University of Cambridge
  • Cambridge, United Kingdom
Recent publications
Significant advancements have occurred in the application of Large Language Models (LLMs) for social simulations. Despite this, their abilities to perform teaming in task-oriented social events are underexplored. Such capabilities are crucial if LLMs are to effectively mimic human-like social behaviors and form efficient teams to solve tasks. To bridge this gap, we introduce MetaAgents, a social simulation framework populated with LLM-based agents. MetaAgents facilitates agent engagement in conversations and a series of decision making within social contexts, serving as an appropriate platform for investigating interactions and interpersonal decision-making of agents. In particular, we construct a job fair environment as a case study to scrutinize the team assembly and skill-matching behaviors of LLM-based agents. We take advantage of both quantitative metrics evaluation and qualitative text analysis to assess their teaming abilities at the job fair. Our evaluation demonstrates that LLM-based agents perform competently in making rational decisions to develop efficient teams. However, we also identify limitations that hinder their effectiveness in more complex team assembly tasks. Our work provides valuable insights into the role and evolution of LLMs in task-oriented social simulations.
Shorter period undulators typically require a higher on-axis magnetic field in order to achieve a practical deflection parameter, K . Recent simulations and experiments have demonstrated that high-temperature superconducting (HTS) undulators, constructed from staggered-array bulk superconductors, can generate high undulator fields with period length as short as 10 mm. This advanced HTS technology has the potential to significantly enhance the photon energy range of synchrotron radiation light sources and free electron laser facilities. This paper reports on the progress made in developing of a 50-period bulk HTS undulator with period length of 12 mm for Shanghai soft x-ray free electron laser facility. It details the engineering design of the undulator prototype, thermal and mechanical analysis of the HTS variable temperature insert, and the current status of the system.
This paper experimentally investigates the characteristics of the linear traveling-wave flux pump by varying the rise-time to fall-time duty ratio, DC offset, and amplitude of triangular magnetization waveforms continuously over time and observing the generated current in the high-temperature superconductor (HTS) magnet. From the experimental results, the asymmetric triangle waveform is observed to have a certain rise-time duty cycle between 15% and 17% that maximizes the generated current and a threshold magnitude of 0.625 A below which no flux pumping is achieved. The results also confirm the ability of the magnitude and duty ratio of the asymmetric triangle waveform to alter the magnitude and direction of the generated current, respectively. Using these properties, a closed-loop control system is implemented in which the magnetization wave amplitude is the scaled difference between a demand current and the actual HTS current, and the duty ratio of the waveform is 1:9 or 9:1 based on the sign of the difference.
Elderly individuals often suffer from underlying medical conditions, resulting in a significant decline in quality of life and a heightened susceptibility to depression. Presently, AI screening tools based on behavioral indicators offer an objective and effective approach to diagnosing depression. However, current AI depression screening tools are primarily tailored to adolescents and adults, exhibiting shortcomings in their applicability and accuracy for elderly individuals with underlying medical conditions. To address the above issues, firstly, this paper constructs a depression dataset for elderly people with underlying diseases by using semi-structured interviews. Secondly, based on cognitive science insights, it is recognized that personality factors significantly influence behavioral expressions and also determine the attitudes of elderly individuals toward current life circumstances/health issues. Therefore, besides annotating depression severity, the Big Five-10 personality scale was utilized to annotate participant personalities. Finally, a late fusion-based multi-task learning framework was proposed, and the effects of introducing gait information and personality annotation on the performance of depression assessment were investigated. The experimental findings affirm the importance of integrating gait information and personality assessment in improving depression detection effectiveness. This study provides valuable foundational resources, as well as beneficial references and insights, for the research on depression in the elderly.
