Amazing Science
702.3K views | +637 today
Amazing Science
Amazing science facts - 3D_printing • aging • AI • anthropology • art • astronomy • bigdata • bioinformatics • biology • biotech • chemistry • computers • cosmology • education • environment • evolution • future • genetics • genomics • geosciences • green_energy • history • language • map • material_science • math • med • medicine • microscopy • nanotech • neuroscience • paleontology • photography • photonics • physics • postings • robotics • science • technology • video
Your new post is loading...
Scooped by Dr. Stefan Gruenwald!

One dollar paper microscope from Stanford can detect parasites in contaminated water with 500x magnification

One dollar paper microscope from Stanford can detect parasites in contaminated water with 500x magnification | Amazing Science |

A team of engineers now describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education.

Microscopes are ubiquitous tools in science, providing an essential, visual connection between the familiar macro-world and the remarkable underlying micro-world. Since the invention of the microscope, the field has evolved to provide numerous imaging modalities with resolution approaching 250 nm and smaller [1]. However, some applications demand non-conventional solutions due to contextual challenges and tradeoffs between cost and performance. For example, in situ examination of specimens in the field provides important opportunities for ecological studies, biological research, and medical screening. Further, ultra-low cost DIY microscopes provide means for hands-on science education in schools and universities. Finally, this platform could empower a worldwide community of amateur microscopists to capture and share images of a broad range of specimens.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

New 'high-entropy' alloy is as light as aluminum but as strong as titanium alloys

New 'high-entropy' alloy is as light as aluminum but as strong as titanium alloys | Amazing Science |

High-entropy alloys are materials that consist of five or more metals in approximately equal amounts. These alloys are currently the focus of significant attention in materials science and engineering because they can have desirable properties. The research team combined lithium, magnesium, titanium, aluminum and scandium to make a nanocrystalline high-entropy alloy that has low density, but very high strength.

"The density is comparable to aluminum, but it is stronger than titanium alloys," says Dr. Carl Koch, Kobe Steel Distinguished Professor of Materials Science and Engineering at NC State and senior author of a paper on the work. "It has a combination of high strength and low density that is, as far as we can tell, unmatched by any other metallic material. The strength-to-weight ratio is comparable to some ceramics, but we think it's tougher - less brittle - than ceramics."

There are a wide range of uses for strong, lightweight materials, such as in vehicles or prosthetic devices. "We still have a lot of research to do to fully characterize this material and explore the best processing methods for it," Koch says.

At this point, the primary problem with the alloy is that it is made of 20 percent scandium, which is extremely expensive.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

There's A Lab Where You Can Pay To Have Your Dog Cloned

There's A Lab Where You Can Pay To Have Your Dog Cloned | Amazing Science |

We’ve come a long way since scientists cloned the first adult mammal, a sheep named Dolly, in 1996. Now, you can pay to have your own dog duplicated using the same technique scientists used to make Dolly. But there’s a catch (aside, of course, from the whole ethical dilemma of incubating your recently deceased pet’s cells inside a random pup): It costs around $US100,000, and there’s only one lab in the world that does it. In South Korea.

To clone a dog, scientists at the Sooam Biotech Research Foundation laboratory do exactly what researchers did to make Dolly. First, they take a few cells from your pet and reprogram them to stop growing — effectively putting their DNA to sleep. Then, using a tiny straw-like device, they suck up the dormant cell and inject it inside another dog cell that’s been emptied of its nucleus, or command center. Then the scientists zap the new cell with electricity, coaxing the two parts to fuse into one cell. Once they make sure the new cell “works,” meaning it can divide and develop on its own, the scientists implant it inside a surrogate mama pup. In a few months, if all goes well, the surrogate dog will give birth to a puppy that looks just like yours.

The new animal won’t be absolutely identical, of course. Missing all the memories of the old animal, for starters. “When thinking of cloning, try to think of an identical twin,” Sooam biologist Insung Hwang explains. “The dog will not be 100% the same — the spots on a Dalmatian clone will be different, for example — but for breeds without such characteristics it will be very hard to tell them apart.”

The lab that oversees the procedure isn’t without controversy, however. Eight years after winning international acclaim for cloning the world’s first dog in 2005, Sooam founder and veterinarian by training Woo Suk Hwang was publically disgraced for falsifying research on human embryo cloning. Hwang (no relation to Insung Hwang) was expelled from Seoul National University, where he did the research, and is still facing criminal charges.

Despite the public outcry, Hwang’s supporters managed to gather more than $US3.5 million to help him start Sooam in 2006. Since then, the lab has cloned more than 400 dogs, mostly pets, reports Nature. In the past few years, Sooam researchers have picked up their pace, producing about 15 puppies a month.

Beyond Dog Cloning:

Some scientists want to use Sooam’s cloning technique to replicate far more than people’s deceased pups. Geneticist George Church and Sooam biologist Insung Hwang, for example, are exploring the possibility of bringing long-extinct animals back to life using samples of their DNA. Church and Hwang are part of a team of researchers who recently autopsied the body of a woolly mammoth who lived about 40,000 years ago and whose blood was surprisingly well preserved, along with her body, in Siberia. The autopsy is featured in detail in a recent Smithsonian documentary called “How To Clone A Woolly Mammoth.”

Andrea J Galan's curator insight, April 4, 5:37 PM
So I clicked on this article because I have a debate on the topic of cloning humans and animals. I find it interesting how people wou.d actAlly spend so much money to create another look alike of their dead dog. Don't get me wrong I love my 13 year old Labrador but I don't think I could handle seeing another dog with her exact same features once she passed. I. Also curious about the welfare of the surrogate mothers. Are they constantly pregnant, do they get a break from being pregnant. I
Scooped by Dr. Stefan Gruenwald!

