Large-scale outflows driven by active galactic nuclei (AGN) can have a profound influence on their host galaxies. The outflow properties themselves depend sensitively on the history of AGN energy injection during the lifetime of the outflow. Most observed outflows have dynamical timescales longer than the typical AGN episode duration, i.e. they have been inflated by multiple AGN episodes. Here, we present a neural-network based approach to inferring the most likely duty cycle and other properties of AGN based on the observable properties of their massive outflows. Our model recovers the AGN parameters of simulated outflows with typical errors $< 25{{\ \rm per\ cent}}$. We apply the method to a sample of 59 real molecular outflows and show that a large fraction of them have been inflated by AGN shining with a rather high duty cycle δAGN > 0.2. This result suggests that nuclear activity in galaxies is clustered hierarchically in time, with long phases of more frequent activity composed of many short activity episodes. We predict that $\sim \! 19{{\ \rm per\ cent}}$ of galaxies should have AGN-driven outflows, but half of them are fossils - this is consistent with currently available data. We discuss the possibilities to investigate AGN luminosity histories during outflow lifetimes and suggest ways to use our software to test other physical models of AGN outflows. The source code of all of the software used here is made public.

Neurogenic stress cardiomyopathy (NSC) is defined as transient cardiac dysfunction occurring after primary brain injury, such as aneurysmal subarachnoid haemorrhage, and characterised by left ventricular systolic dysfunction with reduced ejection fraction and abnormalities of regional wall motion. It may also be suspected if elevated levels of cardiac biomarkers and ECG abnormalities are present. It is a reversible condition with favourable long-term prognosis if diagnosed and treated timely, however, NSC is associated with higher rates of early mortality and complications, including pulmonary oedema, cardiogenic shock, delayed cerebral ischaemia. Early diagnosis of the NSC is important in order to prevent these complications and reduce mortality. Management of the NSC is complicated and a multidisciplinary approach is usually required. Seminars in Cardiovascular Medicine 2019; 25:44-52