Preliminary steps toward artificial protocell computation

Protocells are hypothesised as a transitional phase in the origin of life, prior to the evolution of fully functional prokaryotic cells. The work reported here is being done in the context of the PACE project, which is investigating the fabrication of artificial protocells de novo. We consider here the important open question of whether or how articifial protocells (if or when they are successfully fabricated) might be applied as “computing” devices—what sort of computing might they be suitable for, and how might they be “programmed”? We also present some preliminary analysis of a crude model of such “evolutionary protocell computation”

On Protocell "Computation"

The EU FP6 Integrated Project PACE ('Programmable Artificial Cell Evolution') is investigating the creation, de novo, of chemical 'protocells'. These will be minimal 'wetware' chemical systems integrating molecular information carriers, primitive energy conversion (metabolism) and containment (membrane). Ultimately they should be capable of autonomous reproduction, and be 'programmable' to realise specific desired function. A key objective of PACE is to explore the application of such protocell technology to build novel nanoscale computational devices. In principle, such computation might be realised either at the level of an individual protocell or at the level of self-assembling, multi-cellular, aggregates. In the case of the individual protocell level, a form of 'molecular computation' may be possible in the manner of 'cell signalling networks' in modern cells. This might be particularly appropriate where a protocell is deployed to interface directly with molecular systems, such as in 'smart drug' applications. 'Programming' of molecular computation functionality might be realised by evolutionary techniques, i.e., applying selection to polulations of (reproducing) protocells. Reflexive string rewriting systems may provide an appropriate formal model of molecular computation. The behaviour of minimal reflexive string rewriting systems, incorporated in reproducing containers (protocells), is being explored in simulation. This is a basis for possible design of minimal protocell 'computers'

Cellular computation using classifier systems

The EU FP6 Integrated Project PACE ('Programmable Artificial Cell Evolution') is investigating the creation, de novo, of chemical 'protocells'. These will be minimal 'wetware' chemical systems integrating molecular information carriers, primitive energy conversion (metabolism) and containment (membrane). Ultimately they should be capable of autonomous reproduction, and be 'programmable' to realise specific desired function. A key objective of PACE is to explore the application of such protocell technology to build novel nanoscale computational devices. Our contribution to this project is to investigate approaches to adding minimal computational capability to protocells. We introduce the Molecular Classifier System (MCS) to represent the internal molecular reactions of the protocell. Reactions in the MCS are constrained as follows: The products of the reaction depend on the reactants and the environment in which the reaction took place; The reactions that can happen depend on the physical and chemical structure of the reacting compounds. In our MCS, there are reactants and reaction rules. The rules determine the reactants and the products for a given interaction. These simple computational processes may also help in understanding the origins of Cell Signaling Networks(CSNs). CSNs are complex bio-chemical networks responsible for coordinating and controlling cellular activities. CSNs can therefore be regarded as computational systems. To understand the evolution of such complex computational systems as found in nature, we will distinguish the minimal computational properties fundamental for the survival of a protocell

Sending Out an SMS: The Impact of Automatically Enrolling Consumers Into Overdraft Alerts

Incidental charges incurred by UK consumers on their Personal Current Account (PCA) are steep, especially for small amounts of unplanned borrowing and unpaid items. A recent policy mandates major UK banks to send consumers a text message alert of impending charges, allowing them to act before they incur a charge. Using a unique, large and detailed dataset covering the transactions of 1.5 million consumers across 6 banks, and by looking at large-scale automatic enrolment exercises carried out by two major banks, we estimate the effect of automatically enrolling consumers into these alerts. We find that automatic enrolment into alerts has large effects on charges: (i) automatic enrolment into unpaid item alerts (that inform customers of retry periods) reduces charges by 21-24% and (ii) automatic enrolment into unarranged overdraft alerts reduces charges by 25%. We also estimate average treatment effects for different types of consumers, grouped by their pre-alerts level of incidental charges (rare, occasional or heavy), and find that the benefits of automatic enrolment differ markedly between types of consumers. Those who rarely incur charges can avoid as much as half of charges thanks to alerts, whereas heavy users still incur substantial charges after automatic enrolment. We find strikingly similar patterns across the two banks, for both unpaid item and unarranged overdraft charges, providing reassurance that these findings are not specific to a particular customer base or firm implementation

