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3,996 results on '"Jones Benjamin"'

53. Mapping the gut microbiota and its protective functions against bacterial enterocolitis

Author

Beresford-Jones, Benjamin and Pedicord, Virginia

Subjects
Antimicrobial resistance, Clostridioides difficile, Commensal bacteria, Enterocolitis, Gut microbiota, Host-commensal interactions, Infectious disease, Metagenomics, Microbiota, Mouse models, Mucosal immunology, Salmonella Typhimurium, Shotgun metagenomics
Abstract

The human gastrointestinal tract is colonised by trillions of microbes that actively impact the health of the host. This ecosystem, known as the gut microbiota, varies in composition between individuals and is associated with outcomes of many diseases. However, the underlying physiology of these associations remains largely unknown, preventing development of targeted microbiota therapeutics and clinical interventions. Animal models are essential for studying these host-microbiota interactions and for causally linking them to health outcomes; mice are the most widely used models for achieving this. Despite this, the mouse gut microbiota is poorly characterised compared to humans, limiting translation of research between these hosts. This thesis describes the generation of the largest and most comprehensive catalogue of high-quality mouse gut-derived genomes to date: the Mouse Gastrointestinal Bacteria Catalogue (MGBC). By facilitating the comparison of the human and mouse gut microbiotas, the MGBC demonstrates that only 2.58% of species are shared between these biomes, although over 80% of predicted functions are conserved. Application of species-level taxonomic mapping of these functions to predict the closest functionally-related species between the gut microbiotas of humans and mice demonstrates that these taxa are not necessarily the same as the closest genetically-related species. These analyses were implemented as a bioinformatic toolkit to enable other researchers to identify functionally equivalent species according to their functions of interest, with the aim of improving translation of gut microbiome research between the clinical and laboratory contexts. The MGBC improves coverage of the mouse gut microbiota, yielding metagenome classification rates of over 95%, and enables better resolution for mouse gut metagenomic studies. Nearly 2,500 mouse gut-derived shotgun metagenomes were used to characterise the taxonomic structure of the global mouse gut microbiota and identify factors associated with variation between studies. These analyses found that virtually every species of the mouse gut microbiota varied significantly between study institutes, therefore potentially representing an underlying basis for the irreproducibility crisis observed between mouse studies. This thesis further investigates the role of the gut microbiota in determining outcomes of bacterial enterocolitis caused by Salmonella Typhimurium and Clostridioides difficile. Through this work, Enterocloster clostridioformis was identified as a novel resistance-inducing microbe against Salmonella infection. This phenotype is potentially mediated through induction of protective epithelial responses and expansion of regulatory T cells in the caecal mucosa. Furthermore, by applying the MGBC to explore the association of intra-institutional microbiota variation with outcomes of C. difficile infection, this work identifies taxonomic and functional correlates of resistance and susceptibility. These findings validate the importance of the MGBC for facilitating shotgun metagenomic analyses in mice and highlight the impact of the gut microbiota on outcomes of health and disease. Mouse models will continue to be essential for developing microbiota-directed diagnostic and therapeutic interventions as well as enabling their introduction to clinical practice. This thesis therefore represents multiple advances towards understanding and tackling the obstacles posed by host-specific microbiotas. To this end, I have provided a starting point for efficient and informed translation of gut microbiota research between humans and mice, as well as the means for experimental validation of these analyses.

Published
2022
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54. Bayesian methods for the design and analysis of cluster randomised controlled trials

Author

Jones, Benjamin Gary

Subjects
Bayesian Statistics, Randomised Controlled Trials, Cluster Randomised Trials
Abstract

Cluster Randomised Controlled Trials involve randomising groups of participants, rather than the individual participants themselves, whilst the outcomes are measured on the participants. Whilst there are a number of practical and methodological advantages to such a design, there are also statistical implications, both in terms of study design and sample size calculation, and in analysis. The methodology underpinning the cluster randomised design is now well-established in the statistical literature. However, the overwhelming majority of methodological developments to date have been within the frequentist paradigm, and as such, there is an opportunity to explore methodological developments in the context of Bayesian approaches to the design and analysis of Cluster Randomised Controlled Trials, which is the focus of this thesis. This thesis begins by identifying and quantifying the practical application of Bayesian methods to such cluster randomised trial designs, as well as existing methodological developments in the area, through a methodological systematic review. The review highlights that whilst there have been some efforts to develop Bayesian methodology for Cluster Randomised Controlled Trials, the practical uptake of such methods remains low. Next, a novel application of an informative class of prior distribution, the power prior, is proposed whereby information is borrowed from continuous, clustered, historical data, such as that from a pilot or feasibility study. The performance of this approach is evaluated, and superiority, in comparison to established methods, is demonstrated for certain performance metrics. The novel application of the power prior methodology is then explored in the context of study design and sample size calculation for a Cluster Randomised Controlled Trial, whereby the impact of the use of these new methods is quantified in the context of the impact on type I error and statistical power. It is demonstrated that the adoption of these methods has the potential to reduce sample size requirements, thereby facilitating more efficient trial design and reducing research waste. However, it is also shown that, under the traditional frequentist interpretation, inflated type I error rates can be expected as a result of borrowing information through the power prior. In order to address the limitation of inflated type I error, an approach is presented in which the degree of information borrowing through the power prior is determined in order to control Bayesian type I error at some nominal level. It is shown that by adopting a Bayesian interpretation of design operating characteristics, information borrowing methods can be used whilst maintaining type I error control. Finally, a newly developed R package, PPCRCT is described which allows for straightforward implementation of the methodology presented within this thesis.

Published
2022

55. Adaptability and the Pivot Penalty in Science and Technology

Author

Hill, Ryan, Yin, Yian, Stein, Carolyn, Wang, Xizhao, Wang, Dashun, and Jones, Benjamin F.

Subjects
Computer Science - Digital Libraries, Computer Science - Social and Information Networks, Physics - Physics and Society
Abstract

Scientists and inventors set the direction of their work amidst an evolving landscape of questions, opportunities, and challenges. This paper introduces a measurement framework to quantify how far researchers move from their existing research when producing new works. We apply this framework to millions of scientific publications and patents and uncover a pervasive "pivot penalty", where the impact of new research steeply declines the further a researcher moves from their prior work. The pivot penalty applies nearly universally across scientific publishing and patenting and has been growing in magnitude over the past five decades. While creativity frameworks suggest a benefit to exploratory search by researchers and often emphasize outsider advantages in driving breakthroughs, we find little evidence for such an advantage. The pivot penalty is consistent with increasingly narrow specializations of researchers, and when researchers undertake large pivots, a signature of their work is weak engagement with established mixtures of prior knowledge. Unexpected shocks to the research landscape, which may push researchers away from existing areas or pull them into new ones, further demonstrate substantial pivot penalties. COVID-19 provides a high-scale case study, where many researchers engaged the pandemic, yet the pivot penalty remains severe. The pivot penalty generalizes across fields, career stage, productivity, collaboration, and funding contexts, highlighting both the breadth and depth of the adaptive challenge. Overall, the findings point to large and increasing challenges in adapting to new opportunities and threats. The results have implications for individual researchers, research organizations, science policy, and the capacity of science and society as a whole to confront emergent demands.

