bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Potentially Unmanageable Ice Features
Authors: Shafrova Svetlana , Matskevitch Dmitri , Holub Curtis , Kokkinis Ted 
Published: October 2017

Satellite remote sensing technology plays an important role in ice monitoring and characterization in support of ice management operations for Arctic floating drilling that previously have been described by industry to include three stages: (1) far-field reconnaissance for potentially unmanageable ice features (2) mid-field verification of ice breakability and (3) near-field ice floe size reduction.
The paper discusses the application of satellite remote sensing methods for identification of Potentially Unmanageable Ice Features (PUIF) as well as challenges associated with satellite data interpretation and feature tracking. Examples of PUIF identification using both publicly and commercially available satellite imagery and other remote sensing data collected during the Oden Arctic Technology Research Cruise 2015 (OATRC 2015) are presented and the challenges with the PUIF detection and monitoring are discussed.
In addition, airborne remote sensing systems for PUIF identification, both existing (such as Electromagnetic Induction (EMI)) and under development (such as dual frequency radar, multi-band synthetic aperture radar), are discussed and their capabilities contrasted and compared to satellite-based methods. Furthermore, potential ways of optimally combining airborne and satellite remote sensing are proposed.
Influence of Large Drawdowns in Oil Reservoirs on Fluid Temperature and Fluid Properties
Authors: Islam R. , Hasan A. R. , Kabir C. Shah 
Published: October 2017

The usual assumption of isothermal flow may be unsuitable in low-conductivity formations where large drawdowns occur. The increase in oil temperature associated with Joule-Thompson (J-T) heating triggers the consequent changes in oil viscosity and density. This paper presents an analytical 1D radial-flow model for estimating the transient flowing-fluid temperature in a single-phase oil reservoir. The model allows oil density, viscosity, and the J-T coefficient to vary with pressure and temperature. A rigorous thermodynamic expression based on fluid PVT behavior underpins the proposed model.
A detailed sensitivity analysis has shown the effect of oil production rate on reservoir heating and consequent changes in fluid properties. Specifically, we observed that fluid temperature increase above the original formation temperature occurs with a decrease in formation permeability, an increase in oil viscosity, and a decrease in overall heat-transfer coefficient. Of course, J-T heating increases with increasing flow rate.
Changes in reservoir temperature occur within about 100 ft. from the wellbore. Overall, the lessons learned from this study illuminates the need for reevaluating tubular design, flow-assurance issues related to dissolved solids, and assessment of well productivity index arising from J-T heating.
Consistent VIV Assessment Methodology for Unbonded Flexible Risers
Authors: Ferdi Faycal , Puliafito Marco , Willis Neil 
Published: October 2017

One main objective of assessing vortex-induced vibration (VIV) in deep-water (1000 m) riser design analysis is to determine the VIV fatigue damage. Whilst the VIV assessment methodology is well known for steel catenary risers, the unbonded flexible risers require special attention due to their complex composite behaviour. This is especially true when using the superposition modal approach, which is used in Shear7. The VIV response of unbonded flexible risers when modelled by Shear7 is complex and depends on several parameters, mainly: bending stiffness, modal damping and riser configuration.
Flexible risers exhibit a non-linear moment response due to the stick/slip hysteresis phenomena of the metallic wires. For low curvatures, a flexible pipe is characterised by a high bending stiffness. However, when the applied loads exceed a threshold level given by the friction resistance between the layers, slippage between the layers occur and the corresponding bending stiffness is significantly reduced, which leads to higher curvature levels. This behaviour is characterised by the moment-curvature response, which is specific to each cross section and is highly dependent on operating conditions (pressure, temperature), external conditions (temperature and hydrostatic pressure) and riser configuration (tension distribution).
The objective of this paper is to establish a consistent VIV analysis methodology for unbonded flexible risers taking some of the main critical parameters such as bending stiffness, modal damping, riser configuration and environmental loading into account. This methodology has been developed for a large West African offshore project, where different types of flexible risers with different operating conditions have been assessed. The impact of the pre-slip and post-slip bending stiffness on the VIV response has been studied and an energy-based approach has been used to calculate the modal damping associated with the frictional energy loss due to the stick/slip phenomenon. This energy loss is directly dependent on the curvatures extracted from the modes excited by the oceanic currents acting on the risers. Different riser configurations have also been considered to assess the impact of the vessel offset on the VIV curvature response.
Finally, VIV induced fatigue damage of the flexible risers has been determined using both extreme and long term current profiles assuming steady state current in the VIV model. The fatigue damage has been calculated at several critical locations along each flexible riser by converting the curvature histograms obtained from the VIV assessment into stresses using specific S-N data converting stress cycles into aggregated damage benchmarked against wave-induced damage.
Experimental Investigation of Power Umbilical Damping
Authors: Ottesen Torfinn 
Published: October 2017

