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Bioteeth From Stemcells Will Regrow Complete Tooth, Superior to Implants

Bioteeth From Stemcells Will Regrow Complete Tooth, Superior to Implants | Amazing Science | Scoop.it

Replacing missing teeth with new bioengineered teeth, grown from stem cells generated from a person's own gum cells, is a new method that will be vastly superior to the currently used implant technology.

 

New research, published in the Journal of Dental Research and led by Professor Paul Sharpe, an expert in craniofacial development and stem cell biology at King's College London's Dental Institute, describes advances in the development of this method by sourcing the required cells from a patient's own gum.

 

Research towards producing bioengineered teeth, also called bioteeth, aims to grow new and natural teeth by employing stem cell technology which generates immature teeth (teeth primordia) that mimic those in the embryo. These can be transplanted as small cell pellets into the adult jaw to develop into functional teeth, the researchers say.

 

Remarkably, despite the very different environments, embryonic teeth primordia can develop normally in the adult mouth. Embryonic tooth primordia cells can readily form immature teeth following dissociation into single cell populations and subsequent recombination, but such cell sources are impractical to use in a general therapy.

 

"What is required is the identification of adult sources of human epithelialand mesenchymal [stem] cells that can be obtained in sufficient numbers to make biotooth formation a viable alternative to dental implants," said Sharpe.

 

This challenge was now solved by the researchers, who sucessfully isolated adult human gum (gingival) tissue from patients at the Dental Institute at King's College London, grew more of it in the lab, and then combined it with the cells of mice that form teeth (mesenchyme cells). By transplanting this combination of cells into mice, the researchers were able to grow hybrid human/mouse teeth containing dentine and enamel, as well as viable roots.

 

"Epithelial cells derived from adult human gum tissue are capable of responding to tooth inducing signals from embryonic tooth mesenchyme in an appropriate way to contribute to tooth crown and root formation and give rise to relevant differentiated cell types, following in vitro culture," said Sharpe.

 

"These easily accessible epithelial cells are thus a realistic source for consideration in human biotooth formation. The next major challenge is to identify a way to culture adult human mesenchymal cells to be tooth-inducing, as at the moment we can only make embryonic mesenchymal cells do this."

 

Current implant-based methods of whole tooth replacement fail to reproduce a natural root structure and as a consequence of the friction from eating and other jaw movement, loss of jaw bone can occur around the implant.

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Jennifer Frezza 's curator insight, December 8, 2013 6:28 PM

Isn't science amazing?

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Awesome infographic on the 100+ exoplanets discovered to date

Awesome infographic on the 100+ exoplanets discovered to date | Amazing Science | Scoop.it
NASA’s Kepler mission has discovered more than 100 confirmed planets orbiting distant stars.

Via Guillaume Decugis
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Guillaume Decugis's curator insight, April 25, 2013 4:10 PM

Watch them orbit on scale and sort them by size: great job by the nytimes! 

Gust MEES's curator insight, April 27, 2013 10:37 AM

 

Nice interactive infographic, check it out an learn more...

 

John Purificati's comment, May 7, 2013 4:49 PM
Interesting stuff.
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Patterned hearts: Bioengineers create rubber-like material bearing micropatterns for stronger, more elastic hearts

Patterned hearts: Bioengineers create rubber-like material bearing micropatterns for stronger, more elastic hearts | Amazing Science | Scoop.it

A team of bioengineers at Brigham and Women's Hospital (BWH) is the first to report creating artificial heart tissue that closely mimics the functions of natural heart tissue through the use of human-based materials. Their work will advance how clinicians treat the damaging effects caused by heart disease, the leading cause of death in the United States.


"Scientists and clinicians alike are eager for new approaches to creating artificial heart tissues that resemble the native tissues as much as possible, in terms of physical properties and function," said Nasim Annabi, PhD, BWH Renal Division, first study author. "Current biomaterials used to repair hearts after a heart attack and other cardiovascular events lack suitable functionality and strength. We are introducing an alternative that has the mechanical properties and functions of native heart tissue."


The researchers created MeTro gel-an advanced rubber-like material made from tropoelastin, the protein in human tissues that makes them elastic. The gel was then combined with microfabrication techniques to generate gels containing well-defined micropatterns for high elasticity.

 

The researchers then used these highly elastic micropatterned gels to create heart tissue that contained beating heart muscle cells.

 

"The micropatterned gel provides elastic mechanical support of natural heart muscle tissue as demonstrated by its ability to promote attachment, spreading, alignment, function and communication of heart muscle cells," said Annabi.

 

The researchers state that MeTro gel will provide a model for future studies on how heart cells behave. Moreover, the work lays the foundation for creating more elaborate 3D versions of heart tissue that will contain vascular networks.

 

"This can be achieved by assembling tandem layers of micropatterned MeTro gels seeded with heart muscles cells in different layers," said Ali Khademhosseini, PhD, BWH Division of Biomedical Engineering, co-senior study author. "As we continue to move forward with finding better ways to mend a broken heart, we hope the biomaterials we engineer will allow us to successfully address the limitations of current artificial tissues."


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RFduino: A Device That Will Let You Hack Almost Anything

RFduino: A Device That Will Let You Hack Almost Anything | Amazing Science | Scoop.it

The RFduino is a tiny open source Arduino compatible development board, but with a few twists. Based on a Nordic Semiconductor 32-bit ARM system-on-chip that has built-in support for Bluetooth 4.0, the RFduino runs the same code as Arduino UNO and DUE boards, and it works with any type of sensor, servo, or other device that can communicate with an Arduino microcontroller.

Bluetooth 4.0's Bluetooth Low Energy (BLE) feature allows the microcontroller to run on power sources as small as a button-cell battery for some applications—and the team has developed a "shield" for the CR2032 battery, as well as single- and dual-AAA battery configurations.


