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A Física interessante, sim! É incrível como maus professores transformaram a Física naquele amontoado de fórmulas sem sentido! A Física é mais surpreendente do que a Ficção Científica! Mais incrível que Arquivo X. Newton, Einstein ou Gauss fazem parte da nossa cultura tanto quanto os Beatles, Picasso ou Marx.
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What makes a mammal a mammal? Our spine, say scientists 

What makes a mammal a mammal? Our spine, say scientists  | Física Interessante | Scoop.it
Mammals are unique in many ways. We're warm-blooded and agile in comparison with our reptilian relatives.

But a new study, funded by the National Science Foundation (NSF) and led by Harvard University researchers Stephanie Pierce and Katrina Jones, suggests we're unique in one more way -- the makeup of our spines. The researchers describe their finding in a paper published this week in the journal Science.

"The spine is basically like a series of beads on a string, with each bead representing a single bone -- a vertebra," said Pierce, curator of vertebrate paleontology at Harvard. "In most four-legged animals, like lizards, the vertebrae all look and function the same.

"But mammal backbones are different. The different sections or regions of the spine -- like the neck, thorax and lower back -- take on very different shapes. They function separately and so can adapt to different ways of life, like running, flying, digging and climbing."

While mammal backbones are specialized, the regions that underlie them were believed to be ancient, dating back to the earliest land animals.

Mammals made the most of the existing anatomical blueprint, or so scientists believed. However, the new study is challenging this idea by looking into the fossil record.

"There are no animals alive today that record the transition from a 'lizard-like' ancestor to a mammal," said Jones, lead author of the study. "To do that, we have to dive into the fossil record and look at the extinct forerunners of mammals, the non-mammalian synapsids."

These ancient ancestors hold the key to understanding the origin of mammal-specific characteristics, including the spine.

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The role of random nanostructures for the omnidirectional anti-reflection properties of the glasswing butterfly 

The role of random nanostructures for the omnidirectional anti-reflection properties of the glasswing butterfly  | Física Interessante | Scoop.it

Glasswing butterflies develop nanostructures on their wings that actually give them “anti-reflective” properties. This allows them to reduce the amount of light bouncing their wings & remain transparent in a terrestrial environment, something few animals on the planet can do.

 

The glasswing butterfly (Greta oto) has, as its name suggests, transparent wings with remarkable low haze and reflectance over the whole visible spectral range even for large view angles of 80°. This omnidirectional anti-reflection behaviour is caused by small nanopillars covering the transparent regions of its wings. In difference to other anti-reflection coatings found in nature, these pillars are irregularly arranged and feature a random height and width distribution. Scientists now simulate the optical properties with the effective medium theory and transfer matrix method and show that the random height distribution of pillars significantly reduces the reflection not only for normal incidence but also for high view angles.


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Mum’s a Neanderthal, Dad’s a Denisovan: Researchers Sequence First Ancient Human Hybrid 

Mum’s a Neanderthal, Dad’s a Denisovan: Researchers Sequence First Ancient Human Hybrid  | Física Interessante | Scoop.it
Genetic analysis uncovers a direct descendant of two different groups of early humans.

 

A female who died around 90,000 years ago was half Neanderthal and half Denisovan, according to genome analysis of a bone discovered in a Siberian cave. This is the first time scientists have identified an ancient individual whose parents belonged to distinct human groups. The findings were published on 22 August in Nature1.

 

“To find a first-generation person of mixed ancestry from these groups is absolutely extraordinary,” says population geneticist Pontus Skoglund at the Francis Crick Institute in London. “It’s really great science coupled with a little bit of luck.” The team, led by palaeogeneticists Viviane Slon and Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, conducted the genome analysis on a single bone fragment recovered from Denisova Cave in the Altai Mountains of Russia. This cave lends its name to the ‘Denisovans’, a group of extinct humans first identified on the basis of DNA sequences from the tip of a finger bone discovered [2] there in 2008. The Altai region, and the cave specifically, were also home to Neanderthals.

 

Given the patterns of genetic variation in ancient and modern humans, scientists already knew that Denisovans and Neanderthals must have bred with each other — and with Homo sapiens. But no one had previously found the first-generation offspring from such pairings, and Pääbo says that he questioned the data when his colleagues first shared them. “I thought they must have screwed up something.” Before the discovery of the Neanderthal–Denisovan individual, whom the team has affectionately named Denny, the best evidence for so close an association was found in the DNA of a Homo sapiens specimen who had a Neanderthal ancestor within the previous 4–6 generations [3].


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DNA Nanostructures Strengthened to Survive Harsh Environments 

DNA Nanostructures Strengthened to Survive Harsh Environments  | Física Interessante | Scoop.it

Enhanced durability now makes DNA nanostructures functional for in vivo applications About six years ago, Hendrik Dietz and his team of researchers at Technische Universitaet Muenchen (TUM) finally proved that DNA can assemble an object so that all the parts fit together with atomic precision. Not only that, but Dietz’s research shortened the process from weeks to just minutes.

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These beautiful maps show our impact on the planet

These beautiful maps show our impact on the planet | Física Interessante | Scoop.it

From global shipping to undersea cables and population density, these maps highlight our impact on the planet.