Ocean currents may cause vortex induced vibrations (VIV) of deep-water umbilicals and cables. Since the VIV response may give significant contributions to the total fatigue damage it is important to know the structural damping for relevant curvature levels.
A laboratory test has been performed on a 12.5 m long test specimen to determine the damping for a range of curvature levels that are in the vicinity of the stick-slip transition region. The energy input to maintain steady state oscillations with curvature amplitudes in the range 0.0002–0.001 m−1 was measured. The steady state energy input is consistent with damping ratios obtained using the free decay method.
The structural damping depends on construction temperature and curvature and is less for typically low seawater temperature and low curvatures. The transition between the stick- and the slip regime is seen for typical seawater temperature.
Autonomous Flow Control Device Modelling and Completion Optimisation
Authors: Eltaher Eltazy , Muradov Khafiz , Davies David , Grassick Peter 
Published: October 2017

The functions of the various wellbore completion components and their impact on the given well performance should be fully understood to achieve the full potential of advanced wells completions (AWCs).
Inflow control technology has been a success when installed in many fields. Field trials of the more recently developed Autonomous Flow Control Completions (AFCC) have shown their potential to further improve well performance. However, such (autonomous) discrimination and control of the different fluid phases, presents new modelling challenges that require extension of today’s wellbore/reservoir models and workflows for optimizing the completion design. The modelling challenges associated with this new technology requires more research to correctly quantify their added-value and guide future design improvements in AFCC technology.
This paper discusses how the currently available modelling tools can best designed when only single-phase flow performance data is available. Methods and workflows to improve the modelling accuracy, as well as, to understand the performance of an AFCC in a horizontal well in comparison with passive inflow control technology are presented. Novel methods to visualize and optimize the AFCC are presented and used to optimize the equipment design and identify the technology’s added-value.
Finally, this paper presents a modelling workflow for reservoir and well engineering studies by providing optimal AFCC selection guidelines together with a brief summary of an extension of the work reported here to multi-phase flow in typical AFCCs. Incorrect modelling of the devices Multi-Phase Flow Performance was found to effect the economic evaluation of this promising technology; forming an extra barrier to its early adoption.
Multi-Purpose Offshore-Platforms: Past, Present and Future Research and Developments
Authors: Leira Bernt J. 
Published: October 2017

Energy, fisheries and transport infrastructures are increasingly being established offshore. Facilities such as offshore wind farms may occupy large areas and compete with other users of the maritime space. Accordingly, offshore platforms that can combine many functions within the same infrastructure could offer significant benefits. This applies to economy, optimization of spatial planning and minimization of the impact on the environment.
In the present paper, some proposed innovative designs for multi-use offshore platforms are described. The technical, economical and environmental feasibility of designing, installing, operating, servicing and maintaining such platforms are discussed. The relevant platforms under consideration are targeted towards ocean renewable energy (in particular offshore wind), aquaculture and related transport maritime services.
Innovative designs for multi-use offshore platforms that intend to allow optimal coupling of the various activities and services are highlighted. Issues such as safe and efficient installation, operation, maintenance and monitoring are also briefly discussed in the paper.
Whirling Motion of Monopile Offshore Wind Turbines Subjected to Harmonic and Random Base Excitation
Authors: Cai Zhicheng , Zheng Xiang Yuan 
Published: October 2017

