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Calorie restriction extends life-span in a wide variety of organisms. Although it has been suggested that calorie restriction may work by reducing the levels of reactive oxygen species produced during respiration, the mechanism by which this regimen slows aging is uncertain. Here, we mimicked calorie restriction in yeast by physiological or genetic means(More)
A cause of aging in yeast is the accumulation of circular species of ribosomal DNA (rDNA) arising from the 100-200 tandemly repeated copies in the genome. We show here that mutation of the FOB1 gene slows the generation of these circles and thus extends life span. Fob1p is known to create a unidirectional block to replication forks in the rDNA. We show that(More)
ERM, ER81 and PEA3 are three highly related transcription factors belonging to the ETS family. Together they form the PEA3 group within this family. Little data is yet available regarding the roles of these three genes during embryonic development. A prerequisite to investigations in this field is to obtain an accurate spatio-temporal expression map for the(More)
Identifying the vulnerability of soils to compaction damage becomes an increasingly important issue in the planning and execution of farming operations. Soil compaction models are efficient tools for predicting soil compaction due to agricultural field traffic. Most of these models require the knowledge of the stress/strain relationship, as well as the(More)
The soil compaction by vehicles is a major factor responsible for physical degradation of cultivated soils. Uniaxial confined compression tests are usually performed to characterise the compaction properties of soil. Two main forms of compression curve have been observed: (i) the bi-linear curve having an elastic rebound curve at low stresses and a linear(More)
Soil air permeability is one of the most important parameters which govern the aeration in agricultural soils and thus has a significant effect on the plant growth and crop production. Therefore, it appears important, when analysing the effect of soil compaction due to agricultural machinery, to correlate air permeability with soil capacity parameters such(More)
Soil compaction due to traffic has been increasingly recognized as a considerable problem facing intensive agriculture. Most of the models used to estimate soil deformation during the passage of machines are based on the concept of total stress: then they have neglected an important stress variable for unsaturated soils, i.e. the matrix suction. The aim of(More)
  • Kai CUI, Hubert Boizard, +10 authors Kawtar Saffih
  • 2008
leurs encouragements m'ont permis de surmonter les difficultés pendant ces années de doctorat. La traduction en anglais est donnée lorsque les symboles figurent uniquement dans les articles A aire de contact entre le pneu et le sol, contact area between the tyre and the soil, m 2 A' aire de section de la plaque dans la troisième direction (direction de(More)
Root anchorage function is crucial for tree survival as most trees are exposed to recurrent wind throughout their lifespan. Trees exhibit a large variability of root system architecture (RSA) due genetic and environmental factors. This study aims to understand the links between RSA and tree stability. A 3D biomechanical model was used to simulate tree(More)
Models for predictions of soil compaction following forest traffic represent important decision tools for forest managers in order to choose the best management practices for preserving soil physical quality. In agricultural soil compaction research, analytical models are widely used for this purpose. Our objective was to assess the ability of an analytical(More)
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