bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Simulation of Surface Casing Cementing: Dispersion Effects
Authors: Zhang Ruizi , Frigaard Ian
Published: October 2021

Many numerical studies have been conducted regarding laminar miscible displacement flow in narrow, vertical, eccentric annuli. For the next decade it is likely that primary cementing flows on the scale of the well will continue to be simulated predominantly with 2D gap-averaged (2DGA) models. However, 3D simulations are less common due to the computational cost. The comparison between 2D and 3D models needs further attention, to understand the main discrepancies and thus help to understand primary cementing flows better. In this paper, comparisons of 3D against 2DGA model results show a range of interesting different phenomena, e.g. static layers, dispersive spikes, and instabilities. The predictions of the 2DGA model are the same as the 3D results to a degree. In particular, they are consistent with each other regarding the evolving process, interface shape, etc. However, the main difference with the 2DGA concentration arises from dispersion on the scale of the annular gap. From the recent research of Renteria and Frigaard (J. Fluid Mech., vol. 905, 2020) [1], a variety of dispersive effects are the main discrepancy between experiments and 2DGA results as well. We give representative examples of these flows in surface casing geometries and suggest methods for improvement of the 2DGA model.
Physical Modeling and Simplification of FPSO Topsides Module in Wind Tunnel Model Tests
Authors: Huang Zhenjia (Jerry) , Kim Hyun Joe
Published: October 2021

To evaluate wind load on offshore structures, such as FPSO’s, wind tunnel model test is a common industry practice. Configuration of topsides structures and equipment can be very complex, and it is a practical challenge to model all the structural details for wind tunnel model tests. Sometimes, there may be significant modifications to the topsides over FPSO operation life cycle and there may not be detailed topsides drawing for wind tunnel to use in physical model construction. In practice, wind tunnel laboratories have to simplify physical topsides models. They also use metal meshes to cover the topsides modules to compensate for the force reduction due to the simplification. In order to help establish physical modeling practices of wind tunnel model test, we performed extensive tests using a single topsides module. The original topsides module without simplification and mesh was tested first. Then, two simplifications were adopted in the physical model construction. The module was covered with and without metal mesh of different porosities. Thorough test quality assurance (QA) and quality control (QC) were performed to ensure data quality. Test setup, quality assurance (QA) and results are presented in the paper. The results can be used not only for appropriate physical modeling practices of complex topsides modules, but also for validation of numerical predictions such as Computational Fluid Dynamics (CFD), as well as empirical formulas.
Northern Light Offshore Pipeline – Negative Transport Temperature Inside the HDD
Authors: Blasioli Giuseppe , Marchesani Furio , Badalini Maurizio , Luci Vincenzo , Bekkeheien Tove , Helland Arne Ingvar
Published: October 2021

The transport of CO2 through offshore pipelines is one of the last business that the Operators are beginning to face, in line with the coming needs for climate change mitigations.

The scenario for CO2 Capture, Transport and Storage anticipates capture and treatment at local plants, the transportation by ships in a liquid phase at low temperatures (close to −30 °C) to a terminal for the following offshore submarine transportation in a pipeline up to an injection well, for the final (and permanent) storage underground.

In order to optimize the operating costs for CO2 transport via pipeline, and to reduce energy consumptions, no heating is applied from ship to pipeline inlet. In such case, the pipeline will reach approximately a temperature of −30 °C in the initial landfall section.

The design of the offshore pipeline subject to this operating conditions, very cold fluid inside and a sea water temperature slightly over 0°C outside (North Sea), must face the possibility of ice formation around the pipe.

For the Northern Lights project, this possibility has been analyzed and the HDD (Horizontal Directional Drilling) at landfall resulted the only section where the ice formation could jeopardize the pipeline integrity. Detailed assessment for both normal operating conditions and contingency cases has been performed.

In the former case, a steady state thermal analysis with analytical method (thermal resistances) has been applied to calculate both the longitudinal, along the pipeline axis, and radial temperature profile: all the water inside the HDD freezes. Therefore, a water circulation system has been studied to prevent the ice formation. The pumping system required to ensure enough water flow has been dimensioned considering pressure losses inside the HDD. Power consumption in the order of 3 kW is expected.

The breakdown of the pumps has been analyzed in order to determine the available time before the sea water freeze inside the HDD obstructing any circulation. A transient analysis has been carried out simulating the temperature after water circulation arrest. Both analytical and Finite Element Model have been used to calculate the transient process causing water freezing.
Engineering Criticality Assessments of Floating Offshore Platforms Based on Time Domain Structural Response Analysis
Authors: O’Donnell Jeffrey , Kyoung Johyun , Samaria Sagar , Sablok Anil
Published: October 2021

This paper presents a time-domain S-N fatigue analysis and an approach to reliable and robust engineering criticality assessments to supplement or provide an alternative to S-N fatigue assessments of offshore platform structures based on time domain structural response analysis. It also provides recommendations for industry standards to improve guidance for structural integrity assessments of offshore platforms using fracture mechanics.

Demand continues to grow in the offshore industry to attain value from captured operational data for a number of purposes, including the reduction of uncertainties in structural integrity assessments during design and over the operational lifetime of floating offshore platforms. Recent advances in time domain structural analysis technology demonstrate substantially more accurate assessments of non-linear platform loadings and responses with enhanced computational efficiency. The current S-N approach for fatigue design and integrity assessments calculates a fatigue damage factor that does not address how loading occurs over time (ABS, DNVGL-RP-C203).

