Fragments of Science
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Fragments of Science
The history, present and future and nature of science and their relationship
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Traces of sun storms locked in tree rings could confirm ancient historical dates

Traces of sun storms locked in tree rings could confirm ancient historical dates | Fragments of Science | Scoop.it
Archaeologists believe they have identified a new way of putting accurate dates to great events of prehistory. Rare and spectacular storms on the sun appear to have left their mark in forests and fields around the planet over the past 5,000 years.

Michael Dee, of Oxford University’s research laboratory for archaeology and the history of art, thinks evidence of such solar storms could help put precise years to some of the great uncertainties of history: the construction of Egypt’s Great Pyramid of Giza, the collapse of the ancient Mayan civilisation in Central America, and perhaps even the arrival of the Vikings in the Americas.
Lost cities #7: how Nasa technology uncovered the 'megacity' of Angkor
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Every tree maintains its own almanac in the form of annual growth rings. For decades dendrochronologists have been using tree-ring evidence and radiocarbon dating to build a timetable of events that confirm historical accounts, even those predating the first written chronicles.
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Pre-Hispanic Mexican civilization may have bred and managed rabbits and hares

Pre-Hispanic Mexican civilization may have bred and managed rabbits and hares | Fragments of Science | Scoop.it
Humans living in the pre-Hispanic Mexican city of Teotihuacan may have bred rabbits and hares for food, fur and bone tools, according to a study published Aug. 17, 2016, in the open-access journal PLOS ONE by Andrew Somerville from the University of California San Diego, US, and colleagues.
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This ghostly particle could explain why you exist

This ghostly particle could explain why you exist | Fragments of Science | Scoop.it
Physicists are hunting for a particle that they hope could clue us in on some of the biggest mysteries in the universe. Questions like: Why the heck do we exist?

But after scouring an entire year’s worth of data from the largest particle detector on the planet, scientists at IceCube Neutrino Observatory have some bleak news. They're 99% sure the particle doesn’t exist.
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Mystery of déjà vu explained – it’s how we check our memories

Mystery of déjà vu explained – it’s how we check our memories | Fragments of Science | Scoop.it
The phenomenon seems to be a sign of a healthy memory that forms accurate memories, déjà vu brain scans have revealed for the first time
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Painted 37,000-year-old shell is East Asia’s oldest jewellery

Painted 37,000-year-old shell is East Asia’s oldest jewellery | Fragments of Science | Scoop.it
Ancient artefacts in an East Timor cave reveal that early human settlers here were more advanced than thought, fishing the deep sea and making ornaments
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Researchers develop new strategy to limit side effects of stem cell transplants

Researchers develop new strategy to limit side effects of stem cell transplants | Fragments of Science | Scoop.it
Scientists in Germany have developed a new approach that may prevent leukemia and lymphoma patients from developing graft-versus-host disease (GvHD) after therapeutic bone marrow transplants. The researchers describe the successful application of their strategy in mice in 'Exogenous TNFR2 activation protects from acute GvHD via host T reg cell expansion,' which will be published online Aug. 15 ahead of issue in the Journal of Experimental Medicine.
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Brown dwarfs reveal exoplanets' secrets

Brown dwarfs reveal exoplanets' secrets | Fragments of Science | Scoop.it
Brown dwarfs are smaller than stars, but more massive than giant planets. As such, they provide a natural link between astronomy and planetary science. However, they also show incredible variation when it comes to size, temperature, chemistry, and more, which makes them difficult to understand, too.

New work led by Carnegie's Jacqueline Faherty surveyed various properties of 152 suspected young brown dwarfs in order to categorize their diversity and found that atmospheric properties may be behind much of their differences, a discovery that may apply to planets outside the solar system as well. The work is published by The Astrophysical Journal Supplement Series.

Scientists are very interested in brown dwarfs, which hold promise for explaining not just planetary evolution, but also stellar formation. These objects are tougher to spot than more-massive and brighter stars, but they vastly outnumber stars like our Sun. They represent the smallest and lightest objects that can form like stars do in the Galaxy so they are an important "book end" in Astronomy.

For the moment, data on brown dwarfs can be used as a stand-in for contemplating extrasolar worlds we hope to study with future instruments like the James Webb Space Telescope.

