Stochasticity in an Artificial Neuron using Ag/2D-MoS2/Au Threshold Switching Memristor

Neuromorphic computing comprises of systems that are based on the human brain or artificial neural networks, with the promise of creating a brain inspired ability to learn and adapt, but technical challenges, such as developing an accurate neuroscience model of the functionality of the brain to building devices to support these models, are significantly hindering the progress of neuromorphic systems. This has paved the way for artificial neural networks (ANN) to meet these criteria. The memristor has become an emerging candidate to realize ANN through emulation synapse and neuron behavior. In this work, we are fabricating an Ag/MoS­2/Au threshold switching memristor (TSM), to emulate four critical behaviors of neurons - all-or-nothing spiking, threshold-driven firing, post firing refractory period and stimulus strength-based frequency response. We will also test the innate stochastic behavior of these devices to see if they are voltage dependent, making them a possible application in the integrate and fire neuron. Continuing to emulate biological synapses using memristors can help solve many optimization and machine learning problems, which in turn, can make electronics as energy-efficient as our brain

Madison Manley

Madison is a student at the University of Central Florida, majoring in electrical engineering with a focus on renewable energy. She is interested in nanoelectronics and energy-efficient technology but, likes to explore interdisciplinary subjects that go beyond her knowledge.https://stars.library.ucf.edu/ramp_gallery/1102/thumbnail.jp

Mutagenic Potential of Artificial Athletic Field Crumb Rubber at Increased Temperatures

Rubber tires contain several compounds that are known or suspected carcinogens.  Many carcinogens are mutagens, and fluctuation assays based on the Ames test can be used as an initial screen for mutagenic potential.  Granulated crumb rubber from recycled tires is commonly used in the creation of artificial athletic fields, and the surface temperature of these fields can reach levels far above the ambient temperature.  In this study, crumb rubber samples taken directly from four separate artificial athletic field surfaces were used to make leachates using water at different temperatures.  For each of these fields, leachates obtained in water at 70 ºC showed significant mutagenic potential (p ≤ .001) in Salmonella typhimurium fluctuation assays.  Leachates obtained in water at 40 ºC showed no mutagenic potential for any of the fields tested.  For one field, crumb rubber heated in water at temperatures as low as 50 ºC resulted in significant mutagenic potential (p ≤ 0.001).  Water used in an experiment designed to mimic the irrigation of an artificial athletic field also showed mutagenic potential (p ≤ 0.001) in a fluctuation assay.  These results suggest that at the higher temperatures that can exist on artificial athletic field surfaces, the crumb rubber infill on these artificial athletic fields can become the source of a water soluble agent with mutagenic potential in bacteria

Effect of propranolol and clonidine after severe traumatic brain injury: a pilot randomized clinical trial

Abstract Objective To evaluate the safety, feasibility, and efficacy of combined adrenergic blockade with propranolol and clonidine in patients with severe traumatic brain injury (TBI). Background Administration of adrenergic blockade after severe TBI is common. To date, no prospective trial has rigorously evaluated this common therapy for benefit. Methods This phase II, single-center, double-blinded, pilot randomized placebo-controlled trial included patients aged 16–64 years with severe TBI (intracranial hemorrhage and Glasgow Coma Scale score ≤ 8) within 24 h of ICU admission. Patients received propranolol and clonidine or double placebo for 7 days. The primary outcome was ventilator-free days (VFDs) at 28 days. Secondary outcomes included catecholamine levels, hospital length of stay, mortality, and long-term functional status. A planned futility assessment was performed mid-study. Results Dose compliance was 99%, blinding was intact, and no open-label agents were used. No treatment patient experienced dysrhythmia, myocardial infarction, or cardiac arrest. The study was stopped for futility after enrolling 47 patients (26 placebo, 21 treatment), per a priori stopping rules. There was no significant difference in VFDs between treatment and control groups [0.3 days, 95% CI (− 5.4, 5.8), p = 1.0]. Other than improvement of features related to sympathetic hyperactivity (mean difference in Clinical Features Scale (CFS) 1.7 points, CI (0.4, 2.9), p = 0.012), there were no between-group differences in the secondary outcomes. Conclusion Despite the safety and feasibility of adrenergic blockade with propranolol and clonidine after severe TBI, the intervention did not alter the VFD outcome. Given the widespread use of these agents in TBI care, a multi-center investigation is warranted to determine whether adrenergic blockade is of therapeutic benefit in patients with severe TBI. Trial Registration Number NCT01322048