Articles of interest from Nature have been piling up in the CEH queues. Perhaps a brief mention is better than nothing, before they fall into archive oblivion.Carbon 14: In the Sept 14 issue, there was a give & take between critics of a carbon-14-dated study and the author. The critics pointed out, “We appreciate that Mellars’ review was restricted to radiocarbon dating, principally of bone, but it is recommended practice that multiple methods and materials should be investigated to avoid any possible pitfalls that might be associated with a single technique or sample type.” They decried the need for “much-needed rigour to radiocarbon chronologies.”Bossa Supernova: Also in the Sept 14 issue, David Branch reported a “champagne supernova” in a star not known to go boom. “Thermonuclear supernovae were thought to occur only when white-dwarf stars of a certain mass explode,” he said. “The discovery of a supernova that is way over the mass limit might require a reworking of the model.” See also the press release from Berkeley Lab.Twinkle, huge star: Showing that the best proof of a theory in science is existence, an international team said in the Sept 28 issue (pp 427-429), “Theory predicts and observations confirm that low-mass stars (like the Sun) in their early life grow by accreting gas from the surrounding material. But for stars approx ~10 times more massive than the Sun (approx > 10 solar masses), the powerful stellar radiation is expected to inhibit accretion and thus limit the growth of their mass. Clearly, stars with masses >10 solar masses exist, so there must be a way for them to form.” They presented a theory based on non-spherical accretion.Political science: Environmental activists are another thorn in Big Science’s side. In the Oct 5 issue, an Editorial began, “Not everyone’s opinion is equally valuable.” Eco-terrorists who blow up science labs are just the most outspoken of a larger base of support. Nature advocated dialog with these folks: “signs of paternalism or scepticism about emotional arguments will quickly alienate a section of public opinion whose views, although logically fuzzy, are very firmly held.” They didn’t say what to do about critics of Big Science whose views are logically sound and very firmly held.Hanging by a string: The Oct 5 issue had several articles for and against string theory. The Editors were for it, George Ellis was against it, and Geoff Brumfiel reported the war of words in several new books like Not Even Wrong and The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next. Ellis reviewed the latter and began, “String theorists are setting a worrying trend by downplaying the need for experimental evidence.”History of science and art: The Oct 5 issue mentioned an exhibition of the science and art of Leonardo da Vinci touring Europe.Geo-lithium: How sure are we of the science under our feet? The Oct 5 issue had a news item beginning, “Lithium isotopes provide a fingerprint of recycled material in Earth’s upper mantle. But this fingerprint is different from what had been expected. So do we need to reassess our ideas about how the upper mantle evolves?”Kryptonite-proof superbacteria: The Oct 5 issue investigated how the tiny germ Deinococcus radiodurans can withstand radiation hundreds of times greater than that required to kill ‘normal’ bacteria. The secret is in its super-fast and efficient DNA repair mechanisms. See the Scientific American write-up on this germ.Useful junk: Two French scientists in the Oct 5 issue (pp 521-524) think junk DNA is an “evolutionary force.” They said, “Transposable elements were long dismissed as useless, but they are emerging as major players in evolution. Their interactions with the genome and the environment affect how genes are translated into physical traits.” It seems odd that a major player in evolution would elude discovery this late in the game. “But it is an open question whether the variation in genome size is indirectly associated with host population size, or whether it is directly promoted by environmental stress or by the novel environmental conditions that populations encounter when they invade a new habitat,” they said. “The answer will bear on our understanding of, for example, how ancestral humans adapted after they migrated out of Africa.” Seems a tall order for junk DNA to explain.Give and take: Co-evolution was the theme of two articles in the Oct. 5 issue, one by Gavin Sherlock commenting on another paper by Jensen et al. They considered cell division, discussing the odd observation that while the genes are highly conserved (unevolved) throughout the living world, the expression of these genes is not. This adds greatly to the complexity of theorizing how the cell cycle evolved, because now the genes and their regulators had to co-evolve; in fact, Jensen et al say, “Our current results raise the intriguing possibility that all three levels of regulation have co-evolved.” In addition, they discuss the remarkable phenomenon called “just-in-time assembly” in which certain protein complexes only go into action when key proteins are expressed only at the point in the cycle when they are needed. “It is tempting to speculate on the driving force that leads to the co-evolution,” they said in this paper that, while admiring the complexity observable today, was heavy on speculation about how it got that way. “Together, our results provide a first global view of the evolutionary dynamics of the transcriptional and post-translational regulation of a large and complex biological system,” they said in conclusion. But how much can be inferred about evolution? Not much: “They clearly indicate that although the same general underlying principles, namely just-in-time assembly and multi-layer regulation of functional modules, are widely conserved in eukaryotes, the detailed regulation of individual genes and proteins varies greatly and thus generally cannot be inferred from distantly related organisms.”Zygote to adult: A book review of Eric Davidson’s The Regulatory Genome by Michael Karin in the Oct. 5 issue dealt with a related problem: “All living organisms deploy similar evolutionarily conserved mechanisms to generate energy, replicate their