WHAT??? Time to update those textbooks.
Stromatolites are round, multilayered mineral structures that range from the size of golf balls to weather balloons and represent the oldest evidence that there were living organisms on Earth 3.5 billion years ago.
Scientists who believed life began in the ocean thought these mineral formations had formed in shallow, salty seawater, just like living stromatolites in the World Heritage-listed area of Shark Bay, which is a two-day drive from the Pilbara.
But what Djokic discovered amid the strangling heat and blood-red rocks of the region was evidence that the stromatolites had not formed in salt water but instead in conditions more like the hot springs of Yellowstone.
The discovery pushed back the time for the emergence of microbial life on land by 580 million years and also bolstered a paradigm-shifting hypothesis laid out by UC Santa Cruz astrobiologists David Deamer and Bruce Damer: that life began, not in the sea, but on land.
Stromatolites.Credit: © Ints / Fotolia
Ever shouted at your partner while you slept, or woken up unable to move? From apnoea to exploding heads, here are some strange things that go bump in the night.
A surprisingly common condition in which you stop breathing for 10 seconds or more as you sleep. The lack of oxygen causes your brain to wake you up, or pull you into much lighter sleep. Either way, it can have a profound effect on the quality of your sleep – and that of any bedfellow, as it’s often accompanied by loud snoring.
A terrifying experience, where the body, which naturally becomes paralysed duringREM sleep, is still paralysed when you wake. You are fully conscious but cannot move or speak, sometimes for several minutes. Some people also feel as if they are choking or their chest is being crushed and they may have visual hallucinations. The condition can be exacerbated by sleep deprivation, some drugs, and disorders such as sleep apnoea.
Those jumps or twitches you experience as you nod off, often accompanied by the sensation of falling. The cause remains a mystery. One idea is that you start dreaming before your body becomes paralysed. Another is that the twitches are a by-product of your nervous system relaxing as you drift off.
If you’ve ever punched or shouted at your partner in the night, only to remember nothing next morning, you may have been in the grip of this condition. Here, the body isn’t fully paralysed during REM sleep, so people act out their dreams. Thistends to happen only with bad dreams.
This entails the sensation of a loud noise, like an exploding bomb or a gunshot, as you drift off or wake up. It affects about 1 in 10 of us and it tends to start around age 50. Nobody knows what causes it– perhaps physical changes in the middle ear, or a minor seizure in the brain’s temporal lobe. Despite its name, the condition is harmless.
Image Credit: Toby Leigh
Source: New Scientist (By Catherine de Lange)
Got a chemistry-themed watch for Christmas - good for checking the time periodically 😃
Researchers funded in part by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) have recently shown that magnetic bacteria are a promising vehicle for more efficiently delivering tumor-fighting drugs. They reported their results in the August 2016 issue of Nature Nanotechnology.
Ouajdi Felfoul, Mahmood Mohammadi, Samira Taherkhani, Dominic de Lanauze, Yong Zhong Xu, Dumitru Loghin, Sherief Essa, Sylwia Jancik, Daniel Houle, Michel Lafleur, Louis Gaboury, Maryam Tabrizian, Neila Kaou, Michael Atkin, Té Vuong, Gerald Batist, Nicole Beauchemin, Danuta Radzioch, Sylvain Martel. Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions. Nature Nanotechnology, 2016; DOI: 10.1038/nnano.2016.137
Illustration showing magnetic bacteria delivering drugs to a tumor. Credit: NanoRobotics Laboratory, Polytechnique Montreal
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
aluminium’s protective oxide layer can make it difficult to see its true reactivity in the context of metals reacting with aqueous solutions. (Do not try to recreate experiment without the presence of a trained professional)
Procedure:
Dissolve copper(II) chloride in the hydrochloric acid and set the solution aside. Take a piece of aluminium foil approximately the width of the base of the conical flask and approximately 20 cm long. Roll it loosely just enough to be able to fit through the neck of the flask – use a splint or spatula to gently push it home so it lies on its side on the base of the flask. Have a source of ignition nearby with some splints. Pour the solution inside the flask and swirl the flask gently to get the reaction going.
After a few seconds, the mixture will begin to react vigorously and produce hydrogen gas. Hold the lit splint by the opening of the flask and the gas will ignite. If you have timed it right, the flame will sink back into the flask and dance inside above the reaction with an eerie green color from the copper.
Reaction:
2Al(s) + 3CuCl2(aq) → 2AlCl3(aq) + 3Cu(s)
2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)
The primary objective here is to show how reactive aluminium is. The aluminium oxide layer protects the metal beneath from further reaction with air, water or acid. But chloride ions can ligate aluminium ions at the metal–oxide interface and break down the protective layer, allowing the reaction to proceed. -rsc
Giffed by: rudescience From: This video
Science Fact Friday: Tetrodotoxin, ft. a small gif because I’m avoiding my real obligations. Why does tetrodotoxin not affect its host? More studies need to be done but at least a few species possess mutated sodium ion channels. The tetrodotoxin can’t interact efficiently with the altered channels.
Another interesting tidbit: Animals with tetrodotoxin can lose their toxicity in captivity. It is suspected that the animals accumulate the toxic bacteria as a side-effect of their diet. After several years of captivity on a tetrodotoxin-bacteria-free diet, the bacterial colonies living in the animals die, residual toxin is cleared from the system, and the animal is safe to handle.
If a person suffers a heart attack and survives, chances are their heart muscle will never be quite the same. Indeed, the associated scarring often results in permanent damage that can lead to heart failure and eventual death. Scientists are therefore searching for possible ways to promote regeneration of damaged hearts, and it’s possible that newborn mice may hold the answer. For a few weeks after birth, these animals can almost entirely regenerate their heart tissue after an injury. And new research suggests a key process that may be critical for this regenerative ability: regrowth of nerves. Blocking nerve growth specifically in experimental animals completely prevented the regrowth of damaged heart tissue. In control animals, the nerves regrew into their normal branching patterns—like those pictured. Thus if researchers are to have any hope of regenerating adult hearts after injury, their best bet might be to boost accompanying nerve growth.
Written by Ruth Williams
Image from work by Ian A. White and colleagues
Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, USA
Image copyright held by the American Heart Association
Published in Circulation Research, December 2015
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Happy Valentine’s Day! Hope everybody gets their share of dopamine and oxytocin today. #lovefeelings #scientificliteracy #braininlove #brainfeels
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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