For the present study, engineering criticality assessments (ECAs) based on fracture mechanics theory (BS 7910) are applied utilizing time-domain loading information theory. The ECA returns the smallest initial flaws that can grow to a critical size during a design lifetime, which can serve as an indicator of acceptability during design, a technical basis for in-service inspection intervals and facilitates asset integrity and life extension assessments. Critical initial flaws are calculated using the Paris Law (BS 7910) and cumulative fatigue crack growth in two ways: with and without an integrated and consistent check for fracture instability. The results are compared with those from S-N fatigue analyses and recommendations are provided.
A Joint-Industry Effort to Develop and Verify CFD Modeling Practice for Predicting Hydrodynamic Coefficients on Bare Riser Surfaces
Authors: Jang Hyunchul , Agrawal Madhusuden , Lee Dongwhan , Xu Wei , Huang Jerry , Jiang Fengjian , Jie Wu , Croonenborghs Eloïse
Published: October 2021

Hydrodynamic force coefficients are important parameters in design and assessment of marine risers. The hydrodynamic coefficients are widely used for assessing marine riser responses due to floater motion excitation and vortex-induced vibrations (VIV). Traditionally, the hydrodynamic coefficients have been obtained from physical model tests on short rigid riser sections. Recently, the offshore industry has started to use computational fluid dynamics (CFD) analysis for predicting the hydrodynamic coefficients due to the recent advancement of CFD software and high-performance computing capabilities, but a reliable CFD modeling practice is requested for CFD analysis to be a more widely accepted prediction tool in the industry. A joint industry effort has been made for developing and verifying the reliable CFD modeling practice through a working group of the Reproducible Offshore CFD JIP. In the working group, a CFD modeling practice document was written based on existing practices already validated for model test data, and verified by blind validations with three CFD practitioners. The first year works are focused on the bare riser with circular cross-section, and the second year work will be extended to the other riser sections such as staggered buoyancy module and straked riser.

This paper presents the working group’s first-year verification activities for a bare riser with circular cross-section. The verification works covers three test problems: 1) stationary simulation in steady current, 2) forced-oscillation in calm water, 3) forced-oscillation in steady current. In the stationary simulation, mean drag coefficient, standard deviation of lift coefficient, and Strouhal numbers are compared. In the forced-oscillation simulation in calm water, the fully-submerged riser section oscillates with a sinusoidal motion, and damping and added mass coefficients are compared. In the forced-oscillation simulation in current, the riser section oscillates in cross-flow direction to the steady current, and lift coefficient and added mass coefficient are compared. By following the modeling practice, the CFD predictions are consistent with each other and close to the model test data for a majority of test cases.
Performance Analysis of Offshore Mono-Pile Wind Turbine Co-Located With Floating Photovoltaic Systems in Shark Bay, Australia
Authors: Bahadori Morteza , Ghassemi Hassan
Published: October 2021

In recent years, as more offshore wind farms have been constructed, the possibility of integrating various offshore renewable technologies is increased. Using offshore wind and solar power resources as a hybrid system provides several advantages including optimized marine space utilization, reduced maintenance and operation costs, and relieving wind variability on output power. In this research, both offshore wind and solar resources are analyzed based on accurate data through a case study in Shark Bay (Australia), where bathymetric information confirms using offshore bottom-fixed wind turbine regarding the depth of water. Also, the power production of the hybrid system of co-located bottom-fixed wind turbine and floating photovoltaic are investigated with the technical characteristics of commercial mono-pile wind turbine and photovoltaic panels. Despite the offshore wind, the solar energy output has negligible variation across the case study area, therefore using the solar platform in deep water is not an efficient option. It is demonstrated that the floating solar has a power production rate nearly six times more than a typical offshore wind farm with the same occupied area. Also, output energy and surface power density of the hybrid offshore windsolar system are improved significantly compared to a standalone offshore wind farm. The benefits of offshore wind and solar synergies augment the efficiency of current offshore wind farms throughout the world.
Burst Failure and Reliability Assessment of X-100 to X-120 Ultra-High Strength Pipes
Authors: Bhardwaj U. , Teixeira A. P. , Guedes Soares C.
Published: October 2021

The burst failure and the structural reliability of ultra-high strength (X-100 to X-120) steel pipelines is investigated analytically based on their elastic-plastic collapse behaviour. Structural models for high strength pipes and codes are adopted from literature and their key features are discussed. The models are verified by burst test data for ultra-high-grade steel pipelines. Two statistical measures are used to compare the accuracy of models for ultra-high strength steel pipes. The most accurate theoretical model for ultra-high strength pipes is identified. Limit state functions are formulated based on the strength models for reliability analysis of ultra-high-grade steel pipelines under operational conditions. Probabilistic models are applied to the basic variables of limit state functions. A First-Order Reliability Method is used to assess the reliability for this category of pipelines followed by a sensitivity analysis that identifies the most significant limit state variables. The results of this study can provide vital measures for design and maintenance planning of ultra-high-grade steel pipelines.
Evolution of P-Wave Velocity in Settling Drilling Fluids
Authors: Bhuiyan Mohammad Hossain , Skorpa Ragnhild , Stroisz Anna Magdalena
Published: October 2021

Drilling and completion fluids (muds) are complex suspensions that typically contain weight material (such as barite) to increase the density, and clay particles to increase the viscosity and provide yield stress. In a static column of fluid, barite will inevitably settle. The density of the mud column gradually increases, from free fluid at the top to a compact, and possible gas tight solid at the bottom. The separation mechanism into different phases is complex, thus detailed, systematic fluid experiments is needed to fully understand the properties of settled barite. Wave velocity, commonly used to determine the condition of the borehole (and annulus), could be used to characterize, and possibly identify the different sediment phases in a mud column.

