University of Cambridge Research Outputs (Articles and Conferences)
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Item Open Access Published version Peer-reviewed Fast Neural Network Inverse Model to Maximize Throughput in Ultra-Wideband WDM Systems(Optical Society of America (OSA), 2024-10-21) Gan, Zelin; Shevchenko, Mykyta; Nallaperuma, Sam; Savory, SebUltra-wideband systems expand the optical bandwidth in wavelength-division multiplexed (WDM) systems to serve the increasing data rate demand using the existing install fiber infrastructure. In ultra-wideband transmission, inelastic inter-channel stimulated Raman scattering effect is non-negligible which causes power transfer from shorter-wavelength WDM channels to longer-wavelength WDM channels. Thus, managing launch power is substantial to improve the overall performance. The launch power optimization problem can be solved by the particle swarm optimization method which is sensitive to the objective value and requires intensive objective calculations. Hence, we first propose a fast and accurate deep neural network-based physical layer in this paper which can achieve 99% − 100% throughput compared to the semi-analytical approach with more than 2 orders of magnitude improvement in computation time. To further reduce the computation time, we propose an iterative greedy algorithm enabled by the inverse model to well approximate a sub-optimal solution with less than 6% performance degradation but almost 3 orders of magnitude computation time reduction.Item Open Access Accepted version Peer-reviewed Clinical translation of photoacoustic imaging(Springer Science and Business Media LLC) Park, Jeongwoo; Choi, Seongwook; Knieling, Ferdinand; Clingman, Bryan; Bohndiek, Sarah; Wang, Lihong V; Kim, Chulhong; Park, Jeongwoo [0000-0003-3366-2329]; Choi, Seongwook [0000-0001-9774-058X]; Knieling, Ferdinand [0000-0002-3535-2626]; Wang, Lihong V [0000-0001-9783-4383]; Kim, Chulhong [0000-0001-7249-1257]Photoacoustic imaging (PAI), also known as optoacoustic imaging, is a promising biomedical imaging technique that combines the benefits of rich optical contrast and high ultrasonic spatial resolution to overcome the limited penetration depth of light in living subjects. Basic biomedical research conducted with PAI in preclinical studies has generated much interest and shown outstanding potential for clinical and commercial translation. PAI has captured morphological, functional, and molecular information in studies of living animals and humans, providing intrinsic clinical indicators from early diagnosis through to treatment monitoring. This Review presents the fundamentals of PAI technology and various clinical PAI systems, and addresses key findings from pilot and clinical patient studies of human organ systems. The Review also discusses technical and non-technical challenges in clinical scenarios, emphasizes the importance of standardization in accelerating clinical translation, and summarizes the current state of the PAI regulatory process.Item Embargo Accepted version Peer-reviewed Common pitfalls in drug target Mendelian randomization and how to avoid them(BMC) Gill, Dipender; Dib, Marie-Joe; Cronje, Helene Toinet; Karhunen, Ville; Woolf, Benjamin; Gagnon, Eloi; Daghlas, Iyas; Nyberg, Michael; Drakeman, Donald; Burgess, Stephen; Burgess, Stephen [0000-0001-5365-8760]Background Drug target Mendelian randomization describes the use of genetic variants as instrumental variables for studying the effects of pharmacological agents. The paradigm can be used to inform on all aspects of drug development and has become increasingly popular over the last decade, particularly given the time- and cost-efficiency with which it can be performed even before commencing clinical studies. Main Body In this review, we describe the recent emergence of drug target Mendelian randomization, its common pitfalls, how best to address them, as well as potential future directions. Throughout, we offer advice based on our experiences on how to approach these types of studies, which we hope will be useful for both practitioners and those translating the findings from such work. Conclusions Drug target Mendelian randomization is nuanced and requires a combination of biological, statistical, genetic, epidemiological, clinical, and pharmaceutical expertise to be utilised to its full potential. Unfortunately, these skillsets are relatively infrequently combined in any given study.Item Embargo Accepted version