Energy conservation policies in the light of the energetics of evolution

With more energy efficiency it is possible to do the same—or even more —with less energy. This is why energy efficiency is prompted by many as an absolute remedy for the evils of energy use, such as the environmental pressure or the security of supply. Nevertheless, historically energy consumptions at the world level have always been growing in spite of—or perhaps because of—an increasing level of energy efficiency. Some scholars have called this paradox the rebound effect. The rebound effect (REE) is an unintended consequence of the introduction of more energy-efficient technology. It occurs when the reduction in energy consumption is less than that expected from the magnitude of the increase in energy efficiency. REE and backfire are caused by behavioural and/or other systemic responses to efficiency gains in production or consumption (Maxwell et al. in Addressing the rebound effect, a report for the European Commission DG Environment, 2011). However, this paradoxical nexus between energy efficiency and energy consumption is not only confined to human-made systems: nature exhibits a same type of linkage among energy efficiency, energy growth and complexity. To what extent can the energetics of evolution help us in understanding this conundrum and forge a doable energy policy aimed at reducing energy use by fostering energy efficiency? In this chapter we will analyse current areas of improvement in energy policy targeting energy efficiency in the light of the rebound effect and we will try to advance a different policy framework, based on a deeper understanding of this phenomenon

Energy and environmental flows: Do most financialised countries within the Mediterranean area export unsustainability?

The literature dedicated to the problems of transboundary pollution often aims to verify what the environmental and energy interactions between countries are. Little attention is paid to the financial relations of the phenomenon. We analyze how financial, environmental and energy flows have been redistributed within the main Mediterranean countries, with particular reference to pollution. Applying advanced methods of correlation, we verify the dynamics of transfer processes with the aim of assessing whether the link between economic and financial and environmental flows might support the hypothesis that rich countries export environmental emissions to poor ones. Our results show that richer countries have a significant propensity to export energy, financial flows and polluting emissions. The imbalance is even greater for emissions with local impact. This process is accompanied by a substantial increase in the financial activities of the North Mediterranean countries to the detriment of those of the South, which progressively increase their indebtedness. We find out that the economic and financial development of the North Med is accompanied by an increasing environmental impact measured by the various types of emissions covered by our study. The research shows how the most industrialized countries of the Mediterranean area are increasing the economic and financial gap with respect to the Southern Mediterranean countries

BMP6 binding to heparin and heparan sulfate is mediated by N-terminal and C-terminal clustered basic residues

Background: The bone morphogenetic protein 6 (BMP6) is a crucial inducer of hepcidin, the peptide hormone that regulates the iron availability in our body. Hepcidin expression is influenced by hepatic heparan sulfate (HS) and by heparin administration, suggesting BMP6 interaction with heparin/HS. The BMP2/4 subfamily has been deeply characterized to have a N-terminal heparin/HS binding domain (HBD), whose basic residues contact the sulfate groups on heparin and HS. Such detailed characterization is still required for other, structurally different BMPs, including BMP6. Methods: BMP6 peptides encompassing potential HBDs were analysed on heparin-functionalized plates and microcantilevers, and on membrane HS expressing CHO-K1 cells. Monomeric wild-type BMP6 and mutants were produced, substituting the basic residues with non-charged ones, and their affinity to the heparin-column was measured. The BMP6-heparin interaction was also predicted at atomic level by in silico molecular dynamics. Results: N-terminal and C-terminal BMP6 peptides showed high heparin affinity in solid-phase assays. The mutation of the two sites (R5L, R6S, R7L and K126N, K127N, R129S) abolished the heparin-binding activity of the recombinant monomeric BMP6. Monomeric BMP6 and peptides specifically bound to membrane HS of CHO-K1 cells through the same domains. Molecular dynamic studies supported the role of the two HBDs, suggesting a cooperative behaviour. Conclusions: In BMP6, N-terminal (R5, R6, R7) and C-terminal (K126, K127, R129) domains mediate the interaction with heparin and HS. General significance: This study provides the molecular mechanism supporting the use of heparin to sequester BMP6 and inhibit hepcidin expression, a novel clinical approach for high-hepcidin iron disorders

Hepatic heparan sulfate is a master regulator of hepcidin expression and iron homeostasis in human hepatocytes and mice

Hepcidin is a liver-derived peptide hormone that controls systemic iron homeostasis. Its expression is regulated by the bone morphogenetic protein 6 (BMP6)/SMAD1/5/8 pathway and by the proinflammatory cytokine interleukin 6 (IL6). Proteoglycans that function as receptors of these signaling proteins in the liver are commonly decorated by heparan sulfate, but the potential role of hepatic heparan sulfate in hepcidin expression and iron homeostasis is unclear. Here, we show that modulation of hepatic heparan sulfate significantly alters hepcidin expression and iron metabolism both in vitro and in vivo. Specifically, enzymatic removal of heparan sulfate from primary human hepatocytes, CRISPR/Cas9 manipulation of heparan sulfate biosynthesis in human hepatoma cells, or pharmacological manipulation of heparan sulfate–protein interactions using sodium chlorate or surfen dramatically reduced baseline and BMP6/SMAD1/5/ 8-dependent hepcidin expression. Moreover inactivation of the heparan sulfate biosynthetic gene N-deacetylase and N-sulfotransferase 1 (Ndst1) in murine hepatocytes (Ndst1f/fAlbCre+) reduced hepatic hepcidin expression and caused a redistribution of systemic iron, leading to iron accumulation in the liver and serum of mice. Manipulation of heparan sulfate had a similar effect on IL6-dependent hepcidin expression in vitro and suppressed IL6-mediated iron redistribution induced by lipopolysaccharide in vivo. These results provide compelling evidence that hepatocyte heparan sulfate plays a key role in regulating hepcidin expression and iron homeostasis in mice and in human hepatocytes

Interactions between financial and environmental networks in OECD countries

We analysed a multiplex of financial and environmental networks between OECD countries from 2002 to 2010. Foreign direct investments and portfolio investment showing the flows in equity securities, short-Term, long-Term and total debt, these securities represent the financial layers; emissions of NOx, PM10, SO2, CO2 equivalent and the water footprint associated with international trade represent the environmental layers. We present a new measure of cross-layer correlations between flows in different layers based on reciprocity. For the assessment of results, we implement a null model for this measure based on the exponential random graph theory. We find that short-Term financial flows are more correlated with environmental flows than long-Term investments. Moreover, the correlations between reverse financial and environmental flows (i.e.The flows of different layers going in opposite directions) are generally stronger than correlations between synergic flows (flows going in the same direction). This suggests a trade-off between financial and environmental layers, where, more financialised countries display higher correlations between outgoing financial flows and incoming environmental flows than from lower financialised countries. Five countries are identified as hubs in this finance-environment multiplex: The United States, France, Germany, Belgium-Luxembourg and United Kingdom