Detection of photons from electromagnetic radiation can be considered as the appearance of random events on the time axis. When an attenuator is placed in front of the detector, which attenuates the intensity by a factor of α, the statistical properties of the detected photons are altered. We show that simple relations exist between the statistical functions of the photons detected from the att...

An activator-attenuator model of positive control, a s opposed to the classic repressor-operator model of negative control, is proposed for the major operon-specific mechanism governing expression of the histidine gene cluster of Salmonella typhimurium. Evidence for this mechanism is derived from experiments performed with a coupled in vitro transcription-translation system, as well as with a m...

A wideband CMOS variable gain low noise amplifier suitable for multi-standard radio applications between 75 MHz and 3 GHz is presented. Wideband matching to 50 Ohm (single ended) is achieved using a common-drain feedback stage whereas variable gain is realized using a resistive attenuator. The circuit has been designed in a 65 nm CMOS process and achieves 22 dB maximum gain, 29 dB gain range, 3...

In this letter, a model based disturbance attenuator (MBDA) for robot manipulators is proposed and the stability of the MBDA in robot positioning problems is proved via Liapunov’s direct method. This method does not require an accurate model of a robot manipulator and takes care of disturbances or modelling errors so that the plant output remains relatively unaffected by them. The output error ...

Techniques to precisely characterise RF components at milli-Kelvin temperatures support the development of quantum computing systems utilising these components. In this work, an S-parameter measurement setup integrated circuits has been proposed and for first time, measurements have validated using two independent calibration techniques, thereby providing more confidence in measurements. The te...

In this work we describe a series of improvements to the Salmonella-based salicylate-inducible cascade expression system comprised of a plasmid-borne expression module, where target gene expression is driven by the P(m) promoter governed by the XylS2 regulator, and a genome-integrated regulatory module controlled by the nahR/P(sal) system. We have constructed a set of high and low-copy number p...

Although the maintenance of precise balance between coagulation and fibrinolysis is of utmost importance for normal haemostasis, until recently these two systems were considered as completely separate mechanisms involved in the process of formation and dissolution of blood clot. Thrombin activatable fibrinolysis inhibitor (TAFI) is a recently described attenuator of the fibrinolytic rate and is...

Expression of the rpoBC genes encoding the beta and beta' RNA polymerase subunits of Escherichia coli is autogenously regulated. Although previous studies have demonstrated a post-transcriptional feedback mechanism, complex transcriptional controls of rpoBC expression may also contribute. We show that an attenuator (rpoBa) separating the ribosomal protein (rpl) genes from the rpoBC genes in the...

Commercially available power meters and sensors have measurement ranges up to several watts. Accurate measurements with these devices require periodic calibration with traceable standards. Conventional calibrations typically take place in the 1mW to 10mW range. This range can be extended downwards for highly sensitive diode sensors by means of a calibrated attenuator. Raising the calibration le...

Gene insertion and deletion are considered as the basic operations in DNA processing and RNA editing. Based on these evolutionary transformations, a computing model has been formulated in formal language theory known as insertion-deletion systems. Recently, in [6], a new computing model named Matrix insertion-deletion system has been introduced to model various bio-molecular structures such as ...