Peer-reviewed Thinking food delivery platforms infrastructurally: The practices and politics of Baemin's infrastructuralisation in Seoul(Wiley) Chung, Noel; Chung, Noel [0000-0003-0665-5545]The proliferation of food delivery platforms is profoundly changing the way urbanites eat, work, and move. These platforms increasingly mobilise urban resources and population to function as critical infrastructure in the field of logistics and transportation, giving rise to a new form of governance. This paper traces the infrastructuralisation of Baemin, the largest South Korean food delivery platform. By engaging with critical infrastructure studies, it seeks to make the infrastructuring work of platforms more visible and political, revealing an opening for progressive disruption. Drawing on the empirical data from a mobile ethnography in Seoul, the paper claims that Baemin operationalises distinct sociotechnical arrangements that infrastructurally integrate the labour of couriers in its automated operations and generate ceaseless urban flows. Furthermore, it brings to the fore the significance of couriers’ embodied practices in enabling and sustaining the contingent, hence precarious, operation of the convenient platform-mediated food delivery that many take for granted.Item Embargo Accepted version Peer-reviewed Carer perspectives enable accurate diagnosis of neurodegenerative disease(Wiley) Murley, Alexander; Bowns, Lucy; Camacho, Marta; Williams-Gray, Caroline; Tsvetanov, Kamen; Rittman, Timothy; Barker, Roger; O'Brien, John; Rowe, James; Murley, Alexander [0000-0003-0813-0670]BACKGROUND The history from a relative or carer is an important tool for differentiating neurodegenerative disease. We characterised patterns of carer questionnaire responses, at diagnosis and follow up, on the Cambridge Behavioural Inventory (CBI). METHODS Data-driven multivariate analysis (n=4952 questionnaires) was undertaken for participants (n=2481) with Alzheimer’s (typical/amnestic n=543, language n=50 and posterior cortical n=50 presentations), Parkinson’s (n=740), dementia with Lewy bodies (n=55), multiple system atrophy (n=55), progressive supranuclear palsy (n=422), corticobasal syndrome (n=176), behavioural variant frontotemporal dementia (n=218), semantic (n=125) and non-fluent variant progressive aphasia (n=88) and motor neuron disease (n=12). RESULTS Item-level support vector machine learning gave high diagnostic accuracy between diseases (AUC mean 0.83), despite transdiagnostic changes in memory, behaviour and everyday function. There was progression in CBI subscores over time, which varied by diagnosis. DISCUSSION Our results highlight the differential diagnostic information for a wide range of neurodegenerative diseases contained in a simple, structured collateral history.Item Embargo Accepted version Peer-reviewed Sex Differences in Human Brain Structure at Birth(BMC) Khan, Yumnah; Tsompanidis, Alex; Radecki, Marcin; Dorfschmidt, Lena; Austin, Topun; Suckling, John; Allison, Carrie; Lai, Meng-Chuan; Bethlehem, Richard; Baron-Cohen, SimonBackground: Sex differences in human brain anatomy have been well-documented, though remain significantly underexplored during early development. The neonatal period is a critical stage for brain development and can provide key insights into the role that prenatal and early postnatal factors play in shaping sex differences in the brain. Methods: Here, we assessed on-average sex differences in global and regional brain volumes in 514 newborns aged 0-28 days (236 birth-assigned females and 278 birth-assigned males) using data from the developing Human Connectome Project. We also assessed sex-by-age interactions to investigate sex differences in early postnatal brain development. Results: On average, males had significantly larger intracranial and total brain volumes, even after controlling for birth weight. After controlling for total brain volume, females showed significantly greater total cortical gray matter volumes, whilst males showed greater total white matter volumes. After controlling for total brain volume in regional comparisons, females had significantly increased white matter volumes in the corpus callosum and increased gray matter volumes in the bilateral parahippocampal gyri (posterior parts), left anterior cingulate gyrus, bilateral parietal lobes, and left caudate nucleus. Males had significantly increased gray matter volumes in the right medial and inferior temporal gyrus (posterior part) and right