sun Hai-Hong
Published: September 2018

The 7th generation semi-submersible drilling unit (CSDU) represents a significant step forward for the ultra deepwater drilling units in terms of equipment specifications, operational efficiency, flexibility and reliability. Due to significant Variable Deck Load (VDL) increase, the 7th generation CSDU to be designed with larger main dimensions and particulars compared with its previous generations, which brings up a big challenge of the structural design. This paper presents the structural configuration selection and optimization design based on the profound investigation on the load-resistance characteristics of the overall structures and considering the stress distribution variation of the deck box with the integration of different lower hull configurations. This paper also investigates the effects of different types of upper and lower hull joints on the structural strength and fatigue in way of the main connection regions and provides the major connection optimization design. The optimized configuration and major connections have been used in the structural design of the 7th generation semi-submersible drilling unit.
Laboratory Set-Up for Determination of Cement Sheath Integrity During Pressure Cycling
Authors: Skorpa Ragnhild , Øia Thomas , Taghipour Ali , Vrålstad Torbjørn
Published: September 2018

The annular cement sheath is one of the most important well barrier elements, both during production and after well abandonment. It is however well-known that repeated pressure and temperature variations in the wellbore during production and injection can have a detrimental effect on the integrity of the cement sheath. Degradation of cement sheaths result in formation of cracks and microannuli, which leads to loss of zonal isolation and subsequent pressure build-up in the annulus. It is therefore important to study and understand cement sheath failure mechanisms to prevent such barrier failures.

A unique laboratory set-up with downscaled samples of rock, cement and pipe has been constructed to study cement sheath failure mechanisms such as radial crack formation and debonding during pressure cycling. Cement integrity before and after pressure cycling is monitored by X-ray computed tomography (CT), which enables 3D visualization and quantification of radial cracks formed inside the cement sheath as well as debonding towards casing and formation.

This paper describes this laboratory set-up in detail. Furthermore, some preliminary experimental results are also included that demonstrates the applicability and functionality of the new set-up.
A Simple and Robust Method for Calculating Return Periods of Ocean Waves
Authors: Mackay Edward B. L. , Johanning Lars
Published: September 2018

A new method is introduced for combining the long-term distribution of sea states with the short-term distribution of individual wave or crest heights, conditional on sea state. The method uses a Monte Carlo approach to simulate random realisations of the maximum wave or crest height in each sea state. A peaks-over-threshold analysis is conducted on the random maxima in each sea state in order to estimate the long-term distribution of individual wave or crest heights. The new method is significantly simpler than existing methods such as the equivalent storm approach, requires fewer assumptions and has similar computational times. The new method is applied to a 35 year dataset of wave buoy measurements and is shown to produce almost identical estimates of return values of individual crest heights to the equivalent storm method.
A Steel Lazy Wave Riser for Turret vs. Spread-Moored FPSO in Extreme and Wave-Induced Fatigue Conditions
Authors: Szczepanski David , Balash Cheslav , Martens Marius
Published: September 2018

Here, the performance of a steel lazy-wave riser (SLWR) was numerically investigated and compared to a conventional steel catenary riser (SCR) for an internal turret and spread-moored FPSO in extreme 100-yr return and ambient metocean conditions. As expected, the SLWR demonstrated favourable characteristics by the elimination of local dynamic buckling in the touch down zone (TDZ) via a wave configuration that decouples surface-motion, hence significantly reducing the maximum stress and fatigue damage. Non-collinear waves and current in the oblique direction relative to the vessel heading showed amplified stress concentrations in the sag and hog sections as a response to the increased compressive (heave and pitch) vessel motions. Correspondingly, in the ultimate limit state, a SLWR showed similar stresses for both turret and spread-moored FPSOs. However, the turret-mounted SLWR demonstrated a less superior fatigue life compared to its midship-mounted, spread-moored counterpart, owing to riser hangoff location differences and correspondingly varied motions experienced by the riser.
Nonlinear Deepwater Extreme Wave Height and Modulation Wave Length Relation
Authors: Mohtat Ali , Yim Solomon C. , Osborne Alfred R. , Chen Ming
Published: September 2018