Exome and genome reanalysis from the Solve-RD cohort done with an automated mtDNA-filtering pipeline and MitoPhen-based HPO phenotype similarity scoring uncovered previously undiagnosed mtDNA variants, boosting the diagnostic yield by 0.4%. Our structured phenotype evaluation highlights how integrated mtDNA analyses improve rare disease diagnostics, even when mitochondrial conditions are not initially suspected. Summary The diagnosis of mitochondrial DNA (mtDNA) diseases remains challenging with next-generation sequencing, where bioinformatic analysis is usually more focused on the nuclear genome. We developed a workflow for the evaluation of mtDNA diseases and applied it in a large European rare disease cohort (Solve-RD). A semi-automated bioinformatic pipeline with MToolBox was used to filter the unsolved Solve-RD cohort for rare mtDNA variants after validating this pipeline on exome datasets of 42 individuals previously diagnosed with mtDNA variants. Variants were filtered based on blood heteroplasmy levels (≥1%) and reported association with disease. Overall, 10,157 exome and genome datasets from 9,923 affected individuals from 9,483 families within Solve-RD met the quality inclusion criteria. 136 mtDNA variants in 135 undiagnosed individuals were prioritized using the filtering approach. A focused MitoPhen-based phenotype similarity scoring method was tested in a separate genetically diagnosed "phenotype test cohort" consisting of nuclear gene and mtDNA diseases using a receiving operator characteristic evaluation. We applied the MitoPhen-based phenotype similarity score of >0.3, which was highly sensitive for detecting mtDNA diseases in the phenotype test cohort, to the filtered cohort of 135 undiagnosed individuals. This aided the prioritization of 34 out of 37 (92%) individuals who received confirmed and likely causative mtDNA disease diagnoses. The phenotypic evaluation was limited by the quality of input data in some individuals. The overall pipeline led to an additional diagnostic yield of 0.4% in a cohort where mitochondrial disease was not initially suspected. This highlights the value of our mtDNA analysis pipeline in diverse datasets.
Insects encounter variable temperature conditions in their natural habitats. Under non-optimal temperatures, they experience thermal stress and oxidative damage, which are mitigated by antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO). While short-term effects of thermal stress on antioxidant enzyme activities in insects are well understood, the long-term effects are less explored. We investigated both short-term (3 and 6 h) and long-term (24 h) effects of thermal stress on SOD, CAT and LPO activities in the Parthenium beetle, Zygogramma bicolorata Pallister at cold (15°C), control/optimal (25°C) and hot (35°C) temperatures. Although Z. bicolorata is an effective biocontrol agent for noxious Parthenium weed, no prior study assessed the impact of thermal stress on antioxidant enzyme activities in this beetle. Our results revealed that antioxidant enzymes activities increased above control levels in both larvae and adults when exposed to thermal stress for short durations. Under long-term thermal stress, CAT and LPO activities decreased below control levels, while SOD activity increased. Regardless of temperature conditions, early larval instars exhibited higher enzyme activities compared to later instars. In adults, males showed higher SOD and CAT activities, whereas LPO activity did not differ significantly between sexes. Our findings suggest that short-term thermal stress can stimulate protective enzyme activity in these beetles and help them adapt to suboptimal temperatures. However, prolonged exposure may lead to excessive stimulation, potentially inhibiting protective enzyme activity and causing the beetles to activate alternative pathways to manage thermal stress. Moreover, fourth instars and adult females are the most thermal stress-tolerant stages for Parthenium biocontrol.
Neurofibromatosis 1 (NF1) and attention-deficit hyperactivity disorder (ADHD) are distinct conditions with similarities in developmental course. Research suggests that neurodivergent processes in both conditions begin in the first year, altering infant behaviour and how parents respond, over time reducing social-communicative opportunities for social brain development. This study aimed to investigate parent-infant interactions in both groups relative to typically developing infants (TD) at 10 and 14 months. We hypothesised that the infants with NF1 and infants at elevated likelihood of ADHD (EL-ADHD) would show less attentiveness to their parent and less mutual parent-infant interaction relative to TD controls, that attentiveness-to-parent would be particularly low in infants with NF1, and that liveliness and negative affect would be higher in infants with EL-ADHD. Parents and their infants with NF1, EL-ADHD and TD were videotaped during free play interactions and coded using validated rating scales. The two non-TD groups differed in their interactive patterns from the TD group and each other in ways somewhat consistent with the early behaviours that characterise each group. The NF1 group showed relatively less mutual interactions than the EL-ADHD group, and less parental sensitive responsiveness and parental directiveness than the TD group, while EL-ADHD infants were livelier and showed less negative affect relative to the other groups. Most main effects persisted over time. While longer-term follow-up in larger samples is needed, our findings highlight how children with neurodevelopmental conditions that are not primarily characterised by social communication difficulties may nonetheless come to have distinct social experiences in the first year of life.