RFduino can also run off a USB power source or can be wired directly to a 3-volt DC power source. As a result, the RFduino could be used for a whole host of devices that interact with mobile devices, including remote controls, proximity-switch devices such as alarms, and home automation applications that control LED lighting. It could also allow devices programmed with Arduino Sketches to interact with each other over Bluetooth 4.0—potentially allowing for the development of swarms of smart devices that can talk both to smartphones and notebook computers and their environments.

 

Kazanchian, an electrical engineer with experience in the cellular, consumer electronics, aerospace, and industrial systems industries, founded RF Digital as a wireless electronic component design firm in 1999.  He said that in addition to the Kickstarter backers who have donated money to the project and the support from the Arduino "maker" community, there's already commercial interest in using the component. "We have quite a bit of interest from OEMs with mass-production volume uses and requirements for the RFduino and derivative implementations," he said.

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Richard Platt's curator insight, September 19, 1:19 AM

Great set of examples

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First live observations of a rare deep-sea anglerfish

First live observations of a rare deep-sea anglerfish | Amazing Science | Scoop.it

C. coloratus was first described from a single specimen collected off the coast of Panama during an expedition in 1891 aboard the U.S. Fish Commission steamer Albatross. However, for over 100 years, marine researchers collected deep-sea fish using trawl nets and dredges, so this anglerfish was never seen alive. That changed in 2002, when researchers from MBARI, Moss Landing Marine Laboratories, and the Monterey Bay National Marine Sanctuary used the remotely operated vehicle (ROV) Tiburon to explore Davidson Seamount—an extinct volcano off the coast of Central California.

 

Video: http://www.youtube.com/watch?feature=player_embedded&v=Cl_MbvSUvTk

 

When the researchers first spotted this fish on video from the ROV, they weren’t exactly sure what kind of fish it was. Although C. coloratus had been dredged from deep-sea environments in other ocean basins, it had never been seen in the north Pacific. After the cruise, the researchers recruited ichthyologists from California Academy of Sciences and elsewhere to help them identify the fish.

 

Then, in 2010, MBARI researchers observed six more of these unique fish during ROV dives at Taney Seamounts, another set of extinct volcanoes off the California coast. This time, the research team noticed that not all of the fish were red or rose-colored, as they had previously been described in the scientific literature. Instead, some of the fish were blue.

After comparing the sizes of the fish in ROV videos, the scientists noted that the red fish were larger and more mature, while the blue fish were younger and smaller. From these observations, they inferred that this fish likely begins its life in a transparent larval form, turns blue as a juvenile, and turns red at adulthood.

 

One of the remarkable traits of all anglerfish is their ability to attract prey using parts of their bodies that function as lures. During one ROV dive, the researchers observed C. coloratusdeploying a shaggy, mop-like lure, called an esca, which it dangled from the end of a modified fin near the top of its head. After an unsuccessful attempt at attracting prey, the anglerfish then stowed its fishing gear away in a special cavity located between its eyes.

 

In addition to witnessing the anglerfish using its ”fishing lure” Lundsten and his colleagues also watched C. coloratus move across the seafloor in a manner akin to walking. This behavior is common among C. coloratus’ shallow-water relatives, the frogfish, but had not been observed in C. coloratus. Scientists speculate that 'walking' is more energy efficient than swimming short distances, and that it also disturbs the surrounding seawater less, reducing the chances of startling nearby prey.

 

As a result of MBARI's ROV observations, researchers also learned that C. coloratus can live as deep as 3,300 meters (11,000 feet) below the ocean’s surface. Previous trawl-net collections suggested that the fish lived only at depths of 1,250 to 1,789 meters (4,100 to 5,900 feet).

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Your Brain Calls in Backup to Find Lost Things

Your Brain Calls in Backup to Find Lost Things | Amazing Science | Scoop.it

When you lose something important—a child, your wallet, the keys—your brain kicks into overdrive to find the missing object. But that’s not just a matter of extra concentration. Researchers have found that in these intense search situations your brain actually rallies extra visual processing troops (and even some other non-visual parts of the brain) to get the job done.


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Big drugmakers think small with nanomedicine deals

Big drugmakers think small with nanomedicine deals | Amazing Science | Scoop.it

Is nanomedicine the next big thing? A growing number of top drug companies seem to think so. The ability to encapsulate potent drugs in tiny particles measuring billionths of a metre in diameter is opening up new options for super-accurate drug delivery, increasing precision hits at the site of disease with, hopefully, fewer side effects.

 

Three deals struck this year by privately held Bind Therapeutics, together worth nearly $1 billion if experiments are successful, highlight a new interest in using such tiny carriers to deliver drug payloads to specific locations in the body.

 

U.S.-based Bind is one of several biotechnology firms that are luring large pharmaceutical makers with a range of smart drug nanotechnologies, notably against cancer.

 

And nanomedicine is also being put to work in diagnosis, with tiny particles used to improve imaging in scanners, as well as rapidly detecting some serious infections.

 

In future, researchers hope to combine both treatment and diagnostics in a new approach dubbed "theranostics" that would allow doctors to monitor patients via their medicines.

 

After much hype but limited clinical success, scientists in the nanotechnology field finally see a turning point. "We have been hearing about the promise of nanomedicine for a long time, but it is now really starting to move," said Dan Peer, who runs a nanomedicine laboratory at Tel Aviv University.

 

"There is a new level of confidence in this approach among the big pharmaceutical companies ... We will see more and more products in clinical testing over the next few years and I think that is very exciting."

Nanoparticles made of polymers, gold and even graphene - a newly-discovered form of carbon - are now in various stages of development. In cancer alone, 117 drugs are being assessed using nanoparticle formulations, though most have yet to be tried on patients, according to Thomson Reuters Pharma data.

