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SpineFM: leveraging foundation models for automatic spine X-ray segmentation
Get PDFThis paper introduces SpineFM, a novel pipeline that achieves state-of-the-art performance in the automatic segmentation and identification of vertebral bodies in cervical and lumbar spine radiographs. SpineFM leverages the regular geometry of the spine, employing a novel inductive process to sequentially infer the location of each vertebra along the spinal column. Vertebrae are segmented using Medical-SAM-Adaptor, a robust foundation model that diverges from commonly used CNN-based models. We achieved outstanding results on two publicly available spine X-Ray datasets, with successful identification of 97.8% and 99.6% of annotated vertebrae, respectively. Of which, our segmentation reached an average Dice of 0.942 and 0.921, surpassing previous state-of-the-art methods
Heterogeneous markups cyclicality and monetary policy
Get PDFThis paper revisits the question on the conditional cyclicality of the aggregate markup using a micro-to-macro approach, which highlights the role of firm-level heterogeneous cyclicality, the reallocation of economic activity across firms, and aggregation methods. Using US firm-level data from 1990 to 2016, we find that young firms have procyclical markups conditional on monetary shocks, while older firms show countercyclical markups. Moreover, economic activity reallocates from old to young firms after monetary shocks. Aggregating these responses, we find that the aggregate markup is countercyclical to monetary shocks. Over time, firm aging has changed the distribution of firms, altering the aggregate markup cyclicality, which help reconcile part of the conflicting findings in the literature
Cosmic-ray transport in inhomogeneous media
Get PDFA theory of cosmic-ray transport in multiphase diffusive media is developed, with the specific application to cases in which the cosmic-ray diffusion coefficient has large spatial fluctuations that may be inherently multiscale. We demonstrate that the resulting transport of cosmic rays is diffusive in the long-time limit, with an average diffusion coefficient equal to the harmonic mean of the spatially varying diffusion coefficient. Thus, cosmic-ray transport is dominated by areas of low diffusion even if these areas occupy a relatively small, but not infinitesimal, fraction of the volume. On intermediate time-scales, the cosmic rays experience transient effective subdiffusion, as a result of low-diffusion regions interrupting long flights through high-diffusion regions. In the simplified case of a two-phase medium, we show that the extent and extremity of the subdiffusivity of cosmic-ray transport is controlled by the spectral exponent of the distribution of patch sizes of each of the phases. We finally show that, despite strongly influencing the confinement times, the multiphase medium is only capable of altering the energy dependence of cosmic-ray transport when there is a moderate (but not excessive) level of perpendicular diffusion across magnetic-field lines
The Atacama Cosmology Telescope: high-redshift measurement of structure growth from the cross-correlation of Quaia quasars and CMB lensing from ACT DR6 and Planck PR4
Get PDFWe measure the amplitude of matter fluctuations over a wide range of redshifts by combining CMB lensing observations from ACT DR6 and Planck PR4 with the overdensity of quasars from Quaia, a Gaia and unWISE quasar catalog. Our analysis includes the CMB lensing power spectrum from ACT DR6, the auto-correlation of two Quaia quasar samples centered at z ≃ 1.0 and z ≃ 2.1, and their cross-correlations with CMB lensing from both ACT DR6 and Planck PR4. By performing a series of contamination and systematic null tests, we find no evidence for contamination in the lensing maps, contrary to what was suggested in previous Quaia cross-correlation analyses using Planck PR4 CMB lensing data. From the joint analysis of the quasar auto- and cross-correlations with CMB lensing, and including BOSS BAO data to break the degeneracy between Ω m and σ 8, we obtain σ 8 = 0.802+0.045 -0.057, consistent with ΛCDM predictions from Planck primary CMB measurements. We also find consistent results using DESI BAO data. Combining the CMB lensing auto-spectrum with the cross-correlation measurement improves the constraint on σ 8 by 12% relative to the lensing auto-spectrum alone, yielding σ 8 = 0.804 ± 0.013. This dataset combination also enables a reconstruction of structure growth across redshifts. We infer a 12% constraint on the amplitude of matter fluctuations at z > 3, with a measurement at the median redshift of the signal of σ 8(z̃ = 5.1) = 0.146+0.021 -0.014, consistent with Planck at the 1.4σ level. These results provide one of the highest redshift constraints on the growth of structure to date