The current study investigates the evolution of acoustic wave velocity during compaction/gravity separation of mud. A laboratory setup which allows for a controlled drainage of fluid was used to resemble the sedimentation process. The study was performed on three drilling fluids: two synthetic and one commercial polymer, and three compacted barite samples using two test procedures. The first procedure focuses on investigating acoustic properties during settling. The second procedure was used to investigate the behavior of compacted barite. The result shows a decrease in the wave velocity during settling, whereas increase in the wave velocity in consolidated barite with compaction. The increase or decrease of velocity with compaction can be explained by the relative changes of modulus/stiffness and density of the studied material.
Evaluation of Welding Practices on Sour Service Performance of Carbon Steel Pipeline Girth Welds
Authors: Sidhar Harpreet , Verma Neerav , Kuo Chih-Hsiang , Belota Michael , Wasson Andrew J.
Published: October 2021

In recent past, there have been unforeseen sour service pipeline failures in the oil and gas industry. Sub-optimal microstructure resulting in high hardness (above 250 HV10) in pipeline steel is one of the root causes of such failures. Poor girth weld quality is another leading cause which adversely affects pipeline integrity and safe operations in sour environments. While advancements in welding technologies have led to consistency in production girth welds, effects of welding parameters on performance of carbon steel pipeline girth welds for sour service are not well understood. So, a systematic study is needed to understand the effects of various welding parameters on weld properties and performance.

This paper aims at evaluating the effects of various welding parameters on performance of girth welds to provide welding practice guidelines for sour service pipeline applications. In this effort, several welds on X65 grade line pipe girth welds using commercially available welding consumables were made to study the effects of preheat, hot pass tempering, copper backing, root pass heat input, wire consumable chemistry, single vs. dual torch, metal transfer mode, pipe fit-up (root gap, misalignment), on weld root performance. Detailed microhardness mapping and microstructural characterization were conducted. It was evident that the welding parameters studied have a significant impact on root performance. While preheat and pipe fit-up showed most significant impact on weld root performance, other parameters also affected the root performance by varying degree. Based on these results, recommendations for industry are provided to improve reliability of pipeline girth welds in sour service application.
A performance comparison between m-sequences and linear frequency-modulated sweeps for the estimation of travel-time with a moving source
Authors: Gemba Kay L. , Vazquez Heriberto J. , Fialkowski Joseph , Edelmann Geoffrey F. , Dzieciuch Matthew A. , Hodgkiss William S.
Published: October 2021

This manuscript discusses the utility of maximal period linear binary pseudorandom sequences [also referred to as m-sequences or maximum length sequences (MLSs)] and linear frequency-modulated (LFM) sweeps for the purpose of measuring travel-time in ocean-acoustic experiments involving moving sources. Signal design and waveform response to unknown Doppler (waveform dilation or scale factor) are reviewed. For this two-parameter estimation problem, the well-known wide-band ambiguity function indicates, and moving-source observations corroborate, a significant performance benefit from using MLS over LFM waveforms of similar time duration and bandwidth. The comparison is illustrated with a typical experimental setup of a source suspended aft of the R/V Sally Ride to a depth of∼10 m and towed at∼1 m/s speed. Accounting for constant source motion, the root mean square travel-time variability over a 30 min observation interval is 53 μs (MLS) and 141 μs (LFM). For these high signal-to-noise ratio channel impulse response data, LFM arrival-time fluctuations mostly appear random while MLS results exhibit structure believed to be consistent with source (i.e., towed transducer) dynamics. We conclude with a discussion on signal coherence with integration times up to 11 MLS waveform periods corresponding to ∼27 s.
Increasing precipitation variability on daily-to-multiyear time scales in a warmer world
Authors: Zhang Wenxia , Furtado Kalli , Wu Peili , Zhou Tianjun , Chadwick Robin , Marzin Charline , Rostron John , Sexton David
Published: October 2021

Rainfall will become more variable from day to day and year to year in global wet regions under future warming.
Cancer immunotherapy comes of age
Authors: Dance Amber
Published: October 2021

Oncologists have long rested their treatment plans on three so-called "pillars"—chemotherapy, surgery, and radiation. But in recent years, scientists have been busily erecting a fourth pillar: immunotherapy. The idea of harnessing the immune system to fight cancer has already moved from the lab to the clinic, thanks to technologies such as checkpoint inhibitors and genetically engineered immune cells.

