Cambridge University Research Outputs

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The mission of the University of Cambridge is to contribute to society through the pursuit of education, learning, and research at the highest international levels of excellence. This collection contains the latest research outputs of the University's academic staff and students.

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Now showing 1 - 20 of 36707

Accepted versionOpen Access
Predicting the size of silver nanoparticles synthesised in flow reactors: Coupling population balance models with fluid dynamic simulations
(Elsevier BV, 2023-11) Casado, Cintia; Pinho, Bruno; Marugán, Javier; Torrente-Murciano, Laura; Casado, Cintia [0000-0003-1522-195X]; Marugán, Javier [0000-0003-1195-462X]; Torrente-Murciano, Laura [0000-0002-7938-2587]
Accepted versionEmbargo
Genetic history of Cambridgeshire before and after the Black Death
(American Association for the Advancement of Science) Hui, Ruoyun; Scheib, Christiana; Kivisild, Toomas; Robb, John; Scheib, Christiana [0000-0003-4158-8296]
The extent of the devastation of the Black Death pandemic (1346-53) on European populations is known from documentary sources and its bacterial source illuminated by studies of ancient pathogen DNA. What has remained less understood is the effect of the pandemic on human mobility and genetic diversity at local scale. Here we report 275 new ancient genomes, including 109 with coverage >0.1x, from later medieval and post-medieval Cambridgeshire of individuals buried before and after the Black Death. Consistent with the function of the institutions, we found a lack of close relatives among the friars and the inmates of the hospital in contrast to their abundance in general urban and rural parish communities. While we detect long-term shifts in local genetic ancestry in Cambridgeshire, we find no evidence of major changes in genetic ancestry nor higher differentiation of immune loci between cohorts living before and after the Black Death.
Published versionOpen Access
3D Printable Self‐Sensing Magnetorheological Elastomer
(Wiley) Costi, Leone; Georgopoulou, Antonia; Mondal, Somashree; Iida, Fumiya; Clemens, Frank; Costi, Leone [0000-0001-6023-0228]
AbstractMagnetorheological elastomers (MREs) are a category of smart materials composed of a magnetic powder dispersed in an elastomeric matrix. They are characterized by the ability to change their mechanical properties when an external magnetic field is applied, called magnetorheological (MR) effect. When a conductive filler is added to a magnetorheological elastomer, the resulting hybrid filler composite showcases both MR and piezoresistive effects. For such a reason, these composites are referred to as self‐sensing magnetorheological elastomers. In this case, the synthesized self‐sensing magnetorheological elastomers are based on styrene‐based thermoplastic elastomers (TPS), carbonyl iron particles (CIP), and carbon black (CB). The hybrid filler concept using various coated CIP and constant CB content showed that above 25 vol.% CIP the resistivity increased rapidly. This work proposes the first case of a 3D printable self‐sensing magnetorheological elastomer and cyclic mechanical compression and tensile mode analysis at high deformation (up to 20% and 10%, respectively). The results showcase a magnetoresistive change of up to 68% and a piezoresistive change of up to 42% and 98% in compression and tension, respectively. In addition, the magnetostriction of the self‐sensing samples has been characterized to be 3.6% and 5.6% in the case of CIP 15 and 30 vol.%, respectively.
Accepted versionEmbargo
Evaluating the impacts of a large-scale voluntary REDD+ project in Sierra Leone
(Nature Research) Malan, Mandy; Carmenta, Rachel; Ghosttbauer, Elisabeth; Hofman, Paul; Kontoleon, Andreas; Swinfield, Tom; Voors, Maarten; Kontoleon, Andreas [0000-0003-4769-898X]
Carbon offsets from the REDD+ framework to protect forests are expected to see a 100-fold increase in market value by 2050. However, independent causal impact evaluations are scarce and only a few studies assess benefits to communities themselves, a core objective of REDD+. Following a pre-analysis plan, we use a Before-After-Control-Intervention (BACI) framework to evaluate the impact of a large-scale voluntary REDD+ project in Sierra Leone – the Gola project. We use a panel of both satellite images and household surveys to provide causal evidence of the impact of the project on local deforestation rates and socio-economic indicators over the first five years of its implementation. We find that REDD+ slowed deforestation by 30% relative to control communities while not changing economic wellbeing and conservation attitudes. We find suggestive evidence that the programme increased the value of alternative income sources, by shifting labour away from forest-dependent farming activities. A cost-to-carbon calculation shows REDD+ led to 340,000 tCO2 in avoided emissions per year with an estimated cost of $1.12 per averted tCO2. Our study contributes to developing an evidence base for voluntary REDD+ projects and offers a robust approach to carry out BACI assessments.
