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Posts posted by Memammal
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Thanks again Mike. The first page that you published is readable (together with the intro that I found), but the second one not. Don't worry too much as I think I got the gist of it. Also, the New Scientist Facebook page has a very good diagram/image relating to this article (plus the same intro) where they summarised their findings.
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Thanks Mike. I would love to read the rest of this.
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The next bit of news seems to fit nicely with the above:
QuoteScientists find potential 'missing link' in chemistry that led to life on earth
Origins-of-life researchers have hypothesized that a chemical reaction called phosphorylation may have been crucial for the assembly of three key ingredients in early life forms: short strands of nucleotides to store genetic information, short chains of amino acids (peptides) to do the main work of cells, and lipids to form encapsulating structures such as cell walls. Yet, no one has ever found a phosphorylating agent that was plausibly present on early Earth and could have produced these three classes of molecules side-by-side under the same realistic conditions.
TSRI chemists have now identified just such a compound: diamidophosphate (DAP).
"We suggest a phosphorylation chemistry that could have given rise, all in the same place, to oligonucleotides, oligopeptides, and the cell-like structures to enclose them," said study senior author Ramanarayanan Krishnamurthy, associate professor of chemistry at TSRI. "That in turn would have allowed other chemistries that were not possible before, potentially leading to the first simple, cell-based living entities."
The study, reported today in Nature Chemistry, is part of an ongoing effort by scientists around the world to find plausible routes for the epic journey from pre-biological chemistry to cell-based biochemistry.
Other researchers have described chemical reactions that might have enabled the phosphorylation of pre-biological molecules on the early Earth. But these scenarios have involved different phosphorylating agents for different types of molecule, as well as different and often uncommon reaction environments.
...postdoctoral research associates at TSRI, showed first that DAP could phosphorylate each of the four nucleoside building blocks of RNA in water or a paste-like state under a wide range of temperatures and other conditions.
With the addition of the catalyst imidazole, a simple organic compound that was itself plausibly present on the early Earth, DAP's activity also led to the appearance of short, RNA-like chains of these phosphorylated building blocks.
Moreover, DAP with water and imidazole efficiently phosphorylated the lipid building blocks glycerol and fatty acids, leading to the self-assembly of small phospho-lipid capsules called vesicles--primitive versions of cells.
DAP in water at room temperature also phosphorylated the amino acids glycine, aspartic acid and glutamic acid, and then helped link these molecules into short peptide chains (peptides are smaller versions of proteins).
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One of the great mysteries of modern physics is why antimatter did not destroy the universe at the beginning of time.
To explain it, physicists suppose there must be some difference between matter and antimatter – apart from electric charge. Whatever that difference is, it’s not in their magnetism, it seems.
Physicists at CERN in Switzerland have made the most precise measurement ever of the magnetic moment of an anti-proton – a number that measures how a particle reacts to magnetic force – and found it to be exactly the same as that of the proton but with opposite sign. The work is described in Nature.
“All of our observations find a complete symmetry between matter and antimatter, which is why the universe should not actually exist,” says Christian Smorra, a physicist at CERN’s Baryon–Antibaryon Symmetry Experiment (BASE) collaboration. “An asymmetry must exist here somewhere but we simply do not understand where the difference is.”
Source: Cosmos 23 October 2017. It seems like a pretty sensational claim...and title for the article..?
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This is a pretty cool NY Times article and video re this event.
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^ Thank you for such a detailed response!
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Just a quick comment/question. It was initially predicted that Asteroid 2012 TC4, which is estimated to be 30m in size, will pass Earth at a distance of approx. 6,800kms (which is mighty close). They have since, only in July, recalculated and adjusted that estimate (based on more recent observations) to approx. 50,000kms. This asteroid will pass Earth this Thursday, merely 3 months after its orbit has been more accurately assessed. So, in theory, it could have been the other way around, no? If it was miscalculated the first time and we only find out that this asteroid was actually on route to impact Earth, what can be done in 3 months..? Not much, I assume. This is "only" a 30m asteroid, but even so it could have been extremely dangerous and might have caused major damage if it was heading towards a highly populated city.