subthalamic nucleus. Effect sizes ranged from small for regional comparisons to large for global comparisons. Significant sex-by-age interactions were noted in the left anterior cingulate gyrus and left superior temporal gyrus (posterior parts). Conclusions: Our findings demonstrate that sex differences in brain structure are already present at birth and remain comparatively stable during early postnatal development, highlighting an important role of prenatal factors in shaping sex differences in the brain.Item Embargo Accepted version Peer-reviewed Transport and urban growth in the First Industrial Revolution(Oxford University Press (OUP)) Bogart, Dan; Alvarez-Palau, Eduard; Satchell, Max; Shaw-Taylor, LeighThe Industrial Revolution led to dramatic economic changes which persist to the present. This paper focuses on urban areas in England and Wales, the birthplace of the First Industrial Revolution, and the role of early transport improvements, like improving rivers and roads, building canals, and reducing sailing costs. We estimate how much inter-urban freight transport costs declined from all such innovations between 1680 and 1830 using a new multi-modal transport model. We find that relative to producer prices, transport costs declined by nearly 75%. We then estimate how lower trade costs led to significantly higher urban population through increased market access. Our empirical strategy addresses confounding factors and potential endogeneity. A counterfactual suggests that without any change in the ratio of transport costs to producer prices between 1680 and 1830, the population in 1841 would have been more coastal and inland towns would have been 20 to 25% smaller. In extensions, we show that levels of market access in 1830 had persistent, positive effects on urban population up to 1911. It also led to significantly higher property income, more migration, and fewer unskilled occupations by the mid-nineteenth century. Broadly, early transport improvements significantly shaped the spatial structure of urban economies during the First Industrial Revolution and beyond.Item Open Access Published version Peer-reviewed Core–shell carbon-polymer quantum dot passivation for near infrared perovskite light emitting diodes(IOP Publishing, 2022-07-01) Tountas, Marinos; Soultati, Anastasia; Armadorou, Konstantina-Kalliopi; Ladomenou, Kalliopi; Landrou, Georgios; Verykios, Apostolis; Skoulikidou, Maria-Christina; Panagiotakis, Stylianos; Fillipatos, Petros-Panagis; Yannakopoulou, Konstantina; Chroneos, Alexander; Palilis, Leonidas C; Yusoff, Abd Rashid Bin Mohd; Coutsolelos, Athanassios G; Argitis, Panagiotis; Vasilopoulou, Maria; Soultati, Anastasia [0000-0001-6683-6810]; Ladomenou, Kalliopi [0000-0002-8508-1369]; Chroneos, Alexander [0000-0002-2558-495X]; Vasilopoulou, Maria [0000-0001-8893-1691]Abstract High-performance perovskite light-emitting diodes (PeLEDs) require a high quality perovskite emitter and appropriate charge transport layers to facilitate charge injection and transport within the device. Solution-processed n-type metal oxides represent a judicious choice for the electron transport layer (ETL); however, they do not always present surface properties and energetics compatible with the perovskite emitter. Moreover, the emitter itself exhibits poor nanomorphology and defect traps that compromise the device performance. Here, we modulate the surface properties and interface energetics between the tin oxide (SnO2) ETL with the perovskite emitter by using an amino functionalized difluoro{2-[1-(3,5-dimethyl-2H-pyrrol-2-ylidene-N)ethyl]-3,5-dimethyl-1H-pyrrolato-N}boron compound and passivate the defects present in the perovskite matrix with carbon-polymer core–shell quantum dots inserted into the perovskite precursor. Both these approaches synergistically improve the perovskite layer nanomorphology and enhance the radiative recombination. These properties resulted in the fabrication of near-infrared PeLEDs based on formamidinium lead iodide (FAPbI3) with a high radiance of 92 W sr−1 m−2, an external quantum efficiency (EQE) of 14%, reduced efficiency roll-off and prolonged lifetime. In particular, the modified device retained 80% of the initial EQE (T80) for 33 h compared to 6 h of the reference cell.Item Open Access Published version Peer-reviewed Synthetic approaches for perovskite thin films and single-crystals(Royal Society of Chemistry (RSC), 2023-08-10) Soultati, A; Tountas, M; Armadorou, KK; Yusoff, ARBM; Vasilopoulou, M; Nazeeruddin, MK; Soultati, A [0000-0001-6683-6810]; Armadorou, KK [0000-0002-0355-9411]; Yusoff, ARBM [0000-0002-6871-6916]; Vasilopoulou, M [0000-0001-8893-1691]; Nazeeruddin, MK [0000-0001-5955-4786]Halide perovskites are compelling candidates for the next generation of photovoltaic technologies owing to an unprecedented increase in power conversion efficiency and their low cost, facile fabrication and outstanding semiconductor properties.Item Embargo Accepted version Peer-reviewed Intermediated legitimation: how founders build new venture legitimacy among make-or-break audiences(Academy of Management) Neuberger, I; Mattioli, F; Richards, H; Nyilasy, G; Tracey, P; Tracey, Paul [0000-0002-5877-9817]Many new ventures enter relationships with intermediaries, thereby ceding control to an organization that becomes a make-or-break audience for them. These settings foster intense experiences, suggesting that participating founders are likely to face a distinct set of challenges as they seek to build their venture’s legitimacy. Yet we lack a systematic analysis of new venture legitimation processes in the context of this critical audience type. To build new understanding of these important dynamics, we conducted an ethnographic study of three ventures in an Australian accelerator. Our study reveals three distinct legitimation pathways that ventures may follow when seeking legitimacy from a make-or-break audience – the obedient, pragmatic, and rebellious paths. We find that these pathways are jointly shaped by the expectations of the audience, the emotional experiences of founders, and founders’ reactions to these emotions in the context of perceived venture performance. We contribute to organizational scholarship by identifying a novel set of new venture legitimation pathways that incorporate emotion, conceptualizing “venture work” as a distinct type of social-symbolic work designed to legitimate startups, and shedding new light on the role of new venture support organizations in entrepreneurial ecosystems.Item Embargo Accepted version Peer-reviewed Bi-directional regulation between inflammation and stem 1 cells in the respiratory tract(The Company of Biologists) Chudziak, JakubInflammation plays a crucial role in tissue injury, repair, and disease, orchestrating a complex interplay of immune responses and cellular processes. Recent studies have uncovered the intricate connection between inflammation and stem cell dynamics, shedding light on the central role of stem cells in tissue regeneration. This Review highlights the significance of inflammation in shaping epithelial stem cell dynamics and its implications for tissue repair, regeneration, and aging. We explore the multifaceted interactions between inflammation and stem cells, focusing on how inflammatory signals affect stem cell behavior and fate as well as the remodeling of their niche in the respiratory tract. We also discuss the concept of ‘inflammatory memory’ in epithelial stem cells, where prior inflammatory stimuli endow these cells with enhanced regenerative potential and confer long-lasting protective mechanisms for maintaining tissue integrity and function. Furthermore, we review the impact of cell senescence induced by inflammation on tissue regeneration and aging, delving into the molecular mechanisms underlying the modulation of signaling pathways, epigenetic modifications, and cellular crosstalk. Understanding these dynamic processes not only deepens our knowledge of tissue homeostasis and repair but also holds profound implications for regenerative medicine strategies aimed at preventing pulmonary diseases.Item Embargo Accepted version Peer-reviewed Bronchoscopic diagnosis of severe respiratory infections(MDPI AG) Roder, Maire; Ng, Anthony; Conway Morris, Andrew; Conway Morris, Andrew [0000-0002-3211-3216]Abstract: The diagnosis of severe respiratory infections in intensive care remains an area of uncertainty and involves a complex balancing of risks and benefits. Due to the frequent colonisation of the lower respiratory tract in mechanically ventilated patients, there is an ever-present possibility of microbiological samples being contaminated by by- stander organisms. This, coupled with the frequency of alveolar infiltrates arising from sterile insults, risks over-treatment and antimicrobial-associated harm. The use of bronchoscopic sampling to obtain protected lower respiratory samples has long been advocated to overcome this problem. The use of