Published versionOpen Access
Data Mining in Social Sciences: A Decision Tree Application Using Social and Political Concepts
(Walter de Gruyter GmbH, 2022-11-25) Massou, E; Prodromitis, G; Papastamou, S; Massou, E [0000-0003-0488-482X]; Prodromitis, G [0000-0001-6945-2628]; Papastamou, S [0000-0003-1853-2470]
Abstract In this paper, we investigated the utility of data mining to classify individuals into predefined categories of a target variable, based on their social and political attitude. Data collected for a social psychology study conducted in Greece in 1994 were used for this purpose. We established the theoretical background of our analysis through explanatory factor analysis. We ran the decision tree algorithm CHAID in order to build a predictive model that classifies the study participants in terms of their attitude toward physical and symbolic violence. The CHAID algorithm provided a decision tree that was easily interpreted, and which revealed meaningful predictive patterns. CHAID algorithm showed satisfactory predictive ability and promising alternatives to social psychology data analysis. To the best of our knowledge, there is no other evidence in the literature that the decision tree algorithms can be used to identify latent variables.
Published versionOpen Access
COVID-19 and shielding: experiences of UK patients with lupus and related diseases.
(Oxford University Press (OUP), 2021) Sloan, Melanie; Gordon, Caroline; Lever, Elliott; Harwood, Rupert; Bosley, Michael A; Pilling, Mark; Brimicombe, James; Naughton, Felix; Blane, Moira; Walia, Chanpreet; D'Cruz, David; Harwood, Rupert [0000-0001-9790-2796]
OBJECTIVE: The shielding guidance in the UK for the clinically extremely vulnerable (CEV) commenced on 23 March 2020 in response to the coronavirus disease 2019 (COVID-19) pandemic. The purpose of this study was to explore the impact of the pandemic and shielding on patients with lupus and related systemic autoimmune rheumatic diseases (SARDs). METHODS: This was a mixed-methods cohort study (n = 111) including pre-lockdown baseline surveys (March 2020), follow-up surveys (June 2020) and in-depth interviews during July 2020 (n = 25). RESULTS: Most participants had a high level of anxiety regarding their mortality risk from COVID-19 and supported the concept of shielding. Shielding allocations and communications were perceived as inconsistently applied and delivered. More than half of those not classified as CEV reported feeling abandoned, at increased risk and with no support. Shielding communications increased feelings of being 'cared about', but also increased fear, and the 'vulnerable' labelling was perceived by some to damage social and self-identity. More than 80% of those classified as CEV stated that the classification and subsequent communications had changed their social-mixing behaviour. Despite many negative impacts of COVID-19 and shielding/lockdown being identified, including isolation, fear and reduced medical care, the quantitative data during the pandemic showed increases in most measures of wellbeing (which was low at both time points) from pre-lockdown, including reductions in the impact of fatigue and pain (P-values < 0.001). CONCLUSION: Shielding classifications and communications were, in general, viewed positively, although they were perceived as inconsistently delivered and anxiety-provoking by some participants. More frequent positively framed communication and wellbeing support could benefit all SARD patients. Slower-paced lockdown lifestyles might confer health/wellbeing benefits for some people with chronic diseases.
Accepted versionEmbargo
Non-Native Tone Categorization and Word Learning Across a Spectrum of L1 Tonal Statuses
(Cambridge University Press) Lameris, Tim; Lameris, Tim [0000-0002-1365-3022]
Adults differ in the ease with which they acquire lexical tones in a non-native language. Individual differences have been attributed to several factors, such as the role that pitch plays in a learner’s L1 to signal lexical meaning (L1 tonal status), the shape of the tones to be acquired (tone types), as well as extralinguistic factors (such as musical experience and working memory). Here, we ask whether learners from a spectrum of L1 tonal statuses (Dutch, Swedish and Japanese, and Thai) differ in their tone word learning facility, whilst we simultaneously investigate the effects of tone type, and musical experience and working memory. Our findings suggest that above and beyond L1 tonal status, the strongest predictor of tone word learning was pre-lexical tone processing (measured by a tone categorization task), although the strength of the link between pre-lexical and lexical processing may be modulated by L1 tonal status.
Published versionOpen Access
Understanding the micro and macro politics of health: Inequalities, intersectionality & institutions - A research agenda.