In active systems, whose constituents have non-equilibrium dynamics at local level, fluid-fluid phase separation is widely observed. Examples include the formation of membraneless organelles within cells; the clustering of self-propelled colloidal particles in the absence of attractive forces, and some types of ecological segregation. A schematic understanding of such active phase separation was initially borrowed from what is known for the equilibrium case, in which detailed balance holds at microscopic level. However it has recently become clear that in active systems the absence of detailed balance, although it leave phase separation qualitatively unchanged in some regimes (for example domain growth driven by interfacial tension via Ostwald ripening), can in other regimes radically alter its phenomenology at mechanistic level. For example, microphase separation can be caused by reverse Ostwald ripening, a process that is hard to imagine from an equilibrium perspective. This and other new phenomena arise because, instead of having a single, positive interfacial tension like their equilibrium counterparts, the fluid-fluid interfaces created by active phase separation can have several distinct interfacial tensions governing different properties, some of which can be negative. These phenomena can be broadly understood by studying continuum field theories for a single conserved scalar order parameter (the fluid density), supplemented with a velocity field in cases where momentum conservation is also present. More complex regimes arise in systems described by multiple scalar order parameters (especially with nonreciprocal interactions between these); or when an order parameter undergoes both conserved and non-conserved dynamics (such that the combination breaks detailed balance); or in systems that support orientational long-range order in one or more of the coexisting phases. In this Review, we survey recent progress in understanding the specific role of activity in phase separation, drawing attention to many open questions. We focus primarily on continuum theories, especially those with a single scalar order parameter, reviewing both analytical and numerical work. We compare their predictions with particle-based models, which have mostly been studied numerically although a few have been explicitly coarse-grained to continuum level. We also compare, where possible, with experimental results. In the latter case, qualitative comparisons are broadly encouraging whereas quantitative ones are hindered by the dynamical complexity of most experimental systems relative that of simplified (particle-level or continuum) models of active matter.
Sodium-ion batteries offer improved sustainability over lithium-ion batteries, the benchmark electrolyte being 1 M NaPF6 in carbonate-based solvents. This work investigates the properties of different electrolyte concentrations, finding that 1...
The olfactory system comprises intricate networks of interconnected brain regions that process information across both the local and long-range circuits to extract odorant identity. Similar to pattern recognition in other sensory domains, such as the visual system, recognizing odorant identity likely depends on highly nonlinear interactions between these recurrently connected nodes. In this study, we investigate whether odorant identity can be distinguished through nonlinear interactions in the local field potentials of the olfactory bulb and telencephalic regions (the ventral nucleus of the ventral telencephalon and the dorsal posterior zone of the telencephalon) in anesthetized rainbow trout. Our results show that odorant identity modulates complex information-theoretic measures, specifically information sharing and redundancy across these brain areas, indicating nonlinear processing. In contrast, traditional linear connectivity measures, such as coherence and phase synchrony, showed little or no significant modulation by odorants. These findings suggest that nonlinear interactions encoded by olfactory oscillations carry crucial odor information across the teleost olfactory system, offering insights into the broader role of nonlinear dynamics in sensory processing.