Time's Mysterious Past: New Theories Suggest Big Bang Was Not The Beginning

Time's Mysterious Past: New Theories Suggest Big Bang Was Not The Beginning | Amazing Science |

Tentative new work from Julian Barbour of the University of Oxford, Tim Koslowski of the University of New Brunswick and Flavio Mercati of the Perimeter Institute for Theoretical Physics suggests that perhaps the arrow of time doesn’t really require a fine-tuned, low-entropy initial state at all but is instead the inevitable product of the fundamental laws of physics. Barbour and his colleagues argue that it is gravity, rather than thermodynamics, that draws the bowstring to let time’s arrow fly. Their findings were published in October in Physical Review Letters.
The team’s conclusions come from studying an exceedingly simple proxy for our universe, a computer simulation of 1,000 pointlike particles interacting under the influence of Newtonian gravity. They investigated the dynamic behavior of the system using a measure of its "complexity," which corresponds to the ratio of the distance between the system’s closest pair of particles and the distance between the most widely separated particle pair. The system’s complexity is at its lowest when all the particles come together in a densely packed cloud, a state of minimum size and maximum uniformity roughly analogous to the big bang. The team’s analysis showed that essentially every configuration of particles, regardless of their number and scale, would evolve into this low-complexity state. Thus, the sheer force of gravity sets the stage for the system’s expansion and the origin of time’s arrow, all without any delicate fine-tuning to first establish a low-entropy initial condition.
From that low-complexity state, the system of particles then expands outward in both temporal directions, creating two distinct, symmetric and opposite arrows of time. Along each of the two temporal paths, gravity then pulls the particles into larger, more ordered and complex structures—the model’s equivalent of galaxy clusters, stars and planetary systems. From there, the standard thermodynamic passage of time can manifest and unfold on each of the two divergent paths. In other words, the model has one past but two futures. As hinted by the time-indifferent laws of physics, time’s arrow may in a sense move in two directions, although any observer can only see and experience one. “It is the nature of gravity to pull the universe out of its primordial chaos and create structure, order and complexity,” Mercati says. “All the solutions break into two epochs, which go on forever in the two time directions, divided by this central state which has very characteristic properties.”
Although the model is crude, and does not incorporate either quantum mechanics or general relativity, its potential implications are vast. If it holds true for our actual universe, then the big bang could no longer be considered a cosmic beginning but rather only a phase in an effectively timeless and eternal universe. More prosaically, a two-branched arrow of time would lead to curious incongruities for observers on opposite sides. “This two-futures situation would exhibit a single, chaotic past in both directions, meaning that there would be essentially two universes, one on either side of this central state,” Barbour says. “If they were complicated enough, both sides could sustain observers who would perceive time going in opposite directions. Any intelligent beings there would define their arrow of time as moving away from this central state. They would think we now live in their deepest past.”

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Germanium semiconductor milestone for creating ultrafast circuits

Germanium semiconductor milestone for creating ultrafast circuits | Amazing Science |

A laboratory at Purdue University provided a critical part of the world's first transistor in 1947 – the purified germanium semiconductor – and now researchers here are on the forefront of a new germanium milestone. The team has created the first modern germanium circuit – a complementary metal–oxide–semiconductor (CMOS) device – using germanium as the semiconductor instead of silicon.

"Bell Labs created the first transistor, but the semiconductor crystal made of purified germanium was provided by Purdue physicists," said Peide "Peter" Ye, a Purdue professor of electrical and computer engineering.

Germanium was superseded by silicon as the semiconductor of choice for commercial CMOS technology. However, the industry will soon reach the limit as to how small silicon transistors can be made, threatening future advances. Germanium is one material being considered to replace silicon because it could enable the industry to make smaller transistors and more compact integrated circuits, Ye said. Compared to silicon, germanium also is said to have a "higher mobility" for electrons and electron "holes," a trait that makes for ultra-fast circuits.

In new findings, Purdue researchers show how to use germanium to produce two types of transistors needed for CMOS electronic devices. The material had previously been limited to "P-type" transistors. The findings show how to use the material also to make "N-type" transistors. Because both types of transistors are needed for CMOS circuits, the findings point to possible applications for germanium in computers and electronics, he said.

Findings will be detailed in two papers being presented during the 2014 IEEE International Electron Devices Meeting on Dec. 15-17 in San Francisco. One paper was authored by Ye and graduate students Heng Wu, Nathan Conrad and Wei Luo, the same authors of the second paper together with graduate students Mengwei Si, Jingyun Zhang and Hong Zhou.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

WHO: Malaria deaths halved since 2000 in quest for total eradication

WHO: Malaria deaths halved since 2000 in quest for total eradication | Amazing Science |

The international health community is celebrating what may prove to be a turning point in the global fight against malaria. Deaths from the mosquito-borne disease have been almost halved since the turn of the millennium, according to a new report from the World Health Organization (WHO), with experts saying they’re confident the illness can one day be eradicated entirely.

However, although the malaria mortality rate fell by 47 percent globally and by 54 percent in Africa, the WHO warns that much more still needs to be done. Dozens of countries are reporting insecticide-resistance among their mosquito populations and in Africa — where 90 percent of malaria deaths occur — some 278 million people lack even the basic protection of an insecticide-treated mosquito net.

The disease also continues to disproportionately affect children in poor countries. Of the estimated global malaria death toll of 584,000 in 2013, some 437,000 of those cases were African children under the age of five. However, malaria infections in the African continent have decreased significantly since the year 2000, falling by 23 percent from 173 million to 128 million.

The WHO attributes these gains to the increased spread of established methods, including rapid diagnostic tests (which have risen globally from 46 million 319 million over the past five years); malarial treatment using artemisnin (392 million treatments were bought last year, up from 11 million in 2004); and access to insecticide-treated nets (427 million of which have been distributed in the last two years).

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Quantum Teleportation Reaches Farthest Distance Yet

Quantum Teleportation Reaches Farthest Distance Yet | Amazing Science |
Physicists have teleported a light particle 15 miles (25 kilometers), making it the farthest quantum teleportation yet.

Advances in quantum teleportation could lead to better Internet and communication security, and get scientists closer to developing quantum computers. About five years ago, researchers could only teleport quantum information, such as which direction a particle is spinning, across a few meters. Now, they can beam that information across several miles.

Physicists can't instantly transport matter, but they can instantly transport information through quantum teleportation. This works thanks to a bizarre quantum mechanics property called entanglement. Quantum entanglement happens when two subatomic particles stay connected no matter how far apart they are. When one particle is disturbed, it instantly affects the entangled partner. It's impossible to tell the state of either particle until one is directly measured, but measuring one particle instantly determines the state of its partner.