Prediction of extreme wave heights has always been a challenge in both the naval and energy industries. The survivability and safe operation and design of marine vehicles and devices are highly dependent on the probability distribution of the wave heights of extreme waves. In traditional linear approaches, researchers use various probability distribution functions mostly generated from field measurements and are usually modified with some statistical methods to account for the distribution of wave heights. These approaches do not take into account nonlinearity and instability in wave train behavior and solely relies on linear wave theory assumptions and perhaps some second order effects in more advanced probability models. This study emphasizes the application of modulation wavelengths and periods, resulting from modulational instability analysis of the nonlinear Schrödinger equation (NLS). In this study, state-of-the-art nonlinear Fourier analysis (NLFA) based on NLS is employed to calculate the unstable wave components. The resulting rise time and travel distance for such unstable modes and their maximum possible growth amplitudes are used to derive a range of probable occurrences. Numerical simulation results from CFD computations are used to examine the capability of such an approach in predicting the magnitude and location of extreme wave occurrence. It is shown that application of the proposed NLS-based analytical procedure enables a more accurate prediction of the extreme wave field.
The SWARMs Approach to Integration of Underwater and Overwater Communication Sub-Networks and Integration of Heterogeneous Underwater Communication Systems
Authors: Pacini Francesco , Paoli Giacomo , Cayón Iván , Rivera Tamara , Sarmiento Beatriz , Kebkal Konstantin , Kebkal Oleksiy , Kebkal Veronika , Geelhoed Joost , Schipperijn Bart , Dol Henry , Skogseth Torstein
Published: September 2018

The management of a heterogeneous mix of underwater vehicles needs a robust and reliable communication network, able to connect the remote command and control station (typically ashore or on board of a support ship) with nodes and vehicles in the deep sea. On the basis of this scenario, the infrastructure shall satisfy requirements such as: medium to extremely long distances between the control room and the area of operation; management of a variable number and type of nodes and vehicles (mobile, fixed, underwater, surfaced); a guaranteed bandwidth to send commands and receive platform status and tasks execution information with minimum latency; a high bitrate to transfer sensor data, pictures and videos in “near real time”; etc.

Compared to the available solutions used nowadays for radio communication systems, the underwater environment imposes several constraints on the maximum achievable bandwidth and distance, drastically reducing data transfer rates. This means that the full communication network is a trade-off between different requirements and performances. The SWARMs project approach to this problem is to select, combine and integrate different and heterogeneous communication technologies, components and solutions, in order to obtain the best performances for the management and control of underwater vehicles during the execution of different missions and tasks.

The network is mainly based on commercial components, but specific adaptations were made in order to fulfil the requirements of ad hoc underwater and overwater sub networks in maritime specific scenarios. Several experiments and sea trials have allowed the verification of the performance of the full network and the optimization of its configuration according to the mission needs.
International Standards Used Locally Worldwide: Adopting ISO Standards for the (Offshore) Oil and Gas Industry As National Standard by 34 European Countries in a Single Process
Authors: Dakhorst J. E. J. (Jarno)
Published: September 2018

Standardisation is the process of developing a standard at an international, regional or national level. The oil and gas industry welcomes international standards as tool to do its operations efficiently and responsibly, and to demonstrate to comply with regulations, where applicable. In this way, the oil and gas industry uses international standards as part of their licence to operate. Because the oil and gas industry is acting globally, it would like to prevent that they have to deal with different standards depending on the region or country in which they operate. Therefore, the oil and gas industry strives for international standards that are also adopted as national standards across the world. The European oil and gas industry supports this vision by adopting the international standards as European standards, which will then become the national standard as well in 34 European countries at once. Also in the field of offshore structures and more recently Arctic operations, international standards are being developed or revised to respond to the needs of the industry. These standardisation activities include European involvement to ensure alignment of the standards portfolio of the oil and gas industry.
First-order reversal curve diagrams for characterizing ferroelectricity of Hf0.5Zr0.5O2 films grown at different rates
Authors: Goh Youngin , Jeon Sanghun
Published: September 2018

The ferroelectric properties of Hf0.5Zr0.5O2 (HZO) films deposited by atomic layer deposition using various growth rates were systematically investigated by analyzing first-order reversal curve (FORC) diagrams. The FORC diagram is a valuable methodology for characterization of ferroelectric switching by evaluation of subloop hysteresis. These diagrams are tremendously sensitive to changes in the hysteresis loops which can be used to describe switching characteristics. HZO films with a growth rate of 1.5 Å/cycle showed two oppositely biased regions in switching density plots. When decreasing the growth rate to 1.2 and 0.98 Å/cycle, these internal bias fields disappeared, showing one maximum switching current peak. Furthermore, the device fabricated with a growth rate of 1.2 Å/cycle showed the clearest switching current peak, indicating an increase in the magnitude of the switching current, as well as increased remanent polarization. In this paper, the FORC diagram and the result of pulse switching measurements suggest that the growth rate of the thin film is a crucial factor to determine the high quality of HZO ferroelectric films.
Exact solution for the acoustical impulse response of a line source above an absorbing plane
Authors: Ochmann Martin
Published: September 2018