Grandmothers are often presented as key carers due to low costs and high inclusive fitness returns. Empirically, however, grandmothers are not consistently important. Understanding the factors that promote, or hinder, grandmothering is an important next step. We explore the demographic predictors of the low levels of grandmothering in Agta hunter–gatherers (78 children with 29 grandmothers). Due to generational reproductive timing, grandmothers still had dependent children until, on average 52, creating reproductive overlap. The minimal levels of grandmaternal investment after the age of 60 are explained by declining health and high mortality. This means the ‘helping window’ for grandmothering only spans 7 years. Yet grandmothers are still limited by multiple dependent grandchildren in this period, given high fertility. We suggest then that Agta grandmothering is constrained by (i) reproductive overlap and (ii) grandchildren competition. Accordingly, we tested how (i) the number of children and (ii) grandchildren associated with grandmothering using Bayesian mixed-effect models. We found moderate to strong evidence that more children/grandchildren reduced investment in each grandchild. Consequently, whether Agta grandmothers help appears dependent on demographic schedules, which vary widely both within and between populations. Future formal demographic modelling will then help shed light on the evolution of grandmothering in humans.
Epidemiological modelling plays an important role in global food security by informing strategies for the control and management of invasion and spread of crop diseases. However, the underlying data on spatial locations of host crops that are susceptible to a pathogen are often incomplete and inaccurate, thus reducing the accuracy of model predictions. Obtaining and refining datasets that fully represent a host landscape across territories can be a major challenge when predicting disease outbreaks. Therefore, it would be an advantage to prioritize areas in which data refinement efforts should be directed to improve the accuracy of epidemic prediction. In this paper, we present an analytical method to identify areas where potential errors in mapped host data would have the largest impact on modelled pathogen invasion and short-term spread. The method is based on an analytical approximation for the rate at which susceptible host crops become infected at the start of an epidemic. We show how implementing spatial prioritization for data refinement in a cassava-growing region in sub-Saharan Africa could be an effective means for improving accuracy when modelling the dispersal and spread of the crop pathogen cassava brown streak virus.
The aim of this study was to identify branches of the trigeminal and facial nerves (FNs) relevant to surgical incisions and injections and the scalp block techniques in the frontotemporal region, and to determine their relationships with superficial vascular structures and bony landmarks. Half‐heads from consenting embalmed donors (6 male, 2 female, mean age at death 78.4 years) were used in this study. Detailed dissection was carried out to identify the position of the auriculotemporal nerve (ATN) relative to the superior temporal artery (STA) and the FN in six subjects (5 male, 1 female). The results provide a minimum safe distance of 5 mm between the STA and the frontotemporal branches of the FN at the level of the low edge of the zygoma and 8 mm between the low edge of the zygoma and the FN trunk, providing a pre‐auricular triangle of safety for incisions and injections. Variability between subjects was up to 60%. Microcomputed tomography (microCT) scans were taken from all eight subjects and the three‐dimensional reconstructions were used to identify the supraorbital notch (SON), the zygomaticotemporal foramen (ZTF), and the zygomaticofacial foramen (ZFF). The volume and relative locations of these foramina were calculated for 5–8 subjects. The closest distance between ZTF and the frontozygomatic suture (FZS) ranged from 9 to 21 mm (26% variation); 3 subjects had a single ZTF while 5 subjects had two ZTF. The angle at the center of the orbit between ZFF and the FZS ranged from 156° to 166° (2.5% variation). These findings demonstrate that both traditional cadaveric dissection methods and contemporary microCT methods can be used to investigate the relative locations of nerves or their foramina in the human head. The findings provide anatomical considerations for fronto‐temporal incisions and local anesthesia.