In the new, record-breaking experiment, researchers from the University of Geneva, NASA's Jet Propulsion Laboratory and the National Institute of Standards and Technology used a superfast laser to pump out photons. Every once in a while, two photons would become entangled. Once the researchers had an entangled pair, they sent one down the optical fiber and stored the other in a crystal at the end of the cable. Then, the researchers shot a third particle of light at the photon traveling down the cable. When the two collided, they obliterated each other.

Quantum information has already been transferred dozens of miles, but this is the farthest it's been transported using an optical fiber, and then recorded and stored at the other end. Other quantum teleportation experiments that beamed photons farther used lasers instead of optical fibers to send the information. But unlike the laser method, the optical-fiber method could eventually be used to develop technology like quantum computers that are capable of extremely fast computing, or quantum cryptography that could make secure communication possible.

Keith Wayne Brown's curator insight, December 10, 2014 1:48 PM

the future information

Scooped by Dr. Stefan Gruenwald!

Smoking Still Causes A Large Proportion of Cancer Deaths in the United States

Smoking Still Causes A Large Proportion of Cancer Deaths in the United States | Amazing Science |
More than 30 years ago, a groundbreaking analysis by famed British researchers, Richard Doll and Richard Peto, calculated that 30 percent of all cancer deaths in the United States were caused by smoking. Since that time, no new estimate of this percentage has been published in the scientific literature. During that same time, smoking rates have dropped, but new cancers have been added to the list of those established as caused by smoking and lung cancer death rates among female smokers have increased.

To provide a well-documented estimate for cigarette smoking and cancer mortality in the contemporary United States, researchers led by Eric J. Jacobs, PhD, looked at the most recent data on smoking rates from the National Health Interview Survey (NHIS) as well as data on the risks of smoking derived from epidemiologic studies, to estimate what is called the population attributable fraction (PAF), described as the proportion of cancer deaths in the population caused by smoking.

The authors found that the PAF for active cigarette smoking was 28.7% when estimated conservatively, including only deaths from the 12 cancers currently formally established as caused by smoking by the US Surgeon General. When estimated more comprehensively, including excess deaths from all cancers, the PAF was 31.7% percent. These estimates do not include additional potential cancer deaths from environmental tobacco smoke or other type of tobacco use such as cigars, pipes, or smokeless tobacco.

The authors say despite important declines in smoking prevalence, the PAF for smoking and cancer mortality estimated for 2010 is similar to the 30% estimated by Doll and Peto more than 30 years ago. But that does not indicate that declines in smoking rates have not made important contributions to reducing cancer mortality. Rather, other factors have contributed to increasing the PAF, including the addition of new cancers to the list of those counted as caused by smoking, increases over time in death rates from lung cancer among female smokers, and progress in reducing deaths from cancer caused by factors other than smoking.
Michael Mazo's curator insight, December 13, 2014 1:40 PM

Taking into consideration that most of the incredibly large and thriving tobacco companies are based in America its not surprise to see a large number of lung cancer related deaths to impact our nation. When these companies are reaping profits in any way possible, they will also do anything possible to continue this trend even if that means putting innocent people at risk. Although they pay a hefty tax on the cigarettes they sell, they still continue to large amounts of money and pay for advertising. If one were to stand the way of collecting their money, they would do anything in their power to remove you from the picture. In addition to being so rich, because of all their money it makes them very powerful. It doesn't take an individual to stop a company like this, it takes an entire nation.

Scooped by Dr. Stefan Gruenwald!

Small-Molecule Inhibition of BRDT for Male Contraception

Small-Molecule Inhibition of BRDT for Male Contraception | Amazing Science |

A pharmacologic approach to male contraception remains a longstanding challenge in medicine. Toward this objective, the spermatogenic effects of a selective small-molecule inhibitor (JQ1) of the bromodomain and extraterminal (BET) subfamily of epigenetic reader proteins are being explored. A team of scientists now reports potent inhibition of the testis-specific member BRDT, which is essential for chromatin remodeling during spermatogenesis. Biochemical and crystallographic studies confirm that occupancy of the BRDT acetyl-lysine binding pocket by JQ1 prevents recognition of acetylated histone H4. Treatment of mice with JQ1 reduced seminiferous tubule area, testis size, and spermatozoa number and motility without affecting hormone levels. Although JQ1-treated males mate normally, inhibitory effects of JQ1 evident at the spermatocyte and round spermatid stages cause a complete and reversible contraceptive effect. These data establish a new contraceptive that can cross the blood:testis boundary and inhibit bromodomain activity during spermatogenesis, providing a lead compound targeting the male germ cell for contraception.

National Microscope Exchange's comment, December 10, 2014 1:44 AM
Very Classic Defination
Scooped by Dr. Stefan Gruenwald!

Hooking Up The Brain To A Computer: Human Cyborgs Reveal How We Learn

Hooking Up The Brain To A Computer: Human Cyborgs Reveal How We Learn | Amazing Science |
Hooking the brain up to a computer can do more than let the severely disabled move artificial limbs. It is also revealing the secrets of how we learn

When the patient Scheuermann began losing control of her muscles in 1996, due to her genetic disorder—spinocerebellar degeneration— she gave up her successful business as a planner of murder-mystery-themed events. By 2002 her disease had confined her to a wheelchair, which she now operates by flexing her chin up and down. She retains control of the muscles only in her head and neck. “The signals are not getting from my brain to my nerves,” she explains. “My brain is saying, ‘Lift up!’ to my arm, and my arm is saying, ‘I caaaan't heeeear you.’”

Yet technology now exists to extract those brain commands and shuttle them directly to a robotic arm, bypassing the spinal cord and limbs. Inside Scheuermann's brain are two grids of electrodes roughly the size of a pinhead that were surgically implanted in her motor cortex, a band of tissue on the surface of the brain that controls movement. The electrodes detect the rate at which about 150 of her neurons fire. Thick cables plugged into her scalp relay their electrical activity to a lab computer. As Scheuerman thinks about moving the arm, she produces patterns of electrical oscillations that software on the computer can interpret and translate into digital commands to position the robotic limb. Maneuvering the arm and hand, she can clasp a bar of chocolate or a piece of string cheese before bringing the food to her mouth.