genomes, use genetic information and synthesize basic building-blocks for their cells,” he began. “Yet the myriad shapes and forms of both plants and animals are overwhelming in their variety and extremes. What is even more amazing is that most plants and animals start their life as a single diploid cell (a zygote) created by the union of a sperm and an egg. How these simple cells give rise to such complex creatures with diverse body shapes is a major preoccupation of developmental biologists.”TRON revisited: Can life live in a computer? A German team in the Oct 5 issue investigated biological models in silico. They recognized that this is not a field for initiatives, and that some traditional biologists are skeptical, they said, “Suspicion towards simulations should dissipate as the limitations and advantages of their application are better appreciated, opening the door to their permanent adoption in everyday research.” Surprisingly, at the end, “By discovering design principles, identifying biological modules, and quantitatively understanding how they operate through experiments and simulations, we hope to elucidate biological function,” they said.Readers interested in these subjects may wish to pursue the original sources.This illustrates how the reporting here has to be selective just due to constraints of time and space. Every week, scores of sources and articles from the scientific journals and science news outlets are perused for consideration. For every article that gets mentioned, dozens more have to be passed over. We hope you appreciate getting at least a daily digest of interesting and important happenings in a wide variety of subjects related to origins.(Visited 6 times, 1 visits today)FacebookTwitterPinterestSave分享0
Nelson Mandela by Himself: The Authorised Book of Quotations is a comprehensive resource on the sayings of South Africa’s former president.(Image: Janine Erasmus) The book contains over 2 000 quotations,gathered over six decades, and is expected to lower the many incidenceswhen Mandela is misquoted..(Image: Nelson Mandela Foundation) MEDIA CONTACTS • Sello Hatang NMF communications manager +27 11 547 5600 RELATED ARTICLES • Mvezo school a legacy of Mandela • Mandela a free man 21 years ago • New Mandela book released • SA families give back on Mandela Day • Mandela’s old offices restoresJanine ErasmusThe Nelson Mandela Centre of Memory has published a new, authorised book of quotations from the respected former president – one they hope will help his many admirers to quote him accurately from now on.Nelson Mandela by Himself: The Authorised Book of Quotations was released at the Nelson Mandela Foundation on 27 June 2011, and sales were brisk at the launch function.“We wanted this to be a book of substance,” said the centre’s memory programme head Verne Harris, “and one that wasn’t necessarily based on the well-established narrative of Mandela’s life.”Under the editorship of Mandela Foundation communications manager Sello Hatang and senior researcher Sahm Venter, the new book also aims to make the task of the foundation easier as it receives hundreds of phone calls every month from people wanting to confirm Mandela’s words of wisdom.Although small in size, the book contains over 2 000 sayings by the elder statesman, gathered over six decades. They’re categorised under keywords such as responsibility, humanity, reconciliation, prison, integrity and South Africa – 317 sections in all.The prison category is divided into 26 sub-sections, including comrades, loneliness, and reflections. The South Africa section has 13 sub-categories.The book also includes a timeline of important Mandela events, and a selection of books and documentaries that were used as references.Unpublished materialThe editors, who claim that Mandela is one of the most frequently quoted people in the world, guarantee that each saying is 100% accurate. Hatang and Venter delved into Mandela’s notebooks, letters, speeches and audio material in order to put the collection together. Many quotations are previously unpublished.“We pass through this world but once,” says the quotation inside the covers, “and opportunities you miss will never be available to you again.”“Granddad doesn’t often talk openly about his feelings,” said Ndileka Mandela, daughter of Mandela’s older son Thembekile, at the event, “so this book is a priceless resource and an insight into his thoughts”.“This book is long overdue,” said politician and businesswoman Cheryl Carolus. “For years we’ve looked up to Madiba and his generation as the leaders, but today we are the frontline generation and the future is in our hands. As such, we can all benefit from his wisdom.”Ahead of his timeMandela’s sayings are presented in chronological order within each section, so the reader can track the progression of his thoughts and opinions on any matter. Many subjects are even more important today as they were a decade or two ago.In 1992 Mandela said: “Many of us find it difficult to talk about sex to our children, but nature’s truth is that unless we guide the youth towards safer sex, the alternative is playing into the hands of a killer disease.”HIV/Aids has swept through South Africa’s population in recent years, killing millions. According to the national Department of Health, until 1998 the South African Aids epidemic was the fastest expanding on earth, but it has since slowed. Incidences of mother-to-child transmission, in particular, have dropped from 8% in 2008 to 2% in 2011.“In this regard Granddad was far ahead of his time,” said Ndileka Mandela. “During a Robben Island visit, I was shocked when he asked me very personal questions about my relationships, and warned me about safe sex. You didn’t talk about those things back then.”A poignant entry from 2005 reads simply, “My son has died of Aids.”“Yes, Aids has touched our family,” Ndileka Mandela said, referring to the death of her uncle Makgatho, who passed away at the age of 54.Mandela was adamant that the cause of his son’s death should not be hidden, because treating Aids as something mysterious only adds to the stigma and misinformation that helps the disease to proliferate.
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