 

In a short amount of time, humans have changed the face of planet Earth. Our impact has been so profound, in fact, that scientists have declared the dawn of the Anthropocene epoch, or the age of human influence. Today’s ambitious graphic comes to us from Reldresal, and it looks at this human footprint from a number of different angles. Here are some of the ones we found most interesting.

POPULATION DENSITY

While there are humans present in nearly every part of the world, the overall distribution of population is far from even. As the map above vividly demonstrates, humans cluster in specific places that have the right conditions to support a large population. Massive river deltas such as Ganges-Brahmaputra (Bangladesh) and the Nile (Egypt) are obvious bright spots on the map. Not surprisingly, sparsely populated countries like Australia and Canada are nearly indistinguishable as most people cluster in more habitable places.


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Study finds a flaw in emergent gravity

Study finds a flaw in emergent gravity | Física Interessante | Scoop.it

In recent years, some physicists have been investigating the possibility that gravity is not actually a fundamental force, but rather an emergent phenomenon that arises from the collective motion of small bits of information encoded on spacetime surfaces called holographic screens. The theory, called emergent gravity, hinges on the existence of a close connection between gravity and thermodynamics.

 

Emergent gravity has received its share of criticism, however, and a new paper adds to this by showing that the holographic screen surfaces described by the theory do not actually behave thermodynamically, undermining a key assumption of the theory.

Zhi-Wei Wang, a physicist at Jilin University in Changchun, China, and Samuel L. Braunstein, a professor of quantum computational science at the University of York in the UK, have published their paper on non-thermodynamic surfaces in a recent issue of Nature Communications.

 

"Emergent gravity has very strong claims: that it can explain things like dark matter and dark energy, but also reproduce the decades of work coming out of regular general relativity," Wang told Phys.org. "That last claim is now knocked on its head by our work, so emergent gravity proponents will have their work cut out for themselves in showing consistency with the huge canon of observational results. We've set them back, not necessarily knocked them out."

 

In the cosmological context, surfaces refer generally to any two-dimensional area in spacetime. Some of these surfaces, such as the horizons of black holes and other objects, are confirmed to be thermodynamic. For black hole horizons, this has been known since the 1970s, since the very laws that define black hole mechanics are directly analogous to the laws of thermodynamics. This means that black hole horizons obey thermodynamic principles such as energy conservation and having a positive temperature and entropy.

 

More recently, surfaces that are not horizons have been conjectured to obey the laws of thermodynamics, with the holographic screens in the emergent gravity theory being one example. However, so far these conjectures have not been fully justified.

 

In the new paper, the scientists tested whether different kinds of surfaces obey an analogue of the first law of thermodynamics, which is a special form of energy conservation. Their results reveal that, while surfaces near black holes (called stretched horizons) do obey the first law, ordinary surfaces—including holographic screens—generally do not. The only exception is that ordinary surfaces that are spherically symmetric do obey the first law.

 

As the scientists explain, the finding that stretched horizons obey the first law is not surprising, since these surfaces inherit much of their behavior from the nearby horizons. Still, the scientists caution that the results do not necessarily imply that stretched horizons obey all of the laws of thermodynamics. On the other hand, the finding that ordinary surfaces do not obey the first law is more unexpected, especially as it is one of the key assumptions of emergent gravity. Going forward, researchers will work to understand what this means for the future of emergent gravity, as well as explore other possible implications.


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Vaccines of the future could be as contagious as viruses. A headache for anti-vaxxers.

Vaccines of the future could be as contagious as viruses. A headache for anti-vaxxers. | Física Interessante | Scoop.it
Scientists are taking a leaf from the virus playbook and devising vaccines and antiviral therapies that can spread from host to host.

 

The vaccines we have today are pretty incredible. They've eradicated smallpox, purged rubella from the Americas, and save millions of people each year from dying of diphtheria, tetanus, whooping cough, and measles. When enough people get vaccinated, infectious diseases can’t spread easily and everyone benefits from herd immunity.

 

But it’s hard to reach enough people for this to happen, especially in areas with poor public health infrastructure. So scientists are taking a leaf from the virus playbook. They’re devising vaccines and antiviral therapies that can spread from host to host. These transmissible vaccines will likely first be used in animals that carry diseases that can infect people. Some may use a weakened version of the virus, or attach a piece of the pathogen to a benign virus. Other treatments are aimed at people who are already infected and will prey on the virus dwelling in their cells.

 

It’s early days for these kinds of vaccines and therapies, and scientists still have to show that they are effective and safe to use in wildlife or people. But they could tamp down the spread of HIV and other contagious diseases, and immunize people who would not otherwise be protected. Plus this strategy would be cheaper than vaccinating everyone by hand.


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Female color perception affects evolution of colorful male plumage in birds 

Female color perception affects evolution of colorful male plumage in birds  | Física Interessante | Scoop.it

The expression of a gene involved in female birds' color vision is linked to the evolution of colorful plumage in males, reports a new study from the University of Chicago. The findings, published Nov. 26 in the Proceedings of the Royal Society B, confirm the essential role of female color perception in mate selection and sexual dimorphism.

