Mitochondrial ATP synthase: architecture, function and pathology

Human mitochondrial (mt) ATP synthase, or complex V consists of two functional domains: F1, situated in the mitochondrial matrix, and Fo, located in the inner mitochondrial membrane. Complex V uses the energy created by the proton electrochemical gradient to phosphorylate ADP to ATP. This review covers the architecture, function and assembly of complex V. The role of complex V di-and oligomerization and its relation with mitochondrial morphology is discussed. Finally, pathology related to complex V deficiency and current therapeutic strategies are highlighted. Despite the huge progress in this research field over the past decades, questions remain to be answered regarding the structure of subunits, the function of the rotary nanomotor at a molecular level, and the human complex V assembly process. The elucidation of more nuclear genetic defects will guide physio(patho)logical studies, paving the way for future therapeutic interventions

Strongly qq-additive functions and distributional properties of the largest prime factor

DOI: 10.1017/S000497271500126

A comparative study of natural Tunisian clay types in the formulation of compacted earth blocks

This study investigates the physico-chemical, mineralogical and thermal characteristics of three natural Tunisian clays collected from Gafsa (A1), Zeramdine (A2) and Nabeul (A3). The aim was to promote an appropriate formulation of materials and to obtain optimal compacted earth blocks (CEB). Results of mineralogical analysis of clays revealed the dominance of kaolinite (>13.58%), illite (>25.7%), quartz (>18%) and a minor fraction of smectite phases. Chemical analysis of the clays major elements showed a SiO2 content exceeding 50% and a percentage of Al2O3 higher than 18%. Particle size distribution showed that clay fractions varied from 10 to 20%. Plasticity index defined a plastic character while the values of specific surface area were around 60 m2/g. This discrepancy has an effect on the behavior of these clays in CEB, notably their mechanical properties. From this characterization, it appears that all the sampled clays are suitable as raw material for CEB application. The prepared CEB formulations varied according to compaction energy and binder dosages. In this work, lime served as a binder at different rates (4, 6, 8 and 10%) to ameliorate the quality of CEB. Unconfined Compressive Strength values were determined by Static method test. Then bulk density, shrinkage and porosity values of samples were determined. Compressive strength could reach 7 MPa with lime supplementation in sample A1. The static compaction onto the sand-clay mixture achieved a value of density superior to 2 g cm−3 with lime supplementation in sample A1. Overall, the Gafsa clay was the most suitable for CEB preparation. Also, lime improved the compressive strength of the matrix, in addition to its ecological merits. © 2019 Elsevier Lt