Experimental techniques in neutron scattering

A brief survey of the main experimental techniques associated with neutron diffraction (nuclear and magnetic) and neutron inelastic scattering is presented

Étude par diffraction de neutrons de la structure nucléaire et magnétique de DyAlO3

DyAlO3 is antiferromagnetic below TN = 3.48 ± 0.03 °K. The magnetic space group is Pb'n'rn', the magnetic structure of GxAy type. The angle of the magnetic moment of Dy ions (8.8 ± 0.3 μB at absolute zero) with the a axis, 57° ± 2°, is independent of temperature. Interactions are, for the most part, dipolar.DyAlO3 devient antiferromagnétique en dessous de TN = 3,48 ± 0,03 °K. Le groupe d'espace magnétique est Pb'n'm' , la structure magnétique de type Gx Ay. Le moment magnétique des ions de Dy (8,8 ± 0,3 μB au zéro absolu) fait avec l'axe a un angle de 57 ± 2° indépendant de la température. Les interactions responsables de l'ordre magnétique sont pour la plus grande part d'origine dipolaire

Experimental values of spin dependent nuclear scattering lengths of slow neutrons

The principle of the method of pseudomagnetism for measuring spin dépendent scattering lengths of slow neutrons on nuclei is recalled. A table is given which reviews the results obtained with this method. It contains previously published values, some of them corrected following careful remeasurement, as well as other hitherto unpublished values.Après avoir rappelé le principe de la mesure par la méthode du pseudomagnétisme, des longueurs de diffusion neutroniques dépendant du spin des noyaux on donne un tableau qui rassemble les résultats obtenus par cette méthode. Il contient des valeurs déjà publiées. Mais certaines ont cependant subi des corrections à la suite de nouvelles mesures plus précises. Le tableau contient en outre des résultats nouveaux

Organisation of the entire rabbit progesterone receptor mRNA and of the promoter and 5' flanking region of the gene.

cDNA clones corresponding to the 3' and 5' non coding regions of the rabbit progesterone receptor (rPR) mRNA and genomic clones corresponding to the promoter and 5' flanking region of this gene were isolated and sequenced up to nucleotide -2761. The 3' non coding region is very long (3058-3553 nucleotides) and contains three different polyadenylation sites. Primer extension experiments and S1 mapping showed the existence of 2 transcription initiation sites 699 and 712 bp upstream from the initiator ATG. The promoter region contains two modified TATA boxes: TAGAAA at -17 and TAGA at -37bp. A CAACT sequence is present at position -100 and one consensus binding site for the transcription factor Sp1 is found at position -51. A 317 bp sequence was observed (positions -2590 to -2273) which belongs to the C family of the short interspersed repeats of the rabbit. Sequences resembling the consensus for estrogen and progesterone responsive elements are observed at several locations in the 5' flanking region. The progesterone receptor is present in tissue extracts mainly as a mixture of two molecular species (110 and 79 kDa) whose origin remains currently debated. By Northern blot analysis we have shown, using rabbit and human mRNAs, that these receptor species are not derived from separate mRNAs. Transcription-translation experiments also showed that, at least in vitro, they are not derived by use of different translation initiation sites on the same messenger RNA