Landscape perceptions and social representations of Fallopia spp. in France.

Choices have to be made to manage invasive species because eradication often is not possible. Both ecological and social factors have to be considered to improve the efficiency of management plans. We conducted a social study on Fallopia spp., a major invasive plant taxon in Europe, including (1) a survey on the perception of a landscape containing Fallopia spp. using a photoquestionnaire and (2) an analysis of the social representations of Fallopia spp. of managers and users in one highly invaded area and one less invaded area. The respondents to the photoquestionnaire survey appreciated the esthetics of the landscapes less when tall Fallopia spp. were present. Few people were able to identify and name the plant, and this knowledge negatively affected the appreciation of the photos containing Fallopia spp. The central core of the social representation of Fallopia spp. was composed of the invasive status of the plant, its density, and its ecological impacts. The peripheral elements of the representation depended on the people surveyed. The users highlighted the natural aspect whereas the managers identified the need for control. In the invaded area, the managers qualified the species as "unmanageable," whereas the species was qualified as "foreign" in the less invaded area. Those results provide insights that have to be included when objectives of management plans of these species are selected.

Past, present and future of vasopressin and oxytocin receptor oligomers, prototypical GPCR models to study dimerization processes.

The G protein-coupled receptors (GPCRs) play a major role in the regulation of physiological function. The emergence of the concept of GPCR oligomerization deeply modifies our understanding of their functioning. Much more than a simple association leading to an independent functioning, the GPCR oligomerization affects various steps such as membrane targeting of the receptors, binding of ligands, coupling to the intracellular pathways and internalization. Although significant advances have been performed in proving the existence of GPCR oligomers, its physiological impact remains to be established. Vasopressin and oxytocin receptors have constituted interesting experimental models in oligomer analysis. Because of the pharmacological tools available regarding these receptors and their expression at a high level in various tissues they can constitute very promising models to study the consequences of oligomerization in physiology.

Epitope complementarity and idiotypic interactions: a study of idiotypic-like interactions between anti-cytidine and anti-guanosine A/J mouse monoclonal antibodies--I. Characterization of these interactions.

Idiotypic-like interactions between mAbs directed against cytidine (Cyd) or guanosine (Guo) nucleosides were characterized. These mAbs, Cyd-1 (IgG2b, kappa), Guo-1 (IgG1, kappa) and Guo-2 (IgG1, kappa) were derived from splenocytes of A/J mice immunized with Cyd-KLH or Guo-KLH and recognized the nucleoside base moieties involved in hydrogen bonding. The interactions between Guo-1 or Guo-2 and Cyd-1 involved cross-reactive or distinct-but-neighboring paratope-associated idiotopes. These interactions were characterized by KD values of 4.6 x 10(-6) and 1.8 x 10(-6)M, respectively. The three anti-nucleoside mAbs exhibited Ab2 beta properties and manifested epibody (Ab2 epsilon) activity towards ssDNA. We compared these idiotypic-like reactivities with the anti-idiotypic activity of an intentionally induced IgG1, kappa anti-idiotype mAb prepared with splenocytes from A/J mice immunized with Cyd-1. This Ab2 antibody which bound to Cyd-1 with a KD of 1.1 x 10(-9) M, manifested an Ab2 gamma activity, i.e. it recognized a paratope-associated idiotope on Cyd-1 without exhibiting Ab2 beta properties. In addition, the anti-(Cyd-1) completely inhibited (Cyd-1)-(Guo-1) and (Cyd-1)-(Guo-2) interactions.