When neuroscientists first set out to develop brain-controlled prostheses, they assumed they would simply record neural activity passively, as if taping a speech at a conference. The transcript produced by the monitored neurons would then be translated readily into digital commands to manipulate a prosthetic arm or leg. “Early on there was this thought that you could really decode the mind,” says neuroscientist Karunesh Ganguly of the University of California, San Francisco.

Yet the brain is not static. This extraordinarily complex organ evolved to let its owner react swiftly to changing conditions related to food, mates and predators. The electrical activity whirring inside an animal's head morphs constantly to integrate new information as the external milieu shifts.

Ganguly's postdoctoral adviser, neuroscientist Jose M. Carmena of the University of California, Berkeley, wondered whether the brain might adapt to a prosthetic device as well. That an implant could induce immediate changes in brain activity—what scientists call neuroplasticity—was apparent even in 1969, when Eberhard Fetz, a young neuroscientist at the University of Washington, reported on an electrode placed in a monkey's brain to record a single neuron. Fetz decided to reward the animal with a banana-flavored pellet every time that neuron revved up. To his surprise, the creature quickly learned how to earn itself more bites of fake banana. This revelation—that a monkey could be trained to control the firing rate of an arbitrary neuron in its brain—is what Stanford University neuroscientist Krishna Shenoy calls the “Nobel Prize moment” in the field of brain-computer interfaces.

Scientists were beginning to discover, however, that neurons can adjust their tuning in response to the software. In a 2009 study Carmena and Ganguly detailed two key ways that neurons begin to learn. Two monkeys spent several days practicing with a robotic arm. As their dexterity improved, their neurons changed their preferred direction (to point down rather than to the right, for example) and broadened the range of firing rates they were capable of emitting. These tuning adjustments gave the neurons the ability to issue more precise commands when they dispatched their missives.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Promising new compound rapidly eliminates malaria parasite

Promising new compound rapidly eliminates malaria parasite | Amazing Science |
A promising anti-malarial compound tricks the immune system to rapidly destroy red blood cells infected with the malaria parasite but leave healthy cells unharmed, an international group of researchers has found. Planning has begun for safety trials of the compound in healthy adults.

The compound, (+)-SJ733, was developed from a molecule identified in a previous St. Jude-led study that helped to jumpstart worldwide anti-malarial drug development efforts. Malaria is caused by a parasite spread through the bite of an infected mosquito. The disease remains a major health threat to more than half the world's population, particularly children. The World Health Organization estimates that in Africa a child dies of malaria every minute.

In this study, researchers determined that (+)-SJ733 uses a novel mechanism to kill the parasite by recruiting the immune system to eliminate malaria-infected red blood cells. In a mouse model of malaria, a single dose of (+)-SJ733 killed 80 percent of malaria parasites within 24 hours. After 48 hours the parasite was undetectable.

Planning has begun for safety trials of the compound in healthy adults.

Laboratory evidence suggests that the compound's speed and mode of action work together to slow and suppress development of drug-resistant parasites. Drug resistance has long undermined efforts to treat and block malaria transmission.

"Our goal is to develop an affordable, fast-acting combination therapy that cures malaria with a single dose," said corresponding author R. Kiplin Guy, Ph.D., chair of the St. Jude Department of Chemical Biology and Therapeutics. "These results indicate that SJ733 and other compounds that act in a similar fashion are highly attractive additions to the global malaria eradication campaign, which would mean so much for the world's children, who are central to the mission of St. Jude."

Whole genome sequencing of the Plasmodium falciparum, the deadliest of the malaria parasites, revealed that (+)-SJ733 disrupted activity of the ATP4 protein in the parasites. The protein functions as a pump that the parasites depend on to maintain the proper sodium balance by removing excess sodium.

The sequencing effort was led by co-author Joseph DeRisi, Ph.D., a Howard Hughes Medical Institute investigator and chair of the University of California, San Francisco Department of Biochemistry and Biophysics. Investigators used the laboratory technique to determine the makeup of the DNA molecule in different strains of the malaria parasite.

Researchers showed that inhibiting ATP4 triggered a series of changes in malaria-infected red blood cells that marked them for destruction by the immune system. The infected cells changed shape and shrank in size. They also became more rigid and exhibited other alterations typical of aging red blood cells. The immune system responded using the same mechanism the body relies on to rid itself of aging red blood cells.

Another promising class of antimalarial compounds triggered the same changes in red blood cells infected with the malaria parasite, researchers reported. The drugs, called spiroindolones, also target the ATP4 protein. The drugs include NITD246, which is already in clinical trials for treatment of malaria. Those trials involve investigators at other institutions. "The data suggest that compounds targeting ATP4 induce physical changes in the infected red blood cells that allow the immune system or erythrocyte quality control mechanisms to recognize and rapidly eliminate infected cells," DeRisi said. "This rapid clearance response depends on the presence of both the parasite and the investigational drug. That is important because it leaves uninfected red blood cells, also known as erythrocytes, unharmed."

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Observation of two stars so close to each other that they will end up merging into a supermassive star

Observation of two stars so close to each other that they will end up merging into a supermassive star | Amazing Science |
A study of 'MY Camelopardalis' binary system, published in the journal Astronomy & Astrophysics, shows that the most massive stars are made up by merging with other smaller stars, as predicted by theoretical models.

Most of the stars in our galaxy have been formed in binary or multiple systems, some of which are "eclipsing", this is consists of two or more stars which, observed from Earth, undergo eclipses and mutual transits because of their orbital plane facing our planet. One such system is the eclipsing binary MY Camelopardalis (MY Cam). The journal Astronomy & Astrophysics has published an article on MY Cam, one of the most massive star known, with the results of observations from the Calar Alto Observatory (Almería) signed by astronomers at the University of Alicante, the Astrobiology Centre of the Spanish National Research Council (CAB-CSIC) and the Canaries' Astrophysics Institute (IAC), along with amateur astronomers. The article concludes that MY Cam is the most massive binary star observed and its components, two stars of spectral type O (blue, very hot and bright), 38 and 32 times the Sun's mass, are still on the main sequence and are very close to each other, with an orbital period of less than 1.2 days, in other words, the shortest orbital period in this type of stars. This indicates that the binary was virtually formed as it is now: the stars were almost in contact at the time they were formed.