The WEAVE-TwiLight-Survey: expanding WEAVE’s reach to bright and low-surface-density targets with a novel observing mode
Get PDFCurrent-day multi-object spectroscopic surveys are often limited in their ability to observe bright stars due to their low surface densities, resulting in increased observational overheads and reduced efficiency. Addressing this, we have developed a novel observing mode for WEAVE (William Herschel Telescope Enhanced Area Velocity Explorer) that enables efficient observations of low-surface-density target fields without incurring additional overheads from calibration exposures. As a pilot for the new mode, we introduce the WEAVE-TwiLight-Survey (WTLS), focusing on bright exoplanet-host stars and their immediate surroundings on the sky. High observational efficiency is achieved by superimposing multiple low-target-density fields and allocating the optical fibres in this configuration. We use a heuristic method to define fields relative to a central guide star, which serves as a reference for their superposition. Suitable guide fibres for each merged configuration are selected using a custom algorithm. Test observations have been carried out, demonstrating the feasibility of the new observing mode. We show that merged field configurations can be observed with WEAVE using the proposed method. The approach minimizes calibration times and opens twilight hours to WEAVE’s operational schedule. WTLS is built upon the new observing mode and sourced from the ESA PLATO long-duration-phase fields. This survey will result in a homogeneous catalogue of ∼6300 bright stars, including 62 known planet hosts, laying the groundwork for future elemental abundance studies tracing chemical patterns of planetary formation. This new observing mode (WEAVE-Tumble-Less) expands WEAVE’s capabilities to rarely used on-sky time and low-density field configurations without sacrificing efficiency
Sleep pressure accumulates in a voltage-gated lipid peroxidation memory
Get PDFVoltage-gated potassium (KV) channels contain cytoplasmically exposed β-subunits1,2,3,4,5 whose aldo-keto reductase activity6,7,8 is required for the homeostatic regulation of sleep9. Here we show that Hyperkinetic, the β-subunit of the KV1 channel Shaker in Drosophila7, forms a dynamic lipid peroxidation memory. Information is stored in the oxidation state of Hyperkinetic’s nicotinamide adenine dinucleotide phosphate (NADPH) cofactor, which changes when lipid-derived carbonyls10,11,12,13, such as 4-oxo-2-nonenal or an endogenous analogue generated by illuminating a membrane-bound photosensitizer9,14, abstract an electron pair. NADP+ remains locked in the active site of KVβ until membrane depolarization permits its release and replacement with NADPH. Sleep-inducing neurons15,16,17 use this voltage-gated oxidoreductase cycle to encode their recent lipid peroxidation history in the collective binary states of their KVβ subunits; this biochemical memory influences—and is erased by—spike discharges driving sleep. The presence of a lipid peroxidation sensor at the core of homeostatic sleep control16,17 suggests that sleep protects neuronal membranes against oxidative damage. Indeed, brain phospholipids are depleted of vulnerable polyunsaturated fatty acyl chains after enforced waking, and slowing the removal of their carbonylic breakdown products increases the demand for sleep
The dramaturgy of a health emergency: women’s lived experiences of the Zika epidemic in Brazil: A dramaturgia de uma emergência sanitária: as temporalidades vividas por mulheres na epidemia de zika no Brasil
Get PDFThe official calendar of a health emergency has a direct impact on affected populations, particularly at the times of beginning, peak, end, and after the end. According to the World Health Organization, the Zika virus epidemic was a public health emergency between February and November 2016. The disease is now classified as an endemic arbovirus in several countries in the Global South. In this article, we analyze the chronology of the epidemic for three women affected by Zika in Alagoas, Brazil, who became pregnant at the beginning of the health emergency and whose children died between two and four years after the end of the epidemic. Our focus on the lived experience of these three women complexifies the linear dramaturgy of time in health emergencies. We aim to demonstrate how the health emergency calendar is an artifact that shapes political subjectivities, but also how it simplifies the lived experience of affected women, particularly in the times after the end.O calendário oficial de uma emergência sanitária impacta diretamente as populações afetadas, em particular os marcos temporais de início, pico e fim. Segundo a Organização Mundial de Saúde, a epidemia do vírus zika foi uma emergência de saúde pública entre fevereiro e novembro de 2016, cujo fim resultou na classificação da doença como uma arbovirose endêmica. Neste artigo, analisamos a cronologia da epidemia para três mulheres afetadas pelo zika em Alagoas, Brasil, cuja gravidez ocorreu no tempo do início da emergência sanitária e cujos filhos faleceram entre dois e quatro anos após o decreto de fim da epidemia. O enfoque na experiência vivida das três mulheres complexifica a dramaturgia linear do tempo nas emergências sanitárias. Esperamos demonstrar como o calendário epidêmico é um artefato para a construção de subjetividades políticas, mas não conforma a experiência vivida das mulheres, em particular o vivido depois do decreto de fim de uma emergência sanitária
