![]() In Proceedings of the twenty-eighth annual ACM Symposium on Theory of Computing, pages 212–219. A fast quantum mechanical algorithm for database search. Polynomial-time algorithms for prime factorization and discrete logarithms on a quantum computer. The results show that this approach is effective in evidencing local and general differences between the species-specific heat dissipation patterns, providing a quantitative tool for investigating possible relationships between brain morphology and heat management in paleoneurology.P. Absolute and relative variations are considered in terms of value distribution and residuals from expected models. Numerical modelling and thermic maps are used to describe the values of heat dissipation on the endocranial maps, and methods of comparison of the differences are evaluated accordingly. As case-study, we used samples from humans and chimpanzees, supplying results from intra-specific and inter-specific variation. Here we present a computational approach to describe the patterns of heat dissipation in endocranial casts, providing tools to quantify species-specific differences. Therefore, investigating the relationship between brain shape and heat dissipation patterns can supply indirect information on brain evolution in hominids. Heat dissipation depends upon many factors, including geometry. However, correlations between thermoregulation and brain morphology can provide partial indications on this issue. Paleoneurological evidence based onto fossil record cannot give direct information on metabolism. Despite the high energy loadings associated with brain metabolism in humans, specific thermoregulatory mechanisms are unknown. Extinct humans show a thermic gradient with low temperatures at the temporal lobes and higher values at the fronto-parietal surface related to their wider and flattened brains, while in modern humans this gradient is attenuated by relatively lower thermal loads at the parietal lobes, this being associated with parietal bulging and a more globular brain.īrain thermoregulation is a debated topic in human physiology and evolution. Australopithecines differ from great apes in showing lower loads at the frontal and parietal regions as the result of having taller brains. Great apes display relatively high thermic values along this regions, with gorillas showing larger thermal loads than orangutans or chimpanzees. Our results show that brain size relates to general differences in the heat dissipation patterns among species, while thermic mapping evidence discrete differences localized on the parietal lobes, the temporal lobes and the motor cortex. Searching for morphological correlates of brain metabolism, we performed numerical simulations to describe and to quantify the heat dissipation patterns within the brain volume as a function of the endocranial geometry in a comparative dataset of living and extinct hominoids. Since brain size is constrained by the ability of an organism to efficiently remove the heat produced by neural metabolism, it has been proposed that brain size increase in humans was possible due to the coevolution of a complex vascular system able to efficiently dissipate heat. From an evolutionary perspective, when compared with other primates the human brain is not only bigger but it also consumes a larger amount of energy. Maintaining a constant temperature of the brain is a critical issue as slight variations in cerebral temperature may cause irreversible neural damage or even cause death of the individual.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |