Positive feedback is a ubiquitous regulatory motif that allows systems to convert graded inputs into decisive, all-or-none outputs. Onn Brandman et al. [1] simulated the performance of the multiple interlinked loops, and showed that linking fast and slow positive feedback loops creates a dual-time switch that is both rapidly inducible (due to the fast positive feedback loop) and resistant to no...

In this article, we investigate the use of wavelets for frequency tracking in the presence of high dynamics. In particular, we construct automatic frequency control loops that are based on correlating the incoming sinusoidal signal with Fourierbased functions and with Daubechies-4 wavelet functions. Both loops are compared based on their abilities to track an input frequency with varying degree...

A cell consists of many interacting biomolecular components that form some basic feedback loops, such as positive or negative feedback loops. When biological signals transduce through cascades consisting of various loops they will be affected or even distorted. Especially, how to process various signals buried in various intrinsic and extrinsic noises is an important issue. In this paper, a met...

Periodic and non-periodic components of electrophysiological signals are modelled in terms syncronized sequences closed loops firing neurons correlated according to a Markov chain. Single reproduce fundamental harmonic components, appearing as lines the power spectra at frequencies ranging from 0.5 Hz 100 Hz. Further interesting features brainwave emerge by considering multiple loops. In partic...

Positive feedback is a ubiquitous signal transduction motif that allows systems to convert graded inputs into decisive, all-or-none outputs. Here we investigate why the positive feedback switches that regulate polarization of budding yeast, calcium signaling, Xenopus oocyte maturation, and various other processes use multiple interlinked loops rather than single positive feedback loops. Mathema...

Genetic circuits can implement elaborated tasks of amplitude or frequency signal detection. What type of constraints could circuits experience in the performance of these tasks, and how are they affected by molecular noise? Here, we consider a simple detection process-a signal acting on a two-component module-to analyze these issues. We show that the presence of a feedback interaction in the de...

a tandem agv configuration connects all cells of a manufacturing area by means of non-overlapping, sin-gle-vehicle closed loops. each loop has at least one additional p/d station, provided as an interface between adjacent loops. this study describes the development of three tabu search algorithms for the design of tandem agv systems. the first algorithm was developed based on the basic definiti...

Quorum sensing activation by signal pheromone (CSP) in Streptococcus mutans depends on the membrane-associated receptor ComD, which senses the signal and triggers the signaling cascade for bacteriocin production and other cell density-dependent activities. However, the mechanism of the signal recognition via the ComD receptor in this species is nearly unexplored. Here, we show that the membrane...

Usingjnmdtfiiax cable (coaxial cable with additional coaxial shields, ihssil~t@cd from each other), techniques are discussed which allmwa@muthaY distribution of the signal input positions around a Ensppst.rructure. Also discussed are uses of this kind of multiax cab3e:’:structure for multi-turn loops. In some cases there are Wppcmvements in ttie performance of loops (for measurinq the mazgwtt~c...

-A circuit to dynamically reconfigure the clock frequency of a synchronous digital system according to the changing needs of the application is described in this paper . This paper generally relates to phase locked loops and more particularly to reconfiguration of phase locked loops used for signal synchronization on integrated circuit chips. The circuit changes the clock frequency with a minim...