Optoelectronic Reservoir Computing

Reservoir computing is a recently introduced, highly efficient bio-inspired approach for processing time dependent data. The basic scheme of reservoir computing consists of a non linear recurrent dynamical system coupled to a single input layer and a single output layer. Within these constraints many implementations are possible. Here we report an opto-electronic implementation of reservoir computing based on a recently proposed architecture consisting of a single non linear node and a delay line. Our implementation is sufficiently fast for real time information processing. We illustrate its performance on tasks of practical importance such as nonlinear channel equalization and speech recognition, and obtain results comparable to state of the art digital implementations.Comment: Contains main paper and two Supplementary Material

Triple-marker cardiac MRI detects sequential tissue changes of healing myocardium after a hydrogel-based therapy

Regenerative therapies based on injectable biomaterials, hold an unparalleled potential for treating myocardial ischemia. Yet, noninvasive evaluation of their efficacy has been lagging behind. Here, we report the development and longitudinal application of multiparametric cardiac magnetic resonance imaging (MRI) to evaluate a hydrogel-based cardiac regenerative therapy. A pH-switchable hydrogel was loaded with slow releasing insulin growth factor 1 and vascular endothelial growth factor, followed by intramyocardial injection in a mouse model of ischemia reperfusion injury. Longitudinal cardiac MRI assessed three hallmarks of cardiac regeneration: angiogenesis, resolution of fibrosis and (re)muscularization after infarction. The multiparametric approach contained dynamic contrast enhanced MRI that measured improved vessel features by assessing fractional blood volume and permeability*surface area product, T1-mapping that displayed reduced fibrosis, and tagging MRI that showed improved regional myocardial strain in hydrogel treated infarcts. Finally, standard volumetric MRI demonstrated improved left ventricular functioning in hydrogel treated mice followed over time. Histology confirmed MR-based vessel features and fibrotic measurements. Our novel triple-marker strategy enabled detection of ameliorated regeneration in hydrogel treated hearts highlighting the translational potential of these longitudinal MRI approaches

The 600 yr eruptive history of Villarrica Volcano (Chile) revealed by annually laminated lake sediments

Lake sediments contain valuable information about past volcanic and seismic events that have affected the lake catchment, and they provide unique records of the recurrence interval and magnitude of such events. This study uses a multilake and multiproxy analytical approach to obtain reliable and high-resolution records of past natural catastrophes from similar to 600-yr-old annually laminated (varved) lake sediment sequences extracted from two lakes, Villarrica and Calafquen, in the volcanically and seismically active Chilean Lake District. Using a combination of micro-X-ray fluorescence (mu XRF) scanning, microfacies analysis, grain-size analysis, color analysis, and magnetic-susceptibility measurements, we detect and characterize four different types of event deposits (lacustrine turbidites, tephra-fall layers, runoff cryptotephras, and lahar deposits) and produce a revised eruption record for Villarrica Volcano, which is unprecedented in its continuity and temporal resolution. Glass geochemistry and mineralogy also reveal deposits of eruptions from the more remote Carran-Los Venados volcanic complex, Quetrupillan Volcano, and the Huanquihue Group in the studied lake sediments. Time-series analysis shows 112 eruptions with a volcanic explosivity index (VEI) >= 2 from Villarrica Volcano in the last similar to 600 yr, of which at least 22 also produced lahars. This significantly expands our knowledge of the eruptive frequency of the volcano in this time window, compared to the previously known eruptive history from historical records. The last VEI >= 2 eruption of Villarrica Volcano occurred in 1991. Based on the last similar to 500 yr, for which we have a complete record from both lakes, we estimate the probability of the occurrence of future eruptions from Villarrica Volcano and statistically demonstrate that the probability of a 22 yr repose period (anno 2013) without VEI >= 2 eruptions is <= 1.7%. This new perspective on the recurrence interval of eruptions and historical lahar activity will help improve volcanic hazard assessments for this rapidly expanding tourist region, and it highlights how lake records can be used to significantly improve historical eruption records in areas that were previously uninhabited

Online Training of an Opto-Electronic Reservoir Computer

Reservoir Computing is a bio-inspired computing paradigm for processing time dependent signals. Its analog implementations equal and sometimes outperform other digital algorithms on a series of benchmark tasks. Their performance can be increased by switching from offline to online training method. Here we present the first online trained opto-electronic reservoir computer. The system is tested on a channel equalisation task and the algorithm is executed by an FPGA chip. We report performances close to previous implementations and demonstrate the benefits of online training on a non-stationary task that could not be easily solved using offline methods.info:eu-repo/semantics/publishe

Brain energy rescue:an emerging therapeutic concept for neurodegenerative disorders of ageing

The brain requires a continuous supply of energy in the form of ATP, most of which is produced from glucose by oxidative phosphorylation in mitochondria, complemented by aerobic glycolysis in the cytoplasm. When glucose levels are limited, ketone bodies generated in the liver and lactate derived from exercising skeletal muscle can also become important energy substrates for the brain. In neurodegenerative disorders of ageing, brain glucose metabolism deteriorates in a progressive, region-specific and disease-specific manner — a problem that is best characterized in Alzheimer disease, where it begins presymptomatically. This Review discusses the status and prospects of therapeutic strategies for countering neurodegenerative disorders of ageing by improving, preserving or rescuing brain energetics. The approaches described include restoring oxidative phosphorylation and glycolysis, increasing insulin sensitivity, correcting mitochondrial dysfunction, ketone-based interventions, acting via hormones that modulate cerebral energetics, RNA therapeutics and complementary multimodal lifestyle changes

Contrast-enhanced T1-Mapping MRI for the Assessment of Myocardial Fibrosis

Fibrosis is a common feature of heart disease and is associated with adverse cardiac remodeling and poor clinical outcome. Because of the lack of routine noninvasive patient-specific tissue characterization tools, the development of new treatment strategies for cardiovascular disease specifically targeting undesired fibrosis in the myocardial wall is slow. Cardiovascular magnetic resonance imaging has developed into the gold-standard tool to assess various aspects of myocardial anatomy and function. In recent years, magnetic resonance imaging has also emerged as a promising technique to fulfill the need for a noninvasive assessment of myocardial fibrosis through the use of Gd-based contrast agents and the quantification of the longitudinal relaxation time T1. This paper reviews the current use of T1 mapping for the assessment of myocardial fibrosis, with particular focus on imaging techniques and their validation

AirTAP Briefings (Winter 2019, vol. 19, no. 1)

Articles include: Is more ice the new normal?; TPT, MnDOT create drone safety video; An airport story’s: Granite Falls Municipal Airport; Mankato lighting renovations make taxiways brighter, easier to repair; Annual conference heading to Willmar; More aviation event

Reservoir Computing: Quo Vadis?

Reservoir Computing (RC) is an umbrella term for adaptive computational paradigms that rely on an excitable dynamical system, also called the reservoir. The paradigms have been shown to be particularly promising for temporal signal processing. RC was also explored as a potential candidate for emerging nanoscale architectures. In this article we reflect on the current state of RC and muse about its future. In particular, we propose a set of open problems that we think need to be addressed in order to make RC more mainstream