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From fish to human: Research reveals how fins became legs

From fish to human: Research reveals how fins became legs | Amazing Science | Scoop.it
Vertebrates' transition to living on land, instead of only in water, represented a major event in the history of life. Now, researchers reporting in the December issue of the Cell Press journal Developmental Cell provide new evidence that the development of hands and feet occurred through the gain of new DNA elements that activate particular genes.

In order to understand how fins may have evolved into limbs, researchers led by Dr. Gómez-Skarmeta and his colleague Dr. Fernando Casares at the same institute introduced extra Hoxd13, a gene known to play a role in distinguishing body parts, at the tip of a zebrafish embryo's fin. Surprisingly, this led to the generation of new cartilage tissue and the reduction of fin tissue -- changes that strikingly recapitulate key aspects of land-animal limb development. The researchers wondered whether novel Hoxd13 control elements may have increased Hoxd13 gene expression in the past to cause similar effects during limb evolution. They turned to a DNA control element that is known to regulate the activation of Hoxd13 in mouse embryonic limbs and that is absent in fish.

"We found that in the zebrafish, the mouse Hoxd13 control element was capable of driving gene expression in the distal fin rudiment. This result indicates that molecular machinery capable of activating this control element was also present in the last common ancestor of finned and legged animals and is proven by its remnants in zebrafish," says Dr. Casares.

The picture above depicts a zebrafish embryo which developed a limb that looks more like a leg than a fin, after being engineered to produce the HoxD13 protein within the cells at the tip of the developing fin. Changes in HoxD13 production likely contributed to the transition from fin to leg development, during animal evolution.
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Scientists discover mechanism around Tyk2 and Stat3 that could reduce obesity

Scientists discover mechanism around Tyk2 and Stat3 that could reduce obesity | Amazing Science | Scoop.it
The scientists were able to reverse obesity in mice that do not express Tyk2 by expressing a protein known as signal transducer and activator of transcription-3 (Stat3). Stat3 mediates the expression of a variety of genes that regulate a host of cellular processes. The researchers found that Stat3 formed a complex with a protein known as PR domain containing 16 (PRDM16) to restore the development of BAT and decrease obesity.

“We discovered that Tyk2 levels in mice are regulated by diet. We then tested tissue samples from humans and found that levels of Tyk2 were more than 50 percent lower in obese humans,” said Larner, Martha Anne Hatcher Distinguished Professor in Oncology and co-leader of the Cancer Cell Signaling program at VCU Massey Cancer Center. “Our findings open new potential avenues for research and development of new pharmacological and nutritional treatments for obesity.”

There are two different types of fat – white adipose tissue (WAT) and BAT. WAT is the primary site of energy storage. BAT is responsible for energy expenditure in order to maintain body temperature. BAT deposits are present in all mammals, but until recently, scientists thought BAT was only active in infants and not in adult humans. Only in the last four years have scientists realized that BAT is present in adults and helps to regulate energy expenditure. Additionally, research has shown that diminished BAT activity is associated with metabolic syndrome, a combination of medical disorders that increase the risk of developing cardiovascular disease and diabetes. Researchers estimate metabolic syndrome could affect as much as 25 percent of the U.S. population.

“We have made some very interesting observations in this study, but there are many questions left unanswered,” said Larner. “We plan to further investigate the actions of Tyk2 and Stat3 in order to better understand the mechanisms involved in the development of brown adipose tissue. We’re hopeful this research will help lead to new targets to treat a variety of obesity-related diseases such as cancer, cardiovascular disease and diabetes.”

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New SARS-Like Virus Infects Both Human and Animal Cells

New SARS-Like Virus Infects Both Human and Animal Cells | Amazing Science | Scoop.it
A SARS-like virus discovered this summer in the Middle East may infect more than just humans. The pathogen, a close cousin to the one that caused the 2002 to 2003 SARS outbreak, may also be able to infect cells from pigs and a wide range of bat species, researchers report today. The findings may help public health officials track the source of the outbreak and identify the role of wild animals and livestock in spreading the virus, researchers say.

Scientists first detected the virus in a 60-year-old man from Jeddah, Saudi Arabia, who developed severe pneumonia this past spring. Unable to identify the microbe causing the illness, doctors sent samples to Erasmus MC in Rotterdam, the Netherlands. There, scientists identified the infectious agent as a coronavirus, a group known to cause many ailments, such as the common cold and a variety of gastrointestinal infections. Cases have popped up in Qatar and Jordan as well; in total, researchers have so far confirmed nine infections, including five deaths. Several other cases are suspected but haven't been confirmed.

