Biomedical subjects

Luiz Pinguelli Rosa

Publications and source records attributed to Luiz Pinguelli Rosa.

3 recordsLinked to original sources

PubMed2005

Information processing in brain microtubules.

Models of the mind are based on the idea that neuron microtubules can perform computation. From this point of view, information processing is the fundamental issue for understanding the brain mechanisms that produce consciousness. The cytoskeleton polymers could store and process information through their dynamic coupling mediated by mechanical energy. We analyze the problem of information transfer and storage in brain microtubules, considering them as a communication channel. We discuss the implications of assuming that consciousness is generated by the subneuronal process.

Biophysical Phenomena↗

PubMed2005

Historical CO(2) emission and concentrations due to land use change of croplands and pastures by country.

This work is aimed at estimating the historical land use change emission and concentrations of CO(2) by country. Calculating the area differences of each biome (associated to carbon factors) converted to cropland (including urban areas) and pastures by country we calculated the land use change CO(2) emission over the past 300 years using a new dataset, which is a well known one in the literature: the HYDE land use database. According to IPCC-SR-LULUCF (2000) the net cumulative global CO(2) emission from land use change (1850--1990) is estimated to have been 499+/-205 Tg CO(2), our result is 360 Tg CO(2) for the same period, and Houghton's (Houghton, RA, 2003a. Revised estimates of the annual net flux of carbon to the atmosphere from changes in land use and land management 1850--2000. Tellus 55B, 378--390) result is 492 Tg CO(2). We have also used the Bern model (IPCC-TAR-WG1, 2001) of decay time of CO(2) to estimate the concentrations of CO(2) in the year 1990 due to land use change emission, once the CO(2) emission from the past is still decaying in the atmosphere.

Agriculture↗

PubMed2004

Quantum models of the mind: are they compatible with environment decoherence?

Quantum models of the mind associate consciousness with coherent superposition of states in the brain. Some authors consider consciousness to be the result of a kind of internal quantum measurement process in the brain. In this paper we discuss the ideas of Hameroff-Penrose and Tegmark and their calculation for an estimate of decoherence time. We criticize the Hameroff-Penrose model in the context of a quantum brain model by gravitational collapse orchestrated objective reduction (OOR), assumed by Penrose, and we propose instead that the decoherence process is caused by interaction with the environment. We consider it useful to exploit this possibility because of the growing importance of the decoherence theory in quantum measurement, and also because quantum mechanics can be applied to brain study independently of the Hameroff-Penrose model for mind and consciousness. Our conclusion is that the Hameroff-Penrose model is not compatible with decoherence, but nevertheless the quantum brain can still be considered if we replace gravitational collapse OOR with decoherence. However, our result does not agree with Tegmark's conclusion of refuting not only the Hameroff-Penrose gravitational collapse but also the quantum brain, based on decoherence time calculations in specific cases in the brain. In spite of this fact we also disagree with some points of the response to Tegmark's article given by Hagan, Hameroff, and Tuszynski.

Adaptation, Physiological↗