bronchoscopy further enables accurate cytological assessment of the alveolar space and direct inspection of the proximal airways for signs of fungal infection or alternative pathologies. With a growing range of molecular techniques, including those based on nucleic acid amplification and even alveolar visualisation and direct bacterial detection, the potential for bronchoscopy is increasing concomitantly. Despite this, there remain concerns regarding the safety of the technique and its benefits versus less invasive sampling techniques. These discussions are reflected in the lack of consensus among international guidelines on the topic. This review will consider the benefits and challenges of diagnostic bronchoscopy in the context of severe respiratory infection.Item Embargo Accepted version Peer-reviewed An alternative interpretation of magnetars' traits deduced from the observational data on their outburst fluxes and spectra(Royal Astronomical Society) Ardavan, Houshang; Ardavan, Houshang [0000-0002-9136-3864]By applying the Efron-Petrosian method to the fluxes 𝑆 and distances 𝐷 of the magnetars listed in the Magnetar Outburst Online Catalogue, we show that the observational data are consistent with the dependence 𝑆 ∝ 𝐷−3/2, which characterizes the emission from the superluminally moving current sheet in the magnetosphere of a non-aligned neutron star, at substantially higher levels of significance than they are with the dependence 𝑆 ∝ 𝐷−2. This result agrees with that previously obtained by an analysis of the data in the McGill Online Magnetar Catalog and confirms that, contrary to the currently prevalent view, magnetars’ X-ray luminosities do not exceed their spin-down luminosities. The X-ray spectra of magnetars, moreover, are congruous with the spectral energy distribution (SED) of a broadband non-thermal emission mechanism identical to that at play in rotation-powered pulsars: we show that the SED of the caustics that are generated in certain privileged directions by the magnetospheric current sheet single-handedly fits the observed spectra of 4U 0142+61, 1E 1841-045 and XTE J1810-197 over their entire breadths. Magnetars’ outbursts and their associated radio bursts are predicted to occur when, as a result of large-scale timing anomalies (such as glitches, quakes or precession), one of the privileged directions along which the radiation from the current sheet decays more slowly than predicted by the inverse-square law either swings past or oscillates across the line of sight.Item Open Access Published version Peer-reviewed Efficient and Stable Air-Processed Ternary Organic Solar Cells Incorporating Gallium-Porphyrin as an Electron Cascade Material.(MDPI AG, 2023-10-21) Soultati, Anastasia; Verouti, Maria; Polydorou, Ermioni; Armadorou, Konstantina-Kalliopi; Georgiopoulou, Zoi; Palilis, Leonidas C; Karatasios, Ioannis; Kilikoglou, Vassilis; Chroneos, Alexander; Coutsolelos, Athanassios G; Argitis, Panagiotis; Vasilopoulou, Maria; Soultati, Anastasia [0000-0001-6683-6810]; Armadorou, Konstantina-Kalliopi [0000-0002-0355-9411]; Karatasios, Ioannis [0000-0002-3482-0424]; Chroneos, Alexander [0000-0002-2558-495X]; Coutsolelos, Athanassios G [0000-0001-5682-2968]; Vasilopoulou, Maria [0000-0001-8893-1691]Two gallium porphyrins, a tetraphenyl GaCl porphyrin, termed as (TPP)GaCl, and an octaethylporphyrin GaCl porphyrin, termed as (OEP)GaCl, were synthesized to use as an electron cascade in ternary organic bulk heterojunction films. A perfect matching of both gallium porphyrins' energy levels with that of poly(3-hexylthiophene-2,5-diyl) (P3HT) or poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) polymer donor and the 6,6-phenyl C71 butyric acid methyl ester (PCBM) fullerene acceptor, forming an efficient cascade system that could facilitate electron transfer between donor and acceptor, was demonstrated. Therefore, ternary organic solar cells (OSCs) using the two porphyrins in various concentrations were fabricated where a performance enhancement was obtained. In particular, (TPP)GaCl-based ternary OSCs of low concentration (1:0.05 vv%) exhibited a ~17% increase in the power conversion efficiency (PCE) compared with the binary device due to improved exciton dissociation, electron transport and reduced recombination. On the other hand, ternary OSCs with a high concentration of (TPP)GaCl (1:0.1 vv%) and (OEP)GaCl (1:0.05 and 1:0.1 vv%) showed the poorest efficiencies due to very rough nanomorphology and suppressed crystallinity