On the classification of Kahler-Ricci solitons on Gorenstein del Pezzo surfaces

We give a classification of all pairs (X,v) of Gorenstein del Pezzo surfaces X and vector fields v which are K-stable in the sense of Berman-Nystrom and therefore are expected to admit a Kahler-Ricci solition. Moreover, we provide some new examples of Fano threefolds admitting a Kahler-Ricci soliton.Comment: 21 pages, ancillary files containing calculations in SageMath; minor correction

3D Cardiac Shape Prediction with Deep Neural Networks: Simultaneous Use of Images and Patient Metadata

Large prospective epidemiological studies acquire cardiovascular magnetic resonance (CMR) images for pre-symptomatic populations and follow these over time. To support this approach, fully automatic large-scale 3D analysis is essential. In this work, we propose a novel deep neural network using both CMR images and patient metadata to directly predict cardiac shape parameters. The proposed method uses the promising ability of statistical shape models to simplify shape complexity and variability together with the advantages of convolutional neural networks for the extraction of solid visual features. To the best of our knowledge, this is the first work that uses such an approach for 3D cardiac shape prediction. We validated our proposed CMR analytics method against a reference cohort containing 500 3D shapes of the cardiac ventricles. Our results show broadly significant agreement with the reference shapes in terms of the estimated volume of the cardiac ventricles, myocardial mass, 3D Dice, and mean and Hausdorff distance

Hospital Records of Pain, Fatigue, or Circulatory Symptoms in Girls Exposed to Human Papillomavirus Vaccination: Cohort, Self-Controlled Case Series, and Population Time Trend Studies

Human papillomavirus (HPV) vaccination has been associated with subsequent diffuse symptoms in girls, reducing public confidence in the vaccine. We examined whether girls have nonspecific outcomes of HPV vaccination, using triangulation from cohort, self-controlled case series (SCCS), and population time trend analyses carried out in Denmark between 2000 and 2014. The study population consisted of 314,017 HPV-vaccinated girls and 314,017 age-matched HPV-unvaccinated girls (cohort analyses); 11,817 girls with hospital records (SCCS analyses); and 1,465,049 girls and boys (population time trend analyses). The main outcome measures were hospital records of pain, fatigue, or circulatory symptoms. The cohort study revealed no increased risk among HPV vaccine-exposed girls, with incidence rate ratios close to 1.0 for abdominal pain, nonspecific pain, headache, hypotension/syncope, tachycardia (including postural orthostatic tachycardia syndrome), and malaise/fatigue (including chronic fatigue syndrome). In the SCCS analyses, we observed no association between HPV vaccination and subsequent symptoms. In time trend analyses, we observed a steady increase in these hospital records in both girls and (HPV-unvaccinated) boys, with no relationship to the 2009 introduction of HPV vaccine to Denmark’s vaccination program. This study, which had nationwide coverage, showed no evidence of a causal link between HPV vaccination and diffuse autonomic symptoms leading to hospital contact

Combined hormonal contraceptive use in Europe before and after the European Commission mandated changes in product information

Objectives: We investigated combined hormonal contraceptives (CHC) prescribing patterns (focusing on combined oral contraceptives; COC) in three countries (Netherlands, Denmark, United Kingdom) in a time period preceding and in a time period following the European Commission's decision to update product information, and we estimated changes in incidence of venous thromboembolism (VTE) between the two periods. / Study design: We conducted a drug utilization analysis and a cohort study using routinely collected data. We calculated number, proportion and incidence rate of new users, switchers, and stoppers of COC in both time periods. VTE incidence was calculated in new users of COC and in all women aged 18–49 years. / Results: In all countries, the largest proportion (> 75%) of new users used COC containing levonorgestrel, norethisterone, or norgestimate, (i.e., indicated by European Medicines Agency (EMA) as the safest preparations) in both time periods. Switching did not demonstrate a clear pattern towards these types of COC and distribution of stoppers was similar in both time periods. While the proportion of new users initiating COC containing levonorgestrel, norethisterone, or norgestimate increased slightly, this did not translate to a decrease in the overall VTE incidence. / Conclusion: All three countries had the greatest proportion of women initiating a COC containing levonorgestrel, norethisterone, or norgestimate, and this proportion increased in the period after the European Commission decision albeit the increase was small due to the high percentage of use before the decision. This did not translate into a measureable change in the incidence of VTE. / Implications: Both before and after the European Commission's decision, the largest proportion of new users started with combined oral contraceptives containing levonorgestrel, norethisterone, or norgestimate. Earlier studies had already indicated an increased risk of VTE associated with COC containing other progestogens compared with these preparations, so it is possible that physicians were already preferentially prescribing COC containing levonorgestrel, norethisterone, or norgestimate to new users

