In an interesting case of an archaeologist making an archaeological find in a museum, a previously unidentified dinosaur bone was rediscovered buried in a drawer at the Museum of Geology and Palaeontology in Palermo Italy by a PhD student from the Imperial College London. The student, Alessandro Chiarenza, requested permission to analyze the femur bone and ended up solving two mysteries at once.
The first mystery he solved was exactly which dinosaur the bone came from and how huge these ancient creatures could grow to be. According to a fascinating press release on the EurekAlert website, the fossil has been classified as belonging to the abelisaur:
Alessandro Chiarenza, a PhD student from Imperial College London, last year stumbled across a fossilised femur bone, left forgotten in a drawer, during his visit to the Museum of Geology and Palaeontology in Palermo Italy. He and a colleague Andrea Cau, a researcher from the University of Bologna, got permission from the museum to analyse the femur. They discovered that the bone was from a dinosaur called abelisaur, which roamed the Earth around 95 million years ago during the late Cretaceous period.
Abelisauridae were a group of predatory, carnivorous dinosaurs, characterised by extremely small forelimbs, a short deep face, small razor sharp teeth, and powerful muscular hind limbs. Scientists suspect they were also covered in fluffy feathers. The abelisaur in today’s study would have lived in North Africa, which at that time was a lush savannah criss-crossed by rivers and mangrove swamps. This ancient tropical world would have provided the abelisaur with an ideal habitat for hunting aquatic animals like turtles, crocodiles, large fish and other dinosaurs.
By studying the bone, the team deduced that this abelisaur may have been nine metres long and weighed between one and two tonnes, making it potentially one of the largest abelisaurs ever found. This is helping researchers to determine the maximum sizes that these dinosaurs may have reached during their peak.
Alfio Alessandro Chiarenza, co-author of the study from the Department of Earth Science and Engineering at Imperial, said: “Smaller abelisaur fossils have been previously found by palaeontologists, but this find shows how truly huge these flesh eating predators had become. Their appearance may have looked a bit odd as they were probably covered in feathers with tiny, useless forelimbs, but make no mistake they were fearsome killers in their time.”
Continue to the next page to learn about the second mystery that Chiarenza and Cau solved with this amazing find…
Archaeologists from the University of York in Great Britain have reported an amazingly rare discovery: an etched pendant from the Mesolithic era. The etched artwork on the 11,000-year-old fragile pendant is the earliest known Mesolithic art in Britain.
Crafted from a single piece of shale, the subtriangular three-millimeter-thick artifact was found recently at the early Mesolithic site at Star Carr in North Yorkshire. The pendant contains a series of lines that archaeologists believe may represent a tree, a map, a leaf, or even tally marks.
Engraved motifs on Mesolithic pendants are extremely rare and no other engraved pendants made of shale are known in Europe.
“It was incredibly exciting to discover such a rare object. It is unlike anything we have found in Britain from this period. We can only imagine who owned it, how they wore it, and what the engravings actually meant to them,” says Nicky Milner, professor of archaeology at the University of York.
“One possibility is that the pendant belonged to a shaman—headdresses made out of red deer antlers found nearby in earlier excavations are thought to have been worn by shamans. We can only guess what the engravings mean but engraved amber pendants found in Denmark have been interpreted as amulets used for spiritual personal protection.”
When archaeologists uncovered the pendant last year the lines on the surface were barely visible. They used a range of digital microscopy techniques to generate high resolution images to help determine the style and order of engraving. They also carried out scientific analysis to try to establish if the pendant had been strung or worn and whether pigments had been used to make the lines more prominent.
Star Carr is one of a number of archaeological sites around what was the location of a huge lake which covered much of the Vale of Pickering in the Mesolithic era. The pendant was discovered in lake edge deposits. Initially researchers thought it was natural stone—the perforation was blocked by sediment and the engravings were invisible.
It is the first perforated artifact with engraved design discovered at Star Carr though shale beads, a piece of perforated amber, and two perforated animal teeth have been recovered from the site previously.