of ternary films when the GaCl porphyrin was introduced to the blend, as revealed from X-ray diffraction (XRD) and atomic force microscopy (AFM). The best performing devices also exhibited improved photostability when exposed to sunlight illumination for a period of 8 h than the binary OSCs, attributed to the suppressed photodegradation of the ternary (TPP)GaCl 1:0.05-based photoactive film.Item Embargo Accepted version Peer-reviewed Coherent growth of high-Miller-index facets enhances perovskite solar cells(Nature Research) Li, Shunde; Xiao, Yun; Su, Rui; Xu, Weidong; Luo, Deying; Huang, Pengru; Dai, Linjie; Chen, Peng; Caprioglio, Pietro; Elmestekawy, Karim A; Dubajic, Milos; Chosy, Cullen; Hu, Juntao; Habib, Irfan; Dasgupta, Akash; Guo, Dengyang; Boeije, Yorrick; Zelewski, Szymon J; Lu, Zhangyuchang; Huang, Tianyu; Li, Qiuyang; Wang, Jingmin; Yan, Haoming; Chen, Hao-Hsin; Li, Chunsheng; Lewis, Barnaby AI; Wang, Dengke; Wu, Jiang; Zhao, Lichen; Han, Bing; Wang, Jianpu; Hertz, Laura M; Durrant, James R; Novoselov, Kostya S; Lu, Zheng-Hong; Gong, Qihuang; Stranks, Sam; Snaith, Henry J; Zhu, Rui; Stranks, Sam [0000-0002-8303-7292]Obtaining micron-thick perovskite films of high quality is key to realizing efficient and stable positive (p)-intrinsic (i)-negative (n) perovskite solar cells, but it remains a critical challenge. Here, we report an effective method for producing high-quality, micron-thick formamidinium-based perovskite films by forming coherent grain boundaries, where high- Miller-index-oriented grains grow on the low-Miller-index-oriented grains in a stabilized atmosphere. The resulting micron-thick perovskite films, with enhanced grain boundaries and grains, showed stable material properties and outstanding optoelectronic performances. The small-area solar cells achieved efficiencies of 26.1%. The 1-square-centimeter devices and 5 cm × 5 cm minimodules delivered efficiencies of 24.3% and 21.4%, respectively. The devices processed in a stabilized atmosphere presented a high reproducibility across all four seasons. The encapsulated devices exhibited superior long-term stability under both light and thermal stressors in ambient air.Item Embargo Accepted version Peer-reviewed Homogenized contact in all- perovskite tandems using tailored 2D perovskite(Nature Research) Wang, Yurui; Lin, Renxing; Liu, Chenshuaiyu; Wang, Xiaoyu; Chosy, Cullen; Haruta, Yuki; Bui, Anh Dinh; Li, Minghui; Sun, Hongfei; Zheng, Xuntian; Luo, Haowen; Wu, Pu; Gao, Han; Sun, Wenjie; Nie, Yuefeng; Zhu, Hesheng; Zhou, Kun; Nguyen, Hieu T; Luo, Xin; Li, Ludong; Xiano, Chuanxiao; Saidaminov, Makhsud I; Stranks, Sam; Zhang, Lijun; Tan, Hairen; Stranks, Sam [0000-0002-8303-7292]The fabrication of scalable all-perovskite tandem solar cells is considered an attractive route to commercialize perovskite photovoltaic modules1. However, The certified efficiency of 1-cm2 scale all-perovskite tandem solar cells lags behind their small-area (~0.1 cm2) counterparts. This performance deficit originates from inhomogeneity in wide-bandgap (WBG) perovskite solar cells (PSCs) at a large scale. The inhomogeneity is known to be introduced at the bottom interface and within the perovskite bulk itself. Here we uncover another crucial source for the inhomogeneity – the top interface formed during the deposition of the electron transport layer (ETL, C60). Meanwhile, the poor ETL interface is also a significant limitation of device performance. We address this issue by introducing a mixture of 4-fluorophenethylamine (F-PEA) and 4-trifluoromethyl phenylammonium (CF3-PA) to create a tailored two-dimensional perovskite layer (TTDL), in which F-PEA forms a two-dimensional perovskite at the surface reducing contact losses and inhomogeneity, CF3-PA enhances charge extraction and transport. As a result, we demonstrate a high open-circuit voltage of 1.35 V and an efficiency of 20.5% in 1.77-eV WBG PSCs at a square centimeter scale. By stacking with a narrow-bandgap perovskite sub-cell, we report 1.05 cm2 all perovskite tandem cells delivering 28.5% (certified 28.2%) efficiency, the highest among all reported so far. Our work showcases the importance of treating the top perovskite/ETL contact for upscaling perovskite solar cells.Item Embargo Accepted version Peer-reviewed Front-tracking and gelation in sessile droplet suspensions: what can they tell us about human blood?