Sur la presence d'un riche microplancton siluro-devonien a Acritarches,spores et Chitinozoaires au sommet des schistes et quartzites de Plougastel (Rade de Brest-Finistere); son interet stratigraphique

The upper part of the “Schistes et quartzites de Plougastel” Formation reveals a rich assemblage of microplancton (spores, Acritarchs and Chitinozoans) of lower Lochkovian age. Preliminary studies show that this Formation was beginning within the silurian.     

Binding of Chemically-Modified Oligonucleotides to the Double-Stranded Stem of an RNA Hairpin

Abstract

We monitored the binding of triplex-forming oligopyrimidines to the double-stranded stem of the RNA hairpin responsible for the gag-pol frameshift in HIV-1. Whereas the substitution of 5, propynyl-C for C had a limited effect, the use of a Peptide Nucleic Acid 12mer led to a drastic reduction in the stability of the oligomer/RNA complex.     

A mating method accounting for inbreeding and multi-trait selection in dairy cattle populations

Selection in dairy cattle populations usually takes into account both the breed profiles for many traits and their overall estimated breeding values (EBV). This can result in effective contributions of breeding animals departing substantially from contributions optimised for saving future genetic variability. In this work, we propose a mating method that considers not only inbreeding but also the detailed EBV of progeny or the EBV of sires in reference to acceptance thresholds. Penalties were defined for inbreeding and for inadequate EBV profiles. Relative reductions of penalties yielded by any mating design were expressed on a scale ranging from 0 to 1. A value of 0 represented the average performance of random matings and a value of 1 represented the maximal reduction allowed by a specialized, single-penalty, mating design. The core of the method was an adaptative simulated annealing, where the maximized function was the average of both ratios, under the constraints that both relative penalty reductions should be equal and that the within-herd concentration criterion should be equal to a predefined reasonable value. The method was tested on two French dairy cattle populations originating from the same AI organization. The optimised mating design allowed substantial reductions of penalty: 70% and 64% for the Holstein and the Normandy populations, respectively. Thus, this mating method decreased inbreeding and met various demands from breeders.     

A possible mechanism for the anti-inducing effect of progesterone in rat liver

The mechanism of the anti-inducing effect of progesterone has been explored in the glucocorticoid receptor system from rat liver. Sodium molybdate was used to stop the reaction at the level of the binding step. On the basis of our results we propose that progesterone binds to the receptor on a site (Pro-site) which is different from the one to which binds dexamethasone (Dex-site). Moreover we suggest that progesterone induces the transition to an “incompetent form” which is able to bind dexamethasone.     

Quinyl esters and glucose derivatives of hydroxycinnamic acids during growth and ripening of tomato fruit

Quinyl esters of hydroxycinnamic acids usually occur in greater abundance than their corresponding glucose esters in tomato fruits. During fruit growth and ripening, the predominant derivatives of hydroxycinnamic acids were found to be chlorogenic acid (76%) and the glucosides (84%) respectively. The variations in the ratio of Benedict-reactive (chlorogenic acid) and non-reactive compounds (mainly caffeic acid glucoside) are discussed in relation to their possible role in the regulation of fruit growth and maturation.     

Use of Photolabile Amino-Protecting Groups in the Synthesis of Base-Sensitive DNA SATE-Phosphotriesters

Abstract

The first solid phase syntheses of prooligonucleotide heteropolymers carrying base-sensitive SATE phosphotriester linkages have been performed using the photolabile protecting groups 6-Nitroveratryloxycarbonyl (NVOC) and 2,2′-Di-(2-nitrophenyl)ethyloxycarbonyl) (diNPEOC) and a modified phosphoramidite approach.