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This collection gathers thirteen contributions by a number of historians, friends, colleagues and/or students of Jinty’s, who were asked to pick their favourite article by her and say a few words about it for an event held in her memory on 15 January 2025 at King’s College London. We offer this collection in print now for a wider audience not so much because it has any claim to be exhaustive or authoritative, but because taken all together these pieces seemed to add up to a useful retrospective on Jinty’s work, its wider context, and its impact on the field over the decades. We hope that, for those who know her work well already, this may be an opportunity to remember some of her classic (and a few less classic) articles, while at the same time serving as an accessible introduction to her research for anyone who knew her without necessarily knowing about her field, as well as for a new and younger generation of readers.
Cryptosporidium parvum is a well-established cause of gastrointestinal illness in both humans and animals and often causes outbreaks at animal contact events, despite the availability of a code of practice that provides guidance on the safe management of these events. We describe a large C. parvum outbreak following a lamb-feeding event at a commercial farm in Wales in 2024, alongside findings from a cohort study to identify high-risk exposures. Sixty-seven cases were identified, 57 were laboratory-confirmed C. parvum, with similar genotypes. Environmental investigations found a lack of adherence to established guidance. The cohort study identified 168 individuals with cryptosporidiosis-like illness from 540 exposure questionnaires (distributed via email to 790 lead bookers). Cases were more likely to have had closer contact with lambs (odds ratio (OR) kissed lambs = 2.4, 95% confidence interval (95% CI): 1.2–4.8). A multivariable analysis found cases were more likely to be under 10 years (adjusted OR (aOR) = 4.5, 95% CI: 2.0–10.0) and have had visible faeces on their person (aOR = 3.6, 95% CI: 2.1–6.2). We provide evidence that close contact at lamb-feeding events presents an increased likelihood of illness, suggesting that farms should limit animal contact at these events and that revisions to established codes of practice may be necessary. Enhancing risk awareness among farmers and visitors is needed, particularly regarding children.
Ensemble Kalman methods, introduced in 1994 in the context of ocean state estimation, are now widely used for state estimation and parameter estimation (inverse problems) in many arenae. Their success stems from the fact that they take an underlying computational model as a black box to provide a systematic, derivative-free methodology for incorporating observations; furthermore the ensemble approach allows for sensitivities and uncertainties to be calculated. Analysis of the accuracy of ensemble Kalman methods, especially in terms of uncertainty quantification, is lagging behind empirical success; this paper provides a unifying mean-field-based framework for their analysis. Both state estimation and parameter estimation problems are considered, and formulations in both discrete and continuous time are employed. For state estimation problems, both the control and filtering approaches are considered; analogously for parameter estimation problems, the optimization and Bayesian perspectives are both studied. As well as providing an elegant framework, the mean-field perspective also allows for the derivation of a variety of methods used in practice. In addition it unifies a wide-ranging literature in the field and suggests open problems.
While adapting to future sea-level rise (SLR) and its hazards and impacts is a multidisciplinary challenge, the interaction of scientists across different research fields, and with practitioners, is limited. To stimulate collaboration and develop a common research agenda, a workshop held in June 2024 gathered 22 scientists and policymakers working in the Netherlands. Participants discussed the interacting uncertainties across three different research fields: sea-level projections, hazards and impacts, and adaptation. Here, we present our view on the most important uncertainties within each field and the feasibility of managing and reducing those uncertainties. We find that enhanced collaboration is urgently needed to prioritize uncertainty reductions, manage expectations and increase the relevance of science to adaptation planning. Furthermore, we argue that in the coming decades, significant uncertainties will remain or newly arise in each research field and that rapidly accelerating SLR will remain a possibility. Therefore, we recommend investigating the extent to which early warning systems can help policymakers as a tool to make timely decisions under remaining uncertainties, in both the Netherlands and other coastal areas. Crucially, this will require viewing SLR, its hazards and impacts, and adaptation as a whole.
Recent changes to US research funding are having far-reaching consequences that imperil the integrity of science and the provision of care to vulnerable populations. Resisting these changes, the BJPsych Portfolio reaffirms its commitment to publishing mental science and advancing psychiatric knowledge that improves the mental health of one and all.