The expected development is the merger of both components into a single object over 60 solar masses before any of them have time to evolve significantly. Hence, these results demonstrate the viability of some theoretical models suggesting that most massive stars are formed by merging less massive stars.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

A newly described method linearizes circular chromosomes and caps them with telomeres

A newly described method linearizes circular chromosomes and caps them with telomeres | Amazing Science |

Synthetic biologists often work with circular chromosomes to engineer genetic material because they’re stable and easy to manipulate, but they don’t resemble the natural shape of chromosomes in eukaryotes. Reporting in PNAS this week (November 5), Jef Boeke of NYU Langone Medical Center and postdoc Leslie Mitchell designed a tool, which they dubbed the telomerator, that straightens circular yeast chromosomes and adds telomeres to either end.

“To convert circular DNA to something more akin to a natural chromosome is appealing,” said Timothy Lu, a synthetic biologist at MIT who was not involved in the study. Lu said the telomerator could help advance a number of goals, from designing artificial chromosomes that encode complex pathways to testing the significance of telomere location in the genome. “It’s really a platform technology for downstream applications."

The telomerator includes an endonuclease target—the site where the DNA loop will be severed—flanked by telomere seed sequences that form the basis of telomere construction. The telomerator is inserted into a gene of interest in the circular chromosomes, and when an endonuclease cuts the sequence at the recognition site, each exposed end carries a seed sequence on which to build telomeres. “The reason you can actually linearize the molecule and produce a stable molecule is because this telomere seed sequence gets exposed,” explained Mitchell. She and Boeke engineered the telomerator so that it would be induced only in the presence of galactose, giving scientists an easy way to turn it on by simply changing the growth medium.

The researchers tested the telomerator on a synthetic chromosome designed a few years earlier, cutting it at 54 different genes. For 51 of the permutations, “we got pretty happy yeast at the end of the experiment,” said Boeke. For another three, it appeared that the proximity of essential genes to the new telomere interfered with their expression, a phenomenon known as telomeric silencing. Blocking telomeric silencing rescued the cells’ growth. “I would say we’ve worked out most of the kinks for yeast,” said Boeke. “All you need to decide right now is where you want to put it.”

Yo Suzuki, a synthetic biologist at the J. Craig Venter Institute, said that linearizing DNA is important to avoiding problems in meiotic recombination that can emerge with circular chromosomes. In particular, crossover events between two circular chromosomes can result in a chromosome with two centromeres, which would break during chromosome segregation. “If you have a linear molecule in yeast, you don’t have that problem,” Suzuki said.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

DNA-based memory can record multiple inputs from engineered gene circuits

DNA-based memory can record multiple inputs from engineered gene circuits | Amazing Science |

A new DNA-based recorder allows bioengineers to create cell cultures that detect information in their environment and store it for later use. Such 'designer' cells might in the future be used to monitor water quality in a village, or measure the amount of sugar a person eats. The technique is described this week in Science1.

In synthetic biology, genes are engineered to regulate each other's expression in such a way that they can perform logic operations similar to those in computer circuits. Memory storage has long been considered one of the key components needed to fulfil the promise of this technology.

“Building gene circuits requires not only computation and logic, but a way to store that information,” says bioengineer Timothy Lu of the Massachusetts Institute of Technology in Cambridge. “DNA provides a very stable form of memory and will allow us to do more complex computing tasks.”

In previous synthetic-biology attempts, data storage has been laborious to create. It also recorded only the presence or absence of one particular sensory input, and could be used only for limited applications. In the latest paper, Lu and his colleague Fahim Farzadfard describe how they can record many types of data simultaneously, and can register the accumulation of the input over time, like a car’s odometer counts kilometres. The stored information can then be read out by sequencing the DNA. They dub their method SCRIBE, for Synthetic Cellular Recorders Integrating Biological Events.

“It’s a nice addition to the toolbox”, which could complement other memory-storage techniques, says Jérôme Bonnet, a bioengineer at the Centre for Structural Biochemistry in Montpellier, France, who was not involved in the research. “There’s room for different types of memory in synthetic biology — as in computing you have the hard drive and the RAM.”

In a proof-of-concept experiment described in their latest paper, the team created a colony of Escherichia coli bacteria in which retrons responded to the presence of a chemical, flipping a switch in the E. coli genome that made it resistant to an antibiotic. This transformation did not happen to the same extent inside every E. coli cell in the colony, howeverThe higher the concentration of the triggering chemical, the greater was the proportion of cells that ended up antibiotic resistant.

Unlike previous methods that serve as a digital form of memory — turning on or off like a light switch — SCRIBE could work as an 'analog' form of memory that functions more like a dimmer switch. The memory is not contained in a single E. coli cell, but in the entire culture. “Distributing memory across this population becomes a powerful way of doing things.”

Mike Dele's curator insight, March 20, 2015 7:52 PM

i am thinking towards a situation where the human race will be able to use DNA recorders for combating crime. The idea seems to be an unrealistic one, but if it can be achieved the world might witness one of the  crime  free era of our history, because it will make a criminal investigation  a lot easier and it will also be able to record and give an accurate location of someone if been tracked. 

Scooped by Dr. Stefan Gruenwald!

NASA found ancient lake on Mars capable to support life for thousands of years

NASA found ancient lake on Mars capable to support life for thousands of years | Amazing Science |

An ancient lake on Mars was capable of supporting life for tens or hundreds of thousands of years, researchers reported today based on findings from NASA's Curiosity rover. In March, NASA announced that the lake was once capable of supporting microbial life, but little more was known. Now researchers have shown that the lake existed around 3.5-3.6 billion years ago and actually contained an "Earth-like" environment. "There would have been some snow, maybe ice up in the mountains around the crater rim," John Grotzinger, project scientist for Curiosity, said at a press conference this morning. "It's pretty darn similar to Earth.

