University of Exeter
  • Exeter, Devon, United Kingdom
Recent publications
Accurate assessment of Remaining Useful Lifetime (RUL) of power transformers plays an essential role in improving the reliability of power grid while reducing operating costs. A dynamical RUL prediction technique is proposed in this article through analyzing the individual difference by multi-dimensional fusion of condition monitoring data. Firstly, the on-site Dissolved Gas Analysis (DGA) measurements and the calculated Degree of Polymerization (DP) are fused with the method of Analytic Hierarchy Process (AHP) and Variable Weight Principle (VWP) to construct the power transformer Life Correlation Index (LCI). Secondly, the parameters of Wiener model are updated iteratively by Bayesian rule and Expectation Maximization (EM) algorithm, to obtain the distribution and prediction of residual transformer lifetime. The residual lifetimes of four 500 kV power transformers in operation are calculated, and the predicted remaining lifetimes are 24.73 years, 30.66 years, 2.79 years, and 0.07 years respectively. The effectiveness and reliability are demonstrated by the worst transformer case with the predicted RUL of 0.07 years, in which a short circuit fault of that transformer happened immediately after power-off maintenance. In particular, this method is able to predict the residual lifetime of transformers in a dynamic way, which provides significant practical implications for the assessment management of power transformers.
The climate sensitivity peaks around 310 K in a wide variety of climate models, ranging from idealized single column models to fully comprehensive climate models. Here, we increase CO2 using a clear‐sky three‐dimensional atmospheric model with a radiation scheme which maintains accuracy for high CO2 and temperature levels. In contrast, the Equilibrium Climate Sensitivity (ECS) of our model plateaus around 310 K. We show that this is due to the moistening of the subtropical regions caused by a slowdown in atmospheric circulation, which increases the ECS at very high CO2 values. When relative humidity is fixed, the ECS peak is consistent with single column model results. This work does not rule out that clouds or other complex processes impact the ECS in comprehensive climate models. Though the changes in CO2 here are extreme, this study underlines the importance of changes in atmospheric circulation and relative humidity in quantitative assessments of climate sensitivity.
Herein, a ZrO2 added α-Fe2O3 photoanode that can split water at low applied potential is reported. First, the pristine hematite α-Fe2O3 photoanode was synthesized using an aerosol-assisted chemical vapour deposition (AACVD) method followed by modification with various amounts of ZrO2 (2 to 40%) in the form of thin films on conducting glass substrate. The XRD, Raman spectroscopy and scanning electron microscopy (SEM) analyses confirmed the presence of the monoclinic phase of ZrO2 in the composites with multifaceted particles of compact morphology. The optical analysis showed an increase in the absorbance and variation in band gap of the composites ascribed to the heterogeneity of the material. The photoelectrochemical studies gave a photocurrent density of 1.23 mA cm⁻² at 1.23 V vs. RHE for the pristine hematite and remarkably higher value of 3.06 mA cm⁻² for the optimized amount of ZrO2 in the modified α-Fe2O3 photoanode. To the best of our knowledge, this is the highest photocurrent reported for a ZrO2 containing photoanode. The optimized composite electrode produced nine times more oxygen than that produced by pristine hematite.
Background: Postsurgical outcome measures are crucial to define the efficacy of perioperative pain management; however, it is unclear which are most appropriate. We conducted a prospective study aiming to assess sensitivity-to-change of patient-reported outcome measures assessing the core outcome set of domains pain intensity (at rest/during activity), physical function, adverse events, and self-efficacy. Methods: Patient-reported outcome measures were assessed preoperatively, on day 1 (d1), d3, and d7 after four surgical procedures (total knee replacement, breast surgery, endometriosis-related surgery, and sternotomy). Primary outcomes were sensitivity-to-change of patient-reported outcome measures analysed by correlating their changes (d1ed3) with patients' global impression of change and patients' specific impression of change items as anchor criteria. Secondary outcomes included identification of baseline and patient characteristic variables explaining variance in change for each of the scales and descriptive analysis of various patient-reported outcome measures from different domains and after different surgeries. Results: Of 3322 patients included (18 hospitals, 10 countries), data from 2661 patients were analysed. All patient-reported outcome measures improved on average over time; the median calculated sensitivity-to-change for all patient-reported outcome measures (overall surgeries) was 0.22 (range: 0.07e0.31, scale: 0e10); all changes were independent of baseline data or patient characteristics and similar between different procedures. Conclusions: Pain-related patient-reported outcome measures have low to moderate sensitivity-to-change; those showing higher sensitivity-to-change from the same domain should be considered for inclusion in a core outcome set of patient-reported outcome measures to assess the effectiveness and efficacy of perioperative pain management.