Published
2021

56. Network Quantum Steering

Author

Jones, Benjamin D. M., Šupić, Ivan, Uola, Roope, Brunner, Nicolas, and Skrzypczyk, Paul

Subjects
Quantum Physics
Abstract

The development of large-scale quantum networks promises to bring a multitude of technological applications as well as shed light on foundational topics, such as quantum nonlocality. It is particularly interesting to consider scenarios where sources within the network are statistically independent, which leads to so-called network nonlocality, even when parties perform fixed measurements. Here we promote certain parties to be trusted and introduce the notion of network steering and network local hidden state (NLHS) models within this paradigm of independent sources. In one direction, we show how results from Bell nonlocality and quantum steering can be used to demonstrate network steering. We further show that it is a genuinely novel effect, by exhibiting unsteerable states that nevertheless demonstrate network steering, based upon entanglement swapping, yielding a form of activation. On the other hand, we provide no-go results for network steering in a large class of scenarios, by explicitly constructing NLHS models., Comment: 11 pages, 6 figures

Published
2021
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57. AutoMate: A Dataset and Learning Approach for Automatic Mating of CAD Assemblies

Author

Jones, Benjamin, Hildreth, Dalton, Chen, Duowen, Baran, Ilya, Kim, Vladimir G., and Schulz, Adriana

Subjects
Computer Science - Computer Vision and Pattern Recognition, Computer Science - Graphics, Computer Science - Machine Learning, I.3.5, I.2.10
Abstract

Assembly modeling is a core task of computer aided design (CAD), comprising around one third of the work in a CAD workflow. Optimizing this process therefore represents a huge opportunity in the design of a CAD system, but current research of assembly based modeling is not directly applicable to modern CAD systems because it eschews the dominant data structure of modern CAD: parametric boundary representations (BREPs). CAD assembly modeling defines assemblies as a system of pairwise constraints, called mates, between parts, which are defined relative to BREP topology rather than in world coordinates common to existing work. We propose SB-GCN, a representation learning scheme on BREPs that retains the topological structure of parts, and use these learned representations to predict CAD type mates. To train our system, we compiled the first large scale dataset of BREP CAD assemblies, which we are releasing along with benchmark mate prediction tasks. Finally, we demonstrate the compatibility of our model with an existing commercial CAD system by building a tool that assists users in mate creation by suggesting mate completions, with 72.2% accuracy., Comment: 16 pages, 17 figures, 4 tables

Published
2021

58. Science as a Public Good: Public Use and Funding of Science

Author

Yin, Yian, Dong, Yuxiao, Wang, Kuansan, Wang, Dashun, and Jones, Benjamin F.

Subjects
Computer Science - Digital Libraries, Computer Science - Social and Information Networks, Physics - Physics and Society
Abstract

Knowledge of how science is consumed in public domains is essential for a deeper understanding of the role of science in human society. While science is heavily supported by public funding, common depictions suggest that scientific research remains an isolated or 'ivory tower' activity, with weak connectivity to public use, little relationship between the quality of research and its public use, and little correspondence between the funding of science and its public use. This paper introduces a measurement framework to examine public good features of science, allowing us to study public uses of science, the public funding of science, and how use and funding relate. Specifically, we integrate five large-scale datasets that link scientific publications from all scientific fields to their upstream funding support and downstream public uses across three public domains - government documents, the news media, and marketplace invention. We find that the public uses of science are extremely diverse, with different public domains drawing distinctively across scientific fields. Yet amidst these differences, we find key forms of alignment in the interface between science and society. First, despite concerns that the public does not engage high-quality science, we find universal alignment, in each scientific field and public domain, between what the public consumes and what is highly impactful within science. Second, despite myriad factors underpinning the public funding of science, the resulting allocation across fields presents a striking alignment with the field's collective public use. Overall, public uses of science present a rich landscape of specialized consumption, yet collectively science and society interface with remarkable, quantifiable alignment between scientific use, public use, and funding.

Published
2021

59. Minor-closed classes of binary functions

Author

Jones, Benjamin R.

Subjects
Mathematics - Combinatorics, 05B35 (Primary) 15A03, 05C83(Secondary)
Abstract

Binary functions are a generalisation of the cocircuit spaces of binary matroids to arbitrary functions. Every rank function is assigned a binary function, and the deletion and contraction operations of binary functions generalise matroid deletion and contraction. We give the excluded minor characterisations for the classes of binary functions with well defined minors, and those with an associated rank function. Within these classes, we also characterise the classes of binary functions corresponding to polymatroids, matroids and binary matroids by their excluded minors. This gives a new proof of Tutte's excluded minor characterisation of binary matroids in the more generalised space of binary functions., Comment: 15 pages

Published
2021
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65. Fire effects 10 years after the Anaktuvuk River Tundra fire

Author

Jandt, R. R. (Randi R.), Miller, Eric A. (Fire ecologist), Jones, Benjamin N., United States. Bureau of Land Management. Alaska State Office, Bureau of Land Management (archive.org), Jandt, R. R. (Randi R.), Miller, Eric A. (Fire ecologist), Jones, Benjamin N., and United States. Bureau of Land Management. Alaska State Office

Subjects
Alaska, Anaktuvuk River Tundra (Alaska), Arctic regions, Effect of fires on, Fire ecology, Measurement, Plant communities, Tundras
Published
2021

69. Finding Elliptic Curves With Many Integral Points

Author

Jones, Benjamin

Subjects
Mathematics - Number Theory, 11D25
Abstract

In this paper we construct parameterizations of elliptic curves over the rationals which have many consecutive integral multiples. Using these parameterizations, we perform searches in GMP and Magma to find curves with points of small height, curves with many integral multiples of a point, curves with high multiples of a point integral, and over two hundred curves with more than one hundred integral points. In addition, a novel and complete classification of "self-descriptive numbers" is constructed by bounding the number of zeros such a number must contain., Comment: 23 pages, 2 figures, 5 tables. See ancillary Magma files containing complete search results