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I stand corrected, but afaik the RNA world hypothesis has been more theory and less evidential. This study claims to have demonstrated how small non-living molecules may have given rise to larger molecules that were capable of reproducing themselves, which according to them would have been a key event for life to take hold...in short: life from non-life (which probably would have been a more attention-grabbing title). Furthermore, apparently the size matters....the smallest molecule that exhibited self-ligation activity was a 40-nucleotide RNA. This very basic form of RNA also demonstrated the greatest functional flexibility as it was more general in the kinds of substrates it ligated to itself (although its catalytic efficiency was the lowest).
Area54, if you learned anything more about it from studying the published article, please let us know.
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As reported on the Wits University website: Complex life evolved out of the chance coupling of small molecules
“Life was a chance event, there is no doubt about that,” says Dr Pierre Durand from the Evolution of Complexity Laboratory in the Evolutionary Studies Institute at Wits University, who led a project to find out how exactly these molecules linked up with each other. Their results are published today in the journal Royal Society OS, in a paper entitled "Molecular trade-offs in RNA ligases affected the modular emergence of complex ribozymes at the origin of life”.
Very simple ribonucleic acid (RNA) molecules (compounds similar to Deoxyribonucleic acid (DNA)) can join other RNA molecules to themselves though a chemical reaction called ligation. The random joining together of different pieces or RNA could give rise to a group of molecules able to produce copies of themselves and so kick start the process of life.
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Hi studiot,
Thank you for the kind compliment. This article published by nature.com gives a more detailed overview of the findings, how it fits other evidence and the implications thereof: Oldest Homo sapiens fossil claim rewrites our species' history. Note that these were not new findings per se, but rather a more detailed gathering and processing of existing and additional evidence including more accurate dating of some of the remains.
I do agree with you that the claim about a continental wide early dispersion of Homo sapiens based on similar types of stone tools found elsewhere, seems a bit premature. That being said, I know that scientists have struggled to merge findings in South Africa with a later migration pattern. The above article hints at one such piece of evidence.
Unfortunately they were unable to extract DNA, which implies that they cannot for certain ascertain if- and how these remains tie in with modern humans.
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7 June 2017: Homo sapiens may be at least 100,000 years older than thought. A groundbreaking fossil discovery in Morocco obliterates two decades of scientific consensus that our forefathers emerged in East Africa about 200,000 years ago, according to two studies published in the science journal Nature.
"This material represents the very root of our species, the oldest homo sapiens ever found in Africa or elsewhere," said palaeoanthropologist Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Germany.
Previously, the oldest dated Homo sapiens remains, at 195,000 years, were from Ethiopia. This led to the contention that East Africa was the evolutionary "Garden of Eden" where our species arose before spreading through Africa and beyond. The new results suggest the so-called cradle of humankind was continent-wide, the teams said. The same types of "Middle Stone Age" tools found with the Moroccan group, and dated to roughly the same period, have been found in several spots around Africa, but were previously thought to have been made by a different Homo predecessor. Now it seems likely that they were produced by our own species, living in separate groups spread throughout the continent.
"Long before the out-of-Africa dispersal of Homo sapiens, there was dispersal within Africa,"
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7 June 2017
Scientists have confirmed one of Albert Einstein's century-old theories by witnessing with the Hubble Space Telescope a phenomenon he thought would never be possible to see.
Astronomers have now glimpsed for the first time a distant star's light bending and revealing its mass when an object passes in front of it, known as "gravitational microlensing".
It approves century-old Albert Einstein's theory of gravitational waves.
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June 1, 2017: The Laser Interferometer Gravitational-wave Observatory has made a third detection of gravitational waves, ripples in space and time, demonstrating that a new window in astronomy has been firmly opened. As was the case with the first two detections, the waves were generated when two black holes collided to form a larger black hole.
