Home About us Contact
|
Home About us Contact | ||
|
|
||
Skull Measurements (skull + measurement)
Selected AbstractsThe Craniofacial Reconstruction from the Local Structural Diversity of SkullsCOMPUTER GRAPHICS FORUM, Issue 7 2008Yuru Pei Abstract The craniofacial reconstruction is employed as an initialization of the identification from skulls in forensics. In this paper, we present a two-level craniofacial reconstruction framework based on the local structural diversity of the skulls. On the low level, the holistic reconstruction is formulated as the superimposition of the selected tissue map on the novel skull. The crux is the accurate map registration, which is implemented as a warping guided by the 2D feature curve patterns. The curve pattern extraction under an energy minimization framework is proposed for the automatic feature labeling on the skull depth map. The feature configuration on the warped tissue map is expected to resemble that on the novel skull. In order to make the reconstructed faces personalized, on the high level, the local facial features are estimated from the skull measurements via a RBF model. The RBF model is learnt from a dataset of the skull and the face feature pairs extracted from the head volume data. The experiments demonstrate the facial outlooks can be reconstructed feasibly and efficiently. [source] Taxonomic and biogeographical status of guanaco Lama guanicoe (Artiodactyla, Camelidae)MAMMAL REVIEW, Issue 2 2006BENITO A. GONZÁLEZ ABSTRACT 1We review the status of the four currently recognized guanaco Lama guanicoe subspecies, and provide information about their taxonomy and distribution. The success of guanaco in inhabiting open habitats of South America is based mainly on the flexibility of their social behaviour and ecophysiological adaptations to harsh environments. 2Lönnberg described the first subspecies, L. g. cacsilensis, at the beginning of the 20th century. Forty years later Krumbiegel described L. g. voglii, based on skull measurements and pelage colouration. The other two subspecies, L. g. huanacus and L. g. guanicoe, were classified as subspecies by Krumbiegel based on pelage colouration and body size, while maintaining the original Latin names and descriptors. 3Further guanaco populations have been incorporated into each of these subspecies, based on their proximity to the type locality but without attention to the homogeneity of phenotype or habitat and only limited consideration of Bergmann's rule based on scarce skulls. Two alternative geographical ranges were proposed in the middle and towards the end of the 20th century. Discrepancies occur in the geographical range of each subspecies. 4Molecular studies based on mitochondrial DNA cytochrome b sequences recognized only two subspecies: the Peruvian L. guanicoe cacsilensis and the rest of the populations grouped in the clade recognized as L. g. guanicoe. We conclude that the evolutionary biology of L. guanicoe requires a significant revision with respect to biogeography. Phylogeographical data hold particular value in developing conservation strategies, particularly for some of the reduced and marginal populations and/or subspecies and will support IUCN (The World Conservation Union) Red List classification. [source] Macro-Anatomical and Karyological Features of Two Blind Mole Rat Subspecies (Rodentia: Spalacidae) from TurkeyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2009T. Kankiliç 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] The Distribution of Ganglion Cells in the Equine Retina and its Relationship to Skull MorphologyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2007K. E. Evans Summary It has recently been reported that a strong correlation exists between the distribution of retinal ganglion cells and nose length in the domestic dog. To determine if this phenomenon occurs in another domestic species with diverse skull morphology, the current study examined the distribution of retinal ganglion cells in 30 horses from a variety of breeds. There was a significant variation in the density of ganglion cells found across the retinae. Breed was a significant predictor for ganglion cell density within the visual streak. A strong positive correlation exists between the density of ganglion cells in the visual streak and nasal length. Significant variation was also seen in the area centralis but did not correlate with any of the recorded skull measurements. The findings of this study provide us with further understanding of the equine visual system and the level of variation that exists between individuals of the same species. [source] Are there two cryptic species of the lesser jerboa Jaculus jaculus (Rodentia: Dipodidae) in Tunisia?BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2010Evidence from molecular, cytogenetic data, morphometric Jerboas belonging to the genus Jaculus are widely distributed rodents inhabiting Palearctic desert and semi-desert areas. Previous studies on the lesser Egyptian jerboa Jaculus jaculus showed the existence of various morphological forms of controversial taxonomic status. They were sometimes related to two different species, J. jaculus and Jaculus deserti, although this has not been recognized in recent taxonomic updates. To clarify the systematic status of J. jaculus in Tunisia, we performed molecular (phylogenetic analyses of cytochrome b sequences), morphological (multivariate analyses of 13 skull measurements) and karyotypic (standard preparations from bone marrow cells) analyses on a number of specimens collected from ten localities. Our analyses revealed two monophyletic, well differentiated clades, with a mean genetic divergence value (K2P = 10.9 ± 0.01%), which is within the range of distances generally observed between rodent species. Morphometric analyses clearly separated populations of the two genetic clades from each other. However, karyotypes of individuals from both clades appeared similar. Individuals from both molecular clades/morphometric groups were found in sympatry in most of the localities sampled. These results, as obtained from a restricted area of the total distribution, suggest that there are two separate species within the currently accepted J. jaculus in Tunisia. Alternative hypotheses such as the occurrence of a strong, ancient phylogeographic structure, or the presence of pseudogenes, are also considered to account for the results obtained. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 673,686. [source] | ||||||||||