Not long after touching down in the Gale Crater last August, NASA's Curiosity rover was driven over to Yellowknife Bay, a trough over 16 feet deep made up of basaltic sandstones. It's there, near the edges of the lake where lower levels of dirt are accessible, that researchers tested to see if microorganisms could have existed. In particular, they say that chemolithoautotrophs — a type of microorganism commonly found in caves on Earth — could have existed in the lake's environment, breaking down the area's rocks and minerals for energy as they do on Earth.

The Martian lake would have been around 30 miles long and 3 miles wide, or as Grotzinger puts it, "typical of a small Finger Lake of Upstate New York." The researchers say that liquid water once existed there, and they've previously speculated that it would actually have been drinkable because of its low salinity and neutral acidity level. Actual signs of microbial life haven't been detected yet, but researchers say that an elemental cocktail that would have supported them was certainly present.

The research was presented at the American Geophysical Union and is published in a series of papers in Science.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

New Explanation For Earth's Biggest Migration of Animals

New Explanation For Earth's Biggest Migration of Animals | Amazing Science |

Each day small sea creatures known as plankton rise from deep underwater to the ocean's surface during the night and then return to the depths in daytime. Zoologists describe this “diel” movement, named after the Latin word for day, as Earth’s biggest migration. The stimulus for this mass migration has long puzzled scientists. But a team from the European Molecular Biology Laboratory in Heidelberg, Germany has now discovered a likely answer: melatonin, the hormone that influences humans' sleep patterns so significantly that it's sometimes taken to relieve the effects of jet lag.

The team focused on larvae of the plankton species Platynereis dumerilii, a type of marine worm. “This is the only plankton model species amenable to molecular development, neurobiology, and behavioral studies,” said zoologist Detlev Arendt, who led the study. The team identified a group of brain cells in the larvae that respond to light, run an internal clock that differentiates day from night, and – most important – make melatonin during the night.

The melatonin, channeled through other types of neurons, apparently triggered the worms to begin dropping below the surface. During the day, however, the production of melatonin stops. That seemed to cause the plankton to move back up to the ocean surface.

To confirm melatonin’s role, the team influenced the behavior pattern artificially. “When we exposed the larvae to melatonin during the day, they switched towards night-time behavior,” team member Maria Antonietta Tosches said. “It’s as if they were jet-lagged.” The research, reported in the journal Cell, indicates that melatonin works by influencing the physical process responsible for the larvae’s up-and-down travels.

The process relies on a series of microscopic flippers, called cilia. Arranged in a belt around each larva’s middle, they drive the larvae upward by beating up and down at a rapid rate, rather like the flapping of birds’ wings. Once the larvae reach the surface at dusk, the beating slows down. As a result, the larvae start to sink. By morning, they have settled back down in the depths, which shelter them from the damaging ultraviolet rays that strike the water surface during daylight.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

The harlequin filefish uses 'smell camouflage' to hide from predators

The harlequin filefish uses 'smell camouflage' to hide from predators | Amazing Science |

The harlequin filefish is a master of disguise. The reef-dwelling fish (Oxymonacanthus longirostris) sports a brightly colored pattern that allows it to fade into the coral it calls home. Now, scientists have discovered that the filefish doesn’t just look like a branch of coral—it smells like one, too. The researchers report online today in the Proceedings of the Royal Society B that the animal picks up the smell of the corals it feeds on, which serves as a handy disguise from the cunning predators that use odor to hunt down their prey. To identify this chemical camouflage, the team placed cod—a common predator of reef fish—in tanks with filefish and a species of coral that either matched their diet or a coral species the fish hadn’t been feeding on. The filefish were hidden inside perforated containers within the aquarium so that the cod could only smell, and not see, their prey. The researchers found that cod were much less likely to hang out around the filefish container when the species of coral present matched the reef fish’s last meals. Exactly how the filefish retains the coral smell is still unknown, but the disguise even fooled coral-feeding crabs. When the researchers gave the crabs a choice between their favorite corals and a filefish that fed on their favorite corals, they often chose the filefish. Many invertebrate species, like caterpillars, are known to incorporate compounds from the plants they eat into the outer layer of their skin to hide from hungry predators. But the filefish is the first vertebrate species found to camouflage its smell, which means that the behavior could be even more widespread across the animal kingdom than previously thought.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Paging through history: parchment as a reservoir of ancient DNA for next generation sequencing

Paging through history: parchment as a reservoir of ancient DNA for next generation sequencing | Amazing Science |

Parchment represents an invaluable cultural reservoir. Retrieving an additional layer of information from these abundant, dated livestock-skins via the use of ancient DNA (aDNA) sequencing has been mooted by a number of researchers. However, prior PCR-based work has indicated that this may be challenged by cross-individual and cross-species contamination, perhaps from the bulk parchment preparation process.

A group of scientists now applied next generation sequencing to two parchments of seventeenth and eighteenth century northern English provenance. Following alignment to the published sheep, goat, cow and human genomes, it is clear that the only genome displaying substantial unique homology is sheep and this species identification is confirmed by collagen peptide mass spectrometry. Only 4% of sequence reads align preferentially to a different species indicating low contamination across species. Moreover, mitochondrial DNA sequences suggest an upper bound of contamination at 5%. Over 45% of reads aligned to the sheep genome, and even this limited sequencing exercise yield 9 and 7% of each sampled sheep genome post filtering, allowing the mapping of genetic affinity to modern British sheep breeds. The scientists conclude that parchment represents an excellent substrate for genomic analyses of historical livestock.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Birds, bees, lizards, elephants, and chimpanzees all share a survival trait: They self-medicate

Birds, bees, lizards, elephants, and chimpanzees all share a survival trait: They self-medicate | Amazing Science |

Anyone who has seen a dog eat grass during a walk has witnessed self-medication. The dog probably has an upset stomach or a parasite. The grass helps them vomit up the problem or eliminate it with the feces.

The science of animal self-medication is called zoopharmacognosy, derived from the roots zoo (“animal”), pharma (“drug”), and gnosy (“knowing”). It’s not clear how much knowing or learning is involved, but many animals seem to have evolved an innate ability to detect the therapeutic constituents in plants. Although the evidence is entirely circumstantial, the examples are plentiful. The practice is spreading across the animal kingdom in sometimes surprising ways.

