18 research outputs found

    Prevalence of Dental Pathology in a Juvenile Population from the Ancient Maya site of Altun Ha

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    The present research seeks to assesses the presence and prevalence of two distinct dental pathologies: linear enamel hypoplasia and caries in an ancient Maya juvenile subsample from Altun Ha, Belize spanning the Preclassic (ca. 600 B.C.) through the Terminal Classic (ca. 900 A.D.) periods. Teeth offer a remarkable wealth of information about the human experience in the past. Developmental and post-eruption pathology can provide insight into cultural and evolutionary processes by illuminating social and biological factors such as diet, weaning, illness, and overall health that manifest in observable changes to the composition of teeth. In addition, growth and developmental stages of juveniles provide an ideal framework in which to qualify paleopathological research. From a biological standpoint, high ante-mortem resistance to physiological stress and post-mortem preservation make teeth ideal for analyses of pathology in archaeological contexts. For the analysis of the Altun Ha juvenile subsample, a cohort approach is used in the presentation and discussion of results. Discrete pathologies are analyzed based on age cohorts, individual, tooth type, tooth surface location, and archaeological time period. The results indicate an increase in prevalence of pathology concurrent with increasing dental age as well as a predisposition to pathology among specific tooth types and locations on the crown surface and within the dental arcade as well as temporal shifts in pathology prevalence. These analyses demonstrate the importance of assessing juveniles within the archaeological record with emphasis on the transitory developmental stages experienced by children

    A neural signature of the unique hues

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    Since at least the 17th century there has been the idea that there are four simple and perceptually pure “unique” hues: red, yellow, green, and blue, and that all other hues are perceived as mixtures of these four hues. However, sustained scientific investigation has not yet provided solid evidence for a neural representation that separates the unique hues from other colors. We measured event-related potentials elicited from unique hues and the ‘intermediate’ hues in between them. We find a neural signature of the unique hues 230 ms after stimulus onset at a post-perceptual stage of visual processing. Specifically, the posterior P2 component over the parieto-occipital lobe peaked significantly earlier for the unique than for the intermediate hues (Z = -2.9, p = .004). Having identified a neural marker for unique hues, fundamental questions about the contribution of neural hardwiring, language and environment to the unique hues can now be addressed

    Advances in Global and Local Helioseismology: an Introductory Review

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    Helioseismology studies the structure and dynamics of the Sun's interior by observing oscillations on the surface. These studies provide information about the physical processes that control the evolution and magnetic activity of the Sun. In recent years, helioseismology has made substantial progress towards the understanding of the physics of solar oscillations and the physical processes inside the Sun, thanks to observational, theoretical and modeling efforts. In addition to the global seismology of the Sun based on measurements of global oscillation modes, a new field of local helioseismology, which studies oscillation travel times and local frequency shifts, has been developed. It is capable of providing 3D images of the subsurface structures and flows. The basic principles, recent advances and perspectives of global and local helioseismology are reviewed in this article.Comment: 86 pages, 46 figures; "Pulsation of the Sun and Stars", Lecture Notes in Physics, Vol. 832, Rozelot, Jean-Pierre; Neiner, Coralie (Eds.), 201

    Glucagon

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    In vitro chili pepper biotechnology

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