“This exciting find tells us about the art of the first permanent settlers of Britain after the last Ice Age,” says Chantal Conneller from the University of Manchester. “This was a time when sea-level was much lower than today.
“Groups roamed across Doggerland (land now under the North Sea) and into Britain. The designs on our pendant are similar to those found in southern Scandinavia and other areas bordering the North Sea, showing a close cultural connection between northern European groups at this time.”
The European Research Council, Historic England, and the Vale of Pickering Research Trust funded the work. The discovery is reported in the journal Internet Archaeology.
Dermatological researchers studying how skin ages in humans have discovered enzymatic activity that is directly related to skin ageing. A key enzyme found in the mitochondria of skin cells declines with age, reducing the bio-energy that the cell can produce and leading to aging. In plain English, this means that mitochondria, which are like the batteries of our cells, are unable to produce as much bio-energy, or power, for the skin cells, which causes the cells to work less efficiently and age.
An exciting press announcement on the Science Daily website provides the fascinating details:
A study, published online in the Journal of Investigative Dermatology, has found that the activity of mitochondrial complex II significantly decreases in older skin.
This discovery brings experts a step closer to developing powerful anti-ageing treatments and cosmetic products which may be tailored to counteract the decline in the enzyme’s activity levels.
Findings may also lead to a greater understanding of how other organs in the body age, which could pave the way for drug developments in a number of age-related diseases, including cancer.
Mark Birch-Machin, Professor of Molecular Dermatology at Newcastle University, led the pioneering study with Dr Amy Bowman from his research group.
Professor Birch-Machin said: “As our bodies age we see that the batteries in our cells run down, known as decreased bio-energy, and harmful free radicals increase.
“This process is easily seen in our skin as increased fine lines, wrinkles and sagging appears. You know the story, or at least your mirror does first thing in the morning!
“Our study shows, for the first time, in human skin that with increasing age there is a specific decrease in the activity of a key metabolic enzyme found in the batteries of the skin cells.
“This enzyme is the hinge between the two important ways of making energy in our cells and a decrease in its activity contributes to decreased bio-energy in ageing skin.
“Our research means that we now have a specific biomarker, or a target, for developing and screening anti-ageing treatments and cosmetic creams that may counter this decline in bio-energy.
Having this very specific biomarker now makes new research into anti-aging treatments possible.
[Read on to learn the incredible details of how the study was completed and what the findings may mean for other tissues and organs in the body…]
From botany to space and over to materials engineering, it’s been another tour-de-force week in the world of science!
Here are this week’s most popular stories – as voted by your clicks – from Science Rocks My World:
Is our Milky Way galaxy a zombie, already dead and we don’t know it?
Like a zombie, the Milky Way galaxy may already be dead but it still keeps going. Our galactic neighbor Andromeda almost certainly expired a few billion years ago, but only recently started showing outward signs of its demise.
Galaxies seem to be able to “perish” – that is, stop turning gas into new stars – via two very different pathways, driven by very different processes. Galaxies like the Milky Way and Andromeda do so very, very slowly over billions of years.
How Your Personal ‘Age Gap’ Relates to Your Cancer Risk
How old are you really? Scientists have invented a way to measure it more accurately than just looking at the calendar: Epigenetic age is a new way to measure your biological age. When your biological (epigenetic) age is older than your chronological age, you are at increased risk for getting and dying of cancer.
And the bigger the difference between the two ages, the higher your risk of dying of cancer….
A flower trapped in ancient amber for millions of years belongs to a completely new species.
Lena Struwe, professor of botany in the School of Environmental and Biological Sciences at Rutgers University, discovered that two flowers found encased in amber for at least 15 million years belong to none of the known 200 species of the genus Strychnos…
How a 3D-Printed Dracula Orchid Helped Scientists Understand How it Tricks Bugs
Using a 3D printer, scientists have unlocked the mystery of how plants called Dracula orchids use mimicry to attract flies and ensure their survival.