(Elsevier BV, 2018-03) Gkiouleka, Anna; Huijts, Tim; Beckfield, Jason; Bambra, Clare
This essay brings together intersectionality and institutional approaches to health inequalities, suggesting an integrative analytical framework that accounts for the complexity of the intertwined influence of both individual social positioning and institutional stratification on health. This essay therefore advances the emerging scholarship on the relevance of intersectionality to health inequalities research. We argue that intersectionality provides a strong analytical tool for an integrated understanding of health inequalities beyond the purely socioeconomic by addressing the multiple layers of privilege and disadvantage, including race, migration and ethnicity, gender and sexuality. We further demonstrate how integrating intersectionality with institutional approaches allows for the study of institutions as heterogeneous entities that impact on the production of social privilege and disadvantage beyond just socioeconomic (re)distribution. This leads to an understanding of the interaction of the macro and the micro facets of the politics of health. Finally, we set out a research agenda considering the interplay/intersections between individuals and institutions and involving a series of methodological implications for research - arguing that quantitative designs can incorporate an intersectional institutional approach.
Accepted versionEmbargo
Molecular mechanisms of cationic fusogenic liposome interactions with bacterial envelopes
(American Chemical Society) Scheeder, Anna; Brockhoff, Marius; Ward, Edward; Kaminski Schierle, Gabriele; Mela, Ioanna; Kaminski, Clemens
Although fusogenic liposomes offer a promising approach for the delivery of antibiotic payloads across the cell envelope of Gram-negative bacteria, there is still limited understanding of the individual nanocarrier interactions with the bacterial target. Using super-resolution microscopy, we characterize the interaction dynamics of positively charged fusogenic liposomes with Gram-negative (Escherichia coli) and Gram-positive (Bacillus subtilis) bacteria. The liposomes merge with the outer membrane (OM) of Gram-negative bacteria, while attachment or lipid internalization is observed in Gram-positive cells. Employing total internal reflection fluorescence microscopy, we demonstrated liposome fusion with model supported lipid bilayers. For whole E. coli cells, however, we observed heterogeneous membrane integrations, primarily involving liposome attachment and hemifusion events. With increasing lipopolysaccharide length the likelihood of full-fusion events was reduced. The integration of artificial lipids into the OM of Gram-negative cells led to membrane destabilization, resulting in decreased bacterial vitality, membrane detachment, and improved co-delivery of Vancomycin—an effective antibiotic against Gram-positive cells. These findings provide significant insights into the interactions of individual nanocarriers with bacterial envelopes at the single-cell level, uncovering effects that would be missed in bulk measurements. This highlights the importance of conducting single-particle and single-cell investigations to assess the performance of next-generation drug delivery platforms.
Accepted versionEmbargo
Integration of metal meshes as transparent conducting electrodes into perovskite solar cells
(Wiley) Stranks, Samuel; Stranks, Samuel [0000-0002-8303-7292]
As the demand for photovoltaic technologies continues to grow, the quest for efficient and sustainable transparent conducting electrodes (TCEs) rapidly rises. Traditional solutions, such as indium tin oxide (ITO), face challenges related to indium scarcity and environmental impact. To tackle these issues, we develop a novel metal mesh rear TCE consisting of gold micro-meshes as ITO replacement in perovskite solar cells (PSCs). Our study reveals that optimized Au meshes can guarantee 75% of the extracted photocurrent compared to reference devices with ITO, and a promising power conversion efficiency (PCE) of 8.65%. By utilizing hybrid mesh structures with a 10 nm ITO layer, the PCE further improves to 12.1%, with the extracted current exceeding 80% of the reference. Metal meshes can even serve to replace the opaque metal contact of PSCs, amplifying their functionality and efficiency through bifacial and multi-junction applications. In this study, aerosol jet-printed silver meshes serve as front electrodes, combined with either 5-10 nm of Au, achieving efficient semi-transparent devices (PCE 16.8%), or with 5-10 nm of ITO, providing enhanced bifacial properties while maintaining competitive efficiency. Overall, this work highlights remarkable features of metal meshes, making them promising alternatives to commonly used TCEs in optoelectronic applications.
Accepted versionEmbargo
‘To the Future Turned, We Stand’: Progress and the Temporal Politics of Citizenship in the German Democratic Republic
(Routledge) Mandelbaum, Melina
In both parts of post-war Germany, the promise of progress played a central role in imagining and implementing new frameworks of social belonging and their formalization in the institution of citizenship. This article investigates how ideologies of progress were employed by various political and cultural actors in East Germany to support processes of citizenship formation and the consolidation of an independent statehood. I open with a brief historical discussion to argue that discourses of progress and futurity have played a significant role for all modern nation states independently of their ideological positioning. I will then proceed to show that the GDR, together with other socialist states, stands out in this regard due to the extent that its temporal politics were both modelled by and predicated on the particularity of its economic paradigm: the centrally planned economy. Following an analysis of the realm of formalized politics I will discuss how ideologies of progress manifested and were critically reviewed in the realm of literary production.