Published
2020

70. Adaptive pseudo-time methods for the Poisson-Boltzmann equation with Eulerian solvent excluded surface

Author

Jones, Benjamin, Ullah, Sheik Ahmed, Wang, Siwen, and Zhao, Shan

Subjects
Mathematics - Numerical Analysis
Abstract

This work further improves the pseudo-transient approach for the Poisson Boltzmann equation (PBE) in the electrostatic analysis of solvated biomolecules. The numerical solution of the nonlinear PBE is known to involve many difficulties, such as exponential nonlinear term, strong singularity by the source terms, and complex dielectric interface. Recently, a pseudo-time ghost-fluid method (GFM) has been developed in [S. Ahmed Ullah and S. Zhao, Applied Mathematics and Computation, 380, 125267, (2020)], by analytically handling both nonlinearity and singular sources. The GFM interface treatment not only captures the discontinuity in the regularized potential and its flux across the molecular surface, but also guarantees the stability and efficiency of the time integration. However, the molecular surface definition based on the MSMS package is known to induce instability in some cases, and a nontrivial Lagrangian-to-Eulerian conversion is indispensable for the GFM finite difference discretization. In this paper, an Eulerian Solvent Excluded Surface (ESES) is implemented to replace the MSMS for defining the dielectric interface. The electrostatic analysis shows that the ESES free energy is more accurate than that of the MSMS, while being free of instability issues. Moreover, this work explores, for the first time in the PBE literature, adaptive time integration techniques for the pseudo-transient simulations. A major finding is that the time increment $\Delta t$ should become smaller as the time increases, in order to maintain the temporal accuracy. This is opposite to the common practice for the steady state convergence, and is believed to be due to the PBE nonlinearity and its time splitting treatment. Effective adaptive schemes have been constructed so that the pseudo-time GFM methods become more efficient than the constant $\Delta t$ ones., Comment: 29 pages

Published
2020

71. On the Rank Functions of Powerful Sets

Author

Jones, Benjamin

Subjects
Mathematics - Combinatorics, 05B35 (Primary) 05B99, 15A03 (Secondary)
Abstract

A set $S\subseteq 2^E$ of subsets of a finite set $E$ is \emph{powerful} if, for all $X\subseteq E$, the number of subsets of $X$ in $S$ is a power of 2. Each powerful set is associated with a non-negative integer valued function, which we call the rank function. Powerful sets were introduced by Farr and Wang as a generalisation of binary matroids, as the cocircuit space of a binary matroid gives a powerful set with the corresponding matroid rank function. In this paper we investigate how structural properties of a powerful set can be characterised in terms of its rank function. Powerful sets have four types of degenerate elements, including loops and coloops. We show that certain evaluations of the rank function of a powerful set determine the degenerate elements. We introduce powerful multisets and prove some fundamental results on them. We show that a powerful set corresponds to a binary matroid if and only if its rank function is subcardinal. This paper answers the two conjectures made by Farr and Wang in the affirmative., Comment: 11 pages

Published
2020

72. Quantifying Policy Responses to a Global Emergency: Insights from the COVID-19 Pandemic

Author

Gao, Jian, Yin, Yian, Jones, Benjamin F., and Wang, Dashun

Subjects
Physics - Physics and Society, Computer Science - Digital Libraries, Computer Science - Social and Information Networks
Abstract

Public policy must confront emergencies that evolve in real time and in uncertain directions, yet little is known about the nature of policy response. Here we take the coronavirus pandemic as a global and extraordinarily consequential case, and study the global policy response by analyzing a novel dataset recording policy documents published by government agencies, think tanks, and intergovernmental organizations (IGOs) across 114 countries (37,725 policy documents from Jan 2nd through May 26th 2020). Our analyses reveal four primary findings. (1) Global policy attention to COVID-19 follows a remarkably similar trajectory as the total confirmed cases of COVID-19, yet with evolving policy focus from public health to broader social issues. (2) The COVID-19 policy frontier disproportionately draws on the latest, peer-reviewed, and high-impact scientific insights. Moreover, policy documents that cite science appear especially impactful within the policy domain. (3) The global policy frontier is primarily interconnected through IGOs, such as the WHO, which produce policy documents that are central to the COVID19 policy network and draw especially strongly on scientific literature. Removing IGOs' contributions fundamentally alters the global policy landscape, with the policy citation network among government agencies increasingly fragmented into many isolated clusters. (4) Countries exhibit highly heterogeneous policy attention to COVID-19. Most strikingly, a country's early policy attention to COVID-19 shows a surprising degree of predictability for the country's subsequent deaths. Overall, these results uncover fundamental patterns of policy interactions and, given the consequential nature of emergent threats and the paucity of quantitative approaches to understand them, open up novel dimensions for assessing and effectively coordinating global and local responses to COVID-19 and beyond.

Published
2020

73. A rehabilitation intervention to improve recovery after an episode of delirium in adults over 65 years (RecoverED): study protocol for a multi-centre, single-arm feasibility study

Author

Allan, Louise, O’Connell, Abby, Raghuraman, Shruti, Bingham, Alison, Laverick, Abigail, Chandler, Kirstie, Connors, James, Jones, Benjamin, Um, Jinpil, Morgan-Trimmer, Sarah, Harwood, Rowan, Goodwin, Victoria A., Ukoumunne, Obioha C., Hawton, Annie, Anderson, Rob, Jackson, Thomas, MacLullich, Alasdair M. J., Richardson, Sarah, Davis, Daniel, Collier, Lesley, Strain, William David, Litherland, Rachael, Glasby, Jon, and Clare, Linda

Published
2023
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74. The P323L substitution in the SARS-CoV-2 polymerase (NSP12) confers a selective advantage during infection

Author

Goldswain, Hannah, Dong, Xiaofeng, Penrice-Randal, Rebekah, Alruwaili, Muhannad, Shawli, Ghada T., Prince, Tessa, Williamson, Maia Kavanagh, Raghwani, Jayna, Randle, Nadine, Jones, Benjamin, Donovan-Banfield, I’ah, Salguero, Francisco J., Tree, Julia A., Hall, Yper, Hartley, Catherine, Erdmann, Maximilian, Bazire, James, Jearanaiwitayakul, Tuksin, Semple, Malcolm G., Openshaw, Peter J. M., Baillie, J. Kenneth, Emmett, Stevan R., Digard, Paul, Matthews, David A., Turtle, Lance, Darby, Alistair C., Davidson, Andrew D., Carroll, Miles W., and Hiscox, Julian A.