Understanding wave kinematics is crucial for analysing the thermodynamic effects of sloshing, which can lead to pressure drops in non-isothermal cryogenic fuel tanks. In the research reported here, Faraday waves in a horizontal circular tank (partially filled with water) under vertical excitation are investigated. The tank geometry is referred to as a horizontal circular tank throughout, with its circular face oriented perpendicular to the horizontal plane. Firstly, this paper addresses the eigenvalue problem through linear potential flow theory, in order to provide theoretical evidence of Faraday waves in horizontal circular tanks, the impact the density ratio has on the eigenvalues is then considered. Secondly, an experimental investigation testing multiple liquid fill levels is conducted. A soft-spring nonlinear response is demonstrated throughout the parameter space. The results showed larger sloshing amplitudes for low fill levels and smaller sloshing amplitudes for high fill levels. Asymmetry between anti-nodes at the container sidewalls and through the tank centreline are evident for low fill levels. Moreover, the sloshing wave amplitude at which breaking waves occur is smaller for high fill level conditions. Finally, period tripling was observed for all fill levels tested, confirming nonlinear mode interactions before the onset to wave breaking.
With wide-field phased array feed technology, the Australian Square Kilometre Array Pathfinder (ASKAP) is ideally suited to search for seemingly rare radio transient sources that are difficult to discover previous-generation narrow-field telescopes. The Commensal Real-time ASKAP Fast Transient (CRAFT) Survey Science Project has developed instrumentation to continuously search for fast radio transients (duration $\lesssim$ 1 s) with ASKAP, with a particular focus on finding and localising fast radio bursts (FRBs). Since 2018, the CRAFT survey has been searching for FRBs and other fast transients by incoherently adding the intensities received by individual ASKAP antennas, and then correcting for the impact of frequency dispersion on these short-duration signals in the resultant incoherent sum (ICS) in real time. This low-latency detection enables the triggering of voltage buffers, which facilitates the localisation of the transient source and the study of spectro-polarimetric properties at high time resolution. Here we report the sample of 43 FRBs discovered in this CRAFT/ICS survey to date. This includes 22 FRBs that had not previously been reported: 16 FRBs localised by ASKAP to $\lesssim 1$ arcsec and 6 FRBs localised to $\sim 10$ arcmin. Of the new arcsecond-localised FRBs, we have identified and characterised host galaxies (and measured redshifts) for 11. The median of all 30 measured host redshifts from the survey to date is $z=0.23$. We summarise results from the searches, in particular those contributing to our understanding of the burst progenitors and emission mechanisms, and on the use of bursts as probes of intervening media. We conclude by foreshadowing future FRB surveys with ASKAP using a coherent detection system that is currently being commissioned. This will increase the burst detection rate by a factor of approximately ten and also the distance to which ASKAP can localise FRBs.
We examine the energy distribution of the fast radio burst (FRB) population using a well-defined sample of 63 FRBs from the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope, 28 of which are localised to a host galaxy. We apply the luminosity-volume ($V/V_{\mathrm{max}}$) test to examine the distribution of these transient sources, accounting for cosmological and instrumental effects, and determine the energy distribution for the sampled population over the redshift range $0.01 \lesssim z \lesssim 1.02$. We find the distribution between $10^{23}$ and $10^{26}$ J Hz$^{-1}$ to be consistent with both a pure power-law with differential slope $\gamma=-1.96 \pm 0.15$, and a Schechter function with $\gamma = -1.82 \pm 0.12$ and downturn energy $E_\mathrm{max} \sim 6.3 \, \times 10^{25}$ J Hz$^{-1}$. We identify systematic effects which currently limit our ability to probe the luminosity function outside this range and give a prescription for their treatment. Finally, we find that with the current dataset, we are unable to distinguish between the evolutionary and spectral models considered in this work.
A nonparametric test of dispersion with paired replicates data is described which involves jackknifing logarithmic transformations of the ratio of variance estimates for the pre- and post-treatment populations. Results from a Monte Carlo simulation show that the test performs well under Ho and has good power properties. Examples are given of applying the procedure on psychiatric data.