Procurement and early deployment of artificial intelligence tools for chest diagnostics in NHS services in England: a rapid, mixed method evaluation
Get PDFBackgroundArtificial Intelligence (AI) may support accurate, efficient radiology diagnostics. However, little is known about implementing AI in clinical settings. In 2023, NHS England launched a programme funding 12 networks of 66 NHS Trusts to implement AI for chest diagnostics, including lung cancer.MethodsRapid evaluation (March-September 2024) of procurement and early deployment of AI for chest diagnostics at network (n = 10) and Trust (n = 6) levels. We interviewed network teams, Trust staff, and AI suppliers (n = 51); observed planning, governance, and training (n = 57); and analysed relevant documents (n = 166). The NASSS framework guided thematic analysis.FindingsProcurement and deployment of AI took longer than anticipated. Procurement involved engaging selection panels, assessing tenders, and contracting AI suppliers. Preparation for deployment involved AI integration; governance processes; staff engagement and training; planning patient engagement; and collating impact data; patient communication plans varied and were still developing. Challenges included: engaging staff with high clinical workloads; staff's limited AI knowledge, time to participate, and concerns over appropriate tool usage; managing unsuccessful suppliers' responses; and varied local governance processes, IT systems, and data availability and quality. Enablers included: programme leadership's support; networks sharing expertise and capacity; committed clinical, technical, and procurement specialists and AI suppliers; clinical champions; and dedicated project management.InterpretationImplementing AI involved complex social and technical processes, requiring significant resources. Future implementation may benefit from ensuring sufficient time and capacity, ongoing stakeholder engagement at multiple levels, and greater consideration of patients and equity, diversity, and inclusion. Influential factors identified here mirror research on other healthcare innovations, suggesting AI may not address service challenges as straightforwardly as policymakers anticipate.FundingNational Institute for Health and Care Research (NIHR), Health and Social Care Delivery Research programme (NIHR156380). NJF and AIGR are supported by NIHR Central London Patient Safety Research Collaboration. NJF is an NIHR Senior Investigator
Primary healthcare costs associated with the AstraZeneca COVID-19 vaccine in England
No full textCurrent research on the effectiveness of COVID-19 vaccines has demonstrated their role in reducing hospitalizations and deaths due to SARS-CoV-2. However, evidence regarding the healthcare costs incurred by vaccinated versus unvaccinated individuals in the community remains limited, especially in primary care, the first point of access for most patients. This study estimated the total (all-cause) primary healthcare costs for individuals who received the AstraZeneca COVID-19 vaccine (AZD1222) in England between 2020 and 2021. We conducted an economic analysis utilizing electronic primary healthcare records from the Oxford-Royal College of General Practitioners Clinical Informatics Digital Hub (ORCHID) database, with costs valued according to NHS tariffs. Exact coarsened matching in a time-varying setting was employed to balance patient characteristics between the vaccinated and unvaccinated groups. Our results indicate that vaccinated individuals who received the first dose of the AstraZeneca vaccine incurred significantly lower primary healthcare costs compared to their unvaccinated counterparts. Specifically, at 15 days post-vaccination, vaccinated individuals had total costs that were £47.5 (95 % CI: £42.6 to £52.4) lower. This difference increased to £87.1 (95 % CI: £79.6 to £94.6) at 30 days and £124.0 (95 % CI: £114.3 to £133.7) at 45 days post-vaccination, reflecting a reduction of approximately 33.1 % during this period. These findings carry important implications for healthcare budgeting, resource allocation, and pandemic response policies