The solution of the two-dimensional (2D) wave equation excited by a Dirac delta function above an infinite plane is the 2D impulse response of the half-space. Equivalently, it can be considered as the sound field generated by an infinite line source in three-dimensional (3D) space. For a point source in 3D, it is possible to express the resulting impulse function in closed form if the infinite plane is characterized by a masslike or pure absorbing behavior. Based on the 3D impulse response above an absorbing plane, a closed form solution for a line source over absorbing ground is found. This solution consists of the direct pressure contribution plus a reflected signal. The analytical expression for the reflection factor R is the main result of the work. R is a simple algebraic function of impedance, time, and spatial coordinates. The acoustical field generated by a line source with a general time dependence can be constructed by convolution. For a Gaussian signal, the resulting pressure is computed numerically. For a rectangular pulse, an analytical solution in 3D and 2D is derived. The deviations from the numerically obtained results are very small.
Spectral change and duration as cues in Australian English listeners' front vowel categorization
Authors: Williams Daniel , Escudero Paola , Gafos Adamantios
Published: September 2018

Australian English /iː/, /ɪ/, and /ɪə/ exhibit almost identical average first (F1) and second (F2) formant frequencies and differ in duration and vowel inherent spectral change (VISC). The cues of duration, F1 × F2 trajectory direction (TD) and trajectory length (TL) were assessed in listeners' categorization of /iː/ and /ɪə/ compared to /ɪ/. Duration was important for distinguishing both /iː/ and /ɪə/ from /ɪ/. TD and TL were important for categorizing /iː/ versus /ɪ/, whereas only TL was important for /ɪə/ versus /ɪ/. Finally, listeners' use of duration and VISC was not mutually affected for either vowel compared to /ɪ/.
Sparse representation-based classification of mysticete calls
Authors: Guilment Thomas , Socheleau Francois-Xavier , Pastor Dominique , Vallez Simon
Published: September 2018

This paper presents an automatic classification method dedicated to mysticete calls. This method relies on sparse representations which assume that mysticete calls lie in a linear subspace described by a dictionary-based representation. The classifier accounts for noise by refusing to assign the observed signal to a given class if it is not included into the linear subspace spanned by the dictionaries of mysticete calls. Rejection of noise is achieved without feature learning. In addition, the proposed method is modular in that, call classes can be appended to or removed from the classifier without requiring retraining. The classifier is easy to design since it relies on a few parameters. Experiments on five types of mysticete calls are presented. It includes Antarctic blue whale Z-calls, two types of “Madagascar” pygmy blue whale calls, fin whale 20 Hz calls and North-Pacific blue whale D-calls. On this dataset, containing 2185 calls and 15 000 noise samples, an average recall of 96.4% is obtained and 93.3% of the noise data (persistent and transient) are correctly rejected by the classifier.
Manifold roles of β-arrestins in GPCR signaling elucidated with siRNA and CRISPR/Cas9
Authors: Luttrell Louis M. , Wang Jialu , Plouffe Bianca , Smith Jeffrey S. , Yamani Lama , Kaur Suneet , Jean-Charles Pierre-Yves , Gauthier Christophe , Lee Mi-Hye , Pani Biswaranjan , Kim Jihee , Ahn Seungkirl , Rajagopal Sudarshan , Reiter Eric , Bouvier Michel , Shenoy Sudha K. , Laporte Stéphane A. , Rockman Howard A. , Lefkowitz Robert J.
Published: September 2018

β-Arrestin proteins fine-tune different GPCR-stimulated pathways that converge on ERK1/2 activation.
Covalent inhibitors of EGFR family protein kinases induce degradation of human Tribbles 2 (TRIB2) pseudokinase in cancer cells
Authors: Foulkes Daniel M. , Byrne Dominic P. , Yeung Wayland , Shrestha Safal , Bailey Fiona P. , Ferries Samantha , Eyers Claire E. , Keeshan Karen , Wells Carrow , Drewry David H. , Zuercher William J. , Kannan Natarajan , Eyers Patrick A.
Published: September 2018