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The research, published today in three papers in the journal eLife, presents the long-awaited age of the naledi fossils from the Dinaledi Chamber and announces the new discovery of a second chamber in the Rising Star cave system, containing additional specimens of Homo naledi. These include a child and a partial skeleton of an adult male with a remarkably well-preserved skull. - See more here2
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@rescue341
The site that I referenced earlier is a very good source of basic information pertaining to evolution, plus it is Christian-friendly. The site is biologos.org. Have a look at their series of articles entitled Evolution Basics. Another excellent (secular) site is TalkOrigins. They deal with all the evidence for evolution, most, if not all the anti-evolution claims as well as the origin of our universe & planet.
Having recently debated with proponents of ID and even geocentrism, I know that it can get pretty tricky. Stick to the facts and admit where there are still gaps in our knowledge. Evolution deniers are quick to jump to the origin of life/abiogenesis in order to discredit evolution. Remember that the origin of life has nothing to do with common descent/evolution. In general (and w.r.t. abiogenesis) it is easier to admit that we still don't know everything, but that there are some pretty promising idea's that are being researched (even BioLogos takes this route). The status of evolution as a well-established scientific theory is an important tool. The scientific method provides for anyone who has sufficient evidence to disprove or to question a scientific theory to do so and to provide a better explanation for the natural phenomena associated with said theory. So far evolution has stood the test of time, in fact it has only gone from strength to strength.
Oh and this is highly recommended: Your Inner Fish, A Chapter-By-Chapter Review (or the book/TV series).
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One should never have to argue about facts.
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Seeing that you are a Christian, why don't you educate yourself by reading the BioLogos website. Re the origins of our species, you can start here:
Evolution Basics: From Primate to Human, Part 1
There is no need to avoid the truth.
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Uhmm Raider5678, you need to learn to differentiate between beliefs and scientific knowledge. Like here:
I honestly don't see why evolution can't be real, but I don't believe we evolved from apes. I believe more that we were created, but things can still evolve.For the record, the origin of our species is established scientific knowledge with loads of evidence to support it.
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Third school of thought reminds strongly of Part 1 of 2001: A Space Odyssey by Arthur C. Clarke with a touch of Chariots of the Gods: Was God An Astronaut? by Erich Von Daniken.
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I watched that press conference last night (local time) and I agree with a headline that I just read: "Trump lets loose at bewildering press conference". Bewildering indeed. I was gobsmacked. I would love to see a proper fact check on all the things he said. This man clearly is a narcist of note, a potential dictator obsessed with self-serving propaganda, a unintelligent loose canon who is disconnected from reality...all in all a very dangerous person indeed. I fear for America, I fear for the world.
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According to AFP, Wikipedia editors have now voted to ban the use of articles from The Daily Mail citing the newspaper's "reputation for poor fact-checking, sensationalism, and flat-out fabrication". Good riddance.
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^ Spot on an dealt with here:
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I have just become aware of this new angle to the story:
- The Mail on Sunday can reveal a landmark paper exaggerated global warming
- It was rushed through and timed to influence the Paris agreement on climate change
- America’s National Oceanic and Atmospheric Administration broke its own rules
- The report claimed the pause in global warming never existed, but it was based on misleading, ‘unverified’ data
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Blu-ray Audio Issues - A three-pipe problem?
in Engineering
Posted
Hi GeeKay, maybe I can help you with this. From what you are describing the movie content is defaulted to a high-res audio codec (with this move it is DTS HD Master Audio), while the other parts are not (they would be in standard PCM or DTS/Dolby). So your player or decoder (the Audio Video Receiver or the TV) cannot decode this codec. There are a couple of things that you can do:
Set your Blu-ray player's audio output to PCM (aka LPCM) not bit stream. This *should* resolve the issue as it then outputs in a digital format that your AVR or TV can decode;
But if your Blu-ray player cannot decode the original codec (which would be strange, as the player should automatically read the disc in a format that is compatible - all players & discs are backwards compatible), you need to change the movie's audio format in the disc set-up to PCM or DTS/Dolby Digital. In order to do so, you could try the movie's own menu (each movie at its start should give you the option to change the audio format according to choice), or by pressing the audio set-up button on your Blu-ray player's remote and then toggle through it until you get the desired codec that works.
I trust that this would resolve the issue. If not, there is likely something wrong with the way that the discs were encoded/written.