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F Ramirez Rozzi

Publications and source records attributed to F Ramirez Rozzi.

5 recordsLinked to original sources
PubMed2005

[Correlation between cranial vault size and brain size over time: preliminary MRI evaluation].

OBJECTIVES: To correlate changes of cranial vault measurements of an adult population during the aging process with brain size using the maximum width of the third ventricle in the axial AC-PC plane. MATERIALS AND METHODS: Prospective study of 126 adult subjects (range: 20 to 80 years) with normal brain MRI and without history of neuropsychiatric disorder. MEASUREMENTS INCLUDED: Cranial vault (Maximum length: Glabella-Opisthocranion, Maximum width: euryon-euryon, and maximum height: Basion-Vertex) measurements and maximum width of the third ventricle in the A C-PC plane. RESULTS: Vault measurements (length, width, high) were similar for every age group, irrespective of gender. The variability of cranial vault measurements between individuals was low (<1 cm). Cranial vault measurements were larger for men, but this was not significant when adjusted for body height Comparatively, a gradual widening of the third ventricle, with an exponential behavior, was observed with advancing age. CONCLUSION: Our results indicate that cranial vault measurements are stable over time (between 20-80 years) comparatively to brain atrophy with advancing age. The low variability of cranial vault measurements and their stability over time should be taken into account during segmentation and normalization of brain parenchymal structures.

Adult↗
PubMed2004

Enamel hypoplasias and physiological stress in the Sima de los Huesos Middle Pleistocene hominins.

This study presents an analysis of linear enamel hypoplasias (LEH) and plane-form defects (PFD) in the hominine dental sample from the Sima de los Huesos (SH) Middle Pleistocene site in Atapuerca (Spain). The SH sample comprises 475 teeth, 467 permanent and 8 deciduous, belonging to a minimum of 28 individuals. The method for recording PFD and LEH is discussed, as well as the definition of LEH. The prevalence of LEH and PFD in SH permanent dentition (unilateral total count) is 4.6% (13/280). Only one deciduous tooth (lower dc) showed an enamel disruption. Prevalence by individual ranges from 18.7-30%. The most likely explanation for the relatively low LEH and PFD prevalence in the SH sample suggests that the SH population exhibited a low level of developmental stress. The age at occurrence of LEH and PFD was determined by counting the number of perikymata between each lesion and the cervix of the tooth. Assuming a periodicity of nine days for the incremental lines, the majority of LEH in the SH sample occurred during the third year of life and may be related to the metabolic stress associated with weaning.

Aging↗
PubMedDate not supplied

Can enamel microstructure be used to establish the presence of different species of Plio-Pleistocene hominids from Omo, Ethiopia?

Microstructural characteristics of enamel are minimally influenced by extrinsic / non-genomic factors and are thus potentially important in any attempt to establish the taxonomic attribution of Plio-Pleistocene hominids. The aim of this work is to assess the potential use of enamel microstructural characteristics in attributing teeth from the Omo to different Plio-Pleistocene hominid species. First, the results from this study are compared to data for extant hominoids in order to observe whether Omo teeth show similar or larger variation. This might suggest that more than one species is represented in the Omo sample. Alternatively, a similar or smaller variation would suggest that no more than one species could be reliably recognized in the sample using enamel microstructural characteristics. Secondly, since all previous studies suggest that more than one species is present in the large sample of teeth from the Omo, enamel microstructure characteristics with the largest variability are used to group teeth into morphs. These morphs are compared with previous taxonomic attributions of Omo teeth in order to determine if the morphs grouped teeth in a similar way to previous studies. The results of this study demonstrate that enamel microanatomy characteristics in Plio-Pleistocene hominid teeth from the Omo do not present a larger variation than that observed in extant hominoid species. This suggests that no more than one species can be recognized by using these characteristics. These results also indicate a large overlap in enamel microstructure characteristics between Plio-Pleistocene hominid species from Omo and place serious doubt on the theoretical potential for using enamel microstructural characteristics as a taxonomic tool. The morphs defined in this study do not correspond with any previous taxonomic attributions based on macrostructural analysis of the same teeth and cannot be referred to different species. However, macrostructural characteristics have never been assessed in the same way in extant hominoids and it remains to be seen to what extent these characters reflect interspecific, intraspecific or even intra-individual variation. For now therefore, the taxonomy of Plio-Pleistocene hominids from the Omo still remains unresolved.

Animals↗