Smartphone sensors are used increasingly in the assessment of ataxias. To date, there is no specific consensus guidance regarding a priority set of smartphone sensor measurements, or standard assessment criteria that are appropriate for clinical trials. As part of the Ataxia Global Initiative Digital-Motor Biomarkers Working Group (AGI WG4), aimed at evaluating key ataxia clinical domains (gait/posture, upper limb, speech and oculomotor assessments), we provide consensus guidance for use of internal smartphone sensors to assess key domains. Guidance was developed by means of a literature review and a two stage Delphi study conducted by an Expert panel, which surveyed members of AGI WG4, representing clinical, research, industry and patient-led experts, and consensus meetings by the Expert panel to agree on standard criteria and map current literature to these criteria. Seven publications were identified that investigated ataxias using internal smartphone sensors. The Delphi 1 survey ascertained current practice, and systems in use or under development. Wide variations in smartphones sensor use for assessing ataxia were identified. The Delphi 2 survey identified seven measures that were strongly endorsed as priorities in assessing 3/4 domains, namely gait/posture, upper limb, and speech performance. The Expert panel recommended 15 standard criteria to be fulfilled in studies. Evaluation of current literature revealed that none of the studies met all criteria, with most being early-phase validation studies. Our guidance highlights the importance of consensus, identifies priority measures and standard criteria, and will encourage further research into the use of internal smartphone sensors to measure ataxia digital-motor biomarkers.
Sexual consent has received increased attention in mainstream media, educational, and political settings since the rise of the #MeToo movement in 2017. However, long before #MeToo, sexual consent has been a core practice among people who engage in Bondage and Discipline, Dominance and Submission, Sadism, and Masochism (BDSM). This study examined sexual consent norms among a sexually diverse sample, including people who practice BDSM (n = 116), people who identify with another sexual minority group, such as swingers and sex workers (n = 114), and people who did not identify with a sexual minority group, termed sexual majority group members (n = 158). Explicit consent for both BDSM- and non-BDSM-related activities was rated as more common (descriptively normative) among people who were a member of the BDSM community compared to majority participants. Further, BDSM participants rated consent discussions as less sexually disruptive compared to majority participants. We found no significant group differences in the extent to which people thought sexual consent should be discussed. We also discuss findings from an open-ended question asking participants to recall a recent sexual experience with a new partner. This study demonstrates variability in consent norms between groups and points to the potential to shift sexual consent behaviors among majority participants.
The major histocompatibility complex (MHC) can be useful in guiding conservation planning because of its influence on immunity, fitness, and reproductive ecology in vertebrates. The mandrill (Mandrillus sphinx) is a threatened primate endemic to central Africa. Considerable research in this species has shown that the MHC is important for disease resistance, mate choice, and reproductive success. However, all previous MHC research in mandrills has focused on an inbred semi-captive population, so their genetic diversity may have been underestimated. Here we expand our current knowledge of mandrill MHC variation by performing next-generation sequencing of non-invasively collected fecal samples from a large wild horde in central Gabon. We observe MHC lineages and alleles shared with other primates, and we uncover 45 putative new class II MHC DRB alleles, including representatives of the DRB9 pseudogene, which has not previously been identified in mandrills. We also document methodological challenges associated with fecal samples in NGS-based MHC research. Even with high read depth, the replicability of alleles from fecal samples was lower than that of tissue samples, and allele assignments are inconsistent between sample types. Further, the common assumption that variants with very high read depth should represent true alleles does not appear to be reliable for fecal samples. Nevertheless, the use of degraded DNA in the present study still enabled significant progress in quantifying immunogenetic diversity and its evolution in wild primates.
Using a large ensemble of initialised retrospective forecasts (hindcasts) from a seasonal prediction system, we explore various statistics relating to sudden stratospheric warmings (SSWs). Observations show that SSWs occur at a similar frequency during both El Niño and La Niña northern hemisphere winters. This is contrary to expectation, as the stronger stratospheric polar vortex associated with La Niña years might be expected to result in fewer of these extreme breakdowns. Here we show that this similar frequency may have occurred by chance due to the limited sample of years in the observational record. We also show that in these hindcasts, winters with two SSWs, a rare event in the observational record, on average have an increased surface impact. Multiple SSW events occur at a lower rate than expected if events were independent but somewhat surprisingly, our analysis also indicates a risk, albeit small, of winters with three or more SSWs, as yet an unseen event.
Here we propose Guided PCA, a simple approach to ensure the spectrum of a key target moiety is consistly provided in a high ranking principal component.