Published
2023
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75. Air Quality in Latin American Buildings

Author

Molina, Constanza, Jones, Benjamin, Morantes, Giobertti, Marín-Restrepo, Laura, editor, Pérez-Fargallo, Alexis, editor, Piderit-Moreno, María Beatriz, editor, Trebilcock-Kelly, Maureen, editor, and Wegertseder-Martínez, Paulina, editor

Published
2023
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77. Efficacy and moderators of efficacy of cognitive behavioural therapies with a trauma focus in children and adolescents: an individual participant data meta-analysis of randomised trials

Author

de Haan, Anke, Meiser-Stedman, Richard, Landolt, Markus A, Kuhn, Isla, Black, Melissa J, Klaus, Kristel, Patel, Shivam D, Fisher, David J, Haag, Christina, Ukoumunne, Obioha C, Jones, Benjamin G, Flaiyah, Ashraf Muwafaq, Catani, Claudia, Dawson, Katie, Bryant, Richard A, de Roos, Carlijn, Ertl, Verena, Foa, Edna B, Ford, Julian D, Gilboa-Schechtman, Eva, Tutus, Dunja, Hermenau, Katharin, Hecker, Tobias, Hultmann, Ole, Axberg, Ulf, Jaberghaderi, Nasrin, Jensen, Tine K, Ormhaug, Silje M, Kenardy, Justin, Lindauer, Ramon J L, Diehle, Julia, Murray, Laura K, Kane, Jeremy C, Peltonen, Kirsi, Kangaslampi, Samuli, Robjant, Katy, Koebach, Anke, Rosner, Rita, Rossouw, Jaco, Smith, Patrick, Tonge, Bruce J, Hitchcock, Caitlin, and Dalgleish, Tim

Published
2024
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78. SAPPHIRE: phase III study of sitravatinib plus nivolumab versus docetaxel in advanced nonsquamous non-small-cell lung cancer

Author

Abdel-Karim, Isam, Abdelsalam, Mahmoud, Addeo, Alfredo, Aguado, Carlos, Alexander, Patrick, Alt, Jürgen, Azzi, Georges, Balaraman, Rama, Biesma, Bonne, Blackhall, Fiona, Bohnet, Sabine, Boleti, Ekaterini, Borghaei, Hossein, Bradbury, Penelope, Brighenti, Matteo, Campbell, Nicholas, Campbell, Toby, Canon, Jean-Luc, Cappuzzo, Federico, Costa, Enric Carcereny, Cavanna, Luigi, Cetnar, Jeremy, Chella, Antonio, Chouaid, Christos, Christoph, Daniel, Castán, Javier Cortés, Dakhil, Shaker, de Castro Carpeño, Francisco Javier, de Marinis, Filippo, Delmonte, Angelo, Demedts, Ingel, Demey, Wim, Dits, Joyce, del Pilar Diz Taín, Maria, Gómez, Manuel Dómine, Dorius, Timothy, Dumoulin, Daphne, Duruisseaux, Michaël, Eaton, Keith, González, Emilio Esteban, Evans, Devon, Faehling, Martin, Farrell, Nicholas, Feinstein, Trevor, Font, Enriqueta Felip, Garcia Campelo, Maria Rosario, Garon, Edward, Garrido López, María Pilar, Germonpré, Paul, Gersten, Todd, Cao, Maria Gonzalez, Gopaluni, Srivalli, Greillier, Laurent, Grossi, Francesco, Guisier, Florian, Gurubhagavatula, Sarada, Calderón, Vanesa Gutiérrez, Hakimian, David, Hall, Richard, Jr., Hao, Desirée, Harris, Ronald, Hashemi, Sayed, He, Kai, Hendriks, Lizza, Huang, Chao, Ibrahim, Emad, Jain, Sharad, Johnson, Melissa, Jones, Benjamin, Jones, Monte, Juan Vidal, Óscar José, Juergens, Rosalyn, Kaderbhai, Courèche, Kastelijn, Elisabeth A (Lisanne), Keresztes, Roger, Kio, Ebenezer, Kokowski, Konrad, Konduri, Kartik, Kulkarni, Swati, Kuon, Jonas, Kurkjian, Carla, Labbé, Catherine, Lerner, Rachel, Lim, Farah, Madroszyk-Flandin, Anne, Marathe, Omkar, Martincic, Danko, McClay, Edward, McIntyre, Kristi, Mekhail, Tarek, Misino, Andrea, Molinier, Olivier, Morabito, Alessandro, Morócz, Éva, Müller, Veronika, Nagy, Tünde, Nguyen, Anthony V., Nidhiry, Emmanuel, Okazaki, Ian, Ortega-Granados, Ana Laura, Ostoros, Gyula, Oubre, David, Owen, Scott, Pachipala, Krishna, Park, David, Patel, Pareshkumar, Percent, Ivor, Pérol, Maurice, Peters, Solange, Piet, Berber, Planchard, David, Polychronis, Andreas, Aix, Santiago Ponce, Pons-Tostivint, Elvire, Popat, Sanjaykumar, Pulla, Mariano Provencio, Quantin, Xavier, Quéré, Gilles, Rafique, Noman, Ramaekers, Ryan, Reck, Martin, Reiman, Anthony, Reinmuth, Niels, Reynolds, Craig, Rodríguez-Abreu, Delvys, Romano, Gianpiero, Roque, Tammy, Salzberg, Matthew, Sanborn, Rachel, Sandiego, Sergio, Schaefer, Eric, Schreeder, Marshall, Seetharamu, Nagashree, Seneviratne, Lasika, Shah, Purvi, Shunyakov, Leonid, Slater, Dennis, Parra, Hector Soto, Stigt, Johannes, Stilwill, Joseph, Su, Jingdong, Surmont, Veerle, Swink, Alicia, Szalai, Zsuzsanna, Talbot, Toby, Garcia, Alvaro Taus, Theelen, Willemijn, Thompson, Jonathan, Tiseo, Marcello, Uprety, Dipesh, Uyeki, James, van der Leest, Kornelius Cor, Van Ho, Anthony, van Putten, John, Estévez, Sergio Vázquez, Veatch, Andrea, Vergnenègre, Alain, Ward, Patrick, Weise, Amy, Weiss, Matthias, Whitehurst, Matthew, Zai, Silvia, Zalcman, Gérard, Zuniga, Richard, Borghaei, H., de Marinis, F., Dumoulin, D., Reynolds, C., Theelen, W.S.M.E., Percent, I., Gutierrez Calderon, V., Johnson, M.L., Madroszyk-Flandin, A., Garon, E.B., He, K., Planchard, D., Reck, M., Popat, S., Herbst, R.S., Leal, T.A., Shazer, R.L., Yan, X., Harrigan, R., and Peters, S.

