Synthesis and stereochemical assignments of diastereomeric Ni(II) complexes of glycine Schiff base with (R)-2-(N-{2-[N-alkyl-N-(1-phenylethyl)-amino]acetyl}amino) benzophenone; a case of configurationally stable stereogenic nitrogen

A family of chiral ligands derived from alpha-phenylethylamine and 2-aminobenzophenone were prepared by alkylation of the nitrogen atom. Upon reaction with glycine and a Ni(II) salt, these ligands were transformed into diastereomeric complexes, as a result of the configurational stability of the stereogenic nitrogen atom. Different diastereomeric ratios were observed depending on the substituent R introduced in the starting ligand, and stereochemical assignments were based on X-ray analysis, along with NMR studies and optical rotation measurements.

Inscripciones romanas de Segovia, II: nuevos datos sobre las inscripciones de la muralla junto al Matadero Viejo

[ES] Presentamos nuevos datos sobre inscripciones de la ciudad de Segovja extraídas de la muralla, variaciones en la lectura de seis y una inédita, así como la foto de una que se daba por perdida.

Las unidades organizativas indígenas II: "addenda et corrigenda"

[ES] Se ofrece una puesta al día de la relación de "gentilitates" que completa y, en su caso, corrige la que ofrecimos en nuestro trabajo de 1986. Se añaden los nuevos nombres, repetidos o no, aparecidos desde entonces, se suprimen algunas de las reconstrucciones propuestas y se corrigen otras.

German Eel Model (GEM II) for describing eel, Anguilla anguilla (L.), stock dynamics in the river Elbe system

The eel, Anguilla anguilla (L.), stock of the river Elbe severely decreased during the last decades. Detailed knowledge of the stock dynamics in freshwater and especially of the impact factors is necessary to take effective measures for stock conservation and improvement. The dynamics of the eel stock are modelled based on immigration, stocking, natural mortality and mortalities caused by fishing, angling, cormorants and hydropower plants. The model estimates the number of emigrating eel. Moreover, it enables to study the sensitivity of the estimates related to the uncertainty of the source data of the different influencing factors. The model may be used to develop management strategies and to assess the effi ciency of different management options. Zusammenfassung Der Aalbestand im Elbesystem ist in den letzten Jahrzehnten stark zur