A Probabilistic Distance-Based Stability Quantifier for Complex Dynamical Systems

For a dynamical system, an attractor of the system may represent the `desirable' state. Perturbations acting on the system may push the system out of the basin of attraction of the desirable attractor. Hence, it is important to study the stability of such systems against reasonably large perturbations. We introduce a distance-based measure of stability, called `stability bound', to characterize the stability of dynamical systems against finite perturbations. This stability measure depends on the size and shape of the basin of attraction of the desirable attractor. A probabilistic sampling-based approach is used to estimate stability bound and quantify the associated estimation error. An important feature of stability bound is that it is numerically computable for any basin of attraction, including fractal basins. We demonstrate the merit of this stability measure using an ecological model of the Amazon rainforest, a ship capsize model, and a power grid model

How Network Topology Affects the Strength of Dangerous Power Grid Perturbations

Reasonably large perturbations may push a power grid from its stable synchronous state into an undesirable state. Identifying vulnerabilities in power grids by studying power grid stability against such perturbations can aid in preventing future blackouts. We use two stability measures \unicode{x2014} stability bound, which deals with a system's asymptotic behaviour, and survivability bound, which deals with a system's transient behaviour, to provide information about the strength of perturbations that destabilize the system. Using these stability measures, we have found that certain nodes in tree-like structures have low asymptotic stability, while nodes with a high number of connections generally have low transient stability

Capturing the spatial and temporal variability of urban noise: do low-cost sensors offer a step towards higher resolution noise monitoring?

Populations are being exposed to environmental noise at levels that impact on both mental and physical health, with knock-on effects on productivity and economic performance. Current assessments of exposure are often based on noise levels at building façades, derived from sound propagation models and are usually limited to long-term average noise levels for periods of the day, night or over 24 hours (e.g. Lden). There is a particular lack of information on variations in noise throughout the diurnal cycle and over long time periods. In this study, we deployed 14 low-cost recorders to gather high resolution data on urban noise levels and compared results with those from a conventional noise propagation algorithm. Daily LAeq and diurnal variations in hourly LAeq showed considerable variation in space and time with the middle of the day generally noisiest. Some of these patterns were well captured by the propagation model although it tended to underestimate noise levels from all sources. Although more work is needed, we suggest that well-placed sensors have the potential to enhance exposure assessments e.g. on minor roads and where traffic is not the major noise sourc

Advancing the global public health agenda for NAFLD: a consensus statement

Non-alcoholic fatty liver disease (NAFLD) is a potentially serious liver disease that affects approximately one-quarter of the global adult population, causing a substantial burden of ill health with wide-ranging social and economic implications. It is a multisystem disease and is considered the hepatic component of metabolic syndrome. Unlike other highly prevalent conditions, NAFLD has received little attention from the global public health community. Health system and public health responses to NAFLD have been weak and fragmented, and, despite its pervasiveness, NAFLD is largely unknown outside hepatology and gastroenterology. There is only a nascent global public health movement addressing NAFLD, and the disease is absent from nearly all national and international strategies and policies for non-communicable diseases, including obesity. In this global Delphi study, a multidisciplinary group of experts developed consensus statements and recommendations, which a larger group of collaborators reviewed over three rounds until consensus was achieved. The resulting consensus statements and recommendations address a broad range of topics — from epidemiology, awareness, care and treatment to public health policies and leadership — that have general relevance for policy-makers, health-care practitioners, civil society groups, research institutions and affected populations. These recommendations should provide a strong foundation for a comprehensive public health response to NAFLD

Advancing the global public health agenda for NAFLD: a consensus statement

© Springer Nature Limited 2021, corrected publication 2021Non-alcoholic fatty liver disease (NAFLD) is a potentially serious liver disease that affects approximately one-quarter of the global adult population, causing a substantial burden of ill health with wide-ranging social and economic implications. It is a multisystem disease and is considered the hepatic component of metabolic syndrome. Unlike other highly prevalent conditions, NAFLD has received little attention from the global public health community. Health system and public health responses to NAFLD have been weak and fragmented, and, despite its pervasiveness, NAFLD is largely unknown outside hepatology and gastroenterology. There is only a nascent global public health movement addressing NAFLD, and the disease is absent from nearly all national and international strategies and policies for non-communicable diseases, including obesity. In this global Delphi study, a multidisciplinary group of experts developed consensus statements and recommendations, which a larger group of collaborators reviewed over three rounds until consensus was achieved. The resulting consensus statements and recommendations address a broad range of topics - from epidemiology, awareness, care and treatment to public health policies and leadership - that have general relevance for policy-makers, health-care practitioners, civil society groups, research institutions and affected populations. These recommendations should provide a strong foundation for a comprehensive public health response to NAFLD.info:eu-repo/semantics/publishedVersio