Published
2024
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79. An umbrella review of meta-analyses regarding the incidence of female-specific malignancies after fertility treatment

Author

Saso, Srdjan, Barcroft, Jen F., Kasaven, Lorraine S., Galazis, Nicolas, Ní Dhonnabháin, Bríd, Grewal, Karen J., Bracewell-Milnes, Timothy, Jones, Benjamin P., Getreu, Natalie, Chan, Maxine, Mitra, Anita, Al-Memar, Maya, Ben-Nagi, Jara, Smith, J. Richard, Yazbek, Joseph, Timmerman, Dirk, Bourne, Tom, Ghaem-Maghami, Sadaf, and Verbakel, Jan Y.

Published
2024
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80. U.S. Industrial and Commercial Motor System Market Assessment Report Volume 1: Characteristics of the Installed Base

Author

Rao, Prakash, Sheaffer, Paul, Chen, Yuting, Goldberg, Miriam, Jones, Benjamin, Crop, Jeff, and Hester, Jordan

Abstract

Motor systems are an integral part of our industrial and commercial facilities. They provide the motive force behind the fans, pumps, compressors, chillers, and conveyors in these facilities. Given their centrality to any facility’s operations, they are a critical energy end use to understand, particularly when developing technologies and policies to meet sustainability goals, improve productivity, and enhance resilience. In the late 1990s, the U.S. Department of Energy (DOE) conducted two seminal studies to better understand the installed stock and energy savings opportunities of industrial and commercial motor systems. In the industrial sector, The United States Industrial Electric Motor Systems Market Opportunities Assessment used primary data collected through onsite assessments and led to a greater understanding of the installed base of motor systems, their characteristics, and the opportunities for energy savings (U.S. Department of Energy, 2002). Notable findings included the following:•Industrial motor systems consumed 679 billion kilowatt-hours (kWh) in 1994, representing 23 percent of U.S. electricity consumption.•Cost-effective energy efficiency measures could result in 62-104 billion kWh of energy savings annually.•Sixty-two percent of the energy savings potential was from fan, pump, and compressor end use equipment.•Nearly half of motor system electricity consumption was attributable to approximately 3,500 facilities, or 1.5 percent of U.S. manufacturing facilities.Opportunities for Energy Savings in the Residential and Commercial Sectors with High Efficiency Electric Motors provided an evaluation of the installed stock of motor driven equipment in U.S. commercial and residential buildings and opportunities for utilization of high efficiency motors and variable speed technologies (Arthur D. Little, 1999). Notable findings included the following:•Commercial motor systems consumed 343 billion kWh in 1995, with refrigeration and space conditioning constituting 93 percent of the total.•Cost-effective energy efficiency measures could result in 51 billion kWh of energy savings annually.Due in no small part to these seminal studies, motor system technologies and usage characteristics have changed drastically since the late 1990s. Greater awareness of cost-effective strategies for reducing motor system electricity consumption have been developed and deployed. This includes several software tools, literature, and utility and government programs promoting energy efficiency improvements in motor driven systems. Additionally, several rounds of energy efficiency standards have been enacted, resulting in improved installed motor efficiency. The cost of variable speed drives has dropped substantially, and combined with utility rebate programs, has led to their greater adoption.Further, since these results were published, the U.S. manufacturing sector has undergone a massive transformation. Due to global competition, some sectors have relocated operations overseas. Others have brought operations onshore to avail low cost and abundant natural gas. Additionally, automation and robotics have pervaded the entire sector. Consequently, these two reports likely do not represent the current state of motor driven systems in U.S. industrial and commercial facilities. As cited in recent studies, the lack of current information on motor system electricity consumption and use characteristics limits the ability to conduct analysis on energy savings potential, develop technologies to address energy and productivity gaps, and develop programs to promote energy efficiency practices and technologies for motor systems (International Energy Agency, 2007; UNIDO, 2010; McKane and Hasanbeigi, 2011; Waide and Brunner, 2011). Specifically, the lack of information affects a range of stakeholders:•Governments must rely on outdated information when setting research agendas, developing policies, and designing energy efficiency programs and offerings.•Utilities and energy efficiency programs cannot identify the current market needs or potential impact when designing rebate and energy efficiency programs.•Electric grid planners cannot identify motor system usage characteristics when developing plans to support the resilience of the electric grid.•Manufacturers of motors, motor driven equipment, and drives are hampered when developing technologies to meet the needs of their market.•Motor system end users are limited in their ability to identify energy saving opportunities within their own facilities because they do not have reliable benchmark information.In response to the lack of current information and analysis on industrial and commercial motor systems, the DOE initiated an update to these two studies. Launched in 2016 and led by Lawrence Berkeley National Laboratory (LBNL), the Motor System Market Assessment (MSMA) provides an updated, more comprehensive assessment of the installed stock of motor systems in both the industrial and commercial sectors, a review of the supply chains supporting motor and drives in the U.S., and the performance improvement opportunity available from using best available technologies and maintenance and operation practices. The outcomes of the MSMA are documented in three U.S. Industrial and Commercial Motor System Market Assessment reports, with this report being the first listed:1.Volume 1: Characteristics of the Installed Base (this report) documents the findings on the installed base of motor systems in the U.S. industrial and commercial sectors. Quantification of energy savings potential is not documented in this report but in Volume 3. 2.Volume 2: Motors and Drives Supply Chain Review reviews the state of supply chains for motors and drives installed in U.S. industrial and commercial facilities, focusing on advanced motor and drive technologies and their constituent materials. 3.Volume 3: Energy Savings Opportunity analyzes the energy performance improvement opportunity for the installed base of U.S. industrial and commercial motor systems.This report has been prepared as a reference for motor system stakeholders. It provides factual information as could be best determined by the assessment results and avoids speculating on any findings.

Published
2021

85. New cation-mediated enantioselective transformations and catalytic enantioselective photocyclization

Author

Jones, Benjamin Anthony and Smith, Martin

Subjects
organic chemistry
Abstract

This thesis describes the development of novel catalytic enantioselective reactions. Chapter 1 describes the development of transformations mediated by chiral ammonium salts. The historical context of enantioselective phase transfer catalysis is provided and the key fundamental advances are detailed. The development of a cation-mediated kinetic resolution of atropisomeric biaryls is described as well as the synthesis and resolution of a range of substituted BINOLs. The extension of the chiral cation mediated approach to the dearomatization of 2-naphthols by electrophilic amination and of indoles by C3 alkylation is also described. In both cases, good reactivity and moderate enantioselectivity were achieved. Chapter 2 focuses on the development of a Lewis acid mediated approach to the catalytic enantioselective [6π] photocyclization of acrylanilides. The work is contextualized by a discussion of the previous approaches to enantioselective photochemical reactions covering direct irradiation, triplet energy transfer and photoredox strategies. The elucidation of competing triplet energy transfer and photoredox pathways to the same product is described alongside an account of the design and development of a photocatalyst that engages predominantly in the photoredox pathway. The reaction was tested on a range of substrates to determine the scope and limitations of the method.