Researchers have fully sequenced the virus, which they dubbed hCoV-EMC (short for human coronavirus-Erasmus Medical Center). Scientists knew that the SARS virus uses a receptor called ACE2 to pry open cells. Because these receptors are mainly found deep inside the human lung, patients developed very severe illness that frequently left them too sick to spread SARS to many others; the people most at risk were health care workers who take care of patients. If hCoV-EMC used the same receptor, researchers would have a head start in understanding how it spreads and how to stop it—primarily by protecting health care workers. It might also help them in the development of drugs and vaccines. To find out, the team engineered baby hamster kidney cells to express the human ACE2 receptor. These cells could be infected with the SARS coronavirus, as expected, but not hCoV-EMC. That finding, supported by additional experiments, led them to conclude that the new coronavirus does not use ACE2 to get in.

Epidemiologists also want to know which species of animals it is capable of infecting to keep the new coronavirus from spreading further. To determine what types of animals hCoV-EMC can infect, Drosten and colleagues infected cells from humans, pigs, and a wide variety of bats, the key natural reservoirs of coronaviruses. The new virus could infect all of these types of cells. "It's unusual for a coronavirus to easily go back to bats," Drosten says. "Most coronaviruses come from bats, but once they jump to other species, you could never get them to reinfect bat cells." The SARS virus, for instance, originated in Chinese horseshoe bats, but once it ended up in humans, it had changed so much that scientists were unable to infect bat cells with it. Based on the findings, however, it seems likely that the new coronavirus can infect a wide range of species, Drosten says. That means public health officials may have to start looking for infections and deaths in local wild animal and livestock populations to keep the virus in check, he says.
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After 9 years and 18 expeditions to New Guinea, we now have pictures of every living species of bird of paradise

After 9 years and 18 expeditions to New Guinea, we now have pictures of every living species of bird of paradise | Amazing Science | Scoop.it
It took eight years. But now every bird of paradise species has been photographed in the wild.

Birds of paradise represent an extreme example of Charles Darwin’s theory of sexual selection: Females choose mates based on certain appealing characteristics, thus increasing the odds that those traits will pass from one generation to the next. In New Guinea an abundance of food and a scarcity of predators have allowed the birds to flourish—and to exaggerate their most attractive traits to a degree that even literal-minded scientists have called absurd.

The brilliant plumes have been prized as decorative objects in Asia for thousands of years. Hunters who traded the first specimens to Europeans in the 16th century often removed the birds’ wings and legs to emphasize plumes. This inspired a notion that they were literally the birds of the gods, floating through the heavens without ever alighting, gathering sustenance from the paradisiacal mists.
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The many maps of the brain

The many maps of the brain | Amazing Science | Scoop.it
Your brain has at least four different senses of location — and perhaps as many as 10 — and each is different, according to new research from the Kavli Institute for Systems Neuroscience at the Norwegian University of Science and Technology.

The brain has a number of “modules” dedicated to self-location, they found. Each module contains its own internal GPS-like mapping system that keeps track of movement, and has other characteristics that also distinguish one motion from another.

“We have at least four senses of location,” says Edvard Moser, director of the Kavli Institute. “Each has its own scale for representing the external environment, ranging from very fine to very coarse.

“The different modules react differently to changes in the environment. Some may scale the brain’s inner map to the surroundings, others do not. And they operate independently of each other in several ways.”

This is also the first time that researchers have been able to show that a part of the brain that does not directly respond to sensory input, called the association cortex, is organized into modules. The research was conducted using rats.
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Caltech engineers have created a device that can focus light into a single point just a few nanometers across

Caltech engineers have created a device that can focus light into a single point just a few nanometers across | Amazing Science | Scoop.it
As technology advances, it tends to shrink. From cell phones to laptops—powered by increasingly faster and tinier processors—everything is getting thinner and sleeker. And now light beams are getting smaller, too.