Right ventricular shape and function: cardiovascular magnetic resonance reference morphology and biventricular risk factor morphometrics in UK Biobank

Background The associations between cardiovascular disease (CVD) risk factors and the biventricular geometry of the right ventricle (RV) and left ventricle (LV) have been difficult to assess, due to subtle and complex shape changes. We sought to quantify reference RV morphology as well as biventricular variations associated with common cardiovascular risk factors. Methods A biventricular shape atlas was automatically constructed using contours and landmarks from 4329 UK Biobank cardiovascular magnetic resonance (CMR) studies. A subdivision surface geometric mesh was customized to the contours using a diffeomorphic registration algorithm, with automatic correction of slice shifts due to differences in breath-hold position. A reference sub-cohort was identified consisting of 630 participants with no CVD risk factors. Morphometric scores were computed using linear regression to quantify shape variations associated with four risk factors (high cholesterol, high blood pressure, obesity and smoking) and three disease factors (diabetes, previous myocardial infarction and angina). Results The atlas construction led to an accurate representation of 3D shapes at end-diastole and end-systole, with acceptable fitting errors between surfaces and contours (average error less than 1.5 mm). Atlas shape features had stronger associations than traditional mass and volume measures for all factors (p < 0.005 for each). High blood pressure was associated with outward displacement of the LV free walls, but inward displacement of the RV free wall and thickening of the septum. Smoking was associated with a rounder RV with inward displacement of the RV free wall and increased relative wall thickness. Conclusion Morphometric relationships between biventricular shape and cardiovascular risk factors in a large cohort show complex interactions between RV and LV morphology. These can be quantified by z-scores, which can be used to study the morphological correlates of disease

Characterizing the hypertensive cardiovascular phenotype in the UK Biobank

Aims: To describe hypertension-related cardiovascular magnetic resonance (CMR) phenotypes in the UK Biobank considering variations across patient populations. Methods and results: We studied 39 095 (51.5% women, mean age: 63.9 ± 7.7 years, 38.6% hypertensive) participants with CMR data available. Hypertension status was ascertained through health record linkage. Associations between hypertension and CMR metrics were estimated using multivariable linear regression adjusting for major vascular risk factors. Stratified analyses were performed by sex, ethnicity, time since hypertension diagnosis, and blood pressure (BP) control. Results are standardized beta coefficients, 95% confidence intervals, and P-values corrected for multiple testing. Hypertension was associated with concentric left ventricular (LV) hypertrophy (increased LV mass, wall thickness, concentricity index), poorer LV function (lower global function index, worse global longitudinal strain), larger left atrial (LA) volumes, lower LA ejection fraction, and lower aortic distensibility. Hypertension was linked to significantly lower myocardial native T1 and increased LV ejection fraction. Women had greater hypertension-related reduction in aortic compliance than men. The degree of hypertension-related LV hypertrophy was greatest in Black ethnicities. Increasing time since diagnosis of hypertension was linked to adverse remodelling. Hypertension-related remodelling was substantially attenuated in hypertensives with good BP control. Conclusion: Hypertension was associated with concentric LV hypertrophy, reduced LV function, dilated poorer functioning LA, and reduced aortic compliance. Whilst the overall pattern of remodelling was consistent across populations, women had greater hypertension-related reduction in aortic compliance and Black ethnicities showed the greatest LV mass increase. Importantly, adverse cardiovascular remodelling was markedly attenuated in hypertensives with good BP control

Multi-input and dataset-invariant adversarial learning (MDAL) for left and right-ventricular coverage estimation in cardiac MRI

Cardiac functional parameters, such as, the Ejection Fraction (EF) and Cardiac Output (CO) of both ventricles, are most immediate indicators of normal/abnormal cardiac function. To compute these parameters, accurate measurement of ventricular volumes at end-diastole (ED) and end-systole (ES) are required. Accurate volume measurements depend on the correct identification of basal and apical slices in cardiac magnetic resonance (CMR) sequences that provide full coverage of both left (LV) and right (RV) ventricles. This paper proposes a novel adversarial learning (AL) approach based on convolutional neural networks (CNN) that detects and localizes the basal/apical slices in an image volume independently of image-acquisition parameters, such as, imaging device, magnetic field strength, variations in protocol execution, etc. The proposed model is trained on multiple cohorts of different provenance, and learns image features from different MRI viewing planes to learn the appearance and predict the position of the basal and apical planes. To the best of our knowledge, this is the first work tackling the fully automatic detection and position regression of basal/apical slices in CMR volumes in a dataset-invariant manner. We achieve this by maximizing the ability of a CNN to regress the position of basal/apical slices within a single dataset, while minimizing the ability of a classifier to discriminate image features between different data sources. Our results show superior performance over state-of-the-art methods