Comment on "Regularizing capacity of metabolic networks"

In a recent paper, Marr, Muller-Linow and Hutt [Phys. Rev. E 75, 041917 (2007)] investigate an artificial dynamic system on metabolic networks. They find a less complex time evolution of this dynamic system in real networks, compared to networks of reference models. The authors argue that this suggests that metabolic network structure is a major factor behind the stability of biochemical steady states. We reanalyze the same kind of data using a dynamic system modeling actual reaction kinetics. The conclusions about stability, from our analysis, are inconsistent with those of Marr et al. We argue that this issue calls for a more detailed type of modeling

Behaviour, practice – whatever? A theory-agnostic framework for describing and informing demand-side response

Different theoretical perspectives present diverse interpretations for why and how people may (or may not) be able to vary their electricity consumption patterns, and often propose different approaches to facilitating demand-side response (DSR). The framework set out here is suggested as a way of matching and marrying these various approaches with the goal of exploring how to achieve the maximum possible demand response which people are happy and able to provide. The framework is based around ‘electricity-relevant dimensions’, or factors which may be considered to be associated in some way with a person or people’s electricity use – activities engaged in, location, room temperature, and so on. Within each dimension, any at instant in time, certain states (such as ‘walking’ or ‘watching TV’ for activity) are more or less possible/acceptable than others for a variety of reasons. Effective DSR is understood as involving influencing adoption of those states with lower (or higher, as necessary) electricity outcomes at certain times, from a ‘phase space’ of possible options. This paper describes how the framework can be used to consider the role of DSR interventions with their roots in different theoretical positions, such as changes in material conditions or competencies (associated with social practice theory), or in the framing of messages to activate loss-aversion (behavioural economics). It is intended to prompt consideration of how such approaches (and their proponents) could work together to optimize the potential of DSR programmes and policies, and is illustrated throughout with real and hypothetical examples

L1-determined ideals in group algebras of exponential Lie groups

A locally compact group $G$ is said to be $\ast$-regular if the natural map \Psi:\Prim C^\ast(G)\to\Prim_{\ast} L^1(G) is a homeomorphism with respect to the Jacobson topologies on the primitive ideal spaces \Prim C^\ast(G) and \Prim_{\ast} L^1(G). In 1980 J. Boidol characterized the $\ast$-regular ones among all exponential Lie groups by a purely algebraic condition. In this article we introduce the notion of $L^1$-determined ideals in order to discuss the weaker property of primitive $\ast$-regularity. We give two sufficient criteria for closed ideals $I$ of $C^\ast(G)$ to be $L^1$-determined. Herefrom we deduce a strategy to prove that a given exponential Lie group is primitive $\ast$-regular. The author proved in his thesis that all exponential Lie groups of dimension $\le 7$ have this property. So far no counter-example is known. Here we discuss the example $G=B_5$, the only critical one in dimension $\le 5$

Experiment K-6-08. Biochemical and histochemical observations of vastus medialis

Muscles of the hindlimb in the rat have been used to demonstrate the effects of unloading in weightlessness and in animal models used to mimic weightlessness. The vastus medialis (VM) is discussed here. Samples were obtained from rats exposed to weightlessness for 12 days in Cosmos 1887 (Experiment K-6-08, coordinated by Dr. V.S. Oganov). The principal objective of this study was to ascertain if the vastus medialis responded to 12 days of microgravity exposure. The loss in muscle mass is greatest, -43 percent, when comparing F vs B, and least, -13 percent, when comparing F vs. V. Taken at face value these differences may be misleading. Due to the variability of the muscle weight in the basal group, these muscle mass losses may be exaggerated. In terms of percent water, there were no differences between the flight and the control groups. In spite of the limited sample, researchers conclude that muscle mass changes in the VM are not significant. Although some of the morphological parameters suggest a small degree of atrophy in the vastus medialis, the biochemical analyses (protein, RNA and DNA) suggest that these may be minimal and functionally nonsignificant. The relatively similar CS and LDH activities of VM from F and various control groups, as well as the lack of difference in LPL activity between F and S rats, suggests that there is little or no effect on the oxidative or glycolytic function of this muscle. Since the VM is chiefly a mixed fast twitch muscle, these metabolic indices of energy production are relatively unchanged. The results of VM studies are in agreement with previous observations of another type II fast twitch muscle, the EDL, from SL-3 rats which did not respond markedly to weightlessness and whole body suspension

What motivates retrofitting? Results of a nationally representative sample in Great Britain

Energy use in buildings is one of the largest contributors to total energy consumption. The UK Government established the goal of reducing carbon emissions from homes by 29% by 2020, with energy efficiency improvements forming a central part of the plans. However, the recent ‘Green Deal’ policy to promote energy-efficiency measures in homes through financial incentives had very little uptake. In a nationally representative survey, we assessed framing effects on the hypothetical uptake of free home insulation provided by the energy supplier. The frames tested were: (1) monetary savings, (2) a warmer home, (3) carbon savings, (4) health benefits, and (5) social norms. The option emphasizing monetary savings was associated with significantly higher likeliness to take up the offer than any of the other options, which all received similar mean ratings. Higher trust in the energy supplier was associated with higher likeliness to participate in the scheme. Financial benefits seem to be the greatest incentive for retrofit measures, supporting policy based on them. In this context we critically discuss the apparent failure of the Green Deal, and suggest how the importance of trust in the energy supplier could be used in the future

