Generation of nonvernal-obligate, faster-cycling Noccaea caerulescens lines through fast neutron mutagenesis

Noccaea caerulescens (formerly Thlaspi caerulescens) is a widely studied metal hyperaccumulator. However, molecular genetic studies are challenging in this species because of its vernal-obligate biennial life cycle of 7-9 months. Here, we describe the development of genetically stable, faster cycling lines of N. caerulescens which are nonvernal-obligate. A total of 5500 M(0) seeds from Saint Laurent Le Minier (France) were subjected to fast neutron mutagenesis. Following vernalization of young plants, 79 of plants survived to maturity. In all, 80 000 M(2) lines were screened for flowering in the absence of vernalization. Floral initials were observed in 35 lines, with nine flowering in < 12 wk. Two lines (A2 and A7) were selfed to the M(4) generation. Floral initials were observed 66 and 87 d after sowing (DAS) in A2 and A7, respectively. Silicle development occurred for all A2 and for most A7 at 92 and 123 DAS, respectively. Floral or silicle development was not observed in wild-type (WT) plants. Leaf zinc (Zn) concentration was similar in WT, A2 and A7 lines. These lines should facilitate future genetic studies of this remarkable species. Seed is publicly available through the European Arabidopsis Stock Centre (NASC).

Searching for the perfect surface area normalizing term - a comparison of BET surface area-, geometric surface area- and mass-normalized dissolution rates of anorthite and biotite

Dissolution rates were calculated for a range of grain sizes of anorthite and biotite dissolved under far from equilibrium conditions at pH 3, T = 20 degrees C. Dissolution rates were normalized to initial and final BET surface area, geometric surface area, mass and (for biotite only) geometric edge surface area. Constant (within error) dissolution rates were only obtained by normalizing to initial BET surface area for biotite. The normalizing term that gave the smallest variation about the mean for anorthite was initial BET surface area. In field studies, only current (final) surface area is measurable. In this study, final geometric surface area gave the smallest variation for anorthite dissolution rates and final geometric edge surface area for biotite dissolution rates. (c) 2005 Published by Elsevier B.V.

La Faune marine dans le voyage de Saint brendan anglo-normand

Le Voyage de Saint Brendan présente un univers hybride, à la fois suffisamment réaliste pour y reconnaître des phénomènes scientifiquement vérifiables et profondément symbolique dans ses connotations. Les animaux marins qui y figurent ne sont en rien anthropomorphes, mais se démarquent aussi nettement de l'image donnée par les bestiaires, dans la mesure où leurs actions et caractéristiques ne sont pas en soi porteuses de sens. La faune aquatique est à la fois une menace et une présence protectrice, la providence divine déterminant de cas en cas la nature des rencontres entre moines et poissons, baleines et monstres marins. Ces bêtes sont en elles-mêmes moralement neutres, guidées par l'instinct; mais Benedeit exploite ce trait pour mettre en exergue la soumission de ces créatures à la volonté du Créateur, et leur importance pour Brendan et ses compagnons.