Published
2021

86. Fertility restoration

Author

Jones, Benjamin P., Smith, James Richard, and Ghaem-Maghami, Sadaf

Abstract

Infertility not only results in the loss of reproductive function but has numerous psychological sequalae and is associated with significant long-term emotional burden. There is one group of women whose infertility was traditionally believed to be unconditional and absolute: those with absolute uterine factor infertility (AUFI). Whereas not absolute in nature, a major cause of subfertility, is the consequence to the physiological deterioration of ovarian reserve and oocyte quality that is associated with advancing age. This thesis summarises a series of interrelated studies which contribute significantly to the eventual aim of achieving fertility restoration in these groups. Study 1 details extensive analysis of >200 women with AUFI who are interested in potentially undergoing uterine transplantation (UTx), which represents the largest study of its kind globally to date. It highlights important insights into the screening process of women with AUFI who desire to undergo the UTx, including their perceptions toward UTx and alternative options to acquire motherhood. Moreover, comprehensive pre-operative clinical, biochemical, radiological and psychological evaluation of the women selected to proceed with UTx is detailed, to allow comprehensive insight into this cohort. Study 2 demonstrates novel insight into the motivation of women who wish to altruistically donate their uterus and highlights high levels of acceptability after becoming aware of the risks and expected recovery. Despite the significant associated risks and lengthy recovery process, women who donate their uterus expect to gain psychological and emotional benefit by enabling another woman to bear a child themselves. However, despite desire and motivation to donate, the selection criteria currently implemented universally reduce the number of potential donors significantly. Study 3 presents novel data from 186 male to female (M2F) transgender women that clearly highlights a desire to experience physiological experiences that are unique to women, such as menstruation and gestation, as well as potentially having a physiologically functioning transplanted vagina. The findings suggest transgender women believe the potential benefits of UTx outweigh the significant risks with which it is associated and may improve quality of life, happiness and dysphoric symptoms while enhancing feelings of femininity. This chapter also describes a series of feasibility studies including the demonstration of a technique to undertake transgender UTx in the rabbit model. The final study on fertility restoration in AUFI introduces the concept of endometrial transplantation (ETx), including initial pilot studies that helped develop the initial surgical technique, as well as a short-term viability study, in endometrial autotransplantation. This study represents the first ETx trial undertaken globally, and demonstrated gross and microscopic evidence of viable endometrium following endometrial autotransplantation, along with the achievement of clinical pregnancies. Finally, this thesis presents a detailed account of the prospect of elective oocyte cryopreservation, which currently represents an option to restore reproductive potential in women with age related reproductive decline. Novel insight is demonstrated into the perceptions of such women, having undergone the process, including quantitative analysis of how it impacts quality of life. Detailed outcomes of stimulation cycles are also presented, including new perspectives on markers of oocyte yield in such populations and reproductive outcomes including the attainment of livebirths.

Published
2021
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92. Efficacy and adverse events profile of videolaryngoscopy in critically ill patients: subanalysis of the INTUBE study

