Notes: A detailed comparative study of the optical properties of two rare-earth (RE) sesquisulfide compounds γ−Ce2S3 and γ−Gd2S3, shows that if the two compounds have about the same main absorption edge corresponding to band-to-band S 3p-RE 5d transitions, Ce2S3 exhibits an additional absorption band at lower energies. This band, which is ascribed to the presence of Ce 4f states at the top of the valence band, explains the difference in color between the two compounds. © 1996 American Institute of Physics.

Notes: Proton, deuteron, and carbon NMR methods were applied to study various isotopic species of supercooled and glassy propylene carbonate. The molecular diffusion was investigated via static field gradient diffusometry and yielded evidence for a particularly pronounced enhancement of the translational over the reorientational dynamics. The latter was monitored using measurements of spin-lattice relaxation times and of two-time stimulated echoes. The sin–sin correlation functions exhibited a pronounced dependence on the evolution times. From these results it is concluded that the geometry of molecular reorientation can be described as a superposition of moderately small jump angles (about 30°) and a quasi-diffusive component which is responsible for about one-third of the total angular displacement. Finally, four-time stimulated echoes confirmed that the nonexponential relaxation in propylene carbonate is dynamically heterogeneous in nature. © 2000 American Institute of Physics.

Notes: We present the first observation by transmission electron microscopy of glass densification induced by Bragg grating inscription in two germanosilicate single-mode optical fibers. © 1997 American Institute of Physics.

Notes: The nature and distribution of 14C atrazine (2- chloro- 4 -ethylamino- 6 -isopropylamino-s-tria- zine) residues in resistant and susceptible canola (Brassica napus L.) varieties were studied. Radiolabelled atrazine was applied to the plants just before the flowering stage and continued for 10 days. The plants were harvested 3, 10 and 25 days after the end of the treatment. The roots, shoots and pods of each plant were exhaustively extracted with methanol. The 14C distribution between the methanol extracts and the plant matrix fractions (bound residues) was similar for the two varieties. High-pressure liquid Chromatographie analysis of the methanol extracts showed that they contained two unknown metabolites (possibly conjugates) in addition to atrazine. The bound 14C residues were released by supercritical methanol extraction and analysed by thin-layer chromato- graphy, gas chromatography and high-pressure liquid chromatography. Several 14C components in the released material were detected. Bound atrazine and its two dealkylated metabolites represented only a very small portion (10–18%) of the total bound 14C residues in the plants. Résidus 14C extractibles et liés chez des plantes de canola (Brassica napus) traitées avec de l'atrazine radioactivement marquéeLa nature et la distribution de résidus d'atrazine 14C (2-chloro 4-ethylamino-6-isopropylamino-s-triazine) chez des variétés de canola résistantes et sensibles ont étéétudiés. De l'atrazine radiomarquée a été appliquée aux plantes juste avant la floraison et poursuivie pendant 10 jours. Les plantes ont été récoltées 3, 10 et 25 jours après la fin du traitement. Les racines, tiges et gousses de chaque plante ont été complètement extractées avec du methanol. La distribution du 14C entre les extraits méthanol et les fractions de plantes matricielles (liées) a été similaire pour les 2 variétés. Des analyses HPLC des extraits méthanol ont montré qu'ils contenaient deux metabolites inconnus (probablement combinés) en plus de l'atrazine. Les résidus 14C liés étaient libérés par une extraction au méthanol supercritique et analysé par Chromatographie en couche mince, Chromatographie gazeuze et HPLC. Plusieurs composés dans le matériel libéré ont été détectés. L'atrazine liée et ses deux metabolites dealklyés représentaient seulement une très petite part (10–18%) de la totalité des résidus 14C liés dans les plantes. Gebundene und extrahierbare 14C-Rückstände in mit radioaktiv markiertem Atrazin behandeltem Raps (Brassica napus)Die Art und die Verteilung von Rückständen von 14C-Atrazin (2-Chlor-4-ethylamin-6-iso- propylamin-s-triazin) wurden in resistenten und empfindlichen Varietäten von Raps (Brassica napus) untersucht. Das radioaktiv markierte Herbizid wurde kurz vor der Blüte und 10 Tage weiter auf die Pflanzen ausgebracht. Die Pflanzenproben wurden 3, 10 und 25 Tage nach dem Ende der Behandlung gezogen. Wurzeln, Sprosse und Schoten wurden erschöpfend mit Methanol extrahiert. Die 14C-Verteilung in den Methanolextrakten und im Pflanzenmaterial (gebundene Rückstände) war bei beiden Sorten ähnlich. Bei der HPLC-Analyse wurden in den Methanolextrakten neben Atrazin 2 unbekannte Metaboliten (vermutlich Konjugate) gefunden. Die gebundenen 14C-Rückstände wurden im Überkritischen Verfahren mit Methanol extrahiert und dünnschicht-, gas-und HPL-chromatographisch analysiert. Verschiedene 14C-Verbindungen wurden gefunden. Gebundenes Atrazin und seine beiden de-alkylierten Metaboliten machten nur eine kleinen Anteil (10 bis 18%) der gesamten gebundenen 14C-Rückstände aus.

