Signatures of criticality arise in simple neural population models with correlations

Large-scale recordings of neuronal activity make it possible to gain insights into the collective activity of neural ensembles. It has been hypothesized that neural populations might be optimized to operate at a 'thermodynamic critical point', and that this property has implications for information processing. Support for this notion has come from a series of studies which identified statistical signatures of criticality in the ensemble activity of retinal ganglion cells. What are the underlying mechanisms that give rise to these observations? Here we show that signatures of criticality arise even in simple feed-forward models of retinal population activity. In particular, they occur whenever neural population data exhibits correlations, and is randomly sub-sampled during data analysis. These results show that signatures of criticality are not necessarily indicative of an optimized coding strategy, and challenge the utility of analysis approaches based on equilibrium thermodynamics for understanding partially observed biological systems.Comment: 36 pages, LaTeX; added journal reference on page 1, added link to code repositor

Employing Environmental Data and Machine Learning to Improve Mobile Health Receptivity

Behavioral intervention strategies can be enhanced by recognizing human activities using eHealth technologies. As we find after a thorough literature review, activity spotting and added insights may be used to detect daily routines inferring receptivity for mobile notifications similar to just-in-time support. Towards this end, this work develops a model, using machine learning, to analyze the motivation of digital mental health users that answer self-assessment questions in their everyday lives through an intelligent mobile application. A uniform and extensible sequence prediction model combining environmental data with everyday activities has been created and validated for proof of concept through an experiment. We find that the reported receptivity is not sequentially predictable on its own, the mean error and standard deviation are only slightly below by-chance comparison. Nevertheless, predicting the upcoming activity shows to cover about 39% of the day (up to 58% in the best case) and can be linked to user individual intervention preferences to indirectly find an opportune moment of receptivity. Therefore, we introduce an application comprising the influences of sensor data on activities and intervention thresholds, as well as allowing for preferred events on a weekly basis. As a result of combining those multiple approaches, promising avenues for innovative behavioral assessments are possible. Identifying and segmenting the appropriate set of activities is key. Consequently, deliberate and thoughtful design lays the foundation for further development within research projects by extending the activity weighting process or introducing a model reinforcement.BMBF, 13GW0157A, Verbundprojekt: Self-administered Psycho-TherApy-SystemS (SELFPASS) - Teilvorhaben: Data Analytics and Prescription for SELFPASSTU Berlin, Open-Access-Mittel - 201

Three-dimensional cell culture and tissue engineering in a T-CUP (tissue culture under perfusion)

The aim of this study was to develop and validate a simple and compact bioreactor system for perfusion cell seeding and culture through 3-dimensional porous scaffolds. The developed Tissue Culture Under Perfusion (T-CUP) bioreactor is based on the concept of controlled and confined alternating motion of scaffolds through a cell suspension or culture medium, as opposed to pumping of the fluid through the scaffolds. Via the T-CUP, articular chondrocytes and bone marrow stromal cells could be seeded into porous scaffolds of different compositions and architectures (chronOS, Hyaff-11, and Polyactive) at high efficiency (greater than 75%), uniformity (cells were well distributed throughout the scaffold pores), and viability (greater than 97%). Culture of articular chondrocytes seeded into 4-mm thick Polyactive scaffolds for 2 weeks in the T-CUP resulted in uniform deposition of cartilaginous matrix. Cultivation of freshly isolated human bone marrow nucleated cells seeded into ENGipore ceramic scaffolds for 19 days in the T-CUP resulted in stromal cell-populated constructs capable of inducing ectopic bone formation in nude mice. The T-CUP bioreactor represents an innovative approach to simple, efficient, and reliable 3D cell culture, and could be used either as a model to investigate mechanisms of tissue development or as a graft manufacturing system in the context of regenerative medicine

Central Bank communication and monetary policy: a survey of theory and evidence

Over the last two decades, communication has become an increasingly important aspect of monetary policy. These real-world developments have spawned a huge new scholarly literature on central bank communication —mostly empirical, and almost all of it written in this decade. We survey this evergrowing literature. The evidence suggests that communication can be an important and powerful part of the central bank’s toolkit since it has the ability to move financial markets, to enhance the predictability of monetary policy decisions, and potentially to help achieve central banks’ macroeconomic objectives. However, the large variation in communication strategies across central banks suggests that a consensus has yet to emerge on what constitutes an optimal communication strategy. JEL Classification: E52, E58Central Bank, communication, monetary policy

Central Bank Communication and Monetary Policy: A Survey of Theory and Evidence

Over the last two decades, communication has become an increasingly important aspect of monetary policy. These real-world developments have spawned a huge new scholarly literature on central bank communication—mostly empirical, and almost all of it written in this decade. We survey this ever-growing literature. The evidence suggests that communication can be an important and powerful part of the central bank’s toolkit since it has the ability to move financial markets, to enhance the predictability of monetary policy decisions, and potentially to help achieve central banks’ macroeconomic objectives. However, the large variation in communication strategies across central banks suggests that a consensus has yet to emerge on what constitutes an optimal communication strategy.

Chapitre 35 - Résumé et perspectives de l’utilisation concrète de One Health

Introduction Confrontés à la richesse fascinante des connaissances, des preuves et des orientations potentielles à suivre afin de donner corps au concept One Health, on peut se sentir dépassé, c’est pourquoi ce dernier chapitre a pour objectif de fournir une vue d’ensemble complète des implications de One Health, allant des racines au positionnement actuel sur la scène mondiale de la santé, tout en fournissant des éléments histo..