This paper considers multiple imputation (MI) approaches for handling non-monotone missing longitudinal binary responses when estimating parameters of a marginal model using generalized estimating equations (GEE). GEE has been shown to yield consistent estimates of the regression parameters for a marginal model when data are missing completely at random (MCAR). However, when data are missing at random (MAR), the GEE estimates may not be consistent; the MI approaches proposed in this paper minimize bias under MAR. The first MI approach proposed is based on a multivariate normal distribution, but with the addition of pairwise products among the binary outcomes to the multivariate normal vector. Even though the multivariate normal does not impute 0 or 1 values for the missing binary responses, as discussed by Horton et al. (Am Stat 57:229–232, 2003), we suggest not rounding when filling in the missing binary data because it could increase bias. The second MI approach considered is the fully conditional specification (FCS) approach. In this approach, we specify a logistic regression model for each outcome given the outcomes at other time points and the covariates. Typically, one would only include main effects of the outcome at the other times as predictors in the FCS approach, but we explore if bias can be reduced by also including pairwise interactions of the outcomes at other time point in the FCS. In a study of asymptotic bias with non-monotone missing data, the proposed MI approaches are also compared to GEE without imputation. Finally, the proposed methods are illustrated using data from a longitudinal clinical trial comparing four psychosocial treatments from the National Institute on Drug Abuse Collaborative Cocaine Treatment Study, where patients’ cocaine use is collected monthly for 6 months during treatment.
Studies of agreement commonly occur in psychiatric research. For example, researchers are often interested in the agreement among radiologists in their review of brain scans of elderly patients with dementia or in the agreement among multiple informant reports of psychopathology in children. In this paper, we consider the agreement between two raters when rating a dichotomous outcome (e.g., presence or absence of psychopathology). In particular, we consider logistic regression models that allow agreement to depend on both rater- and subject-level covariates. Logistic regression has been proposed as a simple method for identifying covariates that are predictive of agreement (Coughlin et al., 1992). However, this approach is problematic since it does not take account of agreement due to chance alone. As a result, a spurious association between the probability (or odds) of agreement and a covariate could arise due entirely to chance agreement. That is, if the prevalence of the dichotomous outcome varies among subgroups of the population, then covariates that identify the subgroups may appear to be predictive of agreement. In this paper we propose a modification to the standard logistic regression model in order to take proper account of chance agreement. An attractive feature of the proposed method is that it can be easily implemented using existing statistical software for logistic regression. The proposed method is motivated by data from the Connecticut Child Study (Zahner et al., 1992) on the agreement among parent and teacher reports of psychopathology in children. In this study, parents and teachers provide dichotomous assessments of a child's psychopathology and it is of interest to examine whether agreement among the parent and teacher reports is related to the age and gender of the child and to the time elapsed between parent and teacher assessments of the child.
Fast radio burst (FRB) science primarily revolves around two facets: the origin of these bursts and their use in cosmological studies. This work follows from previous redshift–dispersion measure (z–DM) analyses in which we model instrumental biases and simultaneously fit population parameters and cosmological parameters to the observed population of FRBs. This sheds light on both the progenitors of FRBs and cosmological questions. Previously, we have completed similar analyses with data from the Australian Square Kilometer Array Pathfinder (ASKAP) and the Murriyang (Parkes) Multibeam system. In this manuscript, we use 119 FRBs with 29 associated redshifts by additionally modelling the Deep Synoptic Array (DSA) and the Five-hundred-metre Aperture Spherical radio Telescope (FAST). We also invoke a Markov chain Monte Carlo (MCMC) sampler and implement uncertainty in the Galactic DM contributions. The latter leads to larger uncertainties in derived model parameters than previous estimates despite the additional data and indicate that precise measurements of DM$_\textrm{ISM}$ will be important in the future. We provide refined constraints on FRB population parameters and derive a new constraint on the minimum FRB energy of log $E_{\mathrm{min}}$(erg)=39.47$^{+0.54}_{-1.28}$ which is significantly higher than bursts detected from strong repeaters. This result likely indicates a low-energy turnover in the luminosity function or may alternatively suggest that strong repeaters have a different luminosity function to single bursts. We also predict that FAST will detect 25–41% of their FRBs at $z \gtrsim 2$ and DSA will detect 2–12% of their FRBs at $z \gtrsim 1$.
We have updated the migraine prevention guideline of the Canadian Headache Society from 2012, as there are new therapies available, and additionally, we have provided guidelines for the prevention of chronic migraine, which was not addressed in the previous iteration.