Covalent EGFR family inhibitors bind to and induce the degradation of the pseudokinase TRIB2 to kill cancer cells.
Enterobacter cloacae Complex Sequence Type 171 Isolates Expressing KPC-4 Carbapenemase Recovered from Canine Patients in Ohio
Authors: Daniels Joshua B. , Chen Liang , Grooters Susan V. , Mollenkopf Dixie F. , Mathys Dimitria A. , Pancholi Preeti , Kreiswirth Barry N. , Wittum Thomas E.
Published: September 2018

Companion animals are likely relevant in the transmission of antimicrobial-resistant bacteria.
Enterobacter xiangfangensis
sequence type 171 (ST171), a clone that has been implicated in clusters of infections in humans, was isolated from two dogs with clinical disease in Ohio.
The Combination of Fosfomycin plus Meropenem Is Synergistic for Pseudomonas aeruginosa PAO1 in a Hollow-Fiber Infection Model
Authors: Drusano G. L. , Neely M. N. , Yamada W. M. , Duncanson Brandon , Brown David , Maynard Michael , Vicchiarelli Michael , Louie Arnold
Published: September 2018

Treating high-density bacterial infections is a challenging clinical problem. We have a paucity of new agents that can address this problem.
Refining the Application of Microbial Lipids as Tracers of Staphylococcus aureus Growth Rates in Cystic Fibrosis Sputum
Authors: Neubauer Cajetan , Kasi Ajay S. , Grahl Nora , Sessions Alex L. , Kopf Sebastian H. , Kato Roberta , Hogan Deborah A. , Newman Dianne K.
Published: September 2018

In chronic lung infections, populations of microbial pathogens change and mature in ways that are often unknown, which makes it challenging to identify appropriate treatment options. A promising tool to better understand the physiology of microorganisms in a patient is stable-isotope probing, which we previously developed to estimate the growth rates of
S. aureus
in cystic fibrosis (CF) sputum. Here, we tracked microbial communities in a cohort of CF patients and found that anteiso fatty acids can also originate from other sources in CF sputum. This awareness led us to develop a new workflow for the application of stable-isotope probing in this context, improving our ability to estimate pathogen generation times in clinical samples.
CD4 T Cells, CD8 T Cells, and Monocytes Coordinate To Prevent Rift Valley Fever Virus Encephalitis
Authors: Harmon Jessica R. , Spengler Jessica R. , Coleman-McCray Joann D. , Nichol Stuart T. , Spiropoulou Christina F. , McElroy Anita K.
Published: September 2018

RVFV is found in Africa and the Middle East and is transmitted by mosquitos or through contact with infected animals. Infected individuals can develop mild disease or more severe forms, such as hepatitis or encephalitis. In order to understand why some individuals develop encephalitis, we first need to know which immune functions protect those who do not develop this form of disease. In this study, we used a mouse model of RVFV infection to demonstrate that CD4 T cells, CD8 T cells, and monocytes all contribute to prevention of encephalitis. Their likely mechanism of action is preventing RVFV from ever reaching the brain.
Novel Class of Viral Ankyrin Proteins Targeting the Host E3 Ubiquitin Ligase Cullin-2
Authors: Odon Valerie , Georgana Iliana , Holley Joe , Morata Jordi , Maluquer de Motes Carlos
Published: September 2018

Viruses encode multiple proteins aimed at modulating cellular homeostasis and antagonizing the host antiviral response. Most of these genes were originally acquired from the host and subsequently adapted to benefit the virus. ANK proteins are common in eukaryotes but are unusual amongst viruses, with the exception of poxviruses, where they represent one of the largest protein families. We report here the existence of a new class of viral ANK proteins, termed ANK/BC, that provide new insights into the origin of poxvirus ANK proteins. ANK/BC proteins target the host E3 ubiquitin ligase Cullin-2 via a C-terminal BC box domain and are potent suppressors of the production of inflammatory cytokines, including interferon. The existence of cellular ANK proteins whose architecture is similar suggests the acquisition of a host ANK/BC gene by an ancestral orthopoxvirus and its subsequent duplication and adaptation to widen the repertoire of immune evasion strategies.
Influenza Virus NS1 Protein-RNA Interactome Reveals Intron Targeting
Authors: Zhang Liang , Wang Juan , Muñoz-Moreno Raquel , Kim Min , Sakthivel Ramanavelan , Mo Wei , Shao Dandan , Anantharaman Aparna , García-Sastre Adolfo , Conrad Nicholas K. , Fontoura Beatriz M. A.
Published: September 2018