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Aiming the Shotgun
Authors: Service Robert F.
Published: October 2021

Combinatorial chemistry is a shotgun approach. With it, chemists can rapidly turn out thousands or even millions of different compounds in their search for an active drug or a probe molecule for research or diagnosis. But most of those compounds don't come close to binding to a target. So many researchers in business and academic research are mixing the power of combinatorial chemistry with the finesse of targeted, or rational, drug design to come up with focused libraries of compounds more likely to hit their targets. “It's clearly how the cleverer compounds are being made,” says one researcher.
Activity of the Novel Aminomethylcycline KBP-7072 and Comparators against 1,057 Geographically Diverse Recent Clinical Isolates from the SENTRY Surveillance Program, 2019
Authors: Huband Michael D. , Thompson Jennifer D. , Gurung Nabina D. , Liu Qingmei , Li Li , Zhang Jay , Streit Jennifer M. , Castanheira Mariana
Published: October 2021

KBP-7072 is a novel broad-spectrum tetracycline (aminomethylcycline) antibacterial in clinical development (oral and intravenous formulations) for the treatment of acute bacterial skin and skin structure infections, community-acquired bacterial pneumonia, and complicated intra-abdominal infections. KBP-7072 is active against many of the World Health Organization priority pathogens.
DectiSomes: Glycan Targeting of Liposomal Drugs Improves the Treatment of Disseminated Candidiasis
Authors: Ambati Suresh , Pham Tuyetnhu , Lewis Zachary A. , Lin Xiaorong , Meagher Richard B.
Published: October 2021

Candida albicans
causes life-threatening disseminated candidiasis. Individuals at greatest risk have weakened immune systems.
The Protease SplB of Staphylococcus aureus Targets Host Complement Components and Inhibits Complement-Mediated Bacterial Opsonophagocytosis
Authors: Dasari Prasad , Nordengrün Maria , Vilhena Cláudia , Steil Leif , Abdurrahman Goran , Surmann Kristin , Dhople Vishnu , Lahrberg Julia , Bachert Claus , Skerka Christine , Völker Uwe , Bröker Barbara M. , Zipfel Peter F.
Published: October 2021

The success of bacterial pathogens in immunocompetent humans depends on the control and inactivation of host immunity.
S. aureus
, like many other pathogens, efficiently blocks host complement attack early in infection. Aiming to understand the role of the
S. aureus
-encoded orphan proteases SplA to SplD, we asked whether these proteins play a role in immune escape.
Oxidative Damage Blocks Thymineless Death and Trimethoprim Poisoning in Escherichia coli
Authors: Rao T. V. Pritha , Kuzminov Andrei
Published: October 2021

Mysterious thymineless death strikes cells that are starved for thymine and therefore replicating their chromosomal DNA without dTTP. After 67 years of experiments testing various obvious and not so obvious explanations, thymineless death is still without a mechanism.
GABA induces a hormonal counter-regulatory response in subjects with long-standing type 1 diabetes
Authors: Espes Daniel , Liljebäck Hanna , Hill Henrik , Elksnis Andris , Caballero-Corbalan José , Birnir Bryndis , Carlsson Per-Ola
Published: October 2021

Introduction

Experimentally, gamma-aminobutyric acid (GABA) has been found to exert immune-modulatory effects and induce beta-cell regeneration, which make it a highly interesting substance candidate for the treatment of type 1 diabetes (T1D). In many countries, including those in the European Union, GABA is considered a pharmaceutical drug. We have therefore conducted a safety and dose escalation trial with the first controlled-release formulation of GABA, Remygen (Diamyd Medical).

Research design and methods

Six adult male subjects with long-standing T1D (age 24.8±1.5 years, disease duration 14.7±2.2 years) were enrolled in an 11-day dose escalation trial with a controlled-release formulation of GABA, Remygen. Pharmacokinetics, glucose control and hormonal counter-regulatory response during hypoglycemic clamps were evaluated at every dose increase (200 mg, 600 mg and 1200 mg).

Results

During the trial there were no serious and only a few, transient, adverse events reported. Without treatment, the counter-regulatory hormone response to hypoglycemia was severely blunted. Intake of 600 mg GABA more than doubled the glucagon, epinephrine, growth hormone and cortisol responses to hypoglycemia.

Conclusions

We find that the GABA treatment was well tolerated and established a counter-regulatory response to hypoglycemia in long-standing T1D. Further studies regarding not only the clinical potential of Remygen for beta-cell regeneration but also its potential use as hypoglycemic prophylaxis are warranted.

Trail registration number

NCT03635437and EudraCT2018-001115-73.
Values and other decisional factors regarding treatment of hypercalcaemia of malignancy: a systematic review protocol
Authors: Bassatne Aya , Rahme Maya , Piggott Thomas , Murad M. Hassan , Hneiny Layal , El-Hajj Fuleihan Ghada
Published: October 2021

Introduction

Hypercalcaemia of malignancy (HCM) is the second most common cause of hypercalcaemia and is associated with significant morbidity and mortality. Several treatment options are available including pharmacological therapy with bisphosphonates, denosumab, glucocorticoids and calcimimetics, as well as conventional therapy with hydration and possibly calcitonin. While guidelines have previously considered treatment effects, no guideline has yet considered a range of contextual factors impacting recommendations for the management. The aim of this study was to summarise the available evidence on important decisional factors for the development of guidelines for the treatment of HCM. These include patient’s values and preferences, cost, acceptability, feasibility and equity.