The research, done in the last unlogged watershed in western Ecuador, is a win in the field of evolutionary biology and helps provide information that should benefit conservation efforts…
Beyond invisibility: engineering light with metamaterials
Since ancient times, people have experimented with light, cherishing shiny metals like gold and cutting gemstones to brighten their sparkles. Today we are far more advanced in how we work with this ubiquitous energy.
Starting with 19th-century experimentation, we began to explore controlling how light interacts with matter…
About three-quarters of all astronauts that spend time on the International Space Station (ISS) end up with changes in their vision, which is actually due to structural changes in their eyes themselves. And those changes are actually due to changes in the way fluids move in their bodies while in space.
This great video from NASA tells the whole story:
Thanks to the Science at NASA YouTube channel for this great video!
However, the stability – that is, the ability to remain balanced – of a bicycle with a rider is more difficult to quantify and describe mathematically, especially since rider ability can vary widely. My colleagues and I brought expert and novice riders into the lab to investigate whether they use different balancing techniques.
The physics of staying upright on a bicycle
A big part of balancing a bicycle has to do with controlling the center of mass of the rider-bicycle system. The center of mass is the point at which all the mass (person plus bicycle) can be considered to be concentrated. During straight riding, the rider must always keep that center of mass over the wheels, or what’s called the base of support – an imaginary polygon that connects the two tire contacts with the ground.
Bicycle riders can use two main balancing strategies: steering and body movement relative to the bike. Steering is critical for maintaining balance and allows the bicycle to move to bring the base of support back under the center of mass. Imagine balancing a broomstick on one hand – steering a bicycle is equivalent to the hand motions required to keep the broomstick balanced. Steering input can be provided by the rider directly via handlebars (steering torque) or through the self-stability of the bicycle, which arises because the steer and roll of a bicycle are coupled; a bicycle leaned to its side (roll) will cause a change in its steer angle.
Body movements relative to the bicycle – like leaning left and right – have a smaller effect than steering, but allow a rider to make balance corrections by shifting the center of mass side to side relative to the bicycle and base of support.
Steering is absolutely necessary to balance a bicycle, whereas body movements are not; there is no specific combination of the two to ensure balance. The basic strategy to balance a bicycle, as noted by Karl von Drais (inventor of the Draisine), is to steer into the undesired fall.
Newbies versus pros
While riders have been described using mathematical equations, the equations are not yet useful for understanding the differences between riders of different ability levels or for predicting the stability of a given rider on a given bicycle.
Therefore, the goal of my colleagues’ and my recent work was to explore the types of control used by both novice and expert riders and to identify the differences between the two groups. In our study, expert riders identified themselves as skilled cyclists, went on regular training rides, belonged to a cycling club or team, competed several times per year, and had used rollers for training indoors. Novice riders knew how to ride a bicycle but did so only occasionally for recreation or transportation and did not identify themselves as experts.
We conducted our experiments in a motion capture laboratory, where the riders rode a typical mountain bike on rollers. Rollers constrain the bicycle in the fore-aft direction but allow free lateral (left-right) movement. They require a bicycle rider to maintain balance by pedaling, steering and leaning, as one would outdoors.
A subject preparing to ride the instrumented bicycle in our experimental setup. (Credit: Stephen Cain, CC BY-ND)
We mounted sensors and used a motion capture system to measure the motion of the bicycle (speed, steering angle and rate, roll angle and rate) and the steering torque used by the rider. A force platform underneath the rollers allowed us to calculate the lateral position of the center of mass relative to the base of support; that let us determine how a rider was leaning.
We found that both novice and expert riders exhibit similar balance performance at slow speeds. But at higher speeds, expert riders achieve superior balance performance by employing smaller but more effective body movements and less steering. Regardless of speed, expert riders use smaller and less varying steering inputs and less body movement variation.
We conclude that expert riders are able to use body movements more effectively than novice riders, which results in reducing the demand for both large corrective steering and body movements.
Mysteries remain
Despite our work and that of others in the field, there is still much to be learned about how humans ride and balance bicycles. Most research, including ours, has been limited to straight line riding, which only makes up a fraction of a typical bicycle ride.
