A biological introduction serves to remind us that differentiation is an epigenetic process, that multistationarity can account for epigenetic differences, including those involved in cell differentiation, and that positive feedback circuits are a necessary condition for multistationarity and, by inference, for differentiation. The core of the paper is comprised of a formal description of feedb...

A 3-port isolated circuit providing 1:3 fanout, buffering and amplification over a multi-megahertz bandwidth is presented. The circuit accepts a single input and drives 3 independently isolated output channels, up to +/10 V into 50 ohms. The input and output isolation is supplied via a dual optocoupler, and the power isolation is achieved with DC/DC converters. In each channel, a voltage feedba...

We have done integration and differentiation with simple, single–timeconstant circuits that had τs + 1 in the denominator of their transfer functions. These systems gave an exponentially damped response to step or impulse inputs. In Chapter 8, we showed how a second-order system can give rise to a sinusoidal response. In this chapter, we will discuss a simple circuit that can generate a sinusoi...

Cell communication within tissues is mediated by multiple paracrine signals including growth factors, which control cell survival and proliferation. Cells and the growth factors they produce and receive constitute a circuit with specific properties that ensure homeostasis. Here, we used computational and experimental approaches to characterize the features of cell circuits based on growth facto...

A pulse-coupled neuron (PCN) circuit is proposed. This circuit uses a positive feedback circuit with two capacitors. One corresponds to the sodium ion potential and the other corresponds to the potassium ion potential and can be easily implemented in CMOS technology. The circuit behaves like a real neuron, generating a pulse train in which the frequency increases with an increase of input excit...

corrective feedback (cf) and its different types have long absorbed many scholars and practitioners. as ellis (2009) mentioned some experimental studies need to be carefully designed to discover the relative effectiveness of each of these cf techniques. the goal of this qualitative study was to discover whether the employment of different cf strategies could bring about an attitudinal shift. to...