Methods and analysis

This protocol is registered in PROSPERO (registration number: CRD42021264371). This is a systematic review of observational studies, case series, trials, reviews and qualitative studies involving treatment of adult patients with HCM. We will develop and execute two independent search strategies using five databases: PubMed, Medline (OVID), Embase.com, CINAHL (EBSCO) and Cochrane, and review their combined output. Two reviewers will screen titles and abstracts and full texts and will implement data abstraction from relevant studies independently and in duplicate. The outcomes of interest are the decisional factors that influence drug selection, with possible subgroup summaries by drug class or aetiology of HCM. We will present the data collected in a narrative and thematic approach.

Ethics and dissemination

Ethical approval is not applicable for our study, since we will only collect data from available literature. This systematic review will be submitted to a peer-reviewed journal when completed.
Association of age with clinical features and ablation outcomes of paroxysmal supraventricular tachycardias
Authors: Ávila Pablo , Calvo David , Tamargo María , Uribarri Aitor , Datino Tomas , Arenal Angel , Atienza Felipe , Soto Nina , Fernández-Avilés Francisco , González-Torrecilla Esteban
Published: October 2021

Objective

The role of age in clinical characteristics and catheter ablation outcomes of atrioventricular nodal re-entrant tachycardia (AVNRT) or orthodromic atrioventricular re-entrant tachycardia (AVRT) has been assessed in retrospective studies categorising age by arbitrary cut-offs, but contemporary analyses of age-related trends are lacking. We aimed to study the relationship of age with epidemiological, clinical features and catheter ablation outcomes of AVNRT and AVRT.

Methods

We recruited 600 patients (median age 56 years, 60% female) with a confirmed diagnosis of AVNRT (n=455) or AVRT (n=145) by means of an electrophysiological study. They were interrogated for arrhythmia-related symptoms with a structured questionnaire and followed up to 1 year. We analysed age as a continuous variable using regression models and adjusting for relevant covariables.

Results

Both typical and atypical forms of AVNRT upraised with age while AVRT decreased (p<0.001 by regression). Female sex predominance in AVNRT was not observed in older patients. Overall, these tachycardias became more symptomatic with ageing despite a longer tachycardia cycle length (p<0.001) and regardless of the presence of structural heart disease, with a higher proportion of dizziness, syncope, chest pain or dyspnoea (p<0.005 for all) and a lower presence of palpitations or neck pounding (p<0.001 for both). Age was not associated with catheter ablation acute success, periprocedural complications or 1-year recurrence rates (p>0.05 for all).

Conclusions

Age, evaluated as a continuous variable, had a significant association with the clinical profile of patients with AVNRT and AVRT. Nevertheless, catheter ablation outcomes and complications were not significantly related to patients’ age.
Clinicopathologic analysis of patients undergoing repeat transurethral resection of bladder tumour following an initial diagnosis of urothelial carcinoma with lamina propria invasion and variant/divergent histology
Authors: Mullane Patrick , Joshi Shreyas , Bilen Mehmet , Osunkoya Adeboye O
Published: October 2021

Aims

A subset of patients with urothelial carcinoma (UCa) and lamina propria (LP) invasion in bladder biopsies/transurethral resections (TURs) are at significant risk for recurrence and have increased rates of progression to UCa with muscularis propria (MP) invasion. The clinicopathologic features of this patient population has not been well characterised in the Pathology literature.

Methods

We performed a search through our urologic pathology files and expert consult cases of the senior author for bladder biopsies/TURs of UCa with LP invasion and variant/divergent histology from 2014 to 2020. Patients with a prior diagnosis of UCa with MP invasion or upper tract UCa were excluded. Clinicopathologic data were obtained.

Results

Ninety-five patients with at least one biopsy/TUR of UCa with LP invasion and variant/divergent histology were identified. Mean patient age was 72 years (range: 46–92 years) with a male predominance 2.3:1. Initial variant/divergent histologies identified were: glandular (35.8%), squamous (23.2%), micropapillary (20%), clear cell/lipid rich (12.6%), diffuse/signet ring/plasmacytoid (10.5%), nested (9.5%), sarcomatoid (6.3%), poorly differentiated/anaplastic (4.2%), small cell (2.1%), lymphoepithelioma-like (2.1%), osteoclast-like giant cells (1.1%) and tumour giant cells (1.1%). Two or more variant histologies were identified in 18.9% of these cases. The rate of micropapillary UCa was significantly higher in multifocal tumours compared with unifocal tumours (37% vs 7.1%).

