Even after someone is declared dead, life continues in the body, suggests a surprising new study with important implications.
Gene expression — when information stored in DNA is converted into instructions for making proteinsor other molecules — actually increases in some cases after death, according to the new paper, which tracked postmortem activity and is published in the journal Open Biology.
“Not all cells are ‘dead’ when an organism dies,” senior author Peter Noble of the University of Washington and Alabama State University told Seeker. “Different cell types have different life spans, generation times and resilience to extreme stress.”
In fact, some cells seem to fight to live after the organism has died.
“It is likely that some cells remain alive and are attempting to repair themselves, specifically stem cells,” Noble said.
Scientists have uncovered the first evidence that the human ovary may be able to grow new eggs in adulthood.
If confirmed, the discovery would overturn the accepted view that women are born with a fixed number of eggs and that the body has no capacity to increase this supply. Until now this has been the main constraint on the female reproductive lifespan. The findings, if replicated, would raise the prospect of new treatments to allow older women to conceive and for infertility problems in younger women.
The small study, involving cancer patients, showed that ovarian biopsies taken from young women who had been given a chemotherapy drug had a far higher density of eggs than healthy women of the same age.
Prof Evelyn Telfer, who led the work at the University of Edinburgh, said: “This was something remarkable and completely unexpected for us. The tissue appeared to have formed new eggs. The dogma is that the human ovary has a fixed population of eggs and that no new eggs form throughout life.”
Ovarian biopsies taken from young women who had been given a particular chemotherapy drug showed that the tissue appeared to have formed new eggs. Photograph: Science Picture Co/Getty Images/Science Faction
Spherical structures in the nucleus of nerve cells, so-called nuclear spheres, are suspected to trigger Alzheimer’s disease. A team headed by Dr Thorsten Müller from the research group Cell Signaling in Neurodegeneration has for the very first time demonstrated the presence of the presumably toxic protein aggregates in the human brain. The researchers from Ruhr-Universität Bochum have published their article in the journal Neurobiology of Aging.
The team compared brain samples from Alzheimer’s patients with those of the healthy individuals in the same age group. The result: in the samples taken from Alzheimer’s patients, the number of nuclear spheres was much higher than in those taken from healthy study participants.
Moreover, the group from Bochum analysed in what way nuclear spheres are generated. It was demonstrated in experiments with cell cultures that the amyloid precursor protein (APP) plays a crucial role in this process. APP has long been associated with Alzheimer’s disease. The researchers observed that nuclear sphere generation preferably takes place, if the amyloid precursor protein carries no phosphate group in a specific amino acid. An APP cleavage product, moreover, is contained in the nuclear spheres.
“Extensive nuclear sphere generation in the human Alzheimer’s brain” by Katharina Kolbe, Hassan Bukhari, Christina Loosse, Gregor Leonhardt, Annika Glotzbach, Magdalena Pawlas, Katharina Hess, Carsten Theiss, and Thorsten Müller in Neurobiology of Aging. Published online August 18 2016 doi:10.1016/j.neurobiolaging.2016.08.016
A French man who lives a relatively normal, healthy life - despite missing 90 percent of his brain - is causing scientists to rethink what it is from a biological perspective that makes us conscious.
Despite decades of research, our understanding of consciousness - being aware of one’s existence - is still pretty thin. We know that it’s somehow based in the brain, but then how can someone lose the majority of their neurons and still be aware of themselves and their surroundings?
First described in The Lancet in 2007, the case of the man with the missing brain has been puzzling scientists for almost 10 years.
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A new study has found evidence that brain tumours use fat as their preferred source of energy, bringing into question the decades-long assumption that sugar is their main fuel source.
If confirmed, this could fundamentally change the we treat cancer in the future, because until very recently, scientists have been focussing their efforts on ways to starve cancer cells of their sugar supply.
“For 60 years, we have believed all tumours rely on sugars for their energy source, and the brain relies on sugars for its energy source, so you certainly would think brain tumours would,” lead researcher Elizabeth Stoll, a neuroscientist from Newcastle University in the UK, told Ian Johnston at The Independent.
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Antibiotic resistance has been called one of the biggest public health threats of our time. There is a pressing need for new and novel antibiotics to combat the rise in antibiotic-resistant bacteria worldwide.
Researchers from Florida International University’s Herbert Wertheim College of Medicine are part of an international team that has discovered a new broad-spectrum antibiotic that contains arsenic. The study, published in Nature’s Communication Biology, is a collaboration between Barry P. Rosen, Masafumi Yoshinaga, Venkadesh Sarkarai Nadar and others from the Department of Cellular Biology and Pharmacology, and Satoru Ishikawa and Masato Kuramata from the Institute for Agro-Environmental Sciences, NARO in Japan.