 

Other potential applications include treatments for inflammatory disorders, heart and brain diseases, and pain.

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Smallest Movie Ever: IBM Researchers Create A Nanotech Movie Out Of Atoms

Smallest Movie Ever: IBM Researchers Create A Nanotech Movie Out Of Atoms | Amazing Science | Scoop.it

IBM has made the tiniest stop-motion movie ever – a one-minute video of individual carbon monoxide molecules repeatedly rearranged to show a boy dancing, throwing a ball and bouncing on a trampoline.


Each frame measures 45 by 25 nanometres – there are 25 million nanometres in an inch – but hugely magnified, the movie is reminiscent of early video games, particularly when the boy bounces the ball off the side of the frame accompanied by simple music and sound effects.


Each one of the dots in the animation is one carbon monoxide molecule (one carbon atom and one oxygen atom), on top of a surface of copper. With a scanning tunneling electron microscope, the IBM researchers moved all those atoms by hand, one at a time, to create 242 individual frame of animation, seen at more than 100 million times their actual size.

 It took a team of four scientists two weeks, working 18-hour days, to create A Boy and His Atom, which works out to about 1.3 hours to produce and image each frame.

Although the project is interesting, there is a firm research interest behind it – to define the limits of magnetic data storage.  With these findings the IBM researchers determined that data can successfully be stored with 12 atoms.  Typical transistors used today use about a million atoms. To put this in context, Andreas Heinrich says that this would mean that every movie ever made could be stored on your mobile phone.  


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Leaf Growth & Tree Height Limited By Physics

Leaf Growth & Tree Height Limited By Physics | Amazing Science | Scoop.it

New research indicates that leaf growth may not be as complicated as it seems. When compared species to species, shorter trees exhibit a greater variety of leaf sizes than taller ones, with the tallest trees all having leaves that measure 10 to 20 centimeters in length.

 

The scientists published their findings in the journal Physical Review Letters⊃1;. The narrow size range may be simply explained in the inner workings of trees. If this is correct, this could also explain why the tallest trees can only attain about 100 meters.

 

The team only considered angiosperms like maples and oaks, not gymnosperms, like pines and redwoods. They reviewed data for 1925 species and found that among angiosperms shorter than 30 meters, leaf length varies enormously, from 3 cm all the way up to 60 cm. The range narrows as the trees become taller.

 

The flow of sap and energy throughout the tree is what explains this. A leaf of an angiosperm produces a sugary sap that flows into a network of cells called the phloem, which transports the sap down to the tree’s trunk and through the roots. While it’s in transit, the tree metabolizes the sugar. The flow is driven by the difference in concentration in the sugars, which generates osmotic pressure.

 

The scientists modeled a tree as a pair of cylindrical tubes. A short, permeable tube, which represented the phloem in the leaf, was attached to a long, impermeable tube, the phloem in the trunk. Sap diffuses into the leave phloem and travels down into the trunk phloem. The longer the permeable leaf tube is, the more the surface area it has, so the more easily sap can enter. In the trunk phloem, the longer the tube is, the more resistance it offers to flow.

 

The scientists then considered how the total flow of sap and energy varies with leaf length. If the leaves are big, the resistance from the trunk limits the flow and making the leaves bigger than a certain maximum length yields no additional flow or benefit. On the other hand, if the leaves are very small, their resistance limits the flow. And if the leaf is shorter than a certain minimum length, the sap would flow through the phloem more slowly than it could diffuse through the entire tree.

 

Trees taller than 100 meters simply could not produce leaves that obey both length limits, setting a limit for tree height. Other scientists think that the uniformity of leaf size amongst the tallest trees could come from the comparable environments and conditions that produce them.

 

One way to test how the flow speed varies with the height of a tree and the length of its leaves would be to directly measure it in different species of tall trees, but that might require taking an MRI machine into a rain forest canopy.

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mdashf's curator insight, May 8, 2013 3:11 AM

why some trees are so tall while others are short? well their leaves size will be affected as well deoending on their heights. Its like very tall men will have proportionate to their height smaller fingers. But shorter men and women will grow fingers in many differet ratio to their height. You lose certain privilege if you are tall. 

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Epilepsy Cured in Mice Using A One-Time Transplantation Of MGE Brain Cells

Epilepsy Cured in Mice Using A One-Time Transplantation Of MGE Brain Cells | Amazing Science | Scoop.it

UCSF scientists controlled seizures in epileptic mice with a one-time transplantation of medial ganglionic eminence (MGE) cells, which inhibit signaling in overactive nerve circuits, into the hippocampus, a brain region associated with seizures, as well as with learning and memory. Other researchers had previously used different cell types in rodent cell transplantation experiments and failed to stop seizures.

 

Cell therapy has become an active focus of epilepsy research, in part because current medications, even when effective, only control symptoms and not underlying causes of the disease, according to Scott C. Baraban, PhD, who holds the William K. Bowes Jr. Endowed Chair in Neuroscience Research at UCSF and led the new study. In many types of epilepsy, he said, current drugs have no therapeutic value at all.

 

"Our results are an encouraging step toward using inhibitory neurons for cell transplantation in adults with severe forms of epilepsy," Baraban said. "This procedure offers the possibility of controlling seizures and rescuing cognitive deficits in these patients."


In the UCSF study, the transplanted inhibitory cells quenched this synchronous, nerve-signaling firestorm, eliminating seizures in half of the treated mice and dramatically reducing the number of spontaneous seizures in the rest. Robert Hunt, PhD, a postdoctoral fellow in the Baraban lab, guided many of the key experiments.


he mouse model of disease that Baraban's lab team worked with is meant to resemble a severe and typically drug-resistant form of human epilepsy called mesial temporal lobe epilepsy, in which seizures are thought to arise in the hippocampus. In contrast to transplants into the hippocampus, transplants into the amygdala, a brain region involved in memory and emotion, failed to halt seizure activity in this same mouse model, the researcher found.

