IRC-Safe Graph Autoencoder for Unsupervised Anomaly Detection.

Anomaly detection through employing machine learning techniques has emerged as a novel powerful tool in the search for new physics beyond the Standard Model. Historically similar to the development of jet observables, theoretical consistency has not always assumed a central role in the fast development of algorithms and neural network architectures. In this work, we construct an infrared and collinear safe autoencoder based on graph neural networks by employing energy-weighted message passing. We demonstrate that whilst this approach has theoretically favorable properties, it also exhibits formidable sensitivity to non-QCD structures.

Carotid sinus syndrome is common in very elderly patients undergoing tilt table testing and carotid sinus massage because of syncope or unexplained falls.

BACKGROUND AND AIMS: Although the incidence of falls and syncope increase with age, the underlying mechanisms are not fully understood, particularly in very old patients. We report diagnostic outcomes of tilt table and carotid sinus massage (TT/CSM) testing in a population of older old subjects (82% over 80 years of age) referred for TT/CSM from a falls clinic for assessment of syncope or unexplained falls. METHODS: Prospective observational study between January 1, 2001 and January 1, 2005 involving 290 consecutive subjects undergoing TT/CSM testing according to European Society of Cardiology guidelines for the diagnosis and management of syncope. RESULTS: Combination of TT/CSM provided a positive result in 62% of subjects, and was significantly more likely to be positive in subjects over the age of 80 (68% vs 50%, p=0.001). Carotid sinus syndrome (CSS) was the most common diagnosis, and was significantly more common in subjects over 80 (48% vs 34%, p=0.022) particularly due to a higher incidence of mixed CSS (16% vs 7%, p=0.023). There was no significant difference in the diagnosis of subjects referred due to falls and those reporting syncope (p=0.93). No cardiovascular or neurological adverse events occurred. CONCLUSIONS: In our cohort of very elderly patients, the diagnostic accuracy of tilt testing and carotid sinus massage was high and adverse incidents absent when testing was indicated by a geriatrician experienced in the assessment of falls and syncope. We advocate the use of TT/CSM testing as part of a comprehensive falls/syncope assessment for the diagnostic evaluation of older patients presenting with unexplained falls and/or syncope in whom structured assessment has not identified a cause for their symptoms.