6/9/19, à la pointe de Grave, la foule à la pose de la 1ère pierre du monument commémoratif de l'aide américaine : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55780

6/9/19, Mr [Hugh C.] Wallace à la pose de la 1ère pierre du monument en commémoration de l'aide américaine [avec le président Poincaré et le député des Landes Maurice Damour, à la Pointe-de-Grave] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55781

6/9/19, M. Poincaré pose la première pierre du monument élevé en commémoration de l'aide américaine [en présence d'Hugh C. Wallace et du député des Landes Maurice Damour, à la Pointe-de-Grave] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55782

6/9/19, pose de la 1ère pierre du monument commémoratif de l'aide américaine [le président Poincaré et Maurice Damour, député des Landes, Pointe-de-Grave] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55800

Spatio-temporal sequence of cross-regulatory events in root meristem growth.

A central question in developmental biology is how multicellular organisms coordinate cell division and differentiation to determine organ size. In Arabidopsis roots, this balance is controlled by cytokinin-induced expression of SHORT HYPOCOTYL 2 (SHY2) in the so-called transition zone of the meristem, where SHY2 negatively regulates auxin response factors (ARFs) by protein-protein interaction. The resulting down-regulation of PIN-FORMED (PIN) auxin efflux carriers is considered the key event in promoting differentiation of meristematic cells. Here we show that this regulation involves additional, intermediary factors and is spatio-temporally constrained. We found that the described cytokinin-auxin crosstalk antagonizes BREVIS RADIX (BRX) activity in the developing protophloem. BRX is an auxin-responsive target of the prototypical ARF MONOPTEROS (MP), a key promoter of vascular development, and transiently enhances PIN3 expression to promote meristem growth in young roots. At later stages, cytokinin induction of SHY2 in the vascular transition zone restricts BRX expression to down-regulate PIN3 and thus limit meristem growth. Interestingly, proper SHY2 expression requires BRX, which could reflect feedback on the auxin responsiveness of SHY2 because BRX protein can directly interact with MP, likely acting as a cofactor. Thus, cross-regulatory antagonism between BRX and SHY2 could determine ARF activity in the protophloem. Our data suggest a model in which the regulatory interactions favor BRX expression in the early proximal meristem and SHY2 prevails because of supplementary cytokinin induction in the later distal meristem. The complex equilibrium of this regulatory module might represent a universal switch in the transition toward differentiation in various developmental contexts.

Long sequence duplications, repeats, and palindromes in HIV-1 gp120: length variation in V4 as the product of misalignment mechanism.

We have shown that indels in gp120 V4 are associated to the presence of duplicated and palindromic sequences, suggesting that they may be produced by strand-slippage misalignment mechanism. Indels in V4 involved region-specific duplications 9 to 15 bp long, and repeats of various lengths, associated to trinucleotides AAT. No duplications were found in V3 and C3. The frequency of palindromic sequences in individual genes was found to be significantly higher in gp120 (p < or = 3.00E-7), and significantly lower in Tat (p < or = 9.00E-7) than the average frequency calculated over the full genome. The finding of elements of misalignment in association with indels in V4 suggests that these mutations may occur in proviral DNA after integration of HIV into the host genome. It also implies that occurrence of large indels in gp120 is not random but is directed by the presence and distribution of elements of misalignment in the HIV genome.

Journal d'un combattant de Février, par Philippe Faure, précédé d'un fragment sur l'auteur par Pierre Leroux, et des discours prononcés sur la tombe de Philippe Faure,... publié... par Auguste Desmoulins

Comprend : Lettre ; Fragment d'un ouvrage inédit intitulé : "le Rocher des proscrits"...

Cooccurrence of predominant Panton-Valentine leukocidin-positive sequence type (ST) 152 and multidrug-resistant ST 241 Staphylococcus aureus clones in Nigerian hospitals.

Ninety-six clinical isolates of Staphylococcus aureus from Nigeria were characterized phenotypically and genetically. Twelve multidrug-resistant methicillin (meticillin)-resistant S. aureus (MRSA) isolates carrying a new staphylococcal cassette chromosome mec element and a high proportion of Panton-Valentine leukocidin (PVL)-positive methicillin-susceptible S. aureus (MSSA) isolates were observed. The cooccurrence of multidrug-resistant MRSA and PVL-positive MSSA isolates entails the risk of emergence of a multidrug-resistant PVL-positive MRSA clone.