Revision of genus Melamphaes (Melamphaidae). II. Multi-Raker species: M. polylepis, M. falsidicus sp. nova, M. pachystomus sp. nova, M. macrocephalus, M. leprus

The second part of the publication is devoted to the Melamphaes species (family Melamphaidae), which are characterized by 20 and more rakers on the first gill arch, by seven soft rays in the ventral fin, by absence of a temporal spine, by 14–15 rays in the pectoral fin, and by 11 abdominal vertebrae. M. polylepis is characterized by circumtropical range (Atlantic Ocean, Indian Ocean, western and central Pacific Ocean). Newly described species M. falsidicus is described from the northern Atlantic Ocean, where it was sampled between 34°N and 58°N. Before, this species was defined as M. microps. Another newly described species, M. pachystomus, is described along the Peruvian Coast. M. macrocephalus is redescribed. This species inhabits the eastern tropical Pacific Ocean (approximately between 30°N and 23°S). One of the studied specimens of M. macrocephalus was characterized by larger body size (SL = 128 mm) than was described before for this species. M. leprus is known currently by single findings from the eastern tropical Atlantic Ocean (between 11°N and 4°S). This species was also found in the samples obtain in the Gulf of Guinea.     

The transmission/disequilibrium test: history, subdivision, and admixture.

Disease association with a genetic marker is often taken as a preliminary indication of linkage with disease susceptibility. However, population subdivision and admixture may lead to disease association even in the absence of linkage. In a previous paper, we described a test for linkage (and linkage disequilibrium) between a genetic marker and disease susceptibility; linkage is detected by this test only if association is also present. This transmission/disequilibrium test (TDT) is carried out with data on transmission of marker alleles from parents heterozygous for the marker to affected offspring. The TDT is a valid test for linkage and association, even when the association is caused by population subdivision and admixture. In the previous paper, we did not explicitly consider the effect of recent history on population structure. Here we extend the previous results by examining in detail the effects of subdivision and admixture, viewed as processes in population history. We describe two models for these processes. For both models, we analyze the properties of (a) the TDT as a test for linkage (and association) between marker and disease and (b) the conventional contingency statistic used with family data to test for population association. We show that the contingency test statistic does not have a chi 2 distribution if subdivision or admixture is present. In contrast, the TDT remains a valid chi 2 statistic for the linkage hypothesis, regardless of population history.     

Systematics and the properties of the lanthanides. : Edited by S. P. Sinha. D. Reidel,Dordrecht/Boston/Lancaster, 1983, 648 pp, 195 D fl.

The Δ-α-and Λ-β- forms of [Co(edda)CO₃]^? have been isolated as crystalline diastereoisomeric salts of the cation Δ-[Co(en)₂(ox)]⁺. When each salt is dissolved in 1.0 F aqueous Na₂CO₃ at 25°C an isomeric equilibration process occurs between these species in which the Δ-α form predominates before the eventual racemisation of both anionic species. On proceeding to equilibrium the Λ-β-[Co(edda) CO₃]^? isomer is observed to invert its absolute configuration at the central metal ion in converting to the Δ-α stereoisomer. This is the first reported example of inversion-isomerisation involving the β → α transformation in a chiral complex containing a linear tetradentate.