Published versionOpen Access
Evidence-based climate impact: A financial product framework
(Elsevier BV, 2023-11) Quigley, Ellen
Accepted versionEmbargo
Facile Method for 3D Printing Conformally onto Uneven Surfaces and its Application to Face Masks
(Nature Portfolio) Ji, Zehao; Brion, Douglas AJ; Samson, Kerr DG; Pattinson, Sebastian W
Conventional additive manufacturing processes, where parts are built through layer-wise deposition of material on a horizontal plane, can be limiting when a part must be printed or fit onto uneven surfaces. Such situations will arise with increasing frequency as additive manufacturing application areas such as construction and medical devices continue to grow. In this work, we develop a simple and practical approach to generate toolpaths to print 3D structures onto uneven surfaces conformally. The algorithm uses only conventional planar toolpaths of both the structure to be printed and the substrate to be printed on and converts these to non-planar toolpaths, allowing easy integration with existing additive manufacturing workflows. The technique is demonstrated by printing flexible seals onto bespoke rigid face mask frames conformally via a conventional single-material 3D printer using the generated conformal toolpath. A notable improvement in air seal performance was observed for customized face masks with conformal soft seals compared to conventionally 3D-printed fully rigid face masks. This also shows the potential of the developed toolpath generation method to aid in the prototyping and fabrication of conformal medical and other devices.
Published versionOpen Access
Retrospective Valuation of Experienced Outcome Encoded in Distinct Reward Representations in the Anterior Insula and Amygdala.
(Society for Neuroscience, 2020-11-11) Vestergaard, Martin D; Schultz, Wolfram; Vestergaard, Martin D [0000-0003-0000-8566]; Schultz, Wolfram [0000-0002-8530-4518]
Our ability to evaluate an experience retrospectively is important because it allows us to summarize its total value, and this summary value can then later be used as a guide in deciding whether the experience merits repeating, or whether instead it should rather be avoided. However, when an experience unfolds over time, humans tend to assign disproportionate weight to the later part of the experience, and this can lead to poor choice in repeating, or avoiding experience. Using model-based computational analyses of fMRI recordings in 27 male volunteers, we show that the human brain encodes the summary value of an extended sequence of outcomes in two distinct reward representations. We find that the overall experienced value is encoded accurately in the amygdala, but its merit is excessively marked down by disincentive anterior insula activity if the sequence of experienced outcomes declines temporarily. Moreover, the statistical strength of this neural code can separate efficient decision-makers from suboptimal decision-makers. Optimal decision-makers encode overall value more strongly, and suboptimal decision-makers encode the disincentive markdown (DM) more strongly. The separate neural implementation of the two distinct reward representations confirms that suboptimal choice for temporally extended outcomes can be the result of robust neural representation of a displeasing aspect of the experience such as temporary decline.SIGNIFICANCE STATEMENT One of the numerous foibles that prompt us to make poor decisions is known as the "Banker's fallacy," the tendency to focus on short-term growth at the expense of long-term value. This effect leads to unwarranted preference for happy endings. Here, we show that the anterior insula in the human brain marks down the overall value of an experience as it unfolds over time if the experience entails a sequence of predominantly negative temporal contrasts. By contrast, the amygdala encodes overall value accurately. These results provide neural indices for the dichotomy of decision utility and experienced utility popularized as Thinking fast and slow by Daniel Kahneman.
Accepted versionEmbargo
NEW LIGHT IN CHRISTODORUS: AN ACROSTIC AT ANTH. PAL. 2.72–6
(Classical Association) Leventhal, Max
This note identifies a new acrostic in Christodorus’ sixth century C.E. Ekphrasis of the Baths of Zeuxippus (Anth. Pal. 2) and explains its significance.
Published versionOpen Access
Bioinspired soft bendable peristaltic pump exploiting ballooning for high volume throughput
(IEEE, 2021) Costi, L; Hughes, J; Iida, F; Costi, Leone [0000-0001-6023-0228]; Iida, Fumiya [0000-0001-9246-7190]
Interest in bioinspired peristaltic pumps has grown in popularity among the scientific community in the last decade thanks to their extreme flexibility and their intrinsic compliance. In this paper, we propose a soft peristaltic pump exploiting ballooning. Our aim is to promote and propel forward the ballooned region by controlling the air pressure between the balloon and an external flexible containment tube. Thanks to this mechanism, it is possible to achieve a peristaltic pumping motion with a simple design and using only one control signal. In this paper, we describe the implementation of the pump and the inlet-pump-outlet system, provide an analytical model to predict the pump performance, and experimentally test the device. Finally, the proposed pump is directly compared with the state-of-the-art. We show that it is possible to achieve high flow rates, up to 4.5 frac{mL}{s}, with only a single control signal and relying on a much simpler design, paving the way for more flexible and easy to manufacture peristaltic pumps.