Conclusions

In our cohort of patients undergoing early repeat biopsy/TUR, 75% of patients had persistent UCa. Additionally, almost 25% of patients had a prior diagnosis of UCa without a variant/divergent histology identified. Our findings highlight the critical role of repeat biopsy/TUR especially in a subset of patients who have variant/divergent histology, even in the absence of MP invasion.
Sequential organ failure assessment, ventilator rationing and evolving triage guidance: new evidence underlines the need to recognise and revise, unjust allocation frameworks
Authors: Schmidt Harald , Roberts Dorothy E , Eneanya Nwamaka D
Published: October 2021

We respond to recent comments on our proposal to improve justice in ventilator triage, in which we used as an example New Jersey’s (NJ) publicly available and legally binding Directive Number 2020-03. We agree with Bernard Lo and Doug White that equity implications of triage frameworks should be continually reassessed, which is why we offered six concrete options for improvement, and called for monitoring the consequences of adopted triage models. We disagree with their assessment that we mis-characterised their Model Guidance, as included in the NJ Directive, in ways that undermine our conclusions. They suggest we erroneously described their model as a two-criterion allocation framework; that recognising other operant criterion reveals it ‘likely mitigate[s] rather than exacerbate[s] racial disparities during triage’, and allege that concerns about inequitable outcomes are ‘without evidence’. We highlight two major studies robustly demonstrating why concerns about disparate outcomes are justified. We also show that White and Lo seek to retrospectively—and counterfactually—correct the version of the Model Guideline included in the NJ Directive. However, as our facsimile reproductions show, neither the alleged four-criteria form, nor other key changes, such as dropping the Sequential Organ Failure Assessment score, are found in the Directive. These points matter because (1) our conclusions hence stand, (2) because the public version of the Model Guidance had not been updated to reduce the risk of inequitable outcomes until June 2021 and (3) NJ’s Directive still does not reflect these revisions, and, hence, represents a less equitable version, as acknowledged by its authors. We comment on broader policy implications and call for ways of ensuring accurate, transparent and timely updates for users of high-stakes guidelines.
A ‘prodigious latitude’ of words: vocabularies of illness in 18th-century medical treatises and women’s writing
Authors: Meek Heather
Published: October 2021

In its examination of a selection of 18th-century medical treatises and women’s writing, this essay considers a range of context-specific and historically specific medical vocabularies and tries to illuminate the various linguistic registers of physicians’ and women’s understandings and experiences of physio-emotional illness. In a preprofessionalised world in which medical and literary cultures overlapped significantly and medical knowledge was not yet restricted to a group of formally trained male elites, vocabularies of illness abounded, oftentimes moving freely between the permeable disciplinary boundaries of the age. Physician writers, in their efforts to define and label the cluster of related conditions commonly known as spleen, vapours, melancholy, or hypochondriacal and hysterical affliction, often operated on a principle of humility, embracing uncertainty, admitting fault and assuming a willingness to question their own assumptions. They recognised that elusive processes were at the heart of these conditions, which came with a vast amalgam of physical and psychological symptoms, as well as a long list of possible designations. For their part, Anne Finch, Lady Mary Wortley Montagu, Hester Lynch Piozzi, Elizabeth Carter, Mary Leapor, Elizabeth Tollet, Anna Seward and Susanna Blamire interpreted with a keen eye the medical information available to them, deployed the plethora of words at their disposal and created their own vocabularies of illness. As they formulated a productively unstable, fluctuating lexicon to conceptualise and define spleen and its analogous conditions, these women writers came up with new words and inventive metonyms, and drew at once on the language of medicine, social and domestic inequality, and the natural world to capture experiences of suffering.
Comparing the performance of the novel FAMCAT algorithms and established case-finding criteria for familial hypercholesterolaemia in primary care
Authors: Qureshi Nadeem , Akyea Ralph K , Dutton Brittany , Leonardi-Bee Jo , Humphries Steve E , Weng Stephen , Kai Joe
Published: October 2021

Objective

Familial hypercholesterolaemia (FH) is a common inherited disorder causing premature coronary heart disease (CHD) and death. We have developed the novel Familial Hypercholesterolaemia Case Ascertainment Tool (FAMCAT 1) case-finding algorithm for application in primary care, to improve detection of FH. The performance of this algorithm was further improved by including personal history of premature CHD (FAMCAT 2 algorithm). This study has evaluated their performance, at 95% specificity, to detect genetically confirmed FH in the general population. We also compared these algorithms to established clinical case-finding criteria.

Methods

Prospective validation study, in 14 general practices, recruiting participants from the general adult population with cholesterol documented. For 260 participants with available health records, we determined possible FH cases based on FAMCAT thresholds, Dutch Lipid Clinic Network (DLCN) score, Simon-Broome criteria and recommended cholesterol thresholds (total cholesterol >9.0 mmol/L if ≥30 years or >7.5 mmol/L if <30 years), using clinical data from electronic and manual extraction of patient records and family history questionnaires. The reference standard was genetic testing. We examined detection rate (DR), sensitivity and specificity for each case-finding criteria.

Results

At 95% specificity, FAMCAT 1 had a DR of 27.8% (95% CI 12.5% to 50.9%) with sensitivity of 31.2% (95% CI 11.0% to 58.7%); while FAMCAT 2 had a DR of 45.8% (95% CI 27.9% to 64.9%) with sensitivity of 68.8% (95% CI 41.3% to 89.0%). DLCN score ≥6 points yielded a DR of 35.3% (95% CI 17.3% to 58.7%) and sensitivity of 37.5% (95% CI 15.2% to 64.6%). Using recommended cholesterol thresholds resulted in DR of 28.0% (95% CI 14.3% to 47.6%) with sensitivity of 43.8% (95% CI 19.8% to 70.1%). Simon-Broome criteria had lower DR 11.3% (95% CI 6.0% to 20.0%) and specificity 70.9% (95% CI 64.8% to 76.5%) but higher sensitivity of 56.3% (95% CI 29.9% to 80.2%).