Most studies of animal self-medication, however, are in the great apes. In the 1960s, the Japanese anthropologist Toshisada Nishida observed chimpanzees in Tanzania eating aspella leaves, which had no nutritional value. Harvard primatologist Richard Wrangham saw the same behavior at Jane Goodall’s Gombe reserve, where chimps were swallowing leaves whole. Other scientists noted the same in other chimp colonies. Without chewing, the animals weren’t getting much nutritional benefit. So why do it?

In 1996, biologist Michael Huffman suggested the chimps were self-medicating. Huffman, an American who has worked for years in Japan at the Primate Research Institute at Kyoto University, first saw a parasite-ridden, constipated chimpanzee in Tanzania chew on the leaves of a noxious plant it would normally avoid. By the next day, the chimpanzee was completely recovered (1).

The plants had bristly leaves, rough to the touch. Huffman theorized the chimps were swallowing the plants to take advantage of that roughness, using the leaves and stems to scour their intestines and rid themselves of parasites. Other researchers observed the same practice among other apes across Africa.

Huffman established widely used criteria for judging when an animal is self-medicating. First, the plant eaten cannot be a regular part of the animal’s diet; it is used as medicine not food. Second, the plant must provide little or no nutritional value to the animal. Third, the plant must be consumed during those times of year—for example, the rainy season—when parasites are most likely to cause infections. Fourth, other animals in the group don’t participate (2, 3). If the activity meets these standards, it is safe to assume the animal is self-medicating, Huffman says. Researchers have observed the practice in 25 regions involving 40 different plants.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Berkeley Lab Researchers Set World Record for Compact Particle Accelerator

Berkeley Lab Researchers Set World Record for Compact Particle Accelerator | Amazing Science |

Using one of the most powerful lasers in the world, researchers have accelerated subatomic particles to the highest energies ever recorded from a compact accelerator. The team, from the U.S. Department of Energy’s Lawrence Berkeley National Lab (Berkeley Lab), used a specialized petawatt laser and a charged-particle gas called plasma to get the particles up to speed. The setup is known as a laser-plasma accelerator, an emerging class of particle accelerators that physicists believe can shrink traditional, miles-long accelerators to machines that can fit on a table.

The researchers sped up the particles—electrons in this case—inside a nine-centimeter long tube of plasma. The speed corresponded to an energy of 4.25 giga-electron volts. The acceleration over such a short distance corresponds to an energy gradient 1000 times greater than traditional particle accelerators and marks a world record energy for laser-plasma accelerators.

“This result requires exquisite control over the laser and the plasma,” says Dr. Wim Leemans, director of the Accelerator Technology and Applied Physics Division at Berkeley Lab and lead author on the paper. The results appear in the most recent issue of Physical Review Letters.

Traditional particle accelerators, like the Large Hadron Collider at CERN, which is 17 miles in circumference, speed up particles by modulating electric fields inside a metal cavity. It’s a technique that has a limit of about 100 mega-electron volts per meter before the metal breaks down.

Laser-plasma accelerators take a completely different approach. In the case of this experiment, a pulse of laser light is injected into a short and thin straw-like tube that contains plasma. The laser creates a channel through the plasma as well as waves that trap free electrons and accelerate them to high energies. It’s similar to the way that a surfer gains speed when skimming down the face of a wave.

The record-breaking energies were achieved with the help of BELLA (Berkeley Lab Laser Accelerator), one of the most powerful lasers in the world. BELLA, which produces a quadrillion watts of power (a petawatt), began operation just last year.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Where are my veins? World-first vein viewing technology

Where are my veins? World-first vein viewing technology | Amazing Science |

Do you have hard-to-find veins? Don’t let that stop you from donating blood.  In a world-first study, the Australian Red Cross Blood service is conducting research into the use of leading-edge technology to visualise blood donors’ veins during blood donation.

The vein visualization devices are portable, and project an image of the veins onto the skin’s surface using non-invasive near infra-red technology. The Blood Service is aiming to find out if this procedure reduces anxiety, improves donation comfort and makes donors more likely to donate again.

The study will assess the responses of 300 first-time and 600 return donors aged between 18 and 30 attending the Chatswood and Elizabeth Street Donor Centres in Sydney. "Donor Centre staff have found the technology particularly useful in cases where the vein is not visible to the naked eye” said Dr Dan Waller, one of the senior investigators on the trial.

“We are keen to retain our young donors, and it is important to test if this technology may help us do that.”

No comment yet.
Scooped by Dr. Stefan Gruenwald!

45-year physics mystery shows a path to quantum transistors

45-year physics mystery shows a path to quantum transistors | Amazing Science |
An odd, iridescent material that's puzzled physicists for decades turns out to be an exotic state of matter that could open a new path to quantum computers and other next-generation electronics.

Physicists at the University of Michigan have discovered or confirmed several properties of the compound samarium hexaboride that raise hopes for finding the silicon of the quantum era. They say their results also close the case of how to classify the material—a mystery that has been investigated since the late 1960s.

The researchers provide the first direct evidence that samarium hexaboride, abbreviated SmB6, is a topological insulator. Topological insulators are, to physicists, an exciting class of solids that conduct electricity like a metal across their surface, but block the flow of current like rubber through their interior. They behave in this two-faced way despite that their chemical composition is the same throughout.

The U-M scientists used a technique called torque magnetometry to observe tell-tale oscillations in the material's response to a magnetic field that reveal how electric current moves through it. Their technique also showed that the surface of samarium hexaboride holds rare Dirac electrons, particles with the potential to help researchers overcome one of the biggest hurdles in quantum computing.

These properties are particularly enticing to scientists because SmB6 is considered a strongly correlated material. Its electrons interact more closely with one another than most solids. This helps its interior maintain electricity-blocking behavior.

This deeper understanding of samarium hexaboride raises the possibility that engineers might one day route the flow of electric current in quantum computers like they do on silicon in conventional electronics, said Lu Li, assistant professor of physics in the College of Literature, Science, and the Arts and a co-author of a paper on the findings published in Science.
Miro Svetlik's curator insight, December 11, 2014 4:55 AM

New compounds like this are much needed to simplify the production or even make breakthrough for new kind of quantum circuits. If we harness their properties quantum computing will be again a step closer to the mainstream.