"Brown dwarfs are far easier to study than planets, because they aren't overwhelmed by the brightness of a host star," Faherty explained.
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Researchers discover that DNA naturally fluoresces

Researchers discover that DNA naturally fluoresces | Fragments of Science | Scoop.it
A Northwestern University team recently caught DNA doing something that has never been seen before: it blinked.

For decades, textbooks have stated that macromolecules within living cells, such as DNA, RNA, and proteins, do not fluoresce on their own. Technology instead relies on special fluorescence dyes to enhance contrast when macromolecules are imaged.

But now Professors Vadim Backman, Hao Zhang, and Cheng Sun have discovered that macromolecule structures in living cells do, in fact, naturally fluoresce. This finding could open the next frontier of biological discovery by paving a new way for label-free, super-resolution nanoscopic imaging and expanding the understanding of biological processes.

"Everybody has overlooked this effect because nobody asked the right question," said Backman, Walter Dill Scott Professor of Biomedical Engineering in Northwestern's McCormick School of Engineering. "It sounds cliché, but you get the answer to the question you ask. When we actually asked the right question, we got a very different answer than expected."
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Discovery of a unique subcellular structure determining the orientation of cell division

Discovery of a unique subcellular structure determining the orientation of cell division | Fragments of Science | Scoop.it
The work by Negishi et al., published recently in the electronic journal eLife, has revealed that in the sea squirt embryo, the orientation of the cell division machinery in epithelial cells is controlled by a unique cell membrane structure, which we call an 'invagination.'
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Shelved fossil was a Svalbard jewel

Shelved fossil was a Svalbard jewel | Fragments of Science | Scoop.it
Palaeontologist Jørn Hurum came across the dusty fossil in 2011 down in the storage shelves of the Natural History Museum in Oslo. It had originally been found on Spitzbergen by the geologist Jenö Nagy in 1962.

Now, five years on, Hurum and a group of scientists have published a study showing this to be a remnant of a small bird or bird-like dinosaur that lived about 113 to 100 million years ago.
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Photonic hypercrystals drastically enhance light emission in 2D materials

Photonic hypercrystals drastically enhance light emission in 2D materials | Fragments of Science | Scoop.it
Researchers have developed a method for achieving an order-of-magnitude enhancement of the light emission from a class of two-dimensional (2D) materials called transition metal dichalcogenides (TMDs). The large light enhancement arises when the 2D material is placed on a photonic hypercrystal, which is an artificial optical material first proposed in 2014 by Evgenii E. Narimanov at Purdue University, who is one of the authors of the new study.

The research team is led by Vinod M. Menon, a physics professor at the City College of the City University of New York (CUNY), and Yi-Hsien Lee, a professor of materials science and engineering at National Tsing-Hua University in Hsinchu, Taiwan. Their work is published in a recent issue of Nano Letters.

In recent years, 2D materials such as 2D TMDs have attracted a great deal of attention because their atomic-scale thickness leads to exceptional electronic and optical properties, making them potential candidates for future optoelectronic devices.

2D TMDs are particularly appealing because they spontaneously emit light due to their direct band gaps, which enables electrons to directly emit photons. Currently, however, 2D TMDs don't produce enough light to make them useful as practical light-emitting devices.

In the new study, the researchers have shown that photonic hypercrystal substrates can transform low-light-emitting TMDs into much brighter sources of light.
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Ocean sediment sample holds iron believed to be from a supernova

Ocean sediment sample holds iron believed to be from a supernova | Fragments of Science | Scoop.it
A team of researchers from several institutions in Germany and Austria has found possible evidence of iron from a supernova in sediment cores taken from the floor of the Pacific Ocean. In their paper published in Proceedings of the National Academy of Sciences, the team describes how they analyzed the core samples and why they believe they hold evidence of an ancient supernova.

The study began, the researchers report, when team members came across information regarding magnetotactic bacteria during internet searches. It is a type of bacteria that lives in ocean sediments and absorbs tiny amounts of iron. As sediment builds, the bacteria die leaving behind bits of iron in the layers of sediment. And because they have been at it for millions of years, these sediment layers may contain a type of iron that came from space millions of years ago—iron-60, which prior research has shown is spewed into space when supergiant stars explode.