In April 2014 a series of 30:1 scaled shake table test of the NREL-5MW monopile offshore wind turbine were conducted. Significant whirling motions were observed during the test [1], which were seldom reported for civil engineering and offshore engineering structures. This study is thereby devoted to revealing the mechanism of the whirling motion of a typical tall monoplie offshore wind turbine.
The original shake table model is simplified into a uniform cantilever beam with a large lumped mass on the top. Two nonlinear coupled integro-differential equations of motion containing cubic nonlinearities due to curvature and inertia are used and solved by both analytical and numerical approaches. The ElCentroExp random base excitation and lateral harmonic base excitations with different amplitudes and frequencies are considered in the analysis to fathom the instability mechanism.
The analysis results show that, for harmonic base excitations with frequency within a specific range, when the amplitude of base excitation and the initial perturbation exceed a certain threshold, stable whirling motion response will be triggered and the motion of shake table model will be controlled by whirling. However, the analysis results also demonstrate that, subjected to the ElCentroExp base excitation or its equivalent lateral harmonic base excitations, neither analytical nor numerical approach can produce whirling motion response, regardless of the damping ratio. The LM model will always show planar motion response. This differs significantly from the observation of shake table model test.
Functional Characterization of CTX-M-14 and CTX-M-15 β-Lactamases by
In Vitro
DNA Shuffling
Authors: Po Kathy Hiu Laam , Chan Edward Wai Chi , Chen Sheng 
Published: October 2017

ABSTRACT

This work investigated the molecular events driving the evolution of the CTX-M-type β-lactamases by the use of DNA shuffling of fragments of the
bla
CTX-M-14
and
bla
CTX-M-15
genes. Analysis of a total of 51 hybrid enzymes showed that enzymatic activity could be maintained in most cases, yet hybrids that were active possessed fewer amino acid substitutions than those that were inactive, suggesting that point mutations in the constructs rather than reshuffling of the fragments of the two target genes would more likely cause disruption of CTX-M activity. For example, the P
67
L and L
261
P changes in a CTX-M-14 fragment could completely abolish the activity of the enzyme on all antibiotics tested. Structural analysis showed that L
216
was located in the active-site β sheet and might interact with the adjacent hydrophobic residues to stabilize the active-site β sheet and maintain the integrity of the enzyme active site. Likewise, a single amino acid substitution, E
64
K, was found to exhibit a significant suppressive effect on CTX-M-15 activity. Structural analysis showed that E
64
might form a salt bridge with R
44
, disruption of which might affect CTX-M-15 activity. Further analysis of the structure-function relationship of a range of mutant enzymes confirmed that, as can be expected, unstable enzymes lose their activity and avoid selective events. These findings suggest that the distal pockets could also contribute to the activity of the enzymes and may be regarded as alternative targets for inhibitor development.
Efficacy of Ceftriaxone, Cefepime, Doxycycline, Ciprofloxacin, and Combination Therapy for Vibrio vulnificus Foodborne Septicemia
Authors: Trinh Sonya A. , Gavin Hannah E. , Satchell Karla J. F. 
Published: October 2017

ABSTRACTFoodborneVibrio vulnificusinfections are associated with higher rates of sepsis and mortality than wound infections; however, antibiotic efficacy studies have not been performed in foodborne infection models. The efficacies of ceftriaxone, cefepime, doxycycline, ciprofloxacin, and combination therapy were assessed inV. vulnificusintestinal infection in mice in order to model foodborne infections. In accordance with prior studies of cefotaxime, cefepime was synergistic with doxycycline and ciprofloxacinin vitro; combination therapy significantly decreased bacterial growth, by ≥2 log10units, from that with antibiotic monotherapy (P< 0.01).In vivo, survival rates in the ceftriaxone (50%), doxycycline (79%), and ciprofloxacin (80%) groups were significantly higher than those in the control group (0%) (P< 0.0001). Survival was significantly higher with ceftriaxone-doxycycline (91%) or ceftriaxone-ciprofloxacin (100%) therapy than with ceftriaxone (50%) (P≤ 0.05). Survival with cefepime-doxycycline (96%) or cefepime-ciprofloxacin (90%) therapy was significantly higher than that with cefepime alone (20%) (P< 0.001). There was no difference in survival between the combination therapy groups. Thus, we conclude that combination therapy was the most effective treatment for foodborneV. vulnificussepticemia. In a septic patient with a recent ingestion of raw seafood, cefepime in combination with doxycycline or ciprofloxacin should be initiated for coverage of resistant Gram-negative organisms andV. vulnificuspending a microbiological diagnosis. Once a diagnosis of foodborneV. vulnificussepticemia is established, treatment can safely transition to ceftriaxone in combination with doxycycline or ciprofloxacin.
Tissue Distribution and Elimination of Isavuconazole following Single and Repeat Oral-Dose Administration of Isavuconazonium Sulfate to Rats
Authors: Schmitt-Hoffmann Anne-Hortense , Kato Kota , Townsend Robert , Potchoiba Michael J. , Hope William W. , Andes David , Spickermann Jochen , Schneidkraut Marlowe J. 
Published: October 2017