 

Temporal lobe epilepsy often develops in adolescence, in some cases long after a seizure episode triggered during early childhood by a high fever. A similar condition in mice can be induced with a chemical exposure, and in addition to seizures, this mouse model shares other pathological features with the human condition, such as loss of cells in the hippocampus, behavioral alterations and impaired problem solving.


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Biosciencia's curator insight, May 6, 2013 6:38 AM

Cell therapy has become an active focus of epilepsy research, in part because current medications, even when effective, only control symptoms and not underlying causes of the disease.

Brenda Elliott's curator insight, May 8, 2013 7:00 AM

curative_ that's amazing...

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First Tunguska Meteorite Fragments Finally Discovered

First Tunguska Meteorite Fragments Finally Discovered | Amazing Science | Scoop.it
Nobody knows what exploded over Siberia in 1908, but the discovery of the first fragments could finally solve the mystery.

 

The Tunguska impact event is one of the great mysteries of modern history. The basic facts are well known. On 30 June 1908, a vast and powerful explosion engulfed an isolated region of Siberia near the Podkamennaya Tunguska River.

 

The blast was 1000 times more powerful than the bomb dropped on Hiroshima, registered 5 on the Richter scale and is thought to have knocked down some 80 million trees over an area of 2000 square kilometres. The region is so isolated, however, that historians recorded only one death and just handful of eyewitness reports from nearby.

 

But the most mysterious aspect of this explosion is that it left no crater and scientists have long argued over what could have caused it.

The generally accepted theory is that the explosion was the result of a meteorite or comet exploding in the Earth’s atmosphere. That could have caused an explosion of this magnitude without leaving a crater. Such an event would almost certainly have showered the region in fragments of the parent body but no convincing evidence has ever emerged.

 

In the 1930s, an expedition to the region led by the Russian mineralogist Leonid Kulik returned with a sample of melted glassy rock containing bubbles. Kulik considered this evidence of an impact event. But the sample was somehow lost and has never undergone modern analysis. As such, there is no current evidence of an impact in the form of meteorites.

That changes today with the extraordinary announcement by Andrei Zlobin from the Russian Academy of Sciences that he has found three rocks from the Tunguska region with the telltale characteristics of meteorites. If he is right, these rocks could finally help solve once and for all what kind of object struck Earth all those years ago.

 

Zlobin has not yet carried out a detailed chemical analysis of the rocks that would reveal their chemical and isotopic composition. So the world will have to wait for this to get a better idea of the nature of the body.

 

However, the stony fragments do not rule out a comet since the nucleus could easily contain rock fragments, says Zlobin. Indeed he has calculated that the density of the impactor must have been about 0.6 grams per cubic centimetre, which is about the same as nucleus of Halley’s comet. Zlobin says that together the evidence seems “excellent confirmation of cometary origin of the Tunguska impact.”

 

Clearly there is more work to be done here, particularly the chemical analysis perhaps with international cooperation and corroboration. Then there is also the puzzle of why Zlobin has waited so long to analyse his samples. It’s not hard to imagine that the political changes that engulfed the Soviet Union in the year after his expedition may have played a role in this, but it still requires some explaining.

 

Nevertheless, this has the potential to help clear up one of the outstanding mysteries of the 20th century and finally determine the origin of the largest Earth impact in recorded history. 

 

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Super-hydrophobic self-cleaning surfaces as seen on cicada wings

Super-hydrophobic self-cleaning surfaces as seen on cicada wings | Amazing Science | Scoop.it

Scientists had known that cicada wings are super-water-repellent, or super-hydrophobic. This is different from a great many substances that are simply water-repellent, or hydrophobic — for instance, oil and water famously do not mix. But a number of surfaces such as lotus leaves can make themselves even more water-repellent by covering themselves with microscopic bumps, so water drops can float on top much as mystics can lie on beds of nails. For example, cicada wings are covered in rows of waxy cones about 200 nanometers or billionths of a meter high. In comparison, the average human hair is roughly 100 microns or millionths of a meter wide.

 

Mechanical engineer Chuan-Hua Chen at Duke University in Durham, N.C., and his colleagues were investigating a number of natural and artificial super-hydrophobic surfaces when they noticed drops of water at times rapidly disappeared. They were mystified by this behavior for years until they made observations from a different angle — they used a high-speed video camera to watch the droplets from the side of these materials instead of from above.  "That's when we saw them jumping upward," Chen recalled. The scientists found that when these surfaces are exposed to water vapor, dew can condense on them. When growing droplets fused together, the merged drop then leapt off the super-water-repellant surfaces. These drops, each up to a few microns to a few hundred microns wide, can jump up to a few millimeters in the air.  "We've since found this happens on almost all normal super-hydrophobic surfaces," Chen said. "If you take a lotus leaf or any of the many other super-water-repellant surfaces out there and you let it cool in your freezer and then take it out, as humidity in the air condenses on it, you can see with your bare eyes that water drops will jump in the air."

 

When small water droplets combine on super-water-repellent surfaces, a single bigger drop results that has less surface area than its original parts. As such, energy that is no longer needed to flatten that water across the surface the smaller droplets once occupied gets released, popping the drop upward, Chen explained. "These findings show that super-hydrophobic surfaces don't need water driven by gravity to take contaminants away — jumping droplets can do so," Chen said. "This is a great piece of work that highlights a mechanism that has not been conventionally considered for self-cleaning," said mechanical engineer Evelyn Wang at the Massachusetts Institute of Technology, who did not take part in this research.

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Shark Embryos Eat Each Other in the Womb: Sibling Rivalry at its Finest

Shark Embryos Eat Each Other in the Womb: Sibling Rivalry at its Finest | Amazing Science | Scoop.it

Shark embryos actually cannibalize their littermates while still in the womb; the largest one eats all but one of its siblings. Now, new research reveals why sharks are such bad brothers.