Iron-60, the researchers note, is extremely rare on this planet, with a half-life of just over two and a half million years; thus, any iron-60 present when our planet formed would have disappeared long ago. And since there is no known natural means to produce it, that leaves arrival from space as the logical origin. Prior research has shown that there are two likely sources, micrometeorites and possibly material sent millions of miles across space due to a supernova.

To learn more, they obtained core samples taken from the Pacific Ocean by researchers working on other projects. To look for iron-60 among the much more common iron-56 and other material, they used accelerator mass spectrometry—which is capable of isolating single atoms.
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Liquid light switch could enable more powerful electronics

Liquid light switch could enable more powerful electronics | Fragments of Science | Scoop.it
Researchers have built a record energy-efficient switch, which uses the interplay of electricity and a liquid form of light, in semiconductor microchips. The device could form the foundation of future signal processing and information technologies, making electronics even more efficient.
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Astronomy shown to be set in standing stone

Astronomy shown to be set in standing stone | Fragments of Science | Scoop.it
University of Adelaide research has for the first time statistically proven that the earliest standing stone monuments of Britain, the great circles, were constructed specifically in line with the movements of the Sun and Moon, 5000 years ago.
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Evidence of Stephen Hawking's famous prediction about black holes was just observed for the first time

Evidence of Stephen Hawking's famous prediction about black holes was just observed for the first time | Fragments of Science | Scoop.it
Jeff Steinhauer, a physicist at Technion University in Israel, has created an acoustic black hole and observed particles slipping out of its grasp, providing the strongest evidence to date of one of Stephen Hawking's most famous predictions.

In 1974, Stephen Hawking predicted that black holes might not be the bottomless pits we imagine them to be. According to Hawking's calculations, some information might escape black holes in the form of energy, or Hawking radiation.

Here's how it works: Throughout the universe, matter-antimatter pairs of particles are constantly flickering in and out of existence (because matter and antimatter quickly annihilate each other).

But if one of these particles is dragged into the event horizon of a black hole — the point where not even light can escape — before the pair annihilates, the other particle might slip away as Hawking radiation.
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A hidden force could hold the key to unlocking the mysterious dark universe

A hidden force could hold the key to unlocking the mysterious dark universe | Fragments of Science | Scoop.it
The universe is governed by four fundamental forces.

There’s gravity and electromagnetism, and then the lesser known weak and nuclear forces.

But a group of theoretical physicists at the University of California, Irvine (UCI) thinks there might just be a fifth fundamental force lurking in the shadows.

And this force could revolutionize our understanding of physics, unlocking the mysterious dark universe and potentially even leading to a holy grail of physics: a Grand Unified Theory that merges all of the fundamental forces into one. The researchers explain their findings in a paper published August 11 in the journal Physical Review Letters.

“The four known forces have very obvious jobs holding our universe together,” Jonathan Feng, one of the study’s authors, told Business Insider. “That’s how we discovered them. Gravity holds the planets in orbit around the sun. You see electricity and magnetism in lightning and magnets. The role of this force is going to be much more subtle. If it weren’t, we would have found it a long time ago.”
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Supernova ejected from the pages of history

Supernova ejected from the pages of history | Fragments of Science | Scoop.it
A new look at the debris from an exploded star in our galaxy has astronomers re-examining when the supernova actually happened. Recent observations of the supernova remnant called G11.2-0.3 with NASA's Chandra X-ray Observatory have stripped away its connection to an event recorded by the Chinese in 386 CE.

Historical supernovas and their remnants can be tied to both current astronomical observations as well as historical records of the event. Since it can be difficult to determine from present observations of their remnant exactly when a supernova occurred, historical supernovas provide important information on stellar timelines. Stellar debris can tell us a great deal about the nature of the exploded star, but the interpretation is much more straightforward given a known age.

New Chandra data on G11.2-0.3 show that dense clouds of gas lie along the line of sight from the supernova remnant to Earth. Infrared observations with the Palomar 5-meter Hale Telescope had previously indicated that parts of the remnant were heavily obscured by dust. This means that the supernova responsible for this object would simply have appeared too faint to be seen with the naked eye in 386 CE. This leaves the nature of the observed 386 CE event a mystery.
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We've been wrong about the origins of life for 90 years

We've been wrong about the origins of life for 90 years | Fragments of Science | Scoop.it
For nearly nine decades, science's favorite explanation for the origin of life has been the "primordial soup". This is the idea that life began from a series of chemical reactions in a warm pond on Earth's surface, triggered by an external energy source such as lightning strike or ultraviolet (UV) light. But recent research adds weight to an alternative idea, that life arose deep in the ocean within warm, rocky structures called hydrothermal vents.