 

"This is the first time an aspect of the visual system in birds has been directly associated with plumage evolution," said Natasha Bloch, PhD, who authored the study while a graduate student in ecology & evolution at the University of Chicago. "It tells us color perception plays an important role in the evolution of the spectacular diversity of colors we see in nature."

 

Striking differences in coloration between males and females are found across bird species, but the evolutionary causes of this variation are poorly understood. Female color vision and perception are thought to play a role, but measuring this behavior in the laboratory has proven difficult.

 

To study the link, Bloch focused on opsins - specialized proteins in the retina that are responsible for detecting light. In birds, four types of opsins contribute to color vision, each with different sensitivity ranges for certain wavelengths of light.

 

Bloch measured gene expression levels of these opsins in males and females from 16 species of New World warblers, a family of songbirds common across the Americas. She found that opsin expression varied greatly between species. As this is a measure of opsin abundance and density, her results suggest the species vary in their sensitivity to and ability to perceive color.

 

When gene expression levels were measured against differences in plumage coloration between males and females, one trend stood out. In warbler species where females had high expression of the opsin Sws2, males were much more colorful. Species where Sws2 expression was low showed the reverse trend, with smaller coloration differences between sexes.

 

"The strong relationship seen between Sws2 expression and plumage coloration suggests the expression of this opsin changes female perception and thus female preference for color, which in turn drives the evolution of male plumage," Bloch said.


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How trees secretly talk to each other through a fungal network, called the Wood Wide Web (WoWW) 

How trees secretly talk to each other through a fungal network, called the Wood Wide Web (WoWW)  | Física Interessante | Scoop.it

Trees are talking and sharing resources right under your feet, using a fungal network nicknamed the Wood Wide Web. CrowdScience presenter Marnie Chesterton reveals how plants use the system to support their offspring, while others hijack the network to sabotage their rivals.


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'Molecular movie' captures chemical reaction on atomic scale 

'Molecular movie' captures chemical reaction on atomic scale  | Física Interessante | Scoop.it

A team of physicists from the University of Nebraska-Lincoln, Stanford University and Europe has captured the clearest glimpse yet of a photochemical reaction—the type of light-fueled molecular transformations responsible for photosynthesis, vision and the ozone layer. The researchers precisely recorded how the atomic nuclei and chemical bonds of a five-atom molecule responded when being struck by a laser. Appearing in the June 6 edition of the journal Science, the team's study marks the culmination of a years-long effort to advance the quality of "molecular movies" from that of a rudimentary stop-motion animation to a high-definition motion picture.

 

"People have been modeling these things for a long time, but there was really no good way to test if these models were correct," said Nebraska's Martin Centurion, a Susan J. Rosowski Associate Professor of physics and astronomy. "There is now a way to compare, in detail, what is happening experimentally with what our models would predict. "The reason that's very important is because there are many, many different molecules, and you can excite them with many, many different wavelengths (of light). There's no way you could ever do experiments on everything, so at some point, you need some sort of model that's reliable."

 

Though refining those models will demand years of work and many studies, Centurion said, the Science study has established a new benchmark for using experimental data to better understand photochemical reactions on the atomic scale. That comprehension could eventually yield important applications, he said, whether in the form of solar cells that can store the energy they collect or custom molecules better at catalyzing the reactions that can produce renewable fuels.


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[video] How one cell gives rise to an entire body

One of biology's great mysteries is how a single fertilized egg gives rise to the multitude of cell types, tissues, and organs that fit together to form a body. Now, a combination of single-cell sequencing technologies and computational tools is providing the most detailed picture yet of this complicated process. In three papers published in Science, researchers report taking multiple snapshots of gene activities in most of the cells in developing zebrafish or frog embryos. They then assemble those data, taken at intervals of just minutes to hours, into coherent, cell-by-cell histories of how those embryos take shape.

 

"My first reaction was, ‘Wow!’" says developmental biologist Robert Zinzen of the Berlin Institute for Medical Systems Biology. Just last week, two other papers online in Science traced cell-by-cell gene activity in planaria, simple flatworms, as they regenerated after being cut into pieces. In vertebrates, "the complexity is much higher," Zinzen notes.

 

Yet the researchers managed to track the emerging identities of thousands of cells and their progeny. "I think the future of development will be to routinely single-cell sequence embryos," says Detlev Arendt, an evolutionary developmental biologist at the European Molecular Biology Laboratory in Heidelberg, Germany.

 

All these studies started by gently dissolving embryos of different stages in special solutions, then shaking or stirring them to free individual cells. For each cell, the researchers then determined the sequences of all the strands of messenger RNA (mRNA), which reflect the genes being transcribed.

 

At Harvard University, teams led by Allon Klein, Marc Kirschner, and Sean Megason focused on zebrafish and frogs, two vertebrates that developmental biologists have studied for decades. In their fish study, Klein and Megason analyzed some 92,000 zebrafish cells, compiling mRNA data from seven different embryo stages. Their group started with 4-hour embryos and ended 24 hours after fertilization—the point at which the basic organs have begun to appear. Each cell's pattern of gene activity reveals the developmental direction it is headed, and, ultimately, its final identity.