 

In order to find out why this phenomenon occurs, researchers analyzed shark embryos found in sand tiger sharks which, despite their name and their in utero behavior, are a non-aggressive species. They are only known to attack humans when bothered first. In order to better understand these embryos, the scientists examined them at various stages of gestation. They discovered that the later the pregnancy is, the more likely the remaining shark embryos had just one father.

 

So what does that mean exactly? Before now, researchers weren't sure whether females mated with just one partner or with multiple partners. After a bit of DNA testing, researchers discovered that litters that possessed five to seven embryos had at least two fathers. It's possible that females mated with even more males, though; at the start of gestation, there can be as many as 12 littermates. It could be that the other littermates with different fathers had already been eaten.

 

The cannibalization itself is actually a useful strategy for the sharks. It allows the two remaining babies to grow large enough to be relatively unbothered by predators once they're actually born. What is more surprising, though, is the fact that the two sharks are usually full siblings as opposed to half siblings. This suggests that the largest embryo actually targets other embryos that are from other fathers.

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Jesse Bradley's curator insight, May 5, 2013 7:37 AM

Why do you think that sharks cannibalize in the womb?

 

 

How do you think that sharks culling the weaker embryo's has effected their evolution?

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Tongue bristles help bats lap up nectar

Tongue bristles help bats lap up nectar | Amazing Science | Scoop.it

A rush of blood to the tongue helps some bats slurp up their food. Erect bristles that spring from the tongue tip of a nectar-feeding bat, Glossophaga soricina, help the bats snag sweetness from flowers, a new study finds.

 

As a bat reaches its tongue deep into a flower (or a manmade feeder), muscles stretch out, forcing blood from the middle of the tongue down into hairlike nubs that sprout from the tip, biomechanist Cally Harper and her colleagues at Brown University in Providence, R.I., report. The nubs are like water balloons that fill up when the bat feeds.

 

Those blood-inflated bristles grab lots of nectar quickly, making it easier for the mammals to snatch food on the fly.

 

Scientists had assumed the hairy bristles lining nectar-feeding bats’ tongue tips were like floppy mop strands, limply soaking up liquid. But the new study shows that the tongue bristles are actually much more active.

“It’s like if you walked into your kitchen, picked up the mop out of the corner, and the mop reached down to the floor and spread out all of its tendrils,” says biologist Margaret Rubega of the University of Connecticut in Storrs, who studies hummingbird tongues.

 

To see the bristles in action, Harper and colleagues stuck a high-speed video camera on a clear acrylic feeder, and rigged up fiber optics to shine bright lights on the bats’ tongues. Then the team filled the feeder with sugar water and watched as bats swooped in for the treat.

 

When the animals lapped up the sweet water, the sides of their glistening pink tongues turned bright red and blood-engorged bristles swelled into spikes. Like a multipronged soup ladle, the swollen spikes each pull in some nectar, Harper says.

 

Unlike with other mammals’ tongues, the nubs of nectar-feeding bats have adapted to the flowers the animals drink from, says biologist Alejandro Rico-Guevara, a colleague of Rubega’s at the University of Connecticut. Other nectar-feeding animals such as bees, butterflies and hummingbirds, use different strategies to suck up food, but all have evolved long tongues with special tubes, tweezers or bristles to help them drink.

 

The findings suggest that the honey possum, a mammal with a brush-shaped tongue tip, might also use the inflate-a-bristle technique to gather its treats, Harper says. And perhaps the bats’ tongue action could one day inspire floppy surgical tools that become firm when pumped full of air or liquid, she says.

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Climate change, not human activity, led to megafauna extinction

Climate change, not human activity, led to megafauna extinction | Amazing Science | Scoop.it
Most species of gigantic animals that once roamed Australia had disappeared by the time people arrived, a major review of the available evidence has concluded.

 

The research challenges the claim that humans were primarily responsible for the demise of the megafauna in a proposed "extinction window" between 40,000 and 50,000 years ago, and points the finger instead at climate change.

 

An international team led by the University of New South Wales, and including researchers at the University of Queensland, the University of New England, and the University of Washington, carried out the study. It is published in the Proceedings of the National Academy of Sciences.

 

"The interpretation that humans drove the extinction rests on assumptions that increasingly have been shown to be incorrect. Humans may have played some role in the loss of those species that were still surviving when people arrived about 45,000 to 50,000 years ago -- but this also needs to be demonstrated," said Associate Professor Stephen Wroe, from UNSW, the lead author of the study.

 

"There has never been any direct evidence of humans preying on extinct megafauna in Sahul, or even of a tool-kit that was appropriate for big-game hunting," he said.

 

About 90 giant animal species once inhabited the continent of Sahul, which included mainland Australia, New Guinea and Tasmania.

 

"These leviathans included the largest marsupial that ever lived -- the rhinoceros-sized Diprotodon - and short-faced kangaroos so big we can't even be sure they could hop. Preying on them were goannas the size of large saltwater crocodiles with toxic saliva and bizarre but deadly marsupial lions with flick-blades on their thumbs and bolt cutters for teeth," said Associate Professor Wroe.

 

The review concludes there is only firm evidence for about 8 to 14 megafauna species still existing when Aboriginal people arrived. About 50 species, for example, are absent from the fossil record of the past 130,000 years.

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Marco Bertolini's curator insight, May 7, 2013 3:21 AM

Des scientifiques sont à présent certains qu'un changement climatique a détruit la mégafaune d'Australie.  Et non pas l'action humaine, comme on l'a longtemps cru.  Un avertissement ?