A study published last month in Nature Microbiology suggests the last common ancestor of all living cells fed on hydrogen gas in a hot iron-rich environment, much like that within the vents. Advocates of the conventional theory have been sceptical that these findings should change our view of the origins of life. But the hydrothermal vent hypothesis, which is often described as exotic and controversial, explains how living cells evolved the ability to obtain energy, in a way that just wouldn't have been possible in a primordial soup.

Under the conventional theory, life supposedly began when lightning or UV rays caused simple molecules to join together into more complex compounds. This culminated in the creation of information-storing molecules similar to our own DNA, housed within the protective bubbles of primitive cells. Laboratory experiments confirm that trace amounts of molecular building blocks that make up proteins and information-storing molecules can indeed be created under these conditions. For many, the primordial soup has become the most plausible environment for the origin of first living cells.
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Legions of nanorobots target cancerous tumours with precision

Legions of nanorobots target cancerous tumours with precision | Fragments of Science | Scoop.it
Researchers from Polytechnique Montréal, Université de Montréal and McGill University have just achieved a spectacular breakthrough in cancer research. They have developed new nanorobotic agents capable of navigating through the bloodstream to administer a drug with precision by specifically targeting the active cancerous cells of tumours. This way of injecting medication ensures the optimal targeting of a tumour and avoids jeopardizing the integrity of organs and surrounding healthy tissues. As a result, the drug dosage that is highly toxic for the human organism could be significantly reduced.

This scientific breakthrough has just been published in the prestigious journal Nature Nanotechnology in an article titled "Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions." The article notes the results of the research done on mice, which were successfully administered nanorobotic agents into colorectal tumours.

"These legions of nanorobotic agents were actually composed of more than 100 million flagellated bacteria - and therefore self-propelled - and loaded with drugs that moved by taking the most direct path between the drug's injection point and the area of the body to cure," explains Professor Sylvain Martel, holder of the Canada Research Chair in Medical Nanorobotics and Director of the Polytechnique Montréal Nanorobotics Laboratory, who heads the research team's work. "The drug's propelling force was enough to travel efficiently and enter deep inside the tumours."

When they enter a tumour, the nanorobotic agents can detect in a wholly autonomous fashion the oxygen-depleted tumour areas, known as hypoxic zones, and deliver the drug to them. This hypoxic zone is created by the substantial consumption of oxygen by rapidly proliferative tumour cells. Hypoxic zones are known to be resistant to most therapies, including radiotherapy.

But gaining access to tumours by taking paths as minute as a red blood cell and crossing complex physiological micro-environments does not come without challenges. So Professor Martel and his team used nanotechnology to do it.
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Nanoribbons in solutions mimic nature

Nanoribbons in solutions mimic nature | Fragments of Science | Scoop.it
Graphene nanoribbons (GNRs) bend and twist easily in solution, making them adaptable for biological uses like DNA analysis, drug delivery and biomimetic applications, according to scientists at Rice University.

Knowing the details of how GNRs behave in a solution will help make them suitable for wide use in biomimetics, according to Rice physicist Ching-Hwa Kiang, whose lab employed its unique capabilities to probe nanoscale materials like cells and proteins in wet environments. Biomimetic materials are those that imitate the forms and properties of natural materials.

The research led by recent Rice graduate Sithara Wijeratne, now a postdoctoral researcher at Harvard University, appears in the Nature journal Scientific Reports.

Graphene nanoribbons can be thousands of times longer than they are wide. They can be produced in bulk by chemically "unzipping" carbon nanotubes, a process invented by Rice chemist and co-author James Tour and his lab.

Their size means they can operate on the scale of biological components like proteins and DNA, Kiang said. "We study the mechanical properties of all different kinds of materials, from proteins to cells, but a little different from the way other people do," she said. "We like to see how materials behave in solution, because that's where biological things are." Kiang is a pioneer in developing methods to probe the energy states of proteins as they fold and unfold.