Segregation is a highly nuanced concept that researchers have worked to define and measure over the past several decades. Conventional approaches tend to estimate segregation based on residential patterns. However, the residential dimension does not fully comprise individuals’ interactions with their environment and, consequently, can misrepresent individuals’ lived experiences. To address this gap, we analyse how segregation extends to other dimensions of the urban life. We accomplish this by using the Index of Concentration at the Extremes (ICE) to measure socioeconomic segregation at amenities and on public transit lines. Moreover, we consider the pivotal role that transport plays in democratising access to opportunities. Using transport networks, amenity visitations, and census data, we leverage agent-based models to approximate socioeconomic composition at amenities and on transit lines. Consequently, we can estimate socioeconomic segregation within the United States, for various aspects of urban life. We find that neighbourhoods that are segregated in the residential domain tend to exhibit similar levels of segregation in amenity visitation patterns and transit usage, albeit to a lesser extent. Moreover, we discover that low-income neighbourhoods experience a greater decrease from residential to amenity segregation, than their high-income segregated counterparts, highlighting how mobility can be used as a tool for overcoming residential inequalities, given the proper infrastructure. We identify inequalities embedded into transit service, which impose constraints on residents from segregated areas, limiting the neighbourhoods that they can access within an hour to areas that are similarly disadvantaged. By exploring socioeconomic segregation from a transit perspective, we underscore the importance of conceptualising experiential segregation, while also highlighting how transport systems can contribute to a cycle of disadvantage.
Histories of Third Worldism have received renewed attention from historians in the past decade. Much of the resulting scholarship has focused on the international to the exclusion of the national. This article addresses this relative neglect by focusing on a particular iteration of Third World nation-state-building: co-operative socialism in Forbes Burnham's Guyana. Refuting the argument that co-operative socialism was imitative and implemented for reasons of political expediency only, the article contends that Burnham's doctrine should be regarded as a meaningful attempt at remaking Guyana's society and economy through its core principles of self-sufficiency, self-reliance, and self-discipline. These principles gave rise to a specific conception of citizenship in 1970s Guyana, where the People's National Congress (PNC) sought to link political belonging and participation with a moral ethic premised on the notion of hard work in service of the nation. The article examines how this collectivist understanding of citizenship gave rise to a particular set of struggles at the turn of the 1980s, as the co-operative republic began to collapse. What emerged from these struggles was an alternate but parallel imagining of citizenship espoused by the Working People's Alliance (WPA), which rejected the PNC's vanguardism in favour of empowering the Guyanese people through the creation of non-hierarchical systems of collective authority. The article concludes by arguing that the failure of the WPA's attempt to overthrow the PNC through popular revolt signified the ends of decolonization and Third Worldism in the Caribbean, and the beginnings of new struggles against new forms of coloniality in the guise of the emerging neoliberal and good governance agendas.
We develop a general perturbative theory of finite-coupling quantum thermometry up to second order in probe-sample interaction. By assumption, the probe and sample are in thermal equilibrium, so the probe is described by the mean-force Gibbs state. We prove that the ultimate thermometric precision can be achieved – to second order in the coupling – solely by means of local energy measurements on the probe. Hence, seeking to extract temperature information from coherences or devising adaptive schemes confers no practical advantage in this regime. Additionally, we provide a closed-form expression for the quantum Fisher information, which captures the probe's sensitivity to temperature variations. Finally, we benchmark and illustrate the ease of use of our formulas with two simple examples. Our formalism makes no assumptions about separation of dynamical timescales or the nature of either the probe or the sample. Therefore, by providing analytical insight into both the thermal sensitivity and the optimal measurement for achieving it, our results pave the way for quantum thermometry in setups where finite-coupling effects cannot be ignored.
This special issue draws on new research conducted by the PUblic REnaissance: Urban Cultures of Public Space between Early Modern Europe and the Present project, funded by the Humanities in the European Research Area (see: ). The project considers how public spaces, from street corners to major city squares, were shaped by the everyday activities of ordinary city dwellers between 1450 and 1700. We have focused on the urban fabric, and the ways in which meanings are attached to specific sites in the city (and objects in museum collections) that are often overlooked – the material culture of public space. Our themes are familiar to urban historians – sociability, the circulation of knowledge, information or gossip, authority and its contestation – although by moving between textual sources, maps, the built fabric and museum artefacts, our interdisciplinary and cross-Europe approach is structured around material objects in the early modern period.