 

To trace how the cells and their progeny changed over time, the researchers equipped some of the single-cell fish embryos with genetic tracers: many tiny pieces of unique DNA, injected into the embryos' cytoplasm. As the cells repeatedly divided in the growing embryo, these barcodes found their way into the nucleus and were incorporated in the chromosomes. By the end of the experiment, each lineage of cells ended up with a distinctive combination of barcodes. By merging this information with the gene activity profiles, the research team could trace cell fate through time to see how a fertilized egg gave rise to a variety of specialized cells, such as heart, nerve, and skin.

 

In a separate study, a team led by Harvard developmental biologist Alexander Schier created its own computational method to trace cells in maturing zebrafish. After the group sampled cells every 45 minutes over 9 hours of early embryo growth and sequenced the cells' mRNA, software reconstructed the biography of each cell by taking the gene activity of fully differentiated cells and analyzing which cells in the next-oldest embryo had the most similar gene activity profile. The system worked backward through each embryo stage, all the way to the base of the tree—the starting, undifferentiated cell.

 

"That was computationally very intense," says Schier, noting that the reconstruction showed the initial one-celled embryo gave rise to 25 main cell types.


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Scientists discover how to edit DNA flaws from sperm using CRISPR 

Scientists discover how to edit DNA flaws from sperm using CRISPR  | Física Interessante | Scoop.it

 

  • CRISPR-Cas9 shows promise for correcting genetic defects in a reliable manner 
  • Using the gene-editing system to 'fix' embryos has caused ethical controversy and it is unclear whether or not it is safe
  • New research from Weill Cornell University suggests that DNA in sperm could be fixed with CRISPR using a brief but powerful electrical shock  

 

Scientists may be able fix faulty DNA in a father's sperm before it has even fertilized an egg, according to new research presented this week. 

 

CRISPR gene-editing technology has shown promise for snipping out bad DNA and replacing it in embryos, but as their cells multiply, the fixed DNA may make it into some cells and not others.  Changing the genetic makeup of sperm cells would solve that problem but, so far, scientists have struggled to find a way to gene-edit them without killing them. But scientists at Weill Cornell Medicine in New York think they may have found a way: by delivering an electrical pulse to the sperm, breaking its outer shell and allowing them to deliver CRISPR to the cell. 


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Our first contact with aliens might be with their robots, cyborgs, interstellar probes and AI 

Our first contact with aliens might be with their robots, cyborgs, interstellar probes and AI  | Física Interessante | Scoop.it

Researchers working on Search for Extraterrestrial Intelligence (SETI) efforts hunt for the same thing that their predecessors sought for decades—a sign that life arose, as Carl Sagan would say, on another humdrum planet around another humdrum star and rose up into something technologically advanced.

It could happen any day. A strange radio signal. A weird, brief flash in the night sky. A curiously behaving star with no natural explanation.

 

It could be anything, so SETI researchers are casting a wide net, tracking down as many promising leads as they can. But one thing they’ve started to realize is that if a civilization from another world follows a similar path to our own, then we may be dealing with a whole different form of brainpower. Not a little green person, Vulcan, or strange organism we aren’t yet fathoming, but an artificial intelligence.

 

To understand why the first intelligence we meet might be artificial, we have to go back to early efforts to look for life around other stars. SETI researchers started listening to the cosmos on the assumption that aliens might begin radio transmissions as a first advanced technological step if they’re at all like us. There’s reason to believe that, like our own path, getting from the era of radio to the computing era is a small jump.

 

“By 1900 you had radio; by 1945 you had computers,” Seth Shostak, senior scientist at the SETI Institute, says. “It seems to me that’s a hard arc to avoid.” And from there, it may just be a matter of getting those computers smaller and smaller as they get smarter and smarter. Automated processes learn to adapt on their own, and someday, rudimentary intelligence arrives, just as it has here.

 

“There’s currently an AI revolution, and we see artificial intelligence getting smarter and smarter by the day,” Susan Schneider, an associate professor of cognitive science and philosophy at the University of Connecticut who has written about the intersection of SETI and AI, says. “That suggests to me something similar may be going on at other points in the universe.”

 

Maybe the great filter comes and augmented aliens survive. Then their AI offspring take the wheel. Do a bunch of apes with noisy radio signals and the odd act of nuclear warfare really appeal to them—are they even actively looking for something like us? When it comes to that idea, Shostak says, “It’s not even dangerous (for the aliens). It’s uninteresting. It’s like me putting a sign up in my yard saying ‘attention all ants.’”

 

In this case, we’re the ants. We may not have the resources of an alien society, and if artificial intelligence is supposed to search for signs of far, far advanced technology, we’re barely a blip on their radar. “Earth is actually a relatively young planet so some astrobiologists think if there are civilizations out there, they may be vastly more advanced than us. Sure, we got radio. Then we got computers. Then Moore’s Law turned digital computers into increasingly efficient machines, year-by-year. Machines improved very quickly—much, much more quickly than Darwin's life forms,” Shostak says.

 

Meanwhile, the aliens from the older planets get more advanced. So does their AI. Maybe it becomes the most dominant lifeform on the planet. It takes over its planet, then its star. It sends itself out into the universe in general—or it’s content to stay home for whatever reason. It’s plentiful and abundant and highly advanced, and when it comes across Earth, it doesn’t see anything particularly special. An alien AI may be just a few thousand years ahead of us, technologically, but it may still be advanced enough to grow disinterested in finding ants.