Introduction Eclampsia is a life‐threatening complication of pre‐eclampsia. There are currently no means of reliably identifying women with pre‐eclampsia who are at the highest risk of progression to eclampsia and would thus benefit from prioritization for intensive monitoring and urgent delivery. This is particularly challenging in obstetric settings where resources are limited. We identify risk factors for the progression of pre‐eclampsia to eclampsia in low‐ and middle‐income settings. Material and methods Women diagnosed with pre‐eclampsia were prospectively recruited at a single tertiary referral centre in urban Uganda (2011–2016). Multivariable logistic regression models were used to identify risk factors that predicted the likelihood of progression to eclampsia. Key findings were validated in a geographically, socioeconomically, and ethnically distinct population using population‐wide hospital admission data from Ecuador (2021–2023). Results In urban Uganda, progression from pre‐eclampsia to eclampsia was associated with nulliparity (OR 2.4; 95% CI: 1.1–5.4, p = 0.03), Baganda ethnicity (OR 1.9; 95% CI: 1.1–3.9, p = 0.01), unskilled/unemployed paternal occupation (OR 2.8; 95% CI: 1.3–6.4, p = 0.03), and a trend toward younger maternal age (OR 0.9; 95% CI: 0.9–1.0 per year; p = 0.09). Risk of progression to eclampsia was not related to the severity of pre‐eclampsia or the number of antenatal clinic visits. In Ecuador, population‐wide analysis showed that progression to eclampsia was associated with younger maternal age (p < 0.001) and a trend toward public vs privately funded obstetric care (p = 0.09). Conclusions Eclampsia risk extends beyond clinical markers of pre‐eclampsia severity, with socioeconomic factors and maternal age playing crucial roles in disease progression. A targeted, context‐specific approach prioritizing high‐risk young women with socioeconomic vulnerabilities could optimize healthcare resources and mitigate severe hypertensive disorder risks.
BACKGROUND Hypertensive disorders of pregnancy (HDP) are among the most common pregnancy complications and leading causes of maternal morbidity and mortality worldwide. This study aimed to perform the largest meta-analysis to date comparing conventional and advanced echocardiographic features in HDP against healthy pregnancy. METHODS PubMed (MEDLINE) and EMBASE were systematically searched for research articles published up to March 2024. Included studies reported at least 1 relevant echocardiographic parameter in pregnancies complicated by HDP and normotensive healthy pregnancies separately. A total of 53 studies met the inclusion criteria, comprising 7168 participants (3381 HDP and 3787 controls). RESULTS Myocardial mechanics, as measured by global longitudinal strain (weighted mean difference (WMD), −2.81% [95% CI, −3.70 to −1.91]; P <0.001) and left atrial reservoir strain (WMD, −9.36% [95% CI, −12.73 to −5.99]; P <0.001), were significantly impaired in HDP compared with healthy pregnancy. Furthermore, there were prominent cardiac structural differences, with significantly greater left ventricular mass index (WMD, 12.20 [95% CI, 9.77–14.64]; P <0.001), relative wall thickness (WMD, 0.055 [95% CI, 0.04–0.07]; P <0.001), left atrial size (WMD, 2.34 cm [95% CI, 1.62–3.06]; P <0.001), and left atrial volume index (WMD, 2.38 mL/m ² [95% CI, 1.44–3.32]; P <0.001) in HDP compared with healthy pregnancy. Finally, the ratio between early mitral inflow velocity and early mitral annular velocity average was significantly greater in HDP (WMD, 1.90 [95% CI, 1.42–2.38; P <0.001), indicative of an elevated left ventricular filling pressure. CONCLUSIONS This meta-analysis highlights clinically relevant differences in echocardiographic measures between HDP and healthy pregnancy. These results may enhance the utilization of echocardiography for the risk stratification and management of women with HDP. Advanced myocardial mechanics, including global longitudinal strain and left atrial reservoir strain, likely play a key role in detecting subclinical myocardial dysfunction and guidance for early intervention.
Aziridination of alkenes is an important route to chiral nitrogen‐containing building blocks. Here we report that carbamate‐functionalized allylic alcohols undergo highly enantioselective aziridination using achiral dimeric Rh(II,II) complexes that are ion‐paired with cinchona alkaloid‐derived chiral cations. The aziridine‐containing products are amenable to a variety of further reactions to generate useful groupings of functionality. Furthermore, we show that the carbamate group is effective for directing highly enantioselective benzylic C‐H amination when it is appended to phenethyl alcohols. Intermolecular C‐H amination of phenethyl alcohol derivatives has proven highly challenging to achieve asymmetrically yet gives rise to valuable β‐amino alcohols. Both processes result in rapid access to versatile, highly enantioenriched small molecule building blocks for synthesis and highlight the effectiveness and generality of this chiral cation‐based strategy for asymmetric catalysis. We report studies that probe important structural features of the chiral cation and demonstrate that the ion‐paired complexes can be formed from their individual components without a separate isolation step.