“The antibiotic, arsinothricin or AST, is a natural product made by soil bacteria and is effective against many types of bacteria, which is what broad-spectrum means,” said Rosen, co-senior author of the study published in the Nature journal, Communications Biology. “Arsinothricin is the first and only known natural arsenic-containing antibiotic, and we have great hopes for it.”
Although it contains arsenic, researchers say they tested AST toxicity on human blood cells and reported that “it doesn’t kill human cells in tissue culture.”
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Maryam Mirzakhani was an Iranian mathematician and a professor of mathematics at Stanford University. She was the first-ever female winner of the prestigious Fields Medal prize and the first Iranian to be honoured with the award.
Mirzakhani was born in Tehran, Iran. She attended Farzanegan School, which was part of the National Organization for Development of Exceptional Talents. In both 1994 and 1995 she won the International Mathematical Olympiads for high-school students. In the 1995 International Mathematical Olympiad, she became the first Iranian student to achieve a perfect score and to win two gold medals.
Mirzakhani continued her education at Sharif University of Technology in Tehran, where she earned a BSc in Mathematics. After this, she undertook a a Ph.D. from Harvard University. She worked under the supervision of the Fields Medalist Curtis T. McMullen, and her dissertation focused on Simple Geodesics on Hyperbolic Surfaces and Volume of the Moduli Space of Curves. She had a unique way of working, and “would spend hours on the floor with supersized canvases of paper, sketching out ideas, drawing diagrams and formulae, often leading Anahita [her daughter] to say, “Oh, Mommy is painting again!” Mirzankhani said that “I don’t have any particular recipe [for developing new proofs] … It is like being lost in a jungle and trying to use all the knowledge that you can gather to come up with some new tricks, and with some luck you might find a way out.”
From 2004 to 2008 she was a Clay Mathematics Institute Research Fellow and an assistant professor at Princeton University. She then became a professor at Stanford University where she specialized in theoretical mathematics including moduli spaces, Teichmüller theory, hyperbolic geometry, Ergodic theory and symplectic geometry.”
In 2014, Mirzakhani was awarded the Fields Medal prize for her work on complex geometry and dynamic systems, becoming the first-ever female winner and the first Iranian to be honoured with the award. During her lifetime, she won a number of awards including the 2009 Blumenthal Award for the Advancement of Research in Pure Mathematics and the 2013 Satter Prize of the American Mathematical Society. She worked up until her death in 2017, and was still producing amazing mathematics during her battle with cancer over the last few years.
Sources here, here, here, here and here
This year’s Halloween special wraps up the chemistry behind making a mummy: http://wp.me/p4aPLT-26m
history meme (french edition) → 7 inventions/achievements (2/7) the first vaccine for rabies by Louis Pasteur & Émile Roux
“Pasteur had, in the early 1880s, a vaccine for rabies, but he was a chemist and not a licensed physician, and potentially liable if he injured or killed a human being. In early july 1885, Joseph Meister, a nine year-old-boy, had been badly mauled and bitten by a rabid dog (…). Pasteur injected young Meister with his rabies vaccine: the boy did not develop rabies and recovered fully from his injuries. Pasteur became a hero, and the Parisian Institue which came to be named in his honour, and of which he was the first director, became the global prototype bacteriological and immunological research institute. By demonstrating beyond doubt that many diseases were transmitted by bacteria and could be prevented from becoming active by pasteurization techniques, Pasteur indeed changed the course of history.” – G. L. Geison, The Private Science of Louis Pasteur.
Astronauts are allowed to bring special “crew preference” items when they go up in space. NASA astronaut Don Pettit chose candy corn for his five and a half month stint aboard the International Space Station. But these candy corn were more than a snack, Pettit used them for experimentation.
See how he did it:
Watching a snowflake grow seems almost magical–the six-sided shape, the symmetry, the way every arm of it grows simultaneously. But it’s science that guides the snowflake, not magic. Snowflakes are ice crystals; their six-sided shape comes from how water molecules fit together. The elaborate structures and branches in a snowflake are the result of the exact temperature and humidity conditions when that part of the snowflake formed. The crystals look symmetric and seem to grow identical arms simultaneously because the temperature and humidity conditions are the same around the tiny forming crystals. And the old adage that no two snowflakes are alike doesn’t hold either. If you can control the conditions well enough, you can grow identical-twin snowflakes! (Video credit: K. Libbrecht)
A pharmacist and a little science sideblog. "Knowledge belongs to humanity, and is the torch which illuminates the world." - Louis Pasteur
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