Recombinant production, characterization and industrial application testing of a novel acidic exo/endo-chitinase from Rasamsonia emersonii

An acid-active exo/endo-chitinase; comprising a GH18 catalytic domain and substrate insertion domain; originating from the thermophilic flamentous fungus Rasamsonia emersonii, was expressed in Pichia pastoris. In silico analysis including phylogenetic analysis, and recombinant production, purifcation, biochemical characterisation, and industrial application testing, was carried out. The expressed protein was identifed by SDS-PAGE as a smear from 56.3 to 125.1 kDa, which sharpens into bands at 46.0 kDa, 48.4 kDa and a smear above 60 kDa when treated with PNGase F. The acid-active chitinase was primarily a chitobiosidase but displayed some endo-chitinase and acetyl-glucosamidase activity. The enzyme was optimally active at 50 °C, and markedly low pH of 2.8. As far as the authors are aware, this is the lowest pH optima reported for any fungal chitinase. The acid-active chitinase likely plays a role in chitin degradation for cell uptake in its native environment, perhaps in conjunction with a chitin deacetylase. Comparative studies with other R. emersonii chitinases indicate that they may play a synergistic role in this. The acid-active chitinase displayed some efcacy against non-treated substrates; fungal chitin and chitin from shrimp. Thus, it may be suited to industrial chitin hydrolysis reactions for extraction of glucosamine and chitobiose at low pH

Bio-banding in academy football: Player’s perceptions of a maturity matched tournament

Background: Individual differences in biological maturation impact player selection and development in youth football. Aim: To evaluate players perceptions of competing in a football tournament where they were matched by maturity rather than chronological age. Subjects: Participants included male junior footballers from three professional academies (n = 115). Methods: The study employed multiple methods of analysis, including one sample mean t-tests, equivalence tests, ANOVAs, and thematic analysis of qualitative data derived from open-ended questions. Results and conclusions: Player’s perceived the bio-banding format as providing two main benefits. Early maturing players perceived greater physical and technical challenge, and in turn new opportunities and challenges. Late maturing players perceived less physical and technical challenge, yet greater opportunity to demonstrate technical and tactical abilities. The players reported that they enjoyed and understood the purpose of the bio-banded format, and perceived less risk for injury. Players in all three maturity groups reported more opportunity to engage in leadership behaviours, influence game-play, and express themselves on the ball in the bio-banded format. Bio-banding may facilitate development for both early and late maturing academy players by presenting new learning environments and challenges

On Protocell "Computation"

The EU FP6 Integrated Project PACE (\u27Programmable Artificial Cell Evolution\u27) is investigating the creation, de novo, of chemical \u27protocells\u27. These will be minimal \u27wetware\u27 chemical systems integrating molecular information carriers, primitive energy conversion (metabolism) and containment (membrane). Ultimately they should be capable of autonomous reproduction, and be \u27programmable\u27 to realise specific desired function. A key objective of PACE is to explore the application of such protocell technology to build novel nanoscale computational devices. In principle, such computation might be realised either at the level of an individual protocell or at the level of self-assembling, multi-cellular, aggregates. In the case of the individual protocell level, a form of \u27molecular computation\u27 may be possible in the manner of \u27cell signalling networks\u27 in modern cells. This might be particularly appropriate where a protocell is deployed to interface directly with molecular systems, such as in \u27smart drug\u27 applications. \u27Programming\u27 of molecular computation functionality might be realised by evolutionary techniques, i.e., applying selection to polulations of (reproducing) protocells. Reflexive string rewriting systems may provide an appropriate formal model of molecular computation. The behaviour of minimal reflexive string rewriting systems, incorporated in reproducing containers (protocells), is being explored in simulation. This is a basis for possible design of minimal protocell \u27computers\u27

Les nouveaux diplômés en médecine, dans quelle mesure se considèrent-ils suffisamment préparés pour la pratique clinique ?

L'ouvrage s'interroge sur les cultures de l'évaluation et les dérives évaluatrices. Il questionne l'évaluation sous toutes ses formes en cherchant à identifier ses différents rôles, enjeux et défis à étudier ses éventuelles dérives. La mise en perspective internationale de ces questions permet de voir ce que représente l'évaluation dans différents pays (Espagne, Portugal, France, Royaume-Uni, Liban, Canada anglophone et Canada francophone) et de confronter les regards sur le sujet