Working with Biological Control

At every crossway on the road that leads to the future, each progressive spirit is opposed by a thousand men appointed to guard the past. 

When the control systems fail, the result is disaster. BU may maintain internal stability despite wide fluctuations in environmental variables, but when the control mechanisms are overwhelmed, and stability can no longer be maintained, failure is often cataclysmic. In most instances, the BU dies. If death does not immediately ensue, then there is a severe impairment that pervades the organism. This happens when animals suffer heat stroke in extremely hot circumstances, or when blood pressure Mis during hemorrhage, or when plants wilt irreversibly during drought. Loss of control means death unless some external means intervenes. Even then, help may arrive too late to do any good. 

Great fleas have little fleas upon their backs to bite em. 

And little fleas have lesser fleas, and so ad infinitum. 

And the great fleas themselves, in turn, have greater fleas to go on, While these again have greater still, and greater still, and so on. 

---

Solid/gas biocatalysis consists in the use of a biocatalyst as a solid phase acting on gaseous substrates. Solid/gas bioreactors offer the ability to control precisely all the thermodynamic parameters influencing not only the kinetics of the reactions performed but also the stability of the biocatalysts when working with biological catalyst at elevated temperatures. 

The use of ELISA is broad and it finds applications in many biological laboratories over the last 30 years many tests have been developed and vahdated in different domains such as clinical diagnostics, pharmaceutical research, industrial control or food and feed analytics for instance. Our work has been to redesign the standard ELISA test to fit in a microfluidic system with disposable electrochemical chips. Many applications are foreseen since the biochemical reagents are directly amenable from a conventional microtitre plate to our microfluidic system. For instance, in the last 5 years, we have reported previous works with this concept of microchannel ELISA for the detection of thromboembolic event marker (D-Dimer) [4], hormones (TSH) [18], or vitamin (folic acid) [24], It is expected that similar technical developments in the future may broaden the use of electroanalytical chemistry in the field of clinical tests as has been the case for glucose monitoring. This work also contributes to the novel analytical trend to reduce the volume and time consumption in analytical labs using lab-on-a-chip devices. Not only can an electrophoretic-driven system benefit from the miniaturisation but also affinity assays and in particularly immunoassays with electrochemical detection. 

Biological control systems are often regarded as some sloppy variants of the more precise engineering control systems. Classic control theory considers linear, stable and stationary systems [1-3]. To this could be added well defined. Biological systems are nonlinear, often unstable, and never stationary. They work with small feedback gains, typically less than 10 [4—6] they are interwoven, so completely different systems share common routes (hormones, nerves, etc.) and their properties vary from person to person, even in healthy people. 

---