Our work reveals measurable differences between riders of different skill levels. But their meaning is unclear. Are the differences linked to a higher risk of crashing for the novice riders? Or do the differences simply reflect a different style of control that gets fine-tuned through hours and hours of training rides?
Ideally, we would like to identify the measurements that quantify the balance performance, control strategy and fall risk of a rider in the real world.
With such measurements, we could identify riders at high risk of falling, explore the extent to which bicycle design can reduce fall risk and increase balance performance, and develop the mathematical equations that describe riders of different skill levels.
Wi-Fi is everywhere—invisibly connecting laptops to printers, allowing smartphones to make calls or stream movies without cell service, and letting online gamers battle it out. That’s the upside.
But there’s a downside, too: Using Wi-Fi consumes a significant amount of energy, draining the batteries of all those connected devices.
Now, computer scientists and electrical engineers have demonstrated that it’s possible to generate Wi-Fi transmissions using 10,000 times less power than conventional methods.
The new Passive Wi-Fi system also consumes 1,000 times less power than existing energy-efficient wireless communication platforms, such as Bluetooth Low Energy and Zigbee.
“We wanted to see if we could achieve Wi-Fi transmissions using almost no power at all,” says coauthor Shyam Gollakota, assistant professor of computer science and engineering at the University of Washington. “That’s basically what Passive Wi-Fi delivers. We can get Wi-Fi for 10,000 times less power than the best thing that’s out there.”
“WE WANTED TO SEE IF WE COULD ACHIEVE WI-FI TRANSMISSIONS USING ALMOST NO POWER AT ALL.”
In Passive Wi-Fi, power-intensive functions are handled by a single device plugged into the wall. Passive sensors use almost no energy to communicate with routers, phones and other devices. (Author provided)
Passive Wi-Fi can for the first time transmit Wi-Fi signals at bit rates of up to 11 megabits per second that can be decoded on any of the billions of devices with Wi-Fi connectivity. These speeds are lower than the maximum Wi-Fi speeds but 11 times higher than Bluetooth.
Aside from saving battery life on today’s devices, wireless communication that uses almost no power will help enable an “Internet of Things” reality where household devices and wearable sensors can communicate using Wi-Fi without worrying about power.
To achieve such low-power Wi-Fi transmissions, researchers essentially decoupled the digital and analog operations involved in radio transmissions. In the last 20 years, the digital side of that equation has become extremely energy efficient, but the analog components still consume a lot of power.
ONE PLUGGED-IN DEVICE
The Passive Wi-Fi architecture assigns the analog, power-intensive functions—like producing a signal at a specific frequency—to a single device in the network that is plugged into the wall.
An array of sensors produces Wi-Fi packets of information using very little power by simply reflecting and absorbing that signal using a digital switch. In real-world conditions, researchers found the passive Wi-Fi sensors and a smartphone can communicate even at distances of 100 feet between them.
“All the networking, heavy-lifting, and power-consuming pieces are done by the one plugged-in device,” says coauthor Vamsi Talla, an electrical engineering doctoral student. “The passive devices are only reflecting to generate the Wi-Fi packets, which is a really energy-efficient way to communicate.”
Because the sensors are creating actual Wi-Fi packets, they can communicate with any Wi-Fi enabled device right out of the box.
“Our sensors can talk to any router, smartphone, tablet, or other electronic device with a Wi-Fi chipset,” says coauthor and electrical engineering doctoral student Bryce Kellogg. “The cool thing is that all these devices can decode the Wi-Fi packets we created using reflection so you don’t need specialized equipment.”
The technology could enable entirely new types of communication that haven’t been possible because energy demands have outstripped available power supplies. It could also simplify our data-intensive worlds.
For instance, smart home applications that use sensors to track everything from which doors are open to whether kids have gotten home from school have typically used their own communication platforms because Wi-Fi is so power-hungry.
“Even though so many homes already have Wi-Fi, it hasn’t been the best choice for that,” says coauthor Joshua Smith, associate professor of computer science and engineering and of electrical engineering. “Now that we can achieve Wi-Fi for tens of microwatts of power and can do much better than both Bluetooth and ZigBee, you could now imagine using Wi-Fi for everything.”