A key virulence factor of influenza A virus is the NS1 protein, which inhibits various cellular processes to facilitate viral gene expression. The NS1 protein is localized in the nucleus and in the cytoplasm during infection. In the nucleus, NS1 has functions related to inhibition of gene expression that involve protein-protein and protein-RNA interactions. While several studies have elucidated the protein interactome of NS1, we still lack a clear and systematic understanding of the NS1-RNA interactome. Here we reveal a nuclear NS1-RNA interactome and show that NS1 primarily binds intronic sequences within a subset of pre-mRNAs, including the RIG-I pre-mRNA that encodes the main cytoplasmic antiviral sensor of influenza virus infection. Our data here further suggest that NS1 is necessary and sufficient to impair intron processing of the RIG-I pre-mRNA. These findings support a posttranscriptional role for NS1 in the inhibition of RIG-I expression.
Oxidoreductases and Reactive Oxygen Species in Conversion of Lignocellulosic Biomass
Authors: Bissaro Bastien , Várnai Anikó , Røhr Åsmund K. , Eijsink Vincent G. H.
Published: September 2018

Biomass constitutes an appealing alternative to fossil resources for the production of materials and energy. The abundance and attractiveness of vegetal biomass come along with challenges pertaining to the intricacy of its structure, evolved during billions of years to face and resist abiotic and biotic attacks.
Evaluation of the causal effects between subjective wellbeing and cardiometabolic health: mendelian randomisation study
Authors: Wootton Robyn E , Lawn Rebecca B , Millard Louise A C , Davies Neil M , Taylor Amy E , Munafò Marcus R , Timpson Nicholas J , Davis Oliver S P , Davey Smith George , Haworth Claire M A
Published: September 2018

Objectives

To investigate whether the association between subjective wellbeing (subjective happiness and life satisfaction) and cardiometabolic health is causal.

Design

Two sample, bidirectional mendelian randomisation study.

Setting

Genetic data taken from various cohorts comprised of the general population (mostly individuals of European ancestry, plus a small proportion of other ancestries); follow-up analysis included individuals from the United Kingdom.

Participants

Summary data were used from previous genome wide association studies (number of participants ranging from 83 198 to 339 224), which investigated traits related to cardiovascular or metabolic health, had the largest sample sizes, and consisted of the most similar populations while minimising sample overlap. A follow-up analysis included 337 112 individuals from the UK Biobank (54% female (n=181 363), mean age 56.87 years (standard deviation 8.00) at recruitment).

Main outcome measures

Subjective wellbeing and 11 measures of cardiometabolic health (coronary artery disease; myocardial infarction; total, high density lipoprotein, and low density lipoprotein cholesterol; diastolic and systolic blood pressure; body fat; waist to hip ratio; waist circumference; and body mass index).

Results

Evidence of a causal effect of body mass index on subjective wellbeing was seen; each 1 kg/m
2
increase in body mass index caused a −0.045 (95% confidence interval −0.084 to −0.006, P=0.02) standard deviation reduction in subjective wellbeing. Follow-up analysis of this association in an independent sample from the UK Biobank provided strong evidence of an effect of body mass index on satisfaction with health (β=−0.035 unit decrease in health satisfaction (95% confidence interval −0.043 to −0.027) per standard deviation increase in body mass index, P<0.001). No clear evidence of a causal effect was seen between subjective wellbeing and the other cardiometabolic health measures, in either direction.

Conclusions

These results suggest that a higher body mass index is associated with a lower subjective wellbeing. A follow-up analysis confirmed this finding, suggesting that the effect in middle aged people could be driven by satisfaction with health. Body mass index is a modifiable determinant, and therefore, this study provides further motivation to tackle the obesity epidemic because of the knock-on effects of higher body mass index on subjective wellbeing.
Production costs and potential prices for biosimilars of human insulin and insulin analogues
Authors: Gotham Dzintars , Barber Melissa J , Hill Andrew
Published: September 2018

Introduction

High prices for insulin pose a barrier to treatment for people living with diabetes, with an estimated 50% of 100 million patients needing insulin lacking reliable access. As insulin analogues replace regular human insulin (RHI) globally, their relative prices will become increasingly important. Three originator companies control 96% of the global insulin market, and few biosimilar insulins are available. We estimated the price reductions that could be achieved if numerous biosimilar manufacturers entered the insulin market.

