Numerical Taxonomy (numerical + taxonomy)

Distribution by Scientific Domains

Selected Abstracts

Phenotypic study by numerical taxonomy of strains belonging to the genus Aeromonas

L. Valera
Aims: ,This study was undertaken to cluster and identify a large collection of Aeromonas strains. Methods and Results: ,Numerical taxonomy was used to analyse phenotypic data obtained on 54 new isolates taken from water, fish, snails, sputum and 99 type and reference strains. Each strain was tested for 121 characters but only the data for 71 were analysed using the `SSM' and `SJ' coefficients, and the UPGMA clustering algorithm. At SJ values of , 81∑6% the strains clustered into 22 phenons which were identified as Aer. jandaei, Aer. hydrophila, Aer. encheleia, Aer. veronii biogroup veronii, Aer. trota, Aer. caviae, Aer. eucrenophila, Aer. ichthiosmia, Aer. sobria, Aer. allosaccharophila, Aer. media, Aer. schubertii and Aer. salmonicida. The species Aer. veronii biogroup sobria was represented by several clusters which formed two phenotypic cores, the first related to reference strain CECT 4246 and the second related to CECT 4835. A good correlation was generally observed among this phenotypic clustering and previous genomic and phylogenetic data. In addition, three new phenotypic groups were found, which may represent new Aeromonas species. Conclusions: ,The phenetic approach was found to be a necessary tool to delimitate and identify the Aeromonas species. Significance and Impact of the Study: ,Valuable traits for identifying Aeromonas as well as the possible existence of new Aeromonas species or biotypes are indicated. [source]

Macro-Anatomical and Karyological Features of Two Blind Mole Rat Subspecies (Rodentia: Spalacidae) from Turkey

T. KankiliÁ
Summary The morphometric and karyological analyses of 52 specimens belonging to the two subspecies of Nannospalax leucodon were examined from 14 localities in Turkey. Five karyotypic forms were recorded (2n = 60, the total numbers of chromosomal arms (NF) = 74, the numbers of autosomal arms (NFa) = 70; 2n = 60, NF = 76, NFa = 72; 2n = 60, NF = 82, NFa = 78; 2n = 56, NF = 72, NFa = 68; 2n = 38, NF = 74, NFa = 70). The morphological features of two subspecies were studied using both numerical taxonomy and traditional methods. Thirty skull measurements and four baculum measurements were subjected to discriminant function analysis to find morphometric criteria allowing subspecies identification. Two subspecies were clearly separated from each other by macroanatomical characterictics and numeric characteristics. The first upper molar has four alveoli cubicles in young specimens of Nannospalax leucodon anatolicus, while M1 has 1 cubicle in Nannospalax leucodon cilicicus. In the western subspecies (N. l. anatolicus, 2n = 38), urethra openness is surrounded by three lobes. However, in the eastern subspecies (N. l. cilicicus, 2n = 60), there are two lateral lobes. [source]


ARCHAEOMETRY, Issue 3 2005
At the site of the Greek trading port of Naucratis, located on the Canopic mouth of the Nile inland from Alexandria, Flinders Petrie and later archaeologists encountered sherds of Classical Greek black-figure pottery. We have characterized the pastes of 14 of these specimens, drawn from the collections of the British Museum and the Ashmolean Museum at Oxford, by neutron activation analysis and numerical taxonomy. The ceramics agree in composition with a reference group centred on Athens. We also investigated a small number of additional black-figure sherds from other sites. One specimen, from Ruvo di Puglia (Italy), actually originated in or near Marseilles. There was no evidence for local manufacture of black-figure pottery at Naucratis. [source]