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Ebook Natural Selection and the Evolution of Life Expectancy

Submitted by antoq on Thu, 01/01/2009 - 08:55

This research advances an evolutionary growth theorythat captures the pattern of life expectancy in the process of development, shedding new light on the sources of the remarkable rise in life expectancy since the Agricultural Revolution. The theory suggests that social, economic and environmental changes, that were associated with the transition from hunter-gatherer tribes to sedentary agricultural communities, and ultimately to urban societies, affected the nature of the environmental hazards confronted by the human population, triggering an evolutionary process that had a significant impact on the non-monotonic time path of human longevity.

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Free Ebook Defect chemistry and proton conductivity in Ba-based perovskites

Submitted by antoq on Fri, 11/21/2008 - 02:06

The site incorporation mechanism of M3+ dopants into A2+B4+O3 perovskites controls the overall defect chemistry and thus their transport properties. For charge balance reasons, incorporation onto the A2+ site would require the creation of negatively charged point defects, such as cation vacancies, whereas incorporation onto the B4+ site is accompanied by the generation of positively charged defects, typically oxygen vacancies. Oxygen vacancy content, in turn, is relevant to proton conducting oxides in which protons are introduced via the dissolution of hydroxyl ions at vacant oxygen sites.

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Ebook Menopause and Methodological Doubt

Submitted by antoq on Thu, 02/26/2009 - 07:13

Poor Descartes, imagining that everything on which he had built his life was coming under doubt. Every footing that he had held as solid foundation on which to base thought and decision was disintegrating. It may seem hard to relate to that, but maybe I do have experience that can, in a small way, reflect his. Of course, he had to deal with impending torture of the body and damnation of the soul if his thought did not meet with approval from his audience.

Descartes was attempting to find a solid basis for knowledge by supposing that everything he had learned, or was able to observe through his senses, was doubtful. As he descended further and further into this progressive, methodological doubt he rejected layer after layer that which he had previously held to be true. Eventually, he remained sure of one thing, the famous phrase, cogito ergo sum, I think therefore I am. In his Meditations (Descartes, 1641/1901), he came out of his doubt by ascribing the only possible proof of knowledge to mathematics, and the reduction of any problem to its smallest possible piece. His meditations also sought to prove the existence of God through this process; if he had not, he would have had to face the Inquisition and excommunication that in those times insinuated his eternal damnation.

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