Methods

Data on the price of active pharmaceutical ingredient (API) exported from India were retrieved from an online customs database. Manufacturers of insulins were contacted for price quotes. Where market API prices could not be identified, prices were estimated based on comparison of similarity, in terms of manufacturing process, with APIs for which prices were available. Potential biosimilar prices were estimated by adding costs of excipients, formulation, transport, development and regulatory costs, and a profit margin.

Results

The manufacturing processes for RHI and insulin analogues are similar. API prices were US$24 750/kg for RHI, US$68 757/kg for insulin glargine and an estimated US$100 000/kg for other analogues. Estimated biosimilar prices were US$48–71 per patient per year for RHI, US$49–72 for neutral protamine Hagedorn (NPH) insulin and US$78–133 for analogues (except detemir: US$283–365).

Conclusion

Treatment with biosimilar RHI and insulin NPH could cost ≤US$72 per year and with insulin analogues ≤US$133 per year. Estimated biosimilar prices were markedly lower than the current prices for insulin analogues. Widespread availability at estimated prices may allow substantial savings globally.
Synthesis and antimicrobial activity of novel thienopyrimidine linked rhodanine derivatives
Authors: Kerru Nagaraju , Maddila Surya Narayana , Maddila Suresh , Sobhanapuram Sreedhar , Jonnalagadda Sreekantha B.
Published: September 2018

This work presents the preparation of a new series of N-(substituted phenyl)-2-(4-oxo-5-(4-(thieno[2,3-d]-pyrimidin-4-yloxy)benzylidene)-2-thioxothiazolidin-3-yl)acetamide derivatives (8a–8l). A condensation reaction of thienopyrimidin-2-thioxothiazolidin-4-one derivative (5) with various 2-chloro-N-phenylacetamides (7a–7l) was employed to afford the new thienopyrimidine tagged rhodanine derivatives under acetone solvent in the presence of potassium carbonate (K2CO3). All of the novel target molecules were characterized by IR, 1H NMR, 13C NMR, and LC–MS spectral analyses and were screened for their in vitro antimicrobial activity by using the broth dilution method. Compounds 8c, 8g, and 8h found to have antibacterial potency against E. coli, B. subtilis, B. cereus, and K. pneumonia with minimum inhibitory concentrations (MICs) of 3.25–6.25 μg/mL compared with the standard Gentamicin. Compounds 8c and 8f demonstrated better antifungal potency (MIC = 3.25–6.25 μg/mL) against A. flavus, A. niger, P. marneffei, and C. albicans when compared with Fluconazole.
Saturation in heavy quarkonia spectra with energy-dependent confining potential inN-dimensional space
Authors: Al-Jamel Ahmed
Published: September 2018

We study the energy spectra of Schrödinger Hamiltonian in N-dimensional space with Coulomb plus inverse quadratic term [Formula: see text] and energy-dependent confining potential of the form [Formula: see text]. It is found that the energy spectra exhibit saturation effect, where these spectra are suppressed to finite values at large quantum numbers n and/or [Formula: see text] at any dimensional space N. As a typical application, we obtained a compact mass formula for the spectra of heavy quarkonia ([Formula: see text], [Formula: see text]). It is found that the model is capable of reproducing the mass spectra of these systems with observed saturation governed by a factor [Formula: see text]. The comparison of this work predictions with available experimental data as well as other relevant theoretical works is also presented. The eigenfunctions are expressed in terms of the bi-confluent Heun functions.
Quantum backflow in solutions to the Dirac equation of the spin-1 2 free particle
Authors: Su Hong-Yi , Chen Jing-Ling
Published: September 2018

It was known that a free, non-relativistic particle in a superposition of positive momenta can, in certain cases, bear a negative probability current — hence termed quantum backflow. Here, it is shown that more variations can be brought about for a free Dirac particle, particularly when negative-energy solutions are taken into account. Since any Dirac particle can be understood as an antiparticle that acts oppositely (and vice versa), quantum backflow is found to arise in the superposition (i) of a well-defined momentum but different signs of energies, or more remarkably (ii) of different signs of both momenta and energies. Neither of these cases has a counterpart in non-relativistic quantum mechanics. A generalization by using the field-theoretic formalism is also presented and discussed.
Unruh Effect: Introductory notes to quantum effects for accelerated observers
Authors: Frodden Ernesto , Valdés Nicolás
Published: September 2018

