Programmed cell death (PCD) or apoptosis is a broadly conserved phenomenon in metazoans, whereby activation of canonical signal pathways induces an ordered dismantling and death of a cell. Paradoxically, the constituent proteins and pathways of PCD (most notably the metacaspase/caspase protease mediated signal pathways) have been demonstrated to retain non‐death functions across all phyla including yeast, nematodes, drosophila, and mammals. The ancient conservation of both death and non‐death functions of PCD proteins raises an interesting evolutionary conundrum: was the primordial intent (...) of these factors to induce cell death or to regulate other cellular adaptations? Here, we propose the hypothesis that apoptotic behavior of PCD proteins evolved or were co‐opted from core non‐death functions. (shrink)

This volume is the latest in a series of books and articles stretching back more than three decades on a theme quite startling in its claims and implications: that terrestrial life did not originate on Earth but arrived in the form of cells or bacteria from outer space. The idea of “panspermia,” that the seeds of life are spread from planet to planet, dates to the 19th century with the ideas of Lord Kelvin. It was championed by the Swedish physicist, (...) chemist, and Nobelist Svante Arrhenius at the beginning of the 20th century. Once scientists recognized the difficulties of life surviving in the conditions of interplanetary and interstellar space, by the 1960s a neo-panspermia became popular: not life itself, but prebiotic chemicals were the new seeds of life, made more likely by the discovery of numerous complex organic molecules in meteorites, comets, and interstellar molecular clouds. But the difficulties of synthesizing anything more complicated than amino acids in the wake of the famous Miller-Urey experiment in 1953 kept alive the idea that life itself may be spread throughout the universe. At the center of this work is Chandra Wickramasinghe, a research student of the maverick astronomer Fred Hoyle. In 1962 Hoyle became interested in the origin and nature of interstellar dust, in particular as found in dense molecular clouds, and he and Wickramasinghe set to work on the problem. They became convinced that dust could not form inside molecular clouds, but must have originated in the atmospheres of cool stars, protoplanetary discs, or supernova ejecta, a theory now widely accepted. It was the next steps that became increasingly controversial: that the spectroscopic signature of dust was best explained by complex biomolecules such as cellulose; that biomolecules were assembled into still more complex forms inside comets; and that the living cells and bacteria generated there were responsible for the origin of life on Earth. And not only that: Hoyle and Wickramasinghe argued that the delivery of bacteria from space continues, affecting both the origin and the ongoing evolution of life, and may even be responsible for certain diseases on Earth. These theories were not only reported in reputable scientific journals such as Nature, but also in popular books including Lifecloud (1978), Diseases from Space (1979), and Evolution from Space (1981). Biologists were not impressed; Lynn Margulis, not known for the timidity of her own theories such as endosymbiosis, called the first book “wanton, amusing, promiscuous fiction.”. (shrink)

Observatory sciences and culture in the nineteenth century Content Type Journal Article Pages 1-3 DOI 10.1007/s11016-011-9546-0 Authors Steven Dick, NASA, 21406 Clearfork Ct, Ashburn, VA 20147, USA Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796.

Excerpt from The Principle of Synthetic Unity in Berkeley and Kant This little volume was prepared as a thesis for the degree of Doctor of Philosophy in the University of Michigan. By the advice of Dr. John Dewey I have undertaken to interpret the Metaphysical Notes of Berkeley's Commonplace Book, and as far as possible discover the Principle of Unity which occasionally manifests itself in Berkeley's works and which formed a basis for a Treatise on the Will which Berkeley contemplated (...) but never produced. I wish to express my indebtedness to Dr. Dewey for his assistance in the selection of collateral reading and for his suggestions in the development of the thesis. No literature could be secured bearing upon the interpretation of the Notes, hence the Notes have been classified and such as bear upon the theme under discussion have been used. Often the phraseology has been preserved but where that could not be done the thought has been expressed in phraseology as nearly Berkeleian as the author could select so as to preserve the unity that runs through the Notes. This principle of unity found in Berkely has been compared and contrasted with the Unity of Kant. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works. (shrink)

In the bracket mushroom, Schizophyllum commune, a recessive genetic alteration, mnd, causes abnormally hyperplastic three‐dimensional mounds of hyphae to rise from the surface of both haploid and dikaryotic mycelia. mnd, although not a genetic block in the fruiting body developmental pathway, is at least partially epistatic to fruiting. Within dikaryons containing both mutant and wild‐type nuclei, [mnd + mnd+], a nonreciprocal somatic recombination event can lead to stable conversion of the mnd+ region of the wild‐type nucleus to mnd. This transformation (...) to the homoallelic [mnd + mnd] condition involves no genomic areas other than the mnd region and permanently prevents any further fruiting. Studies relating to the recombination mechanism have ruled out a diploid intermediate state and other concomitants of orthodox somatic recombination, as well as whole chromosome transfer. Instead, a novel form of internuclear genetic transfer is postulated whereby a nearby locus, mob+, controls the mobilization of the mnd chromosomal region alone from one nucleus to the other within the binucleate cells of dikaryotic mycelia. (shrink)