 

We might be like cats or goldfish compared to humans and they may not want to have anything to do with us. Our goldfish status could put us in a weird place. We may be just as likely to encounter biological life on a scale unimaginable to us right now, or we may make contact with their probes before we find them. We may find a semi-intelligent Bracewell beacon from afar, or one may swoop through our backyard, its AI trained to home in on the fingerprints of our civilization. We may find robots sent by the aliens, or we may find out robots are the aliens.

 

At a base level, its possible to imagine that our first meeting with intelligent life beyond Earth might not be with something living and breathing, but with a different kind of fellow explorer—who just might happen to be a machine.


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The story of moonshine symmetry, number theory, and the monster

The story of moonshine symmetry, number theory, and the monster | Física Interessante | Scoop.it

In 1978, the mathematician John McKay noticed what seemed like an odd coincidence. He had been studying the different ways of representing the structure of a mysterious entity called the monster group, a gargantuan algebraic object that, mathematicians believed, captured a new kind of symmetry. Mathematicians weren’t sure that the monster group actually existed, but they knew that if it did exist, it acted in special ways in particular dimensions, the first two of which were 1 and 196,883.

 

McKay, of Concordia University in Montreal, happened to pick up a mathematics paper in a completely different field, involving something called the j-function, one of the most fundamental objects in number theory. Strangely enough, this function’s first important coefficient is 196,884, which McKay instantly recognized as the sum of the monster’s first two special dimensions.

 

Most mathematicians dismissed the finding as a fluke, since there was no reason to expect the monster and the j-function to be even remotely related. However, the connection caught the attention of John Thompson, a Fields medalist now at the University of Florida in Gainesville, who made an additional discovery. The j-function’s second coefficient, 21,493,760, is the sum of the first three special dimensions of the monster: 1 + 196,883 + 21,296,876. It seemed as if the j-function was somehow controlling the structure of the elusive monster group.


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Water-worlds are very common on Earth-size exoplanets – some may even contain vast amounts of water 

Water-worlds are very common on Earth-size exoplanets – some may even contain vast amounts of water  | Física Interessante | Scoop.it
Scientists have shown that water is likely to be a major component of those exoplanets (planets orbiting other stars) which are between two to four times the size of Earth. It will have implications for the search of life in our Galaxy.

 

Scientists have shown that water is likely to be a major component of those exoplanets (planets orbiting other stars) which are between two to four times the size of Earth. It will have implications for the search of life in our Galaxy. The work is presented at the Goldschmidt conference in Boston.

 

The 1992 discovery of exoplanets orbiting other stars has sparked interest in understanding the composition of these planets to determine, among other goals, whether they are suitable for the development of life. Now a new evaluation of data from the exoplanet-hunting Kepler Space Telescope and the Gaia mission indicates that many of the known planets may contain as much as 50% water. This is much more than the Earth's 0.02% (by weight) water content.

 

"It was a huge surprise to realize that there must be so many water-worlds," said lead researcher Dr Li Zeng (Harvard University),

Scientists have found that many of the 4000 confirmed or candidate exoplanets discovered so far fall into two size categories: those with the planetary radius averaging around 1.5 that of the Earth, and those averaging around 2.5 times the radius of the Earth.

 

Now a group of International scientists, after analyzing the exoplanets with mass measurements and recent radius measurements from the Gaia satellite, have developed a model of their internal structure. "We have looked at how mass relates to radius, and developed a model which might explain the relationship," said Li Zeng. The model indicates that those exoplanets which have a radius of around x 1.5 Earth radius tend to be rocky planets (of typically x5 the mass of the Earth), while those with a radius of x2.5 Earth radius (with a mass around x10 that of the Earth) are probably water worlds."

 

"This is water, but not as commonly found here on Earth," said Li Zeng. "Their surface temperature is expected to be in the 200 to 500 degree Celsius range. Their surface may be shrouded in a water-vapor-dominated atmosphere, with a liquid water layer underneath. Moving deeper, one would expect to find this water transforms into high-pressure ices before we reaching the solid rocky core. The beauty of the model is that it explains just how composition relates to the known facts about these planets."

 

Li Zeng continued, "Our data indicate that about 35% of all known exoplanets which are bigger than Earth should be water-rich. These water worlds likely formed in similar ways to the giant planet cores (Jupiter, Saturn, Uranus, Neptune) which we find in our own solar system. The newly-launched TESS mission will find many more of them, with the help of ground-based spectroscopic follow-up. The next generation space telescope, the James Webb Space Telescope, will hopefully characterize the atmosphere of some of them. This is an exciting time for those interested in these remote worlds."

 

Professor Sara Seager, Professor of Planetary Science at Massachusetts Institute of Technology, and deputy science director of the recently-launched TESS (Transiting Exoplanet Survey Satellite) mission, which will search for exoplanets, said:

"It's amazing to think that the enigmatic intermediate-size exoplanets could be water worlds with vast amounts of water. Hopefully atmosphere observations in the future -- of thick steam atmospheres -- can support or refute the new findings."