These pedagogical notes are dedicated to a derivation of the Unruh effect. There is a special emphasis on the transparency of the arguments and the exhibition of detailed calculations. We assume the reader has a basic knowledge of quantum mechanics and relativity. The notes can hopefully be used in a self-contained way by advanced undergraduate or beginning graduate students.
Entropy in a d-dimensional charged black hole
Authors: Ali Shad , Wang Xin-Yang , Liu Wen-Biao
Published: September 2018

Christodoulou and Rovelli have shown that the interior volume of a Schwarzschild black hole grows linearly with time. The entropy of a scalar field in this interior volume of a Schwarzschild black hole has been calculated and shown to increase linearly with the advanced time too. In this paper, considering Hawking radiation from a d-dimensional charged black hole, we investigate the proportional relation between the entropy of the scalar field in the interior volume and the Bekenstein–Hawking entropy using the method of our previous work. We also derive this proportionality relation using Hamiltonian analysis and find a consistent result. We then investigate the proportionality coefficient with respect to d and find that it gradually decreases as the dimension of space–time increases.
Effect of dielectric environment on plasmonic resonance absorption of graphene nanoribbon arrays
Authors: Guo Zi-Zheng
Published: September 2018

The plasmonic resonance absorption properties of a periodic graphene nanoribbon array are studied in this paper. We discuss the effect of the asymmetricity of the dielectric environment on the plasmonic resonance of the graphene nanoribbon array in order to know which combination of the two dielectric materials surrounding the graphene is most advantageous. The results show that, regardless of the graphene in symmetric and asymmetrical environments, the absorption peak of plasmon resonance shifts to longer wavelengths (shifts red) with the increase of the changing permittivity (permittivities) on one or both sides. This absorption characteristic of the graphene periodic array to external electromagnetic waves originates from the wavelength dependence of the intrinsic graphene plasmons on the environmental medium.
Pressure-induced reversible metallization and phase transition in Zinc Telluride
Authors: Zhuang Yukai , Dai Lidong , Li Heping , Hu Haiying , Liu Kaixiang , Yang Linfei , Pu Chang , Hong Meiling
Published: September 2018

The crystalline and electronic structural properties of Zinc Telluride (ZnTe) are investigated systematically up to [Formula: see text]25 GPa using a diamond anvil cell (DAC) in conjunction with a series of advanced optical and electrical testing methods at both non-hydrostatic and hydrostatic conditions. Based on Raman spectroscopy and AC impedance spectroscopy, ZnTe undergoes two phase transitions from initial zinc-blende phase to cinnabar phase at 7–9 GPa, then it transforms to Cmcm phase at 11–13 GPa under the non-hydrostatic condition. Meantime, the semiconductor to metal phase transition is verified by the temperature-dependent conductivity measurements. In these studies, the pressure points of phase transition and metallization of ZnTe are approximately same under the hydrostatic condition. The feeble influence of non-hydrostatic and hydrostatic conditions on the phase transition and metallization of ZnTe can be reasonably explained by its own crystalline structure from atomic force microscopy and high-resolution transmission electron microscopy.
A Knowledge-Based Real-Time Vision System for Monitoring the Inside of a Fluid Bed Heat Exchanger Chamber
Authors: Kim HyungJun
Published: September 2018

In this paper, we present a vision system with a special camera for knowledge-based real-time monitoring of the inside of a fluid bed heat exchanger (FBHE) chamber in a thermal power plant. With the proposed system, it is possible to monitor the internal flux condition and analyze the inner temperature of a chamber. Due to the fact that the mixture of coal and sand inside a chamber flows by very quickly, there is an immense amount of smoke and dust, which make it difficult to capture images and analyze an existing system. An adaptive average method is proposed here to observe the background internal environment of an FBHE chamber. The experimental results show that real-time monitoring is possible, even under hot and dusty conditions. Preliminary experimental results confirm expectations about the possibility and effectiveness of the developed device for commercialized real-time monitoring systems. They demonstrate that a single camera with embedded image processing software can concurrently analyze the degree of fluidization of a mixture and the temperature of the chamber inside, even in extremely harsh and hazardous conditions. We aim to eventually develop an image analysis system that combines image processing and knowledge engineering techniques.