Conclusions

In primary care, in patients with cholesterol documented, FAMCAT 2 performs better than other case-finding criteria for detecting genetically confirmed FH, with no prior clinical review required for case finding.

Trial registration number

NCT03934320.
Time delay in the strong field limit for null and timelike signals and its simple interpretation
Authors: Liu Haotian , Jia Junji
Published: October 2021

Gravitational lensing can happen not only for null signals but also timelike signals such as neutrinos and massive gravitational waves in some theories beyond GR. In this work we study the time delay between different relativistic images formed by signals with arbitrary asymptotic velocity v in general static and spherically symmetric spacetimes. A perturbative method is used to calculate the total travel time in the strong field limit, which is found to be a quasi-power series of the small parameter $$a=1-b_c/b$$

a
=
1
-

b
c

/
b

where b is the impact parameter and $$b_c$$

b
c

is its critical value. The coefficients of the series are completely fixed by the behaviour of the metric functions near the particle sphere $$r_c$$

r
c

and only the first term of the series contains a weak logarithmic divergence. The time delay $$\Delta t_{n,m}$$

Δ

t

n
,
m

to the leading non-trivial order was shown to equal the particle sphere circumference divided by the local signal velocity and multiplied by the winding number and the redshift factor. By assuming the Sgr A* supermassive black hole is a Hayward one, we were able to validate the quasi-series form of the total time, and reveal the effects of the spacetime parameter l, the signal velocity v and the source/detector coordinate difference $$\Delta \phi _{sd}$$

Δ

ϕ

sd

on the time delay. It is found that as l increases from 0 to its critical value $$l_c$$

l
c

, both $$r_c$$

r
c

and $$\Delta t_{n,m}$$

Δ

t

n
,
m

decrease. The variation of $$\Delta t_{n+1,n}$$

Δ

t

n
+
1
,
n

for l from 0 to $$l_c$$

l
c

can be as large as $$7.2\times 10^1$$

7.2
×

10
1

[s], whose measurement then can be used to constrain the value of l. While for ultra-relativistic neutrino or gravitational wave, the variation of $$\Delta t_{n,m}$$

Δ

t

n
,
m

is too small to be resolved. The dependence of $$\Delta t_{n,-n}$$

Δ

t

n
,
-
n

on $$\Delta \phi _{sd}$$

Δ

ϕ

sd

shows that to temporally resolve the two sequences of images from opposite sides of the lens, $$|\Delta \phi _{sd}-\pi |$$

|
Δ

ϕ

sd

-
π
|

has to be larger than a certain value, or equivalently if $$|\Delta \phi _{sd}-\pi |$$

|
Δ

ϕ

sd

-
π
|

is small, the time resolution of the observatories has to be good.
Vector-meson production and vector meson dominance
Authors: Xu Y.-Z. , Chen S.-Y. , Yao Z.-Q. , Binosi D. , Cui Z.-F. , Roberts C. D.
Published: October 2021

We consider the fidelity of the vector meson dominance (VMD) assumption as an instrument for relating the electromagnetic vector-meson production reaction $$e + p \rightarrow e^\prime + V + p$$

e
+
p
→

e
′

+
V
+
p

to the purely hadronic process $$V + p \rightarrow V+p$$

V
+
p
→
V
+
p

. Analyses of the photon vacuum polarisation and the photon-quark vertex reveal that such a VMD Ansatz might be reasonable for light vector-mesons. However, when the vector-mesons are described by momentum-dependent bound-state amplitudes, VMD fails for heavy vector-mesons: it cannot be used reliably to estimate either a photon-to-vector-meson transition strength or the momentum dependence of those integrands that would arise in calculations of the different reaction amplitudes. Consequently, for processes involving heavy mesons, the veracity of both cross-section estimates and conclusions based on the VMD assumption should be reviewed, e.g., those relating to hidden-charm pentaquark production and the origin of the proton mass.
Strong and electromagnetic decays of the radially excited $$D_s$$ and $$B_s$$ mesons in light cone QCD sum rules
Authors: Bilmis S.
Published: October 2021

Recently, LHCb Collaboration announced the discovery of radial excitations of $$D_s$$

D
s

and $$B_s$$

B
s

mesons. In present work, we calculate the most promising strong and electromagnetic decay widths of radially excited $$D_s(2S)$$

D
s

(
2
S
)

and $$B_s(2S)$$

B
s

(
2
S
)

mesons within the light cone QCD sum rules method.
Erratum to: Thermodynamic products for Sen Black hole
Authors: Pradhan Parthapratim
Published: October 2021

A correction to this paper has been published: 10.1140/epjc/s10052-016-3976-1
A Vector Quantization-Based Spike Compression Approach Dedicated to Multichannel Neural Recording Microsystems
Authors: Ahmadi-Dastgerdi Nazanin , Hosseini-Nejad Hossein , Amiri Hadi , Shoeibi Afshin , Gorriz Juan Manuel
Published: October 2021