Published versionOpen Access
Bioinspired Soft Bendable Peristaltic Pump Exploiting Ballooning for High Volume Throughput
(Institute of Electrical and Electronics Engineers (IEEE), 2022) Costi, L; Hughes, J; Biggins, J; Iida, F; Costi, L [0000-0001-6023-0228]; Hughes, J [0000-0001-8410-3565]; Iida, F [0000-0001-9246-7190]
Interest in bioinspired peristaltic pumps has grown in popularity among the scientific community in the last decade thanks to their extreme flexibility and their intrinsic compliance. In this paper, we propose a soft peristaltic pump exploiting ballooning. Our aim is to promote and propel forward the ballooned region by controlling the air pressure between the balloon and an external flexible containment tube, to achieve a peristaltic pumping motion with a simple design and using only one control signal. This paper describes the implementation of the pump and the inlet-pump-outlet system, provides an analytical model to predict the pump performance, and showcases experimental results. We also implement a computer simulation to further characterize the device. We show that it is possible to achieve high volumetric flow rates, up to 4.4mL/s, with only a single control signal, paving the way for more flexible and easy to manufacture peristaltic pumps.
Published versionOpen Access
Aneuploidy during development in facultative parthenogenetic Drosophila
(Springer Science and Business Media LLC) Sperling, AL; Glover, DM; Sperling, AL [0000-0001-6298-4832]; Glover, DM [0000-0003-0956-0103]
AbstractFrom concatenated chromosomes to polyploidization, large-scale genome changes are known to occur in parthenogenetic animals. Here, we report mosaic aneuploidy in larval brains of facultatively parthenogenetic Drosophila. We identified a background of aneuploidy in D. mercatorum strains and found increased levels of aneuploidy in the larval brain tissue of animals arising parthenogenetically versus those arising from sexual reproduction. There is also intra-individual variation in germline-derived aneuploidy within the same strain. To determine if this is a general feature of facultative parthenogenesis in drosophilids, we compared sexually reproduced and parthenogenetic offspring from an engineered facultative parthenogenetic strain of D. melanogaster. In addition to germline-derived aneuploidy, this revealed somatic aneuploidy that increased by up to fourfold in parthenogens compared to sexually reproduced offspring. Therefore, the genetic combination identified in D. mercatorum that causes facultative parthenogenesis in D. melanogaster results in aneuploidy, which indicates that the loss of mitotic control resulting in parthenogenesis causes subsequent genome variation within the parthenogenetic offspring. Our findings challenge the assumption that parthenogenetic offspring are near genetic replicas of their mothers.
Published versionOpen Access
Reducing health inequalities through general practice.
(Elsevier BV, 2023-06) Gkiouleka, Anna; Wong, Geoff; Sowden, Sarah; Bambra, Clare; Siersbaek, Rikke; Manji, Sukaina; Moseley, Annie; Harmston, Rebecca; Kuhn, Isla; Ford, John
Although general practice can contribute to reducing health inequalities, existing evidence provides little guidance on how this reduction can be achieved. We reviewed interventions influencing health and care inequalities in general practice and developed an action framework for health professionals and decision makers. We conducted a realist review by searching MEDLINE, Embase, CINAHL, PsycINFO, Web of Science, and Cochrane Library for systematic reviews of interventions into health inequality in general practice. We then screened the studies in the included systematic reviews for those that reported their outcomes by socioeconomic status or other PROGRESS-Plus (Cochrane Equity Methods Group) categories. 159 studies were included in the evidence synthesis. Robust evidence on the effect of general practice on health inequalities is scarce. Focusing on common qualities of interventions, we found that to reduce health inequalities, general practice needs to be informed by five key principles: involving coordinated services across the system (ie, connected), accounting for differences within patient groups (ie, intersectional), making allowances for different patient needs and preferences (ie, flexible), integrating patient worldviews and cultural references (ie, inclusive), and engaging communities with service design and delivery (ie, community-centred). Future work should explore how these principles can inform the organisational development of general practice.
Accepted versionEmbargo
The Influence of Gender Dynamics on Women’s Experiences in Martial Arts: A Scoping Review
(Springer Science and Business Media LLC, 2023-09) Lindsay, Rosie; Horne, Jo; Shaw, Jill; Kentzer, Nichola; Bacon, Wendi; Lindsay, Rosie [0000-0002-9176-4828]