The researchers will present a paper describing their results in March at the 13th USENIX Symposium on Networked Systems Design and Implementation. The National Science Foundation, the University of Washington, and Qualcomm funded the work.
If you’ve ever wondered what the folds in our brains have to do with our intelligence or how they relate to some illnesses like schizophrenia or autism, here is a awesome tour-de-force video that covers a ton of brain-folding science in just 3 minutes:
With much gratitude to our colleagues at the PHD Comics YouTube Channel!
Like a zombie, the Milky Way galaxy may already be dead but it still keeps going. Our galactic neighbor Andromeda almost certainly expired a few billion years ago, but only recently started showing outward signs of its demise.
Galaxies seem to be able to “perish” – that is, stop turning gas into new stars – via two very different pathways, driven by very different processes. Galaxies like the Milky Way and Andromeda do so very, very slowly over billions of years.
How and why galaxies “quench” their star formation and change their morphology, or shape, is one of the big questions in extragalactic astrophysics. We may now be on the brink of being able to piece together how it happens. And part of the thanks goes to citizen scientists who combed through millions of galactic images to classify what’s out there.
Galaxies grow by making new stars
Galaxies are dynamic systems that continually accrete gas and convert some of it into stars.
Like people, galaxies need food. In the case of galaxies, that “food” is a supply of fresh hydrogen gas from the cosmic web, the filaments and halos of dark matter that make up the largest structures in the universe. As this gas cools and falls into dark matter halos, it turns into a disk that then can cool even further and eventually fragment into stars.
As stars age and die, they can return some of that gas back into the galaxy either via winds from stars or by going supernova. As massive stars die in such explosions, they heat the gas around them and prevent it from cooling down quite so fast. They provide what astronomers call “feedback”: star formation in galaxies is thus a self-regulated process. The heat from dying stars means cosmic gas doesn’t cool into new stars as readily, which ultimately puts a brake on how many new stars can form.
Most of these star-forming galaxies are disk- or spiral-shaped, like our Milky Way.
Left: a spiral galaxy ablaze in the blue light of young stars from ongoing star formation; right: an elliptical galaxy bathed in the red light of old stars. (Credit: Sloan Digital Sky Survey)
But there’s another kind of galaxy that has a very different shape, or morphology, in astronomer-parlance. These massive elliptical galaxies tend to look spheroidal or football-shaped. They’re not nearly so active – they’ve lost their supply of gas and therefore have ceased forming new stars. Their stars move on far more unordered orbits, giving them their bulkier, rounder shape.
These elliptical galaxies differ in two major ways: they no longer form stars and they have a different shape. Something pretty dramatic must have happened to them to produce such profound changes. What?
Blue=young and red=old?
The basic division of galaxies into star-forming spiral galaxies blazing in the blue light of massive, young and short-lived stars, on the one hand, and quiescent ellipticals bathed in the warm glow of ancient low-mass stars, on the other, goes back to early galaxy surveys of the 20th century.
But, once modern surveys like the Sloan Digital Sky Survey (SDSS) began to record hundreds of thousands of galaxies, objects started emerging that didn’t quite fit into those two broad categories.
A significant number of red, quiescent galaxies aren’t elliptical in shape at all, but retain roughly a disk shape. Somehow, these galaxies stopped forming stars without dramatically changing their structure.
At the same time, blue elliptical galaxies started to surface. Their structure is similar to that of “red and dead” ellipticals, but they shine in the bright blue light of young stars, indicating that star formation is still ongoing in them.
How do these two oddballs – the red spirals and the blue ellipticals – fit into our picture of galaxy evolution?
Galaxy Zoo allows citizen scientists to classify galaxies. Screenshot by Kevin Schawinski, CC BY-ND
Send in the citizen scientists
As a graduate student in Oxford, I was looking for some of these oddball galaxies. I was particularly interested in the blue ellipticals and any clues they contained about the formation of elliptical galaxies in general.