Consumer Demand for Blockchain-Enabled Peer-to-Peer Electricity Trading in the United Kingdom: An online survey experiment

Peer-to-peer (P2P) energy trading could help address grid management challenges in a decentralizing electricity system, as well as provide other social and environmental benefits. Many existing and proposed trading schemes are enabled by blockchain, a distributed ledger technology (DLT) relying on cryptographic proof of ownership rather than human intermediaries to establish energy transactions. This study used an online survey experiment (n = 2064) to investigate how consumer demand for blockchain-enabled peer-to-peer energy trading schemes in the United Kingdom varies depending on how the consumer proposition is designed and communicated. The analysis provides some evidence of a preference for schemes offering to meet a higher proportion of participants’ energy needs and for those operating at the city/region (as compared to national or neighbourhood) level. People were more likely to say they would participate when the scheme was framed as being run by their local council, followed by an energy supplier, community energy organization, and social media company. Anonymity was the most valued DLT characteristic and mentioning blockchain’s association with Bitcoin led to a substantial decrease in intended uptake. We highlight a range of important questions and implications suggested by these findings for the introduction and operation of P2P trading schemes

Knowing me, knowing you: the role of trust, locus of control and privacy concern in acceptance of domestic electricity demand-side response

Choosing to take part in a demand-side response (DSR) programme entails accepting external influence over one’s energy consumption patterns, such as through price or direct load control (DLC) signals. If participation is low, the programme will be ineffective. How might people’s perceptions of their relationship with the influencing entity affect the likelihood of participation? This study used a representative survey of Great Britain (N=2002) to explore the importance of trust, privacy concern and locus of control for acceptance of different approaches to influencing electricity consumption. Survey respondents were randomly shown a description of one of five DSR products (static time of use [TOU] tariff, static TOU with automated response to price changes, dynamic TOU, dynamic TOU with automated response, and DLC), framed as being offered by their electricity supplier. They then responded to a number of scales including those intended to measure trust in their supplier, privacy concern and locus of control. Controlling for demographic variables, trust in electricity supplier was significantly positively associated with acceptance of all tariffs, although the effect size was smaller for the automated TOU tariffs. The specific measure of trust in the supplier to ensure a reliable electricity supply was significantly negatively associated with acceptance of the dynamic TOU tariff. Privacy concern was significantly negatively associated with acceptance of all tariffs, with the strongest effect for the automated dynamic TOU tariff. Locus of control was a significant factor only in the case of DLC, where external locus was related to higher acceptance. These results suggest the existing low levels of trust in energy companies in the UK may present a challenge in securing uptake of DSR, and an opportunity to trusted entrants from other sectors. Automation within the home may mitigate trust concerns, but people must have confidence in the privacy of this arrangement. DLC may be viewed especially positively by people who currently perceive themselves to have little control over their energy use, but protections should be in place to ensure they are not exploited

Two energy suppliers are better than one: survey experiments on consumer engagement with local energy in GB

Usually consumers have a single energy supplier. Permitting consumers to take on additional contracts with local suppliers in a multiple-supplier model could support growth of local renewable energy. The aims of this study were to assess the attractiveness of a multiple-supplier model and to understand whether consumers would be more likely to engage with local energy suppliers in a multiple-supplier model or the current single supplier model. An additional aim was to explore the role of default effects and cognitive biases associated with remaining with incumbent suppliers (loss-aversion, cognitive effort and implied endorsement). Two nationally representative survey experiments were conducted in Great Britain (n = 1042, n = 762). Results showed that participants were significantly more likely to engage with local energy suppliers under a multiple-supplier model than the current single supplier model. In one experiment, consumers’ preference for adding a local supplier under a multiple-supplier model was so strong that it overcame default effects. The perception that the supplier has been recommended (i.e. implied endorsement) was the most robust mechanism associated with remaining with default suppliers, suggesting that explicit endorsement of local energy suppliers may encourage uptake. Results suggest multiple-supplier models are likely to be a promising avenue for increased energy market engagement

Establishing a Systems Biology approach to drug discovery and therapy design: Physiomics Plc

Steered by Professor David Fell of Oxford Brookes University, Physiomics plc, an Oxford-based biotechnology innovation company has, since 2008, firmly established itself as a leading light in systems biology approaches to drug discovery and latterly in therapy design, demonstrable through contracts with three major international pharmaceutical companies. Through its strong advocacy of this approach the sector has invested in and adopted new computational biology processes. As Physiomics has continued to grow, it has expanded its own specialist research team, in many cases recruiting scientists trained within Fell’s Brookes-based research group