Le parti-cartel en Italia. Un tableau contrasté

In che misura il modello del cartel party può essere applicato ai partiti italiani della seconda repubblica ? Attraverso una nalisi degli aspetti organizzativi, e dei programmi dei partiti gli autori mostrano un quadro ambiguo del processo di cartellizzazione in Itali

La fin de la \uab partitocratie \ubb italienne : une ouverture de l\u2019espace de la comp\ue9tition politique?

Notre analyse du cas italien d\ue9voile au final un tableau mitig\ue9 en ce qui concerne les principaux \ue9l\ue9ments du syndrome de la cartellisation d\ue9crit par Katz et Mair. Nous avons explor\ue9 les facteurs qui sont cens\ue9s \ueatre \ue0 l\u2019origine de cette transformation des partis et d\ue9termin\ue9 que si certains \ue9l\ue9ments se retrouvaient plut\uf4t bien dans le cas italien, alors que d\u2019autres n\u2019y correspondaient pas. La distance croissante entre les partis et la soci\ue9t\ue9 civile a sans conteste affect\ue9 la politique italienne et cr\ue9\ue9 les conditions favorables au ph\ue9nom\ue8ne d\ue9crit par les deux auteurs. Cependant, la structure de la comp\ue9tition politique n\u2019a \ue9t\ue9 que partiellement favorable \ue0 une v\ue9ritable cartellisation des partis. Au cours de la Seconde R\ue9publique, l\u2019asym\ue9trie entre les partis s\u2019est estomp\ue9e et la reconnaissance mutuelle est devenue la norme, au moment m\ueame \u2013 cela doit \ueatre soulign\ue9 \u2013 o\uf9 de nouveaux partis ne correspondant pas au mod\ue8le du parti-cartel faisait leur apparition et o\uf9 la vie politique devenait de plus en plus comp\ue9titive. A c\uf4t\ue9 de cet ensemble de causes h\ue9t\ue9rog\ue8nes, on rel\ue8ve \ue9galement des r\ue9sultats mitig\ue9s concernant la variable d\ue9pendante. D\u2019un c\uf4t\ue9, il est manifeste que le financement public est devenu de plus en plus important et que les programmes des partis ont nettement converg\ue9. De l\u2019autre, il para\ueet difficile de tirer des conclusions en ce qui concerne le contr\uf4le de la t\ue9l\ue9vision publique et le d\ue9clin de l\u2019importance de l\u2019origine publique des parlementaires. Notre recherche confirme ainsi le caract\ue8re multiforme du mod\ue8le du parti-cartel, l\u2019importance d\u2019explorer de mani\ue8re plus analytique ses diff\ue9rentes dimensions, mais aussi le besoin de mieux comprendre les liens causaux entre facteurs explicatifs et effets

Nicotinic acetylcholine receptor contains multiple binding sites: evidence from binding of alpha-dendrotoxin.

We have studied the stoichiometry of the binding of the long alpha-neurotoxins from the venom of Dendroaspis viridis (alpha-dendrotoxin) and Naja naja siamensis (alpha-cobratoxin) to the membrane-bound acetylcholine receptor (AcChoR) from Torpedo californica electric organ. The number of toxin molecules bound to one AcChoR molecule was determined by simultaneous-quantitative gas-phase microsequencing of all the amino acid sequences present in AcChoR-alpha-neurotoxin complexes. This method permits the use of homogeneous (nonradiolabeled) preparations of native toxins to obtain molar ratios of neurotoxin-receptor complexes. The stoichiometry obtained for alpha-cobratoxin was 2.1 +/- 0.2 (n = 4), in agreement with the accepted view that alpha-cobratoxin, like alpha-bungarotoxin, binds to the two alpha subunits, which are constituent polypeptides of the AcChoR molecule. alpha-Dendrotoxin gave a stoichiometry of 4.1 +/- 0.5 (n = 12); therefore, the AcChoR molecule contains four binding sites for this alpha-neurotoxin, two of which are recognized by alpha-cobratoxin. In support of this contention we have also found that when the AcChoR is saturated with alpha-bungarotoxin, addition of alpha-dendrotoxin markedly accelerates the dissociation of the bound alpha-bungarotoxin, demonstrating that the occupancy of the additional two sites by the latter toxin influences and decreases the affinity of the former toxin for its two binding sites. The fact that the AcChoR molecule is a pseudosymmetric complex of five highly homologous peptides suggests the possibility that as many as five binding sites for cholinergic ligand could be present, one on each subunit