She said Tour suggested her lab have a look at the mechanical properties of GNRs. "It's a little extra work to study these things in solution rather than dry, but that's our specialty," she said.
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Physicists confirm possible discovery of fifth force of nature

Physicists confirm possible discovery of fifth force of nature | Fragments of Science | Scoop.it
Recent findings indicating the possible discovery of a previously unknown subatomic particle may be evidence of a fifth fundamental force of nature, according to a paper published in the journal Physical Review Letters by theoretical physicists at the University of California, Irvine.

"If true, it's revolutionary," said Jonathan Feng, professor of physics & astronomy. "For decades, we've known of four fundamental forces: gravitation, electromagnetism, and the strong and weak nuclear forces. If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe, with consequences for the unification of forces and dark matter."

The UCI researchers came upon a mid-2015 study by experimental nuclear physicists at the Hungarian Academy of Sciences who were searching for "dark photons," particles that would signify unseen dark matter, which physicists say makes up about 85 percent of the universe's mass. The Hungarians' work uncovered a radioactive decay anomaly that points to the existence of a light particle just 30 times heavier than an electron.

"The experimentalists weren't able to claim that it was a new force," Feng said. "They simply saw an excess of events that indicated a new particle, but it was not clear to them whether it was a matter particle or a force-carrying particle."
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Scientists count microscopic particles without microscope

Scientists count microscopic particles without microscope | Fragments of Science | Scoop.it
Scientists from Russia and Australia put forward a simple new way of counting microscopic particles in optical materials. A laser beam passing through such a material splits and forms a pattern of numerous bright spots on a projection screen. The researchers found that the number of these spots corresponds to the number of particles in the material. This finding allows to determine the material structure without resorting to microscopy. The work was published in Scientific Reports.
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Researchers demonstrate acoustic levitation of a large sphere

Researchers demonstrate acoustic levitation of a large sphere | Fragments of Science | Scoop.it
When placed in an acoustic field, small objects experience a net force that can be used to levitate the objects in air. In a new study, researchers have experimentally demonstrated the acoustic levitation of a 50-mm (2-inch) solid polystyrene sphere using ultrasound—acoustic waves that are above the frequency of human hearing.

The demonstration is one of the first times that an object larger than the wavelength of the acoustic wave has been acoustically levitated. Previously, this has been achieved only for a few specific cases, such as wire-like and planar objects. In the new study, the levitated sphere is 3.6 times larger than the 14-mm acoustic wavelength used here.

The researchers, Marco Andrade and Julio Adamowski at the University of São Paulo in Brazil, along with Anne Bernassau at Heriot-Watt University in Edinburgh, UK, have published a paper on the acoustic levitation demonstration in a recent issue of Applied Physics Letters.
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Scientists are one step closer to understanding nuclear fusion power

Scientists are one step closer to understanding nuclear fusion power | Fragments of Science | Scoop.it
Researchers have developed a new way to explore some of the most extreme environments in the universe by combining three separate branches of physics.
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Researchers immobilize underwater bubbles

Researchers immobilize underwater bubbles | Fragments of Science | Scoop.it
Controlling bubbles is a difficult process and one that many of us experienced in a simplistic form as young children wielding a bubble wand, trying to create bigger bubbles without popping them. A research team in CINaM-CNRS Aix-Marseille Université in France has turned child's play into serious business.

They demonstrated they could immobilize a microbubble created from water electrolysis as if the Archimedes' buoyant force that would normally push it to the surface didn't exist. This new and surprising phenomenon described this week in Applied Physics Letters, from AIP Publishing, could lead to applications in medicine, the nuclear industry or micromanipulation technology.

While bubbles are observed frequently in nature, it is not easy to control their diameter, position or time of formation. Previous work by the French research team explored how to control the hydrogen and oxygen gas bubbles formed by the breakdown of water using electricity. They showed that if one of the electrodes is tip-shaped—with a curvature radius at its apex ranging from 1 nanometer to 1 micrometer—and an alternating electric current with defnite values of amplitude and frequency was used, microbubbles could be produced at a single point at the apex of the nanoelectrode.

In the current work, the team has demonstrated a new and surprising phenomenon: the immobilization of a single microbubble in water. After a bubble is produced (at the apex of the nanoelectrode), it is immobilized by rapidly increasing the frequency of the electric current. It is a stable situation: No matter which direction the electrode moves, the bubble remains above and at the same distance from the electrode.
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