(American Chemical Society) Bhatt, Sheila; Bhatt, Sheila [0009-0007-6174-7852]Recently-developed imaging techniques have been used to examine redistribution of human red blood cells and comparator particles dispersed in carrier fluids within evaporating droplets. We demonstrate that progressive gelation initiates along an annular front, isolating a central pool which briefly remains open to particulate advection before gelation completes across the droplet centre. Transition to an elastic solid is evidenced by cracking initiating proximal to front-locations. The arrested flow of cellular components, termed a ‘halted front’, has been investigated using a time-lapse analysis ‘signature’. The presence of a deformable bio-cellular component is seen to be essential for front-halting. We show a dependence of front-halt radius on cell volume-fraction, potentially offering a low-cost means of measuring haematocrit. A simple model yields an estimate of the gel zero-shear yield-stress. This approach to understanding the drying dynamics of blood droplets may lead to a new generation of point-of-care diagnostics.Item Embargo Accepted version Peer-reviewed The Return of Joint Enterprise(Cambridge University Press) Virgo, GrahamA case note on the decision of the Court of Appeal in Seed [2024] EWCA Crim 650 on the criminal liability of accessories.Item Embargo Accepted version Peer-reviewed Covenantal Pluralism in Zimbabwe—From Ecumenical Councils to Grassroots Ecumenism(Taylor and Francis) Maxwell, David; Maxwell, David [0000-0002-1701-5917]Despite Christian adherence at 85%, high levels of religious literacy, and constitutional provision for religious freedom, the prospects for covenantal pluralism in Zimbabwe are limited. The Zimbabwean church is divided by denomination, theology, and ethnicity. These divisions have roots in the colonial era, but they have been exacerbated by the post-colonial state since independence in 1980. From the 2000s, the regime has sought to split the church through persecution, fear, selective patronage, and the creation of clientelist Christian bodies. Nevertheless, there have been propitious moments of cooperation and solidarity amongst ecumenical councils and new movements of grassroots ecumenism.Item Open Access Accepted version Peer-reviewed Phenotypic variation in the lipopolysaccharide O-antigen of Salmonella Paratyphi A and implications for vaccine development.(Elsevier BV, 2024-10-08) Mylona, Elli; Pereira-Dias, Joana; Keane, Jacqueline A; Karkey, Abhilasha; Dongol, Sabina; Khokhar, Fahad; Tran, Tuan-Anh; Cormie, Claire; Higginson, Ellen; Baker, Stephen; Mylona, Elli [0000-0002-2638-0713]Enteric fever remains a major public health problem in South and Southeast Asia. The recent roll-out of the typhoid conjugate vaccine protecting against S. Typhi exhibits great promise for disease reduction in high burden areas. However, some endemic regions remain vulnerable to S. Paratyphi A due to a lack of licensed vaccines and inadequate WASH. Several developmental S. Paratyphi A vaccines exploit O-antigen as the target antigen. It has been hypothesised that O-antigen is under selective and environmental pressure, with mutations in O-antigen biosynthesis genes being reported, but their phenotypic effects are unknown. Here, we aimed to evaluate O-antigen variation in S. Paratyphi A originating from Nepal, and the potential effect of this variation on antibody binding. O-antigen variation was determined by measuring LPS laddering shift following electrophoresis; this analysis was complemented with genomic characterisation of the O-antigen region. We found structural O-antigen variation in <10 % of S. Paratyphi A organisms, but a direct underlying genetic cause could not be identified. High-content imaging was performed to determine antibody binding by commercial O2 monoclonal (mAb) and polyclonal antibodies, as well as polyclonal sera from convalescent patients naturally infected with S. Paratyphi A. Commercial mAbs detected only a fraction of an apparently "clonal" bacterial population, suggesting phase variation and nonuniform O-antigen composition. Notably, and despite visible subpopulation clusters, O-antigen structural changes did not appear to affect the binding ability of polyclonal human antibody considerably, which led to no obvious differences in the functionality of antibodies targeting organisms with different O-antigen conformations. Although these results need to be confirmed in organisms from alternative endemic areas, they are encouraging the use of O-antigen as the target antigen in S. Paratyphi A vaccines.