Notes: Abstract Aims/hypothesis. The identification of mutations in hepatocyte nuclear factors-1α, –4α, –1β and insulin promoter factor-1 in maturity onset diabetes of the young (MODY) has highlighted the role that transcription factors may have in the development of diabetes. This result has focused molecular genetic studies of diabetes on other transcription factors expressed in the pancreatic beta cell. The basic helix-loop-helix transcription factor BETA2/NEUROD1 (gene symbol, NEUROD1) and the paired box homeodomain transcription factor PAX4 (PAX4) have an important role in islet and beta-cell development. We have examined the contribution of these transcription factors to the development of MODY and late-onset Type II (non-insulin-dependent) diabetes mellitus. Methods. Linkage studies have been done in MODY families reported to have no mutations in the five known MODY genes and in affected sibling pairs from families with late-onset Type II diabetes. Mutation screening of the coding regions of both genes was also realised by SSCP followed by sequencing in MODY patients and in probands with late-onset Type II diabetes. Results. There was no evidence of linkage with the markers for NEUROD1 and PAX4 either with MODY or late-onset Type II diabetes. Mutation screening showed single nucleotide polymorphisms, several of which resulted in amino acid substitutions : NEUROD1, Ala45Thr; PAX4, Pro321His and Pro334Ala. These amino acid sequence variants were not associated with Type II diabetes. Conclusion/interpretation. Our results indicate that NEUROD1 and PAX4 are not a common cause of either MODY or late-onset Type II diabetes in the French Caucasian population. [Diabetologia (1999) 42: 480–484]

Notes: Abstract Amphipholis squamata is a small ophiuroid with a worldwide distribution except for Polar regions. Global populations of A. squamata are morphologically uniform but inter- and intrapopulational variability occurs at levels from the population to the genotype. The species is polychromatic and two colour varieties (dark-brown and spotted) from two adjacent populations (separated from each other for only 20 years) in a lagoonal system (Sicily) were compared using bioluminescence and life-history traits as indicators of variability. The dark-brown variety was dominant in Lago Nuovo and the spotted one was dominant in Porto Vecchio. Important variations were observed within populations, however, there were significant differences in life-history traits and luminous capabilities between the dark-brown and spotted varieties. The dark-brown variety invested more energy in somatic growth than reproduction (1 cohort each year and growth rate of 0.279 mm each month), whereas energy was devoted mainly to reproduction in the spotted variety (4 cohorts each year and growth rate of 0.171 mm each month). The chronology of the life cycles was completely different between the two varieties. Fertilization occurred mainly in spring for the spotted but only in autumn for the dark-brown. Recruitment occurred mainly in autumn for spotted and in spring for dark-brown individuals. Finally, significant differences were observed for maximal intensity of emitted light and kinetic parameters between the two varieties.