Implantable high-density multichannel neural recording microsystems provide simultaneous recording of brain activities. Wireless transmission of the entire recorded data causes high bandwidth usage, which is not tolerable for implantable applications. As a result, a hardware-friendly compression module is required to reduce the amount of data before it is transmitted. This paper presents a novel compression approach that utilizes a spike extractor and a vector quantization (VQ)-based spike compressor. In this approach, extracted spikes are vector quantized using an unsupervised learning process providing a high spike compression ratio (CR) of 10–80. A combination of extracting and compressing neural spikes results in a significant data reduction as well as preserving the spike waveshapes. The compression performance of the proposed approach was evaluated under variant conditions. We also developed new architectures such that the hardware blocks of our approach can be implemented more efficiently. The compression module was implemented in a 180-nm standard CMOS process achieving a SNDR of 14.49[Formula: see text]dB and a classification accuracy (CA) of 99.62% at a CR of 20, while consuming 4[Formula: see text][Formula: see text]W power and 0.16[Formula: see text]mm2 chip area per channel.
A New Task Offloading Strategy for Scheduling BoT Applications in a Mobile Edge Computing Environment
Authors: Lu Chenyu , Li Mingjun , Zhang Qiyan , Yin Lu , Sun Jin
Published: October 2021

This paper proposes a new metaheuristic algorithm for scheduling BoT applications, consisting of many independent tasks that can be processed in parallel, in a mobile edge computing environment under mobile device’s energy constraint. We formulate this energy-constrained BoT scheduling problem as an integer program. To solve the formulated optimization problem, we propose an efficient scheduling metaheuristic that employs the whale optimization algorithm (WOA) framework to determine the most appropriate task offloading solution. We use a task sequence to represent the offloading solution. The proposed algorithm starts with using the small-size-first policy to generate the initial solution, which is identified as the best individual in the initial whale population. We develop a cost-effective mapping operator to map each whale individual onto a feasible task sequence. We further design a greedy search-based task assignment strategy to determine the assignment of BoT tasks onto MEC servers under the energy constraint, such that the completion time of BoT applications can be determined and used as the fitness value of the corresponding whale individual. Built upon the WOA framework and DM operator, we develop the metaheuristic algorithm to iteratively update the population and explore better solutions. Experimental results show that the proposed scheduling algorithm outperforms the baseline algorithm in terms of both computational efficiency and scheduling performance when scheduling BoT applications in a MEC environment.
The page curve and baby universes
Authors: Marolf Donald , Maxfield Henry
Published: October 2021

Black hole thermodynamics suggests that in order to describe the physics of distant observers, one may model a black hole as a standard quantum system with a density of states set by the Bekenstein–Hawking entropy [Formula: see text]. This idea has long been considered to be in strong tension with Hawking’s prediction that radiation from black holes is nearly thermal, and with low-energy gravity more generally. But the past two years have shown that low-energy gravity does offer a self-consistent description of black hole evaporation consistent with the above idea, and which in particular reproduces the famous Page curve. We provide a brief overview of this new paradigm, focusing on Lorentz-signature asymptotically-flat spacetimes and emphasizing operationally defined observables that probe the entropy of Hawking radiation.
Approximate perfect fluid solutions with quadrupole moment
Authors: Abishev Medeu , Beissen Nurzada , Belissarova Farida , Boshkayev Kuantay , Mansurova Aizhan , Muratkhan Aray , Quevedo Hernando , Toktarbay Saken
Published: October 2021

We investigate the interior Einstein’s equations in the case of a static, axially symmetric, perfect fluid source. We present a particular line element that is specially suitable for the investigation of this type of interior gravitational fields. Assuming that the deviation from spherically symmetry is small, we linearize the corresponding line element and field equations and find several classes of vacuum and perfect fluid solutions. We find some particular approximate solutions by imposing appropriate matching conditions.
FRACTIONAL POWER SERIES APPROACH FOR THE SOLUTION OF FRACTIONAL-ORDER INTEGRO-DIFFERENTIAL EQUATIONS
Authors: AKBAR MUHAMMAD , NAWAZ RASHID , AHSAN SUMBAL , NISAR KOTTAKKARAN SOOPPY , SHAH KAMAL , MAHMOUD EMAD E. , ALQARNI M. M.
Published: October 2021

Fractional differential and integral equations are focus of the researchers owing to their tremendous applications in different field of science and technology, such as physics, chemistry, mathematical biology, dynamical system and engineering. In this work, a power series approach called Residual Power Series Method (RPSM) is applied for the solution of fractional (non-integer) order integro-differential equations (FIDEs). The Caputo sense is used for calculating fractional derivatives. Comparison of the obtained solution is made with the Trigonometric Transform Method (TTM) and Optimal Homotopy Asymptotic Method (OHAM). There is no restrictive condition on the proposed solution. The presented technique is simple in applicability and easily computable.
Wavelet-based estimation in a semiparametric regression model
Authors: de Dieu Nkou Emmanuel , Nkiet Guy Martial
Published: October 2021

In this paper, we introduce a wavelet-based method for estimating the effective dimension reduction (EDR) space in the semiparametric regression model introduced by Li [Sliced inverse regression for dimension reduction, J. Amer. Statist. Assoc. 86 (1991) 316–327]. This method is obtained by using linear wavelet estimators of the density and regression functions that are involved in the covariance matrix of conditional expectation whose eigenvectors span the EDR space. Then, consistency of the proposed estimators is proved. A simulation study that allows one to evaluate the performance of the proposal with comparison to existing methods is presented.