At one point, I spent a whole week going through almost 50,000 galaxies from SDSS by eye, as none of the available algorithms for classifying galaxy shape was as good as I needed it to be. I found quite a few blue ellipticals, but the value of classifying all of the roughly one million galaxies in SDSS with human eyes quickly became apparent. Of course, going through a million galaxies by myself wasn’t possible.
A short time later, a group of collaborators and I launched galaxyzoo.org and invited members of the public – citizen scientists – to participate in astrophysics research. When you logged on to Galaxy Zoo, you’d be shown an image of a galaxy and a set of buttons corresponding to possible classifications, and a tutorial to help you recognize the different classes.
By the time we stopped recording classifications from a quarter-million people, each of the one million galaxies on Galaxy Zoo had been classified over 70 times, giving me reliable, human classifications of galaxy shape, including a measure of uncertainty. Did 65 out of 70 citizen scientists agree that this galaxy is an elliptical? Good! If there’s no agreement at all, that’s information too.
Tapping into the “wisdom of the crowd” effect coupled with the unparalleled human ability for pattern recognition helped sort through a million galaxies and unearthed many of the less common blue ellipticals and red spirals for us to study.
The galaxy color-mass diagram. Blue, star-forming galaxies are at the bottom, in the blue cloud. Red, quiescent galaxies are at the top, in the red sequence. The ‘green valley’ is the transition zone in between. (Credit: Schawinski+14, CC BY-ND)
Unwittingly living in the green valley?
The crossroads of galaxy evolution is a place called the “green valley.” This may sound scenic, but refers to the population between the blue star-forming galaxies (the “blue cloud”) and the red, passively evolving galaxies (the “red sequence”). Galaxies with “green” or intermediate colors should be those galaxies in which star formation is in the process of turning off, but which still have some ongoing star formation – indicating the process only shut down a short while ago, perhaps a few hundred million years.
As a curious aside, the origin of the term “green valley” may actually go back to a talk given at the University of Arizona on galaxy evolution where, when the speaker described the galaxy color-mass diagram, a member of the audience called out: “the green valley, where galaxies go to die!” Green Valley, Arizona, is a retirement community just outside of the university’s hometown, Tucson.
For our project, the really exciting moment came when we looked at the rate at which various galaxies were dying. We found the slowly dying ones are the spirals and the rapidly dying ones are the ellipticals. There must be two fundamentally different evolutionary pathways that lead to quenching in galaxies. When we explored these two scenarios – dying slowly, and dying quickly – it became obvious that these two pathways have to be tied to the gas supply that fuels star formation in the first place.
Imagine a spiral galaxy like our own Milky Way merrily converting gas to stars as new gas keeps flowing in. Then something happens that turns off that supply of fresh outside gas: perhaps the galaxy fell into a massive cluster of galaxies where the hot intra-cluster gas cuts off fresh gas from the outside, or perhaps the dark matter halo of the galaxy grew so much that gas falling into it gets shock heated to such a high temperature that it cannot cool down within the age of the universe. In any case, the spiral galaxy is now left with just the gas it has in its reservoir.
Since these reservoirs can be enormous, and the conversion of gas to stars is a very slow process, our spiral galaxy could go on for quite a while looking “alive” with new stars, while the actual rate of star formation declines over several billion years. The glacial slowness of using up the remaining gas reservoir means that by the time we realize that a galaxy is in terminal decline, the “trigger moment” occurred billions of years ago.
The Andromeda galaxy, our nearest massive spiral galaxy, is in the green valley and likely began its decline eons ago: it is a zombie galaxy, according to our latest research. It’s dead, but keeps on moving, still producing stars, but at a diminished rate compared to what it should if it were still a normal star-forming galaxy. Working out whether the Milky Way is in the green valley – in the process of shutting down – is much more challenging, as we are in the Milky Way and cannot easily measure its integrated properties the way we can for distant galaxies.
Even with the more uncertain data, it looks like the Milky Way is just at the edge, ready to tumble into the green valley. It’s entirely possible that the Milky Way galaxy is a zombie, having died a billion years ago.