Control of OXPHOS efficiency by complex I in brain mitochondria

In the present work we have analysed the efficiency (P/O ratio) of energy production by oxidative phosphorylation (OXPHOS) in rat brain, liver and heart mitochondria. This study has revealed tissue-specific differences in the mean values of P/O ratios and ATP production rates. A marked dependence of the P/O ratio on the respiration rates has been observed with complex I (NADH:ubiquinone oxidoreductase), but not with complex II (succinate dehydrogenase) respiratory substrates. The physiological impact of the P/O variations with complex I substrates has been further confirmed by extending the analysis to brain mitochondria from three independent groups of animals utilized to study the effects of dietary treatments on the age-related changes of OXPHOS. The general site-specificity of the rate-dependent P/O variability indicates that the decoupling, i.e. decreased coupling between electron transfer and proton pumping, is likely to be mostly due to slip of mitochondrial complex I. These findings suggest an additional mechanism for the pivotal role played by the energy-conserving respiratory complex I in the physiological and adaptive plasticity of mitochondrial OXPHOS

Sustainable planning: The carrying capacity approach

The housing need forecast that has to be adopted in local housing policy and land use zoning is today the subject of significant disputes that intersect urban planning and sociological, demographic and geographical aspects. The main contrast is between those who propose a limiting approach based on the need to guarantee the sustainability of urban settlements and those who, conversely, believe that this policy is the cause of significant gentrification, especially in areas where tourist pressure is added to the housing one. A more coherent approach provides for the definition of the territorial carrying capacity on the basis of an adequate number of convenience indicators whose number and characteristics depend on both objectives set and context in which it operates. The thesis of a Research Project carried out at the Department of Architecture of the Federico II University of Naples is that this approach, applied to degraded Mediterranean metropolitan suburbs, allows substantial improvements in the ecological and social qualities of urban settlements, transforming the anthropic pressure from detractor into driver for increasing urban sustainability. This paper illustrates the results of the Research Project achieved with the application of the carrying capacity approach in the town plan project of a medium-small municipality in the metropolitan suburbs of Naples