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Individual Brain Cells Track Where We Are and How We Move

Individual Brain Cells Track Where We Are and How We Move | Amazing Science | Scoop.it

Leaving the house in the morning may seem simple, but with every move we make, our brains are working feverishly to create maps of the outside world that allow us to navigate and to remember where we are.

 

Take one step out the front door, and an individual brain cell fires. Pass by your rose bush on the way to the car, another specific neuron fires. And so it goes. Ultimately, the brain constructs its own pinpoint geographical chart that is far more precise than anything you'd find on Google Maps.

 

But just how neurons make these maps of space has fascinated scientists for decades. It is known that several types of stimuli influence the creation of neuronal maps, including visual cues in the physical environment -- that rose bush, for instance -- the body's innate knowledge of how fast it is moving, and other inputs, like smell. Yet the mechanisms by which groups of neurons combine these various stimuli to make precise maps are unknown.

 

To solve this puzzle, UCLA neurophysicists built a virtual-reality environment that allowed them to manipulate these cues while measuring the activity of map-making neurons in rats. Surprisingly, they found that when certain cues were removed, the neurons that typically fire each time a rat passes a fixed point or landmark in the real world instead began to compute the rat's relative position, firing, for example, each time the rodent walked five paces forward, then five paces back, regardless of landmarks. And many other mapping cells shut down altogether, suggesting that different sensory cues strongly influence these neurons.

 

Finally, the researchers found that in this virtual world, the rhythmic firing of neurons that normally speeds up or slows down depending on the rate at which an animal moves, was profoundly altered. The rats' brains maintained a single, steady rhythmic pattern.

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Stop the Autonomous Killer Robots on the Battlefield

Stop the Autonomous Killer Robots on the Battlefield | Amazing Science | Scoop.it

With the rapid development and proliferation of robotic weapons, machines are starting to take the place of humans on the battlefield. Some military and robotics experts have predicted that “killer robots”—fully autonomous weapons that could select and engage targets without human intervention—could be developed within 20 to 30 years. At present, military officials generally say that humans will retain some level of supervision over decisions to use lethal force, but their statements often leave open the possibility that robots could one day have the ability to make such choices on their own power.

 

Human Rights Watch and Harvard Law School’s International Human Rights Clinic (IHRC) believe that such revolutionary weapons would not be consistent with international humanitarian law and would increase the risk of death or injury to civilians during armed conflict. A preemptive prohibition on their development and use is needed.


A relatively small community of specialists has hotly debated the benefits and dangers of fully autonomous weapons. Military personnel, scientists, ethicists, philosophers, and lawyers have contributed to the discussion. They have evaluated autonomous weapons from a range of perspectives, including military utility, cost, politics, and the ethics of delegating life-and-death decisions to a machine. According to Philip Alston, then UN special rapporteur on extrajudicial, summary or arbitrary executions, however, “the rapid growth of these technologies, especially those with lethal capacities and those with decreased levels of human control, raise serious concerns that have been almost entirely unexamined by human rights or humanitarian actors.” It is time for the broader public to consider the potential advantages and threats of fully autonomous weapons.

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Pacific Cove's curator insight, September 6, 2013 9:29 PM

 Some military and robotics experts have predicted that “killer robots”—fully autonomous weapons that could select and engage targets without human intervention—could be developed within 20 to 30 years. 

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Muscles in old mice made young again

Muscles in old mice made young again | Amazing Science | Scoop.it

Researchers have identified for the first time a key factor responsible for declining muscle repair during aging, and discovered that a common drug halts the process in mice.

 

A dormant reservoir of stem cells is present inside every muscle, ready to be activated by exercise and injury to repair any damage. When needed, these cells divide into hundreds of new muscle fibers that repair the muscle. At the end of the repairing process some of the cells also replenish the pool of dormant stem cells so that the muscle retains the ability to repair itself again and again.

 

The researchers carried out a study on old mice and found the number of dormant stem cells present in the pool reduces with age, which could explain the decline in the muscle’s ability to repair and regenerate as it gets older.

When these old muscles were screened the team found high levels of FGF2, a protein that has the ability to stimulate cells to divide. While encouraging stem cells to divide and repair muscle is a normal and crucial process, they found that FGF2 could also awaken the dormant pool of stem cells even when they were not needed. The continued activation of dormant stem cells meant the pool was depleted over time, so when the muscle really needed stem cells to repair itself the muscle was unable to respond properly.

 

Researchers then attempted to inhibit FGF2 in old muscles to prevent the stem cell pool from being kick-started into action unnecessarily. By administering a common FGF2 inhibitor drug they were able to inhibit the decline in the number of muscle stem cells in the mice.

 

“Preventing or reversing muscle wasting in old age in humans is still a way off, but this study has for the first time revealed a process which could be responsible for age-related muscle wasting, which is extremely exciting,” says Albert Basson, Senior Lecturer from the department of craniofacial development and stem cell biology at the King’s College London Dental Institute.

 

“The finding opens up the possibility that one day we could develop treatments to make old muscles young again. If we could do this, we may be able to enable people to live more mobile, independent lives as they age.”

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Intelligence in the ocean: Whales give each other tips about new fishing techniques

Intelligence in the ocean: Whales give each other tips about new fishing techniques | Amazing Science | Scoop.it

Whales are one the most fascinating and intelligent creatures we know and we certainly want to protect these biggest fishes, or actually mamals, in the sea. But luckily whales are not helpless against the latest ecological changes. A new study found they work together in adapting to their environments, just like us.

 

For a period of 27 years a team of researchers monitored the fishing habits of a community of American humpback whales. The dimishing of their usual prey in the 1980′s led some of the whales to invent a new hunting technique: first hitting their tail on the water before diving down.

But it weren’t just these few smart ones that benefited from their own innovation. The whales were intelligent enough to also pass it on to the others. In 2007 around 40 percent of the population was using the new fishing skill.

