Geologic Time Scale 2004 – why, how, and where next!

A Geologic Time Scale (GTS2004) is presented that integrates currently available stratigraphic and geochronologic information. The construction of Geologic Time Scale 2004 (GTS2004) incorporated different techniques depending on the data available within each interval. Construction involved a large number of specialists, including contributions by past and present subcommissions officers of the International Commission on Stratigraphy (ICS), geochemists working with radiogenic and stable isotopes, stratigraphers using diverse tools from traditional fossils to astronomical cycles to database programming, and geomathematicians. Anticipated advances during the next four years include formalization of all Phanerozoic stage boundaries, orbital tuning extended into the Cretaceous, standardization of radiometric dating methods and resolving poorly dated intervals, detailed integrated stratigraphy for all periods, and on-line stratigraphic databases and tools. The geochronological science community and the International Commission on Stratigraphy are focusing on these issues. The next version of the Geologic Time Scale is planned for 2008, concurrent with the planned completion of boundary-stratotype (GSSP) definitions for all international stages.     

Biogenic Amines Stimulate Regeneration of Cilia in Tetrahymena thermophila1

ABSTRACT Serotonin and catecholamines affect the regeneration of cilia in Tetrahymena thermophila in a dose-dependent manner: micromolar concentrations are stimulatory, whereas millimolar concentrations have little or no effect. This conclusion is based on motility measurements in regenerating cells and on ciliary counts in scanning electron micrographs. In addition, the recognition mechanism for each hormone appears to be specific and independent. Our results suggest an evolutionary link with hormonal mechanisms in multicellular eukaryotes.     

Taxonomy, biogeography and evolution of Euproctus (Amphibia: Salamandridae), with the resurrection of the genus Calotriton and the description of a new endemic species from the Iberian Peninsula

A phylogeny of West Palearctic Salamandridae based on 1208 bp of mtDNA sequences (300 bp of cytb, 346 bp of 12S rRNA and 562 bp of 16S rRNA) indicates the European brook newts (Euproctus) are polyphyletic. To reflect revised relationships, the Tyrrhenian species (E. montanus ( Savi, 1838 ) and E. platycephalus ( Gravenhorst, 1829 )) are retained in Euproctus Genè, 1839 , while the genus Calotriton Gray, 1858 is resurrected to include the Pyrenean brook newt ( Calotriton asper ( Dugès, 1852 ) comb. nov. ) and a new species from the massif of El Montseny, Catalonia, Spain, described herein as Calotriton arnoldi sp. nov. , which is both morphologically and genetically distinct. Although according to the principle of priority Megapterna Savi, 1838 should take precedence over Euproctus Genè, 1839 , for the sake of nomenclatural stability and in line with Art. 23.9.1 of the International Code of Zoological Nomenclature, Megapterna is considered a nomen oblitum and Euproctus a nomen protectum. The polyphyly of Euproctus (s.l.) contradicts previous, well‐accepted, biogeographical hypotheses and represents a clear case of convergence, involving several morphological traits and a unique reproductive behaviour that is advantageous in stream situations. Molecular dating suggests the Western brook newt lineage (C. asper+C. arnoldi) originated towards the end of the Miocene (8.3 ± 0.11 Mya) and is part of a well‐supported monophyletic assemblage, which also includes Neurergus kaiseri ( Schmidt, 1952 ) and a clade formed by Triturus karelinii ( Strauch, 1870 ), T. carnifex ( Laurenti, 1768 ), T. pygmaeus ( Wolterstoff, 1905 ) and T. marmoratus ( Latreille, 1800 ). Speciation separating E. montanus and E. platycephalus might have coincided with the onset of the Messinian salinity crisis. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 145 , 555–582.     

Induction of Unresponsiveness to Canine Renal Allografts by Total Body Irradiation and Bone Marrow Transplantation

RECENT progress in the definition of the DL-A antigens within a closely bred colony of beagles maintained at the Mary Imogene Basset Hospital (Cooperstown colony) has shown that these antigens are components of the principal system of histocompatibility (DL-A) in the dog^1–3. Dausset and associates⁴ have described the segregation of DL-A antigens in 679 offspring of 151 consecutive matings within the Coopers-town colony. Through methods of backcross analysis, 23 DL-A haplotypes (that is, specificities determined by the DL-A region of one single chromosome) have been identified and the DL-A genotypes of 1,302 offspring of 517 matings in this colony have been defined⁴. This combined genetic and serological information has provided an opportunity to reassess the reported survival rates of allogeneic bone marrow transplantation in serologically matched littermate dogs⁵. We describe here the long term survival of bone marrow transplants and renal allografts obtained from the same donors in nine littermate and three non-littermate recipients selected on the basis of genetic and serological criteria of DL-A compatibility in the Cooperstown colony. The results are contrasted with the survival of twenty-two renal allografts performed in untreated recipients selected on the basis of similar criteria.