ABSTRACT

Quantitative whole-body autoradiography was used to assess the distribution and tissue penetration of isavuconazole in rats following single and repeated oral-dose administration of radiolabeled isavuconazonium sulfate, the prodrug of isavuconazole. Following a single-dose administration of radiolabeled isavuconazonium sulfate (labeled on the active moiety), radioactivity was detectable within 1 h postdose in 56 of 65 tissue/fluid specimens. The highest maximum concentrations (
C
max
) were observed in bile and liver (66.6 and 24.7 μg eq/g, respectively). The lowest
C
max
values were in bone and eye lens (0.070 and 0.077 μg eq/g, respectively). By 144 h postdose, radioactivity was undetectable in all tissues/fluids except liver (undetectable at 336 h) and adrenal gland tissues (undetectable at 672 h). Following daily administration for up to 21 days, 1-h-postdose
C
max
values were the highest on or before day 14 in all except seven tissues/fluids, of which only rectum mucosa and small intestine mucosa had
C
max
values >25% higher than all other 1-h-postdose values. For 24-h-postdose
C
max
values, only large intestine, large intestine mucosa, and urine had the highest
C
max
values at day 21. The penetration of single oral doses of unlabeled isavuconazole (25 mg/kg of body weight isavuconazonium sulfate) and voriconazole (50 mg/kg) into rat brain (assessed using liquid chromatography-tandem mass spectrometry) was also compared. Brain concentration/plasma concentration ratios reached approximately 1.8:1 and 2:1, respectively. These data suggest that isavuconazole penetrates most tissues rapidly, reaches a steady state in most or all tissues/fluids within 14 days, does not accumulate in tissues/fluids over time, and achieves potentially efficacious concentrations in the brain.
Development and Qualification of an Opsonophagocytic Killing Assay To Assess Immunogenicity of a Bioconjugated Escherichia coli Vaccine
Authors: Abbanat Darren , Davies Todd A. , Amsler Karen , He Wenping , Fae Kellen , Janssen Sarah , Poolman Jan T. , van den Dobbelsteen Germie P. J. M. 
Published: October 2017

ABSTRACT

The global burden of disease caused by extraintestinal pathogenic
Escherichia coli
(ExPEC) is increasing as the prevalence of multidrug-resistant strains rises. A multivalent ExPEC O-antigen bioconjugate vaccine could have a substantial impact in preventing bacteremia and urinary tract infections. Development of an ExPEC vaccine requires a readout to assess the functionality of antibodies. We developed an opsonophagocytic killing assay (OPA) for four ExPEC serotypes (serotypes O1A, O2, O6A, and O25B) based on methods established for pneumococcal conjugate vaccines. The performance of the assay was assessed with human serum by computing the precision, linearity, trueness, total error, working range, and specificity. Serotypes O1A and O6A met the acceptance criteria for precision (coefficient of variation for repeatability and intermediate precision, ≤50%), linearity (90% confidence interval of the slope of each strain, 0.80, 1.25), trueness (relative bias range, −30% to 30%), and total error (total error range, −65% to 183%) at five serum concentrations and serotypes O2 and O25B met the acceptance criteria at four concentrations (the lowest concentration for serotypes O2 and O25B did not meet the system suitability test of maximum killing of ≥85% of
E. coli
cells). All serotypes met the acceptance criteria for specificity (opsonization index value reductions of ≤20% for heterologous serum preadsorption and ≥70% for homologous serum preadsorption). The assay working range was defined on the basis of the lowest and highest concentrations at which the assay jointly fulfilled the target acceptance criteria for linearity, precision, and accuracy. An OPA suitable for multiple
E. coli
serotypes has been developed, qualified, and used to assess the immunogenicity of a 4-valent
E. coli
bioconjugate vaccine (ExPEC4V) administered to humans.
RNA Interference Screening Reveals Host CaMK4 as a Regulator of Cryptococcal Uptake and Pathogenesis
Authors: Srikanta Deepa , Hole Camaron R. , Williams Matthew , Khader Shabaana A. , Doering Tamara L. 
Published: October 2017