Author

Anstey, Matthew, Colica, Sandra, Brewster, David, Simpson, Shannon, Regli, Adrian, O'Grady, Ross, Litton, Edward, Ferrier, Janet, Bartholdy, Roland, Tabah, Alexis, Bowen, David, Rowley, Rebecca, Gatward, Jonathan, Alonso, Julio, Varkey, Sneha, Palaniswamy, Vijayanand, Chimunda, Timothy, Reza, Syed T., Hossain, Mozaffer, Islam, Motiul, Hamid, Tarikul, Parotto, Matteo, Ajami, Samareh, Steel, Andrew, Del Sorbo, Lorenzo, Goffi, Alberto, Randall, Ian, Adhikari, Neill K.J., Mehesry, Tasneem H., Vera, Maria M., Bugedo, Guillermo, Labarca, Gonzalo, Silva, Monica, Ma, Wuhua, Li, Yongxing, Wu, Jiayan, Wu, Lun, Radivojević, Renata Curić, Matas, Marijana, Ivančan, Višnja, Pavlek, Mario, Mihaljević, Slobodan, Jumić, Aleksandra, Moguš, Mate, Tucić, Iva, Michalek, Pavel, Flaksa, Marek, Aguirre-Bermeo, Hernan, Tirape-Castro, Hugo, García Aguilera, Maria F., Montenegro, Diana Alvarez, Tutillo, Diego Morocho, Tutillo León, Jose A., Winiszewski, Hadrien, Piton, Gael, Aissaoui, Nadia, Augy, Jean-Loup, Champigneulle, Benoit, Zlotnik, Diane, Muller, Grégoire, Jacquier, Sophie, Hraiech, Sami, Guervilly, Christophe, Plantefeve, Gaetan, Contou, Damien, Ricard, Jean Damien, Besset, Sebastien, Colin, Gwenhael, Pouplet, Caroline, Mirouse, Adrien, Azoulay, Elie, Boissier, Florence, Frat, Jean-Pierre, Mercier, Emmanuelle, Salmon-Gandonnière, Charlotte, Lascarrou, Jean-Baptiste, Martin, Maelle, Ferre, Alexis, Legriel, Stephane, Bruel, Cedric, Philippard, Francois, Zarka, Jonathan, Chemouni, Frank, Hamzaoui, Olfa, Sztrymf, Benjamin, Brunin, Yannick, Pili-Floury, Sébastien, Constantin, Jean-Michel, Godet, Thomas, Maraffi, Tommaso, Dessap, Armand Mekontso, Jozwiak, Mathieu, Marin, Nathalie, Guitton, Christophe, Chudeau, Nicolas, Gros, Alexandre, Boyer, Alexandre, Papandreou, Eleni, Petsiou, Athanasia, Papanikolaou, Metaxia, Kyparissi, Aikaterini, Tileli, Maria, Makris, Alexandros, Tsiftsis, Dimitrios, El-Fellah, Nadia, Karametos, Ilias, Nakou, Evi, Chalkias, Athanasios, Arnaoutoglou, Eleni, Katsoulis, Panagiotis, Pouriki, Sofia, Vagdatli, Kyriaki, Dimitropoulou, Aikaterini, Kothekar, Amol, Baliga, Nishanth, Korula, Sara V., Philip, Sam, Singh, Lalit, Agrawal, Nipun, Jeswani, Deepak, Jeswani, Deepti, Jha, Simant, Singh, Nitesh, Bhattacharyya, Mahuya, Das, Amit, Kuragayala, Swarna D., Kesavarapu, Subba R., Shah, Bhagyesh, Kaushik, Shuchi, Sunil, Nilu, Gnanadurai, Kingsly, Singh, Atul K., Singh, Dinesh K., Khunteta, Sudhir, Gupta, Kulbhusahn, Sanyal, Rhik, Midya, Abhirup, Tyagi, Vijay N., Bendre, Prashant, Prashant, Kumar, Chaurasia, Satish, Mishra, Prasanna, Dash, Sampat, Sundrani, Omprakash, Lalwani, Jaya, Jain, Nikhilesh, Agrawal, Kehari, Ray, Banambar, Meher, Ranjan, Saravanabavan, Lakshmikanthcharan, Munusamy, Satheesh, Gupta, Manish, Ahmad, Meraj, Gopalakrishna, Kadarapura N., Suparna, Bharadwaj, Surath, Manimala R., Munta, Kartik, Jagiasi, Bharat, Srivastava, Anand, Sahu, Samir, Mrinal, Sircar, Kumar, Singh Sujeet, Shah, Mehul, Patel, Mayur, Bamane, Shrirang, Narkhede, Amit, Chawla, Rajesh, Chawla, Aakanksha, Maheshwarappa, Harish Mallapura, Manjunath, Ramya Ballekatte, Rahmani, Lua, Laffey, John G., Rona, Roberto, Benini, Annalisa, Russotto, Vincenzo, Rundo, Annalisa, Luzi, Annalisa, Esposito, Clelia, Nespoli, Moana R., Pradella, Andrea, Lungu, Ramona, Baccari, Laura, Chiumiento, Fernando, Mariano, Karim, Cotoia, Antonella, De Rosa, Silvia, Boni, Elisa, Palmese, Salvatore, Gammaldi, Renato, Spadaro, Savino, Santoro, Lida, Cracchiolo, Andrea N., Palma, Daniela M., Pinciroli, Riccardo, Giovannini, Ilaria, Calamai, Italo, Spina, Rosario, Cappellini, Iacopo, Tutino, Lorenzo, Bellissima, Agrippino, Maugeri, Jessica G., Riva, Ivano, Fabretti, Fabrizio, Brazzi, Luca, Sales, Gabriele, Montrucchio, Giorgia, Orsello, Alberto, Costamagna, Andrea, Canavosio, Federico G., Pelagalli, Lorella, Marcelli, Maria E., Cortegiani, Andrea, Tramarin, Jacopo, Musso, Stefania, Tarantino, Stefano, Di Giacinto, Ida, Licciardi, Anna L., Montini, Luca, De Pascale, Gennaro, Giacomucci, Angelo, Russo, Pierpaolo, Longhini, Federico, Garofalo, Eugenio, Ferluga, Massimo, Moro, Valeria, Cascella, Marco, Di Caprio, Barbara, Di Fenza, Raffaele, Nespoli, Francesca, Bassini, Ospedale E., Muttini, Stefano, Pezzi, Angelo, Elhadi, Muhammed, Ghula, Mohamed, Ahmed, Hazem Abdelkarem, Khaled, Ala, Elhadi, Ahmed, Alhadi, Abdulmueti, Mazlan, Mohd Z., Wan Hassan, Wan Mohd N., Hasan, Shahnaz, Jamaluddin, Muhamad F.H., Samat, Noryani Mohd, Ismail, Muhamad A., Alias, Anita, Hwa, Ngu Pei, Irtiza, Ismail Nahla, Khalidah, Hapiz, Kiok, Lee Chew, Nordin, Norbaniza Mohd, Wan Ismail, Wan N., Ali, Mohd N., Sánchez-Hurtado, Luis, Toledo-Salinas, Otoniel, Landaverde, Antonio, Sosa, Miguel A., Gonzalez, Mayra Martinez, Lopez Nava, Claudia L., San Juan Roman, Nandyelly, Gonzalez, Maria, Espinoza, Missael, González, Daira, Flores, Fernando, Pantoja Leal, Jesus N., Loza Gallardo, Luis R., Young, Paul, Mistry, Ravi, Browne, Alexander, Crone, Petra, Chandwani, Juhi, Hossein, Sazzad, Koul, Salman S., Aman, Rubina, Ali, Syed M., Akhtar, Shazia N., Jankowski, Milosz, Bielanski, Piotr, Mudyna, Wojciech, Franczyk, Pawel, Galkin, Piotr, Skowronski, Lukasz, Gaszynski, Tomasz, Piegat, Mariusz, Catorze, Nuno, Pinto, Marcia, Leonor, Tiago, Fernandes, Marco, Campos, Patricia, Aragão, Irene, Costa, Paulo F., Franco, Daniela G., Basto, Marta, Nogueira, Carla, Cunha, Rui P., Costa, Vasco, Lomivorotov, Vladimir, Nikitenko, Artem, Belsky, Vladislav, Furman, Mikhail, Magomedov, Marat, Baturova, Vera, Karelov, Alexey, Marova, Nadezhda, Almekhlafi, Ghaleb, Alghamdi, Adnan, Maseda, Emilio, Suarez de la Rica, Alejandro, Gonzalez, Jesus Flores, Ruiz, Miryam Pérez, Roca, Oriol, Santafe, Manel, Fernandez, Gemma Goma, Escudero-Acha, Patricia, González-Castro, Alejandro, Agvald-Öhman, Christina, Broman, Lina, Spangfors, Martin, Hannesdottir, Katrin, Persson, Elin, Rosell, Jon, Sperber, Jesper, Ohlsson, Annika, Von Seth, Magnus, Pedrotti, Niccolò, Wahlstrom, Carl, Meirik, Maria, Bandert, Anna, Krog, Ditte, Kuo, Lu-Cheng, Shin, Ming-Hann, Chien, Jung-Yien, Ku, Shih-Chi, Ruan, Sheng-Yuan, Huang, Chun-Kai, Yeh, Yu-Chang, Chao, Anne, Wang, Kuo-Chuan, Chiu, Ching-Tang, Lee, Chien-Chang, Chou, Nai-Kuan, Szakmany, Tamas, Jones, Benjamin, Jones, Laura, Della Torre, Valentina, Sinah, Ayush, Quayle, Alice, Cheetham, Olivia, Syed, Yadullah, Mensah, Kwabena, Edmunds, Christopher, Kaye, Callum T., Bauer, Philippe R., Odeyemi, Yewande E., Nates, Joseph, Laserna, Andres, Mosier, Jarrod, Hypes, Cameron, Gottesman, Eric, Mastroianni, Fiore, Fein, Daniel G., Zhao, Dawn, Fonseca Fuentes, Xavier E., Gallo de Moraes, Alice, Sandefur, Benjamin J., Khan, Akram, Matos, Dubier, Kaufman, David A., Lehr, Andrew, Bigatello, Luca, Bonney, Iwona, Lascarrou, Jean Baptiste, Tassistro, Elena, Antolini, Laura, Bauer, Philippe, Szułdrzyński, Konstanty, Camporota, Luigi, Putensen, Christian, Pelosi, Paolo, Sorbello, Massimiliano, Higgs, Andy, Greif, Robert, Grasselli, Giacomo, Valsecchi, Maria G., Fumagalli, Roberto, Foti, Giuseppe, Caironi, Pietro, Bellani, Giacomo, and Myatra, Sheila N.