Background Progression free survival (PFS) is a critical clinical outcome endpoint during cancer management and treatment evaluation. Yet, PFS is often missing from publicly available datasets due to the current subjective, expert, and time-intensive nature of generating PFS metrics. Given emerging research in multi-modal machine learning (ML), we explored the benefits and challenges associated with mining different electronic health record (EHR) data modalities and automating extraction of PFS metrics via ML algorithms. Methods We analyzed EHR data from 92 pathology-proven GBM patients, obtaining 233 corticosteroid prescriptions, 2080 radiology reports, and 743 brain MRI scans. Three methods were developed to derive clinical PFS: 1) frequency analysis of corticosteroid prescriptions, 2) natural language processing (NLP) of reports, and 3) computer vision (CV) volumetric analysis of imaging. Outputs from these methods were compared to manually annotated clinical guideline PFS metrics. Results Employing data-driven methods, standalone progression rates were 63% (prescription), 78% (NLP), and 54% (CV), compared to the 99% progression rate from manually applied clinical guidelines using integrated data sources. The prescription method identified progression an average of 5.2 months later than the clinical standard, while the CV and NLP algorithms identified progression earlier by 2.6 and 6.9 months, respectively. While lesion growth is a clinical guideline progression indicator, only half of patients exhibited increasing contrast-enhancing tumor volumes during scan-based CV analysis. Conclusion Our results indicate that data-driven algorithms can extract tumor progression outcomes from existing EHR data. However, ML methods are subject to varying availability bias, supporting contextual information, and pre-processing resource burdens that influence the extracted PFS endpoint distributions. Our scan-based CV results also suggest that the automation of clinical criteria may not align with human intuition. Our findings indicate a need for improved data source integration, validation, and revisiting of clinical criteria in parallel to multi-modal ML algorithm development.
Memristors based on 2D materials have emerged as promising candidates for use in artificial synaptic devices and energy‐efficient neuromorphic computing. Limited understanding of the fundamental switching mechanisms hinders device optimization and stalls commercialization. Conventional analysis techniques are often destructive, and only offer a static characterization of the device after electrical cycling, providing limited insights into switching dynamics. In this study, an operando approach utilizing plasmon enhancement of optical signals is used to investigate a two‐terminal vertical device based on monolayer hexagonal boron nitride. Real‐time photoluminescence and dark‐field scattering measurements reveal that conductive filaments (CFs) form through the migration of metallic ions from the electrode. The modification of a photoluminescence signal near 620 nm and a redshift of dark‐field scattering indicating a refractive index change of roughly 1 are detected when voltage is applied across the nanodevice. These optical changes are interpreted to show that this CF formation is mediated by point defect structures. This highlights the crucial role of defects in the switching dynamics. This finding resolves the ongoing debate in the literature about the mechanism of CF formation and paves the way for defect engineering as a step‐changing pathway to the optimization of these devices.
This paper argues that recent initial teacher education policy in England, combining curricular control and marketisation, presents a case of systemic curricular injustice. The initial teacher education core content framework, the government mandated content for all initial teacher education in England, represents a centralised curriculum that ignores local contexts and needs. Combined with the impact of the accreditation process for all providers embedded within the Initial Teacher Training (ITT) Market Review, these policies create a two‐pronged system of exclusion: the core content framework restricts intellectual access to alternative ways of thinking about education, whilst the ITT Market Review restricts physical access to teacher education seeking to present such alternative approaches. Combining and mutually reinforcing social and spatial injustices, this paper argues that the policy space in England is actively producing and reproducing structural inequalities.
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Andreas Bender
  • Department of Chemistry
Yarjan Abdul Samad
  • Cambridge Graphene Centre
Marius Mada
  • Department of Clinical Neurosciences
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