Methods:
We undertook a systematic review to identify new studies since the last guideline. For studies identified, we performed data extraction and subsequent meta-analyses where possible. We composed a summary of the evidence found and undertook a modified Delphi recommendation process. We provide recommendations for treatments identified and additionally expert guidance on the use of the treatments available in important clinical situations.
Results:
We identified 61 studies that were included in this evidence update and identified 16 therapies we focused on. The anti-calcitonin gene-related peptide (CGRP) agents were approved by Health Canada between 2018 and 2024 and provide additional options for episodic and chronic migraine prevention. We also summarize evidence for the use of propranolol, topiramate and onabotulinumtoxinA in addition to anti-CGRP agents as treatments for chronic migraine. We have downgraded topiramate to a weak recommendation for use and gabapentin to a weak recommendation against its use in episodic migraine. We have weakly recommended the use of memantine, levetiracetam, enalapril and melatonin in episodic migraine.
Conclusion:
Based on the evidence synthesis, we provide updated recommendations for the prevention of episodic and chronic migraine utilizing treatments available in Canada. We additionally provided expert guidance on their use in clinical situations.
Reducing rehospitalization has been a primary focus of hospitals and payors. Recurrence of Clostridioides difficile infection (CDI) is common and often results in rehospitalization. Factors that influence rehospitalization for CDI are not well understood.
Objective:
To determine the risk factors that influence rehospitalization caused by CDI.
Design:
A retrospective cohort study from January 1, 2018, to December 31, 2018, of patients aged ≥18 who tested positive for C. difficile while hospitalized.
Setting:
Academic hospital.
Methods:
The risk of rehospitalization was assessed across exposures during and after the index hospitalization using a Cox proportional hazards model. The primary outcome of this study was 60-day CDI-related rehospitalization.
Results:
There were 559 hospitalized patients with a positive CD test during the study period, and 408 patients were included for analysis. All-cause rehospitalization was 46.1% within 60 days of the index hospital discharge. Within 60 days of discharge, 68 patients developed CDI, of which 72.5% (49 of 68) were rehospitalized specifically for the management of CDI. The risk of rehospitalization in patients with CDI was higher among patients who were exposed to systemic antibiotics ([adjusted hazard ratio] aHR: 2.78; 95% CI, 1.36–5.64) and lower among patients who had post-discharge follow-up addressing C. difficile (aHR: 0.53; 95% CI, 0.28–0.98).
Conclusions:
Exposure to systemic antibiotics increased the risk of rehospitalization due to CDI, while post-discharge follow-up decreased the risk of rehospitalization due to CDI. Comprehensive transitions of care for hospitalized patients with C. difficile may reduce the risk of CDI-related rehospitalization.
Shark vertebrae and their centra (vertebral bodies) are high-performance structures able to survive millions of cycles of high amplitude strain despite lacking a repair mechanism for accumulating damage. Shark centra consist of mineralized cartilage, a biocomposite of bioapatite (bAp), and collagen, and the nanocrystalline bAp's contribution to functionality remains largely uninvestigated. Using the multiple detector energy-dispersive diffraction (EDD) system at 6-BM-B, the Advanced Photon Source, and 3D tomographic sampling, the 3D functionality of entire centra were probed. Immersion in ethanol vs phosphate-buffered saline produces only small changes in bAp d-spacing within a great hammerhead centrum. EDD mapping under in situ loading was performed an entire blue shark centrum, and 3D maps of bAp strain showed the two structural zones of the centrum, the corpus calcareum and intermedialia, contained opposite-signed strains approaching 0.5%, and application of ~8% nominal strain did not alter these strain magnitudes and their spatial distribution.
Synthetic aluminous hematites and goethites have been examined by Fourier-transform infrared spectroscopy. For aluminous hematites prepared at 950°C a linear relationship exists between Al content and the location of the band near 470 cm−1, up to 10 mole % Al substitution which is shown to be the solubility limit. The spectra of aluminous goethites prepared in two different ways are qualitatively similar to each other, but differ as to the relationship between the position of the band near 900 cm−1 and the Al content. The spectra of the two series of hematites produced by calcining the goethites at 590°C also show a strong dependence of band position and intensity on the goethite preparative method.