Background Soil-associated Mucorales fungi frequently host bacterial endosymbionts that produce damaging endotoxins important for plant pathology. Our work and clinical reports suggest an important and unanticipated role for endosymbionts in human disease. The endosymbiont Mycetohabitants rhizoxinica was associated with bacteriemia in an immunocompromised individual where its host Rhizopus microsporus caused mucormycosis. Our data demonstrate the endosymbiont Ralstonia pickettii can impact virulence of its R. microsporus host. Together, these data suggest Mucorales endosymbionts can influence both fungal and bacterial infections; however, their frequency and diversity in Mucormycosis is unknown. This project investigates the frequency and diversity of bacterial endosymbionts in Mucorales clinical isolates. Methods Mucorales isolates from mucormycosis patients via the UK National Mycology Reference Laboratory and the Instituto Nacional de Rehabilitacion, Mexico, were identified by ITS1/2 PCR or MALDI-TOF. Fungal isolates (YPG agar, 5 days, 30 oC) were subjected to phenol/chloroform DNA extraction. Bacterial presence was assessed by 16s RNA PCR, and resulting bands identified by nanopore sequencing. In parallel, WGS of total DNA confirmed bacterial presence and identity. Bacteria were also physically isolated from homogenized fungal mycelia (nutrient broth, 80rpm, 37oC, 4 days) harvested under sterile conditions. Bacteria from supernatants (LB, Blood agar, 30 and 37 oC ± 5% CO2, 4-10 days) were identified by 16s RNA PCR and Nanopore sequencing. Results In total, 27 Mucorales isolates (R. arrhizus/delemar n=7; R. microsporus n=6; Lichtheimia corymbifera n=4; L. ramosa n=3; Mucor circinelloides n=4; others n=3) were evaluated for bacteria presence. 17/27 (62%) were 16s RNA positive. Culture identified 6 bacterial species (R. pickettii, Niallia circulans, Peribacillus simplex, Roseomonas mucosa, Micrococcus luteus, Staphylococcus pasteuri). Mucorales isolates originated from cutaneous 11/27 (41%); respiratory 8/27 (29%); and sinus-orbital diseases 7/27 (26%). Conclusion The presence of bacterial endosymbionts in clinical isolates of Mucorales is frequent, diverse and can potentially influence fungi in causing disease among individuals at risk. Disclosures All Authors: No reported disclosures
Floods are amongst the most severe natural disasters. Accurate flood risk maps are vital for emergency response operations and long-term flood defence planning. Currently the validation of such maps is often neglected and suffers from a lack of high-quality data. The proliferation of social media usage worldwide in recent years has supplied access to large amounts of data linked to flooding, and the detection of real-world events using such data is termed ‘social sensing’. In this paper we investigate the use of social sensing for the validation of flood risk maps. We apply this methodology to 7 years’ worth of flood related Tweets in order to perform a comparison to long term planning flood risk maps in England. The results show that there is a low level of correlation between the collection of socially sensed floods and high-risk flood areas as well as highlighting areas with high levels of socially sensed flooding that have low levels of flood risk, showcasing the potential importance of social media data for use in flood risk validation and planning policy.
Background The early detection and diagnosis of cancer to reduce avoidable mortality and morbidity is a challenging task in primary health care. There is a growing evidence base on how to enable earlier cancer diagnosis, but well-recognised gaps and delays exist around the translation of new research findings into routine clinical practice. Implementation research aims to accelerate the uptake of evidence by health care systems and professionals. We aimed to identify priorities for implementation research in early cancer diagnosis in primary care. Methods We used a RAND/UCLA modified Delphi consensus process to identify and rank research priorities. We asked primary care physicians, patients and researchers to complete an online survey suggesting priorities for implementation research in cancer detection and diagnosis. We summarised and presented these suggestions to an 11-member consensus panel comprising nine primary care physicians and two patients. Panellists independently rated the importance of suggestions on a 1–9 scale (9 = very high priority; 1 = very low priority) before and after a structured group discussion. We ranked suggestions using median ratings. Results We received a total of 115 suggested priorities for implementation research from 32 survey respondents (including 16 primary care professionals, 11 researchers, and 4 patient and public representatives; 88% of respondents were UK-based). After removing duplicates and ineligible suggestions, we presented 37 suggestions grouped within 17 categories to the consensus panel. Following two rounds of rating, 27 suggestions were highly supported (median rating 7–9). The most highly rated suggestions concerned diagnostic support (e.g., access to imaging) interventions (e.g., professional or patient education), organisation of the delivery of care (e.g., communication within and between teams) and understanding variations in care and outcomes. Conclusions We have identified a set of priorities for implementation research on the early diagnosis of cancer, ranked in importance by primary care physicians and patients. We suggest that researchers and research funders consider these in directing further efforts and resources to improve population outcomes.
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Junning Chen
  • College of Engineering, Mathematics and Physical Sciences
Kristine Hill
  • Department of Sociology and Philosophy
Exeter, Devon, United Kingdom
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