Computer image enhancement and analysis of cementum increments as applied to teeth of Gazella gazella

Digital cementum luminance analysis (DCLA): a tool for the analysis of climatic and seasonal signals in dental cementum

“…Twenty-seven Soay specimens, nine Swiss ibex and 15 Italian ibex of varying age and sex were analysed, and lower M1s were extracted, encapsulated, and made into ground thin-sections using established techniques (Lieberman et al, 1990;Pike-Tay, 1991;O'Brien, 2001;Wall, 2004). Once extracted, each molar was embedded in resin, sliced longitudinally down the centre, and each face was polished.…”

“…Difficulties in counting bands, and identifying the outermost band that relates directly to the season of death, makes robust analysis in cementum studies impossible. Difficulties can arise due to the examination of distorted areas of the root, differences in preparation methods, a lack of knowledge of cementum formation, 'false' or 'split' slow growth lines, and subjectivity owing to poor resolution of increments (Lieberman et al, 1990;Pike-Tay, 1991). A number of methodological issues have consequently arisen for archaeologists and zoologists concerning the replicability and precision of season-of-death estimates, and the ability to measure the optical variation which could be a quantifiable variable of environment, or at the very least, a measure of nutritional intake and food hardness.…”

“…Particularly notable was work accomplished in the early and mid-1990s which utilised graphical representations of cementum bands using NIH Image (Lieberman et al, 1990;Lieberman & Meadow, 1992;Lieberman, 1994;Burke, 1995). However, as noted in Wall & Wall (2006), the 640 Â 480 pixel resolution probably did not allow for numerical analysis of the luminance graphs, but simply graphical representations of 'relative' luminance.Therefore, two problems exist that we seek to resolve.…”

“…Next, the relationship between the environment and cementum growth, as assessed by digital cementum luminance analysis (DCLA), will be studied in two different species. The first study analyses Ovis aries, Soay in order to test whether the optical properties of cementum can be quantified absolutely (rather than relatively -see Lieberman et al, 1990) and correlated with ecological variables. To control for as many factors as possible, half of the population is from a single birth and death cohort and the entire population is from one area.…”

Apuntes sobre estacionalidad y subsistencia de los grupos humanos del Cantábrico occidental en torno al 13000 bp

“…Así, la opacidad y la espesura de la última banda depositada nos confirmará la época de muerte. Han sido muchos los biólogos que han empleado este procedimiento para estudiar las estructuras de edad en poblaciones animales actuales (Aitken 1975;Beasley et al 1992;Debeljak 1996;Gordon 1993;Grue y Jensen 1979;Jones y Boyde 1974;Keiss 1969;Klevezal y Pucek 1987;Liebermann y Meadow 1992;Lieberman et al 1990;Low y Cowan 1963;Lowe 1967;Mitchell 1963;Novakowski 1965;Pailhaugue 1998a;Spinage 1976;Stallibrass 1982).…”