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Ness Crouch's curator insight, August 25, 5:37 PM
This is an interesting field to discuss for children, as they are growing up a world where it is normal that planets exist around other stars. 
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Fake news enters a whole new level: This Face2Face software can make any person on video appear to say anything a source actor wants them to say. 

You know how they say, "Show me pictures or video, or it didn't happen"? Well, the days when you could trust what you see on video in real time are officially coming to an end thanks to a new kind of face tracking.

 

A team from Stanford, the Max Planck Institute for Informatics and the University of Erlangen-Nuremberg has produced a video demonstrating how its software, called Face2Face, in combination with a common webcam, can make any person on video appear to say anything a source actor wants them to say.

 

In addition to perfectly capturing the real-time talking motions of the actor and placing them seamlessly on the video subject, the software also accounts for real-time facial expressions, including distinct movements such as eyebrow raises.

 

To show off the system, the team used YouTube videos of U.S. President George W. Bush, Russian President Vladimir Putin and Republican presidential candidate Donald Trump. In each case, the facial masking is flawless, effectively turning the video subject into the actor's puppet.

 

It might be fun to mix this up with something like "Say it with Trump," but for now the software is still in the research phase. "Unfortunately, the software is currently not publicly available — it's just a research project," team member Matthias Niessner told Mashable. "However, we are thinking about commercializing it given that we are getting so many requests." We knew this kind of stuff was possible in the special effects editing room, but the ability to do it in real time — without those nagging "uncanny valley" artifacts — could change how we interpret video documentation forever.


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What Data Scientists Really Do, According to 35 Data Scientists 

What Data Scientists Really Do, According to 35 Data Scientists  | Física Interessante | Scoop.it
Many of my guests are skeptical not only of the fetishization of artificial general intelligence by the mainstream media (including headlines such as VentureBeat’s “An AI god will emerge by 2042 and write its own bible. Will you worship it?”), but also of the buzz around machine learning and deep learning

Via Pierre Levy
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Loose ends: Almost 1 in 5 human genes still have unresolved coding status 

Loose ends: Almost 1 in 5 human genes still have unresolved coding status  | Física Interessante | Scoop.it

More than 17 years after the sequencing of the human genome (HUGO), the human proteome is still under revision. One in eight of the 22,210 coding genes listed by the Ensembl/GENCODE, RefSeq and UniProtKB reference databases are annotated differently across the three sets. Scientists have now carried out an in-depth investigation on the 2,764 genes classified as coding by one or more sets of manual curators and not coding by others. Data from large-scale genetic variation analyses suggests that most are not under protein-like purifying selection and so are unlikely to code for functional proteins. A further 1,470 genes annotated as coding in all three reference sets have characteristics that are typical of non-coding genes or pseudogenes. These potential non-coding genes also appear to be undergoing neutral evolution and have considerably less supporting transcript and protein evidence than other coding genes. The researchers believe that the three reference databases currently overestimate the number of human coding genes by at least 2000, complicating and adding noise to large-scale biomedical experiments. Determining which potential non-coding genes do not code for proteins is a difficult but vitally important task since the human reference proteome is a fundamental pillar of most basic research and supports almost all large-scale biomedical projects.


Via Dr. Stefan Gruenwald
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Massive astrophysical objects governed by the subatomic Schrödinger Equation 

Massive astrophysical objects governed by the subatomic Schrödinger Equation  | Física Interessante | Scoop.it

Quantum mechanics is the branch of physics governing the sometimes-strange behaviour of the tiny particles that make up our universe. Equations describing the quantum world are generally confined to the subatomic realm—the mathematics relevant at very small scales is not relevant at larger scales, and vice versa. However, a surprising new discovery from a Caltech researcher suggests that the Schrödinger Equation—the fundamental equation of quantum mechanics—is remarkably useful in describing the long-term evolution of certain astronomical structures.

 

The work, done by Konstantin Batygin, a Caltech assistant professor of planetary science and Van Nuys Page Scholar, is described in a paper appearing in the March 5 issue of Monthly Notices of the Royal Astronomical Society. Massive astronomical objects are frequently encircled by groups of smaller objects that revolve around them, like the planets around the sun. For example, supermassive black holes are orbited by swarms of stars, which are themselves orbited by enormous amounts of rock, ice, and other space debris. Due to gravitational forces, these huge volumes of material form into flat, round disks. These disks, made up of countless individual particles orbiting en masse, can range from the size of the solar system to many light-years across.

 

Astrophysical disks of material generally do not retain simple circular shapes throughout their lifetimes. Instead, over millions of years, these disks slowly evolve to exhibit large-scale distortions, bending and warping like ripples on a pond. Exactly how these warps emerge and propagate has long puzzled astronomers, and even computer simulations have not offered a definitive answer, as the process is both complex and prohibitively expensive to model directly.

 

While teaching a Caltech course on planetary physics, Batygin (the theorist behind the proposed existence of Planet Nine) turned to an approximation scheme called perturbation theory to formulate a simple mathematical representation of disk evolution. This approximation, often used by astronomers, is based upon equations developed by the 18th-century mathematicians Joseph-Louis Lagrange and Pierre-Simon Laplace. Within the framework of these equations, the individual particles and pebbles on each particular orbital trajectory are mathematically smeared together. In this way, a disk can be modelled as a series of concentric wires that slowly exchange orbital angular momentum among one another.