ABSTRACT

Cryptococcus neoformans
, the causative agent of cryptococcosis, is an opportunistic fungal pathogen that kills over 200,000 individuals annually. This yeast may grow freely in body fluids, but it also flourishes within host cells. Despite extensive research on cryptococcal pathogenesis, host genes involved in the initial engulfment of fungi and subsequent stages of infection are woefully understudied. To address this issue, we combined short interfering RNA silencing and a high-throughput imaging assay to identify host regulators that specifically influence cryptococcal uptake. Of 868 phosphatase and kinase genes assayed, we discovered 79 whose silencing significantly affected cryptococcal engulfment. For 25 of these, the effects were fungus specific, as opposed to general alterations in phagocytosis. Four members of this group significantly and specifically altered cryptococcal uptake; one of them encoded CaMK4, a calcium/calmodulin-dependent protein kinase. Pharmacological inhibition of CaMK4 recapitulated the observed defects in phagocytosis. Furthermore, mice deficient in CaMK4 showed increased survival compared to wild-type mice upon infection with
C. neoformans
. This increase in survival correlated with decreased expression of pattern recognition receptors on host phagocytes known to recognize
C. neoformans
. Altogether, we have identified a kinase that is involved in
C. neoformans
internalization by host cells and in host resistance to this deadly infection.
Model of Chronic Equine Endometritis Involving a Pseudomonas aeruginosa Biofilm
Authors: Ferris Ryan A. , McCue Patrick M. , Borlee Grace I. , Glapa Kristina E. , Martin Kevin H. , Mangalea Mihnea R. , Hennet Margo L. , Wolfe Lisa M. , Broeckling Corey D. , Borlee Bradley R. 
Published: October 2017

ABSTRACTBacteria in a biofilm community have increased tolerance to antimicrobial therapy. To characterize the role of biofilms in equine endometritis, six mares were inoculated withlux-engineeredPseudomonas aeruginosastrains isolated from equine uterine infections. Following establishment of infection, the horses were euthanized and the endometrial surfaces were imaged for luminescence to localize adherentlux-labeled bacteria. Samples from the endometrium were collected for cytology, histopathology, carbohydrate analysis, and expression of inflammatory cytokine genes. Tissue-adherent bacteria were present in focal areas between endometrial folds (6/6 mares). The Pel exopolysaccharide (biofilm matrix component) and cyclic di-GMP (biofilm-regulatory molecule) were detected in 6/6 mares and 5/6 mares, respectively, from endometrial samples with tissue-adherent bacteria (P< 0.05). A greater incidence (P< 0.05) of Pel exopolysaccharide was present in samples fixed with Bouin's solution (18/18) than in buffered formalin (0/18), indicating that Bouin's solution is more appropriate for detecting bacteria adherent to the endometrium. There were no differences (P> 0.05) in the number of inflammatory cells in the endometrium between areas with and without tissue-adherent bacteria. Neutrophils were decreased (P< 0.05) in areas surrounding tissue-adherent bacteria compared to those in areas free of adherent bacteria. Gene expression of interleukin-10, an immune-modulatory cytokine, was significantly (P< 0.05) increased in areas of tissue-adherent bacteria compared to that in endometrium absent of biofilm. These findings indicate thatP. aeruginosaproduces a biofilm in the uterus and that the host immune response is modulated focally around areas with biofilm, but inflammation within the tissue is similar in areas with and without biofilm matrix. Future studies will focus on therapeutic options for elimination of bacterial biofilm in the equine uterus.