Scooped by Dr. Stefan Gruenwald!

California's drought is the worst in 1,200 years, evidence suggests

California's drought is the worst in 1,200 years, evidence suggests | Amazing Science |
As California finally experiences the arrival of a rain-bearing Pineapple Express this week, two climate scientists have shown that the drought of 2012-2014 has been the worst in 1,200 years.

Daniel Griffin, an assistant professor in the Department of Geography, Environment and Society at the University of Minnesota, and Kevin Anchukaitis, an assistant scientist at Woods Hole Oceanographic Institution, asked the question, "How unusual is the ongoing California drought?" Watching the severity of the California drought intensify since last autumn, they wondered how it would eventually compare to other extreme droughts throughout the state's history.

To answer those questions, Griffin and Anchukaitis collected new tree-ring samples from blue oak trees in southern and central California. "California's old blue oaks are as close to nature's rain gauges as we get," says Griffin. "They thrive in some of California's driest environments." These trees are particularly sensitive to moisture changes and their tree rings display moisture fluctuations vividly.

As soon as the National Oceanic and Atmospheric Administration (NOAA) released climate data for the summer of 2014, the two scientists sprang into action. Using their blue oak data, they reconstructed rainfall back to the 13th century. They also calculated the severity of the drought by combining NOAA's estimates of the Palmer Drought Severity Index (PDSI), an index of soil moisture variability, with the existing North American Drought Atlas, a spatial tree-ring based reconstruction of drought developed by scientists at Columbia University's Lamont-Doherty Earth Observatory. These resources together provided complementary data on rainfall and soil moisture over the past millennium. Griffin and Anchukaitis found that while the current period of low precipitation is not unusual in California's history, these rainfall deficits combined with sustained record high temperatures created the current multiyear severe water shortages. "While it is precipitation that sets the rhythm of California drought, temperature weighs in on the pitch," says Anchukaitis.

"We were genuinely surprised at the result," says Griffin, a NOAA Climate & Global Change Fellow and former WHOI postdoctoral scholar. "This is California--drought happens. Time and again, the most common result in tree-ring studies is that drought episodes in the past were more extreme than those of more recent eras. This time, however, the result was different." While there is good evidence of past sustained, multi-decadal droughts or so-called "megadroughts"' in California, the authors say those past episodes were probably punctuated by occasional wet years, even if the cumulative effect over decades was one of overall drying. The current short-term drought appears to be worse than any previous span of consecutive years of drought without reprieve.

Tree rings are a valuable data source when tracking historical climate, weather and natural disaster trends. Floods, fires, drought and other elements that can affect growing conditions are reflected in the development of tree rings, and since each ring represents one year the samples collected from centuries-old trees are a virtual timeline that extend beyond the historical record in North America.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Chemists create ‘artificial chemical evolution’ for the first time

Chemists create ‘artificial chemical evolution’ for the first time | Amazing Science |

Scientists have taken an important step towards the possibility of creating synthetic life with the development of a form of artificial evolution in a simple chemistry set without DNA.

A team from the University of Glasgow’s School of Chemistry report in a new paper in the journal Nature Communications today (Monday 8 December) on how they have managed to create an evolving chemical system for the first time. The process uses a robotic ‘aid’ and could be used in the future to ‘evolve’ new chemicals capable of performing specific tasks.

The researchers used a specially-designed open source robot based upon a cheap 3D printer to create and monitor droplets of oil in water-filled Petri dishes in their lab. Each droplet was composed from a slightly different mixture of four chemical compounds.

Droplets of oil move in water like primitive chemical machines, transferring chemical energy to kinetic energy. The researchers’ robot used a video camera to monitor, process and analyse the behaviour of 225 differently-composed droplets, identifying a number of distinct characteristics such as vibration or clustering.

The team picked out three types of droplet behavior – division, movement and vibration – to focus on in the next stage of the research. They used the robot to deposit four droplets of the same composition, then ranked the droplets in order of how closely they fit the criteria of behaviour identified by the researchers. The chemical composition of the ‘fittest’ droplet was then carried over into a second generation of droplets, and the process of robotic selection was begun again.

Over the course of 20 repetitions of the process, the researchers found that the droplets became more stable, mimicking the natural selection of evolution.

The research team was led by Professor Lee Cronin, the University of Glasgow’s Regius Chair of Chemistry. Professor Cronin said: “This is the first time that an evolvable chemical system has existed outside of biology. Biological evolution has given rise to enormously complex and sophisticated forms of life, and our robot-driven form of evolution could have the potential to do something similar for chemical systems.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

NASA reentered the field of manned spaceflight as it launched the first Orion crew capsule into space today

NASA reentered the field of manned spaceflight as it launched the first Orion crew capsule into space today | Amazing Science |

NASA marked a major milestone Friday as the Orion spacecraft completed its first voyage to space, traveling farther than any spacecraft designed for astronauts has been in more than 40 years. “Today’s flight test of Orion is a huge step for NASA and a really critical part of our work to pioneer deep space on our Journey to Mars,” said NASA Administrator Charles Bolden. “The teams did a tremendous job putting Orion through its paces in the real environment it will endure as we push the boundary of human exploration in the coming years.”

Following a perfect launch and more than four hours in Earth's orbit, NASA's Orion spacecraft is seen from an unpiloted aircraft descending under three massive red and white main parachutes and then shortly after its bullseye splashdown in the Pacific Ocean, 600 miles southwest of San Diego. During the uncrewed test, Orion traveled twice through the Van Allen belt, where it experienced periods of intense radiation, and reached an altitude of 3,600 miles above Earth. The spacecraft hit speeds of 20,000 mph and weathered temperatures approaching 4,000 degrees Fahrenheit as it entered Earth’s atmosphere.

NASA marked a major milestone Friday on its journey to Mars as the Orion spacecraft completed its first voyage to space, traveling farther than any spacecraft designed for astronauts has been in more than 40 years. “Today’s flight test of Orion is a huge step for NASA and a really critical part of our work to pioneer deep space on our Journey to Mars,” said NASA Administrator Charles Bolden. “The teams did a tremendous job putting Orion through its paces in the real environment it will endure as we push the boundary of human exploration in the coming years."

No comment yet.