 

As an analogy, in our own solar system, one can imagine breaking each planet into pieces and spreading those pieces around the orbit the planet takes around the sun, such that the sun is encircled by a collection of massive rings that interact gravitationally. The vibrations of these rings mirror the actual planetary orbital evolution that unfolds over millions of years, making the approximation quite accurate.


Via Dr. Stefan Gruenwald
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A Complete Taxonomy of Fractal Curves

A Complete Taxonomy of Fractal Curves | Física Interessante | Scoop.it
A curve that bends and curls at every level of maginifation is a fractal curve. It has a fractional dimension between 1 and 2, A curve which is so curvey that it essentially visits every point in a planar area is a spacefilling curve, and it defines a continuous mapping from a lower-dimensional space (a line) into a higher-dimensional space (a plane). Its dimension is 2. The fascinating thing about these curves is that they are self-similar and tiling by nature. There are infinitely many ways that fractal curves can be crafted so that they fill space. These ways can be expressed in elegant geometrical rules, as demonstrated by Koch Construction, the application of L-systems to Turtle Geometry, and Iterated Function Systems.

Viewing a space-filling curve with only a few levels of fractal recursion reveals the beautiful logic of its convoluted path. This page is dedicated to the awesome world of fractal curves, and the infinite ways a single curly line can fill the space between 1 and 2 dimensions.

Via Dr. Stefan Gruenwald
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Sci-Hub Proves That Piracy Can be Extremely Useful for Academics 

Sci-Hub Proves That Piracy Can be Extremely Useful for Academics  | Física Interessante | Scoop.it

Despite two lost legal battles in the US, domain name seizures, and millions of dollars in damage claims, Sci-Hub continues to offer unauthorized access to academic papers. The site's founder says that she would rather operate legally, but copyright gets in the way. Sci-Hub is not the problem she argues, it's a solution, something many academics tend to agree with.

 

Sci-Hub has often been referred to as “The Pirate Bay of Science,” but that description really sells the site short. While both sites are helping the public to access copyrighted content without permission, Sci-Hub has also become a crucial tool that arguably helps the progress of science.

 

The site allows researchers to bypass expensive paywalls so they can read articles written by their fellow colleagues. The information in these ‘pirated’ articles is then used to provide the foundation for future research.

 

What the site does is illegal, according to current law, but Sci-Hub is praised by thousands of researchers and academics around the world. In particular, those who don’t have direct access to the expensive journals but aspire to excel in their academic field.

 

While publishers such as Elsevier convinced the courts that Sci-Hub is a force of evil, many scientists see it as an extremely useful tool. They don’t want research locked up behind paywalls, they want it to be read, to inspire.


Via Dr. Stefan Gruenwald
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Siberian Worms Survived More Than 30,000 Years Stuck in Permafrost 

Siberian Worms Survived More Than 30,000 Years Stuck in Permafrost  | Física Interessante | Scoop.it

30,000 years ago, a ground squirrel burrowed out a spot for itself, about 10 inches in diameter at its widest, where it brought back seeds and other grassy and fruited plants to nibble on. The place where the squirrel chose to make its burrow is now known as Siberia, and the burrow is close to 100 feet below the surface and in a layer of permafrost.

 

The squirrel, of course, is long gone. But tiny roundworms, a type of nematode, that also made their home there have lasted those tens of thousands of years, frozen and immobile. Now, though, scientists in Russia have revived them, making these worms—all of them female worms—the first multicellular organisms to have survived being frozen in Arctic permafrost.

 

The permafrost layer of the polar parts of the world contains all sorts of tiny creatures, including bacteria, algae, yeasts, and amoebas, as well as moss spores and seeds. After spending thousands of years in deep freeze, these bits of life are thawing out, as the poles heat up and the permafrost softens. Previously, scientists found that a giant virus that they named Pithovirus was still viable after 30,000 years.

 

In a new paper, published in Doklody Biological Sciences, the scientists describe how they analyzed 300 samples of permafrost. Of those, only two samples had viable nematodes in them. One came from the squirrel burrow; another came from a different permafrost deposit, part of a core drilling near the Alazeya River. That sample was about 42,000 years old.

 

The samples contained two different types of roundworms, Panagrolaimus detritophagus and Plectus parvus. The scientists let them thaw out, and once they had, the worms seemed ready to go on with their lives, eating and moving, which is about the extent of what ringworms do with themselves.


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Facile, general, and effective strategy to prepare 2D, 1D, and 0D carbon nanomaterials 

Facile, general, and effective strategy to prepare 2D, 1D, and 0D carbon nanomaterials  | Física Interessante | Scoop.it

Carbon materials (CMs) exhibit great application potentials in diverse fields due to their high electric conductivity, good chemical stability, and unique microstructure. Traditionally, CMs were prepared by the carbonization of low-vapor-pressure natural products or synthetic polymers. But they suffer from some distinct disadvantages, such as difficulty in tailoring the microstructures and chemical compositions of the obtained products, or complicated and slow polymerization processes. Up to now, it is still a significant challenge to develop a facile, low-cost, and highly controllable method for preparing CM with desired constituents and structures in a large scale.