 

Didn’t all these whales just discover the tail-on-the-water-thing themselves? No, say the researchers. Their analysis revealed that the new behavior spreaded roughly along the lines of social networks. Yes, whales have them too, apparently.

 

So culture is not something uniquely human. These marine animals, very distinct from our own primate lineage, also are able to transmit knowledge and keep traditions. It’s actually not so surprising if you know that whales also teach each other their mysterious songs. Maybe many years from now we find out that all this time they have been singing about fishing techniques.

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Self-assembling furniture 'grows like popcorn'

Assembling your own furniture, after you have brought it home from the showroom, is a nightmare for many people. So, what if flat-pack furniture was smart enough to assemble itself?

Belgian designer and engineer Carl de Smet is experimenting with a kind of smart foam technology, which he believes could do just that. Once heated to a set temperature, the material he works with, shape memory polyurethane (SMPU), will expand to a given design.

Currently working with scaled-down models, de Smet is close to building the technology to achieve the effect with full-size furniture.

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Injectable nano-network controls blood sugar in diabetics for days at a time

Injectable nano-network controls blood sugar in diabetics for days at a time | Amazing Science | Scoop.it

In a promising development for diabetes treatment, researchers have developed a network of nanoscale particles that can be injected into the body and release insulin when blood-sugar levels rise, maintaining normal blood sugar levels for more than a week in animal-based laboratory tests. The work was done by researchers at North Carolina State University, the University of North Carolina at Chapel Hill, the Massachusetts Institute of Technology and Children's Hospital Boston.

 

The new, injectable nano-network is composed of a mixture containing nanoparticles with a solid core of insulin, modified dextran and glucose oxidase enzymes. When the enzymes are exposed to high glucose levels they effectively convert glucose into gluconic acid, which breaks down the modified dextran and releases the insulin. The insulin then brings the glucose levels under control. The gluconic acid and dextran are fully biocompatible and dissolve in the body.

 

Each of these nanoparticle cores is given either a positively charged or negatively charged biocompatible coating. The positively charged coatings are made of chitosan (a material normally found in shrimp shells), while the negatively charged coatings are made of alginate (a material normally found in seaweed).

 

When the solution of coated nanoparticles is mixed together, the positively and negatively charged coatings are attracted to each other to form a "nano-network." Once injected into the subcutaneous layer of the skin, the nano-network holds the nanoparticles together and prevents them from dispersing throughout the body. Both the nano-network and the coatings are porous, allowing blood -- and blood sugar -- to reach the nanoparticle cores.

 

"This technology effectively creates a 'closed-loop' system that mimics the activity of the pancreas in a healthy person, releasing insulin in response to glucose level changes," Gu says. "This has the potential to improve the health and quality of life of diabetes patients."

 

Gu's research team is currently in discussions to move the technology into clinical trials for use in humans.

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Scientists have crossed two strains of avian flu virus to create one that can be transmitted through the air

Scientists have crossed two strains of avian flu virus to create one that can be transmitted through the air | Amazing Science | Scoop.it

As the world is transfixed by a new H7N9 bird flu virus spreading through China, a study reminds us that a different avian influenza — H5N1 — still poses a pandemic threat.

 

A team of scientists in China has created hybrid viruses by mixing genes from H5N1 and the H1N1 strain behind the 2009 swine flu pandemic, and showed that some of the hybrids can spread through the air between guinea pigs.

 

Flu hybrids can arise naturally when two viral strains infect the same cell and exchange genes. This process, known as reassortment, produced the strains responsible for at least three past flu pandemics, including the one in 2009.

 

There is no evidence that H5N1 and H1N1 have reassorted naturally yet, but they have many opportunities to do so. The viruses overlap both in their geographical range and in the species they infect, and although H5N1 tends mostly to swap genes in its own lineage, the pandemic H1N1 strain seems to be particularly prone to reassortment.

 

“If these mammalian-transmissible H5N1 viruses are generated in nature, a pandemic will be highly likely,” says Hualan Chen, a virologist at the Harbin Veterinary Research Institute of the Chinese Academy of Sciences, who led the study.

 

“It's remarkable work and clearly shows how the continued circulation of H5N1 strains in Asia and Egypt continues to pose a very real threat for human and animal health,” says Jeremy Farrar, director of the Oxford University Clinical Research Unit in Ho Chi Minh City, Vietnam.

 

Chen's results are likely to reignite the controversy that plagued the flu community last year, when two groups found that H5N1 could go airborne if it carried certain mutations in a gene that produced a protein called haemagglutinin (HA). Following heated debate over biosecurity issues raised by the work, the flu community instigated a voluntary year-long moratorium on research that would produce further transmissible strains. Chen’s experiments were all finished before the hiatus came into effect, but more work of this nature can be expected now that the moratorium has been lifted.

 

“I do believe such research is critical to our understanding of influenza,” says Farrar. “But such work, anywhere in the world, needs to be tightly regulated and conducted in the most secure facilities, which are registered and certified to a common international standard.”

 

Virologists have created H5N1 reassortants before. One study found that H5N1 did not produce transmissible hybrids when it reassorts with a flu strain called H3N2. But in 2011, Stacey Schultz-Cherry, a virologist at St. Jude Children's Research Hospital in Memphis, Tennessee, showed that pandemic H1N1 becomes more virulent if it carries the HA gene from H5N1.

 

Chen’s team mixed and matched seven gene segments from H5N1 and H1N1 in every possible combination, to create 127 reassortant viruses, all with H5N1’s HA gene. Some of these hybrids could spread through the air between guinea pigs in adjacent cages, as long as they carried either or both of two genes from H1N1 called PA and NS. Two further genes from H1N1, NA and M, promoted airborne transmission to a lesser extent, and another, the NP gene, did so in combination with PA.