Published
2023
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93. Optimising Trotter-Suzuki Decompositions for Quantum Simulation Using Evolutionary Strategies

Author

Jones, Benjamin D. M., O'Brien, George O., White, David R., Campbell, Earl T., and Clark, John A.

Subjects
Computer Science - Neural and Evolutionary Computing, Quantum Physics
Abstract

One of the most promising applications of near-term quantum computing is the simulation of quantum systems, a classically intractable task. Quantum simulation requires computationally expensive matrix exponentiation; Trotter-Suzuki decomposition of this exponentiation enables efficient simulation to a desired accuracy on a quantum computer. We apply the Covariance Matrix Adaptation Evolutionary Strategy (CMA-ES) algorithm to optimise the Trotter-Suzuki decompositions of a canonical quantum system, the Heisenberg Chain; we reduce simulation error by around 60%. We introduce this problem to the computational search community, show that an evolutionary optimisation approach is robust across runs and problem instances, and find that optimisation results generalise to the simulation of larger systems., Comment: A version of this paper is to appear in GECCO'19

Published
2019

94. Early-career setback and future career impact

Author

Wang, Yang, Jones, Benjamin F., and Wang, Dashun

Subjects
Physics - Physics and Society, Computer Science - Digital Libraries
Abstract

Setbacks are an integral part of a scientific career, yet little is known about whether an early-career setback may augment or hamper an individual's future career impact. Here we examine junior scientists applying for U.S. National Institutes of Health (NIH) R01 grants. By focusing on grant proposals that fell just below and just above the funding threshold, we compare "near-miss" with "near-win" individuals to examine longer-term career outcomes. Our analyses reveal that an early-career near miss has powerful, opposing effects. On one hand, it significantly increases attrition, with one near miss predicting more than a 10% chance of disappearing permanently from the NIH system. Yet, despite an early setback, individuals with near misses systematically outperformed those with near wins in the longer run, as their publications in the next ten years garnered substantially higher impact. We further find that this performance advantage seems to go beyond a screening mechanism, whereby a more selected fraction of near-miss applicants remained than the near winners, suggesting that early-career setback appears to cause a performance improvement among those who persevere. Overall, the findings are consistent with the concept that "what doesn't kill me makes me stronger." Whereas science is often viewed as a setting where early success begets future success, our findings unveil an intimate yet previously unknown relationship where early-career setback can become a marker for future achievement, which may have broad implications for identifying, training and nurturing junior scientists whose career will have lasting impact.

Published
2019
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100. The influence of steel composition on the strain ageing response of high strength pearlitic wire

Author

Jones, Benjamin, Rainforth, Mark, and Hobson, Shaun

Abstract

The aim of the EngD was to identify if cost effective compositional adjustments can be made to a commercial high carbon steel to retard or even eliminate the strain ageing reaction observed in cold drawn high strength wire. This was tested via the production of a set of experimental steels, with systematically varied compositions, identified after a literature review, discussions with British Steel on previous work/experience and thermodynamic modelling of the cementite stability. The experimental steels were produced in a vacuum induction melt furnace to ensure precise control over composition, forged and hot rolled to rod. The rod samples were then heat treated to the appropriate starting microstructure (fully pearlitic) and drawn to wire. The set of experimental steels were artificially aged and tested alongside a commercially produced steel wire for comparison. A selection of available global and localised experimental techniques was used to characterise the strain ageing response: DSC, Torsion and Tensile Testing, Magnetic Sensors, (S)TEM and APT. Generally, high variation was observed during testing. The heterogeneous pearlitic microstructure following severe plastic deformation and the subsequent strain ageing response leads to localised regions of enhanced cementite dissolution, which leads to variation of mechanical properties during testing. Differential scanning calorimetry measurements suggested a nickel addition may partially delay the initial stage of strain ageing. Magnetic sensor measurements showed clear differences between steel compositions, although the differences cannot be exclusively attributed to the strain ageing response, as the redistribution of alloying elements or carbide precipitation is likely contributing. Chemical analysis of carbon resulted a great deal of measurement error, which made accurate determination of carbon concentration challenging. Measured differences between steel compositions in the carbon concentration of cementite were attributed to error and experimental variation. Significantly more chemical analysis data is required to ascertain if alloying elements can improve cementite stability with strain ageing. However, energy dispersive x-ray spectroscopy suggested carbon may be segregating to dislocations, which has also been reported in the literature. Thus, suggesting a dislocation based mechanism of cementite dissolution may be active. The effects of silicon, nickel, cobalt and vanadium on the strain ageing kinetics require further characterisation over a wider range of drawing and ageing conditions to determine their suitability for commercial use. However, when considering the improved ductility of a nickel containing steel shown in section 3.1 - British Steel R&D Study - Influence of Nickel on Pearlite Stability and the potentially delayed initial stage of strain ageing, as observed by DSC observations (Figure 6:1), a nickel addition may in fact have a minor beneficial effect on torsional ductility with strain ageing. Reducing manganese content as much as reasonably achievable is also recommended. Therefore, alternative alloying additions may be required to meet tensile strength specifications. Silicon may be a suitable alternative. Vanadium is also effective at increasing tensile strength and may be suitable. Vanadium carbides or nitrides may provide alternative strengthening following the dissolution of cementite, or where amorphous cementite is present following severe wire drawing.

Published
2020

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