 

A research team led by Prof. YU Shuhong and Prof. LIANG Haiwei from the University of Science and Technology of China (USTC) proposes a simple, effective, and versatile method to prepare a series of functional CMs from small organic molecules (SOMs) by a transition metal assisted carbonization process. This work was published on Science Advances entitled as "Transition metal-assisted carbonization of small organic molecules toward functional carbon materials" on July 27th (Science Advances 2018, 4, eaat0788).

 

Preparation of CMs. (A) Schematic illustration of the preparation process of CMs. (B) Structures of the investigated SOMs for the CM preparation. Small organic molecules (SOMs) as precursors for preparing CMs have some distinct advantages, such as common availability, relatively low cost, and diverse element species with various contents. Previous efforts on the transformation of SOMs into CMs almost relied on harsh synthesis conditions, e.g. pyrolysis in sealed reactors, chemical vapor deposition, or salt-melt-based ionothermal carbonization, due to the high volatility of SOMs at evaluated temperatures. To address this, the research group led by Prof. YU Shuhong and Prof. LIANG Haiwei develops a method of transition metal assisted carbonization of SOMs.

 

The transition metals can catalyze the preferential formation of thermally stable intermediate polymeric structures and thus avoid the direct sublimation of SOMs during the heating process, which guarantees the successful preparation of CMs with high carbon yield. Researchers have found that totally fifteen SOMs and nine TMSs can be employed as carbon precursors and catalysts respectively for preparing CMs. Besides, two hard templates can used in the method to enhance the porosity of obtained CMS. All of research results indicate that the method is a simple, effective, and versatile method to prepare CMs.

 

The prepared CM exhibited three different prominent microstructures (including bamboo-like multi-walled carbon nanotube, micrometer-sized nanosheets and irregular particles) that were highly dependent on the molecular structures of SOMs. Besides, the CMs possessed high specific surface areas, large pore volumes, abundant heteroatoms as well as highly graphitic structures. As a results, the CM showed great application potentials for heterogeneous catalysis, e.g. selective oxidization of ethylbenzene and hydrogenation of nitrobenzene, and electrocatalysis, e.g. hydrogen evolution reaction and oxygen reduction reaction. This work opens a new window for the synthesis of CMs with desired constituents and structures.


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Single-celled architects inspire new DNA origami architecture 

Single-celled architects inspire new DNA origami architecture  | Física Interessante | Scoop.it

Diatoms are tiny, unicellular creatures, inhabiting oceans, lakes, rivers, and soils. Through their respiration, they produce close to a quarter of the oxygen on earth, nearly as much as the world's tropical forests. In addition to their ecological success across the planet, they have a number of remarkable properties. Diatoms live in glasslike homes of their own design, visible under magnification in an astonishing and aesthetically beautiful range of forms.

 

Researchers have found inspiration in these microscopic, jewel-like products of nature since their discovery in the late 18th century. In a new study, Arizona State University (ASU) scientists led by Professor Hao Yan, in collaboration with researchers from the Shanghai Institute of Applied Physics of the Chinese Academy of Sciences and Shanghai Jiaotong University led by Prof. Chunhai Fan, have designed a range of diatom-like nanostructures.

 

To achieve this, they borrow techniques used by naturally-occurring diatoms to deposit layers of silica -- the primary constituent in glass -- in order to grow their intricate shells. Using a technique known as DNA origami, the group designed nanoscale platforms of various shapes to which particles of silica, drawn by electrical charge, could stick.

 

The new research demonstrates that silica deposition can be effectively applied to synthetic, DNA-based architectures, improving their elasticity and durability. The work could ultimately have far-reaching applications in new optical systems, semiconductor nanolithography, nano-electronics, nano-robotics and medical applications, including drug delivery.

 

Yan is the Milton D. Glick Distinguished Professor of Chemistry and Biochemistry and directs the Biodesign Center for Molecular Design and Biomimetics. The group's findings are reported in the advanced online of the journal NatureResearchers like Yan and Fan create sophisticated nanoarchitectures in 2- and 3-dimensions, using DNA as a building material. The method, known as DNA origami, relies on the base-pairing properties of DNA's four nucleotides, whose names are abbreviated A,T,C and G.

 

The ladder-like structure of the DNA double-helix is formed when complementary strands of nucleotides bond with each other -- the C nucleotides always pairing with Gs and the As always pairing with Ts. This predictable behavior can be exploited in order to produce a virtually limitless variety of engineered shapes, which can be designed in advance. The nanostructures then self-assemble in a test tube.

 

In the new study, researchers wanted to see if architectures designed with DNA, each measuring just billionths of a meter in diameter, could be used as structural frameworks on which diatom-like exoskeletons composed of silica could grow in a precise and controllable manner. Their successful results show the power of this hybrid marriage of nature and nanoengineering, which the authors call DNA Origami Silicification (DOS).


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The labs growing human embryos for longer than ever before 

The labs growing human embryos for longer than ever before  | Física Interessante | Scoop.it
New techniques are providing unprecedented views into human development — and raising ethical questions.

Via Dr. Stefan Gruenwald
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Antonios Bouris's curator insight, July 6, 12:01 AM

The labs growing human embryos for longer than ever before