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Counting cracks in glass gives speed of projectile

Counting cracks in glass gives speed of projectile | Amazing Science | Scoop.it

A shattered windshield has a story to tell. The key to hearing it is counting the cracks. The number of cracks that emerge in a plate of glass or Plexiglas relates to the speed of the object that broke it, researchers demonstrate. This simple relationship could prove useful for forensic scientists, archaeologists and even astronomers.

 

Over the past century, most research into cracks has focused on parameters that determine whether a material remains intact when struck.

Nicolas Vandenberghe and his colleagues at Aix-Marseille University in France decided to try something different: They wanted to push glass and other materials past their breaking points and study the resulting fractures. They wondered if they could connect the patterns of cracks to the properties of the impact that created them, something no one had done before, Vandenberghe says.

 

So he and his team set up a shooting gallery. The targets were small squares of glass and Plexiglas between 0.5 millimeters and 3 millimeters thick. The researchers’ weapon was a gun filled with pressurized air that fired 4-millimeter-wide steel balls, about the size of BB’s, at speeds ranging up to 432 kilometers per hour.

 

Knowing that cracks emerge within a matter of microseconds of impact, Vandenberghe employed a high-speed camera that shoots 30,000 frames per second to capture the instant of collision. His team broke more than 100 plates and then counted the cracks that extended outward in a star-shaped pattern from the point of impact.

 

The photographic evidence revealed a clear connection: After taking into account the type of material and its thickness, the number of cracks doubled for every fourfold increase in the ball’s speed. For example, a 70-kph pellet caused an average of four cracks in 1-millimeter-thick Plexiglas plates, while a 280-kph one made eight.

 

The study’s approach is clever, says Alan Zehnder, a mechanical engineer at Cornell University. But he points out that most impacts do not lead to such orderly, star-shaped crack patterns. He also notes that Vandenberghe’s materials were on a smaller scale than most everyday examples: The plates in the experiment are much thinner than a typical windowpane, he says, and the steel balls were significantly smaller than rocks that shatter windshields.

 

Still, the study could yield useful understanding of star-shaped cracks. Vandenberghe wonders whether forensic scientists could derive new information from broken windows at a crime scene. His work could also help archaeologists to reconstruct cracked ceramic pottery or astronomers to decipher the collisions that produced fractures on the surface of a planet or moon.

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Global carbon dioxide levels near worrisome milestone: CO2 will soon surpass 400 ppm!

Global carbon dioxide levels near worrisome milestone: CO2 will soon surpass 400 ppm! | Amazing Science | Scoop.it

Near the moonscape summit of the Mauna Loa volcano in Hawaii, an infrared analyser will soon make history. Sometime in the next month, it is expected to record a daily concentration of carbon dioxide in the atmosphere of more than 400 parts per million (p.p.m.), a value not reached at this key surveillance point for a few million years.

There will be no balloons or noisemakers to celebrate the event.

 

Researchers who monitor greenhouse gases will regard it more as a disturbing marker of humanity’s power to alter the chemistry of the atmosphere and by extension, the climate of the planet. At 400 p.p.m., nations will have a difficult time keeping global warming in check, says Corinne Le Quéré, a climate researcher at the University of East Anglia in Norwich, UK, who says that the impact “is getting very dangerously close to reaching the 2 °C target that governments around the world have pledged not to exceed”.

 

It will be a while, perhaps a few years, before the global CO2 concentration averaged over an entire year, passes 400 p.p.m.. But topping that value at Mauna Loa is significant because researchers have been monitoring the gas there since 1958, longer than any other spot. “It’s a time to take stock of where we are and where we’re going,” says Ralph Keeling, a geochemist at the Scripps Institution of Oceanography in La Jolla, California, who oversees that centre’s CO2 monitoring efforts on Mauna Loa. That gas record, known as the Keeling curve, was started by his father, Charles Keeling.

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Unleashing oxygen: ‘Superlattice’ structure could give a huge boost to oxygen reaction in fuel cells

Unleashing oxygen: ‘Superlattice’ structure could give a huge boost to oxygen reaction in fuel cells | Amazing Science | Scoop.it

New research at MIT could dramatically improve the efficiency of fuel cells, which are considered a promising alternative to batteries for powering everything from electronic devices to cars and homes.


Fuel cells make electricity by combining hydrogen, or hydrocarbon fuels, with oxygen. But the most efficient types, called solid oxide fuel cells (SOFC), have drawbacks that have limited their usefulness — including operating temperatures above 700 degrees Celsius (roughly 1300 degrees Fahrenheit). Now, MIT researchers have unraveled the properties of a promising alternative material structure for a key component of these devices.

 

The new structure, a “superlattice” of two compounds interleaved at a tiny scale, could serve as one of the two electrodes in the fuel cell. The complex material, discovered about six years ago and known as LSC113/214, is composed of two oxides of the elements lanthanum, strontium and cobalt. While one of the oxides was already known as an especially good material for such electrodes, the combination of the two is far more potent in promoting oxygen reduction than either oxide alone.


The key to the material’s performance, she explains, is the marriage of complementary qualities from its two constituents. One of the oxides allows superior conduction and transfer of electrons, while the other excels at holding onto oxygen atoms; to perform well as a fuel cell’s cathode — one of its two electrodes — a material needs to have both qualities. 

The close proximity of the two materials in this superlattice causes them to “borrow” one another’s attributes, the MIT team found. The result is a material whose reactivity exceeds that of the best materials currently used in fuel cells, Yildiz says: “It’s the best of the two worlds.”

Now that the MIT team has analyzed LSC113/214, it may be possible to discover even better materials by conducting systematic searches, Yildiz says; the team is now working on that. “If we can crack this problem, then we can make great strides in improving the performance,” adds Tuller, a professor of ceramics and electronic materials in MIT’s Department of Materials Science and Engineering.

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