Engineers at the California Institute of Technology (Caltech) have created a device that can focus light into a point just a few nanometers (billionths of a meter) across—an achievement they say may lead to next-generation applications in computing, communications, and imaging. Because light can carry greater amounts of data more efficiently than electrical signals traveling through copper wires, today's technology is increasingly based on optics. The world is already connected by thousands of miles of optical-fiber cables that deliver email, images, and the latest video gone viral to your laptop. As we all produce and consume more data, computers and communication networks must be able to handle the deluge of information. Focusing light into tinier spaces can squeeze more data through optical fibers and increase bandwidth. Moreover, by being able to control light at such small scales, optical devices can also be made more compact, requiring less energy to power them. But focusing light to such minute scales is inherently difficult. Once you reach sizes smaller than the wavelength of light—a few hundred nanometers in the case of visible light—you reach what's called the diffraction limit, and it's physically impossible to focus the light any further. But now the Caltech researchers, co-led by assistant professor of electrical engineering Hyuck Choo, have built a new kind of waveguide—a tunnellike device that channels light—that gets around this natural limit. The waveguide is made of amorphous silicon dioxide—which is similar to common glass—and is covered in a thin layer of gold. Just under two microns long, the device is a rectangular box that tapers to a point at one end.

Instead of focusing the light alone—which is impossible due to the diffraction limit—the new device focuses these coupled electron oscillations, called surface plasmon polaritons (SPPs). The SPPs travel through the waveguide and are focused as they go through the pointy end. Because the new device is built on a semiconductor chip with standard nanofabrication techniques, says Choo, the co-lead and the co-corresponding author of the paper, it is easy integrate with today's technology Previous on-chip nanofocusing devices were only able to focus light into a narrow line. They also were inefficient, typically focusing only a few percent of the incident photons, with the majority absorbed and scattered as they traveled through the devices. With the new device, light can ultimately be focused in three dimensions, producing a point a few nanometers across, and using half of the light that's sent through, Choo says. (Focusing the light into a slightly bigger spot, 14 by 80 nanometers in size, boosts the efficiency to 70 percent). The key feature behind the device's focusing ability and efficiency, he says, is its unique design and shape.
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Princeton’s nanomesh nearly triples solar cell efficiency

Princeton’s nanomesh nearly triples solar cell efficiency | Amazing Science | Scoop.it

There is huge potential in solar power. The sun is a giant ball of burning hydrogen in the sky, and it’s going to be sticking around for at least a few more billion years. For all intents and purposes, it’s a free source of energy. Sadly, humanity hasn’t been very good at harnessing its power directly. Our current methods of capturing the sun’s energy are very inefficient. For example, modern silicon and indium-tin-oxide-based solar cells are approaching the theoretical limit of 33.7% efficiency. Well, a research team at Princeton has used nanotechnology to create a mesh that increases efficiency over organic solar cells nearly three fold.

Led by Stephen Chou, the team has made two dramatic improvements: reducing reflectivity, and more effectively capturing the light that isn’t reflected. As you can see by the illustration below by Dimitri Karetnikov, Princeton’s new solar cell is much thinner and less reflective. By utilizing sandwiched plastic and metal with the nanomesh, this so-called “Plasmonic Cavity with Subwavelength Hole array” or “PlaCSH” substantially reduces the potential for losing the light itself. In fact, it only reflects about 4% of direct sunlight, leading to a 52% higher efficiency than conventional, organic solar cells.

PlaCSH is also capable of capturing a large amount of sunlight even when the sunlight is dispersed on cloudy days, which results in an amazing 81% increase in efficiency under indirect lighting conditions when compared to conventional organic solar cell technology. All told, PlaCSH is up to 175% more efficient than conventional solar cells. As you can see in the image to the right, the difference in reflectivity between conventional and PlaCSH solar cells is really quite dramatic.

The gold mesh that sits on top is incredibly small. It’s only 30 nanometers thick. The holes in the mesh are a mere 175nm in diameter. This replaces the much thicker traditional top layer made out of indium-tin-oxide (ITO). This is the most important part of the innovation. Because the mesh is actually smaller than the wavelength of the light it’s trying to collect, it exploits the bizarre way that light works in subwavelength structures. This unique physical property allows the researchers to effectively capture the light once it enters the holes in the mesh instead of letting much of it reflect away. The bottom layer of the cell remains the same, but this implementation allows the semiconducting layer of plastic in the middle of the cell to be much thinner.

The research team believes that the cells can be made cost effectively using a nanofabrication method that Chou himself invented over a decade ago. Most importantly, it replaces the costly ITO element from solar cells. This will be affordable, and much more flexible than the brittle ITO layer of traditional solar cells. While research is still being done using semiconducting materials other than plastic, this method should work for silicon and gallium arsenide solar cells as well, so it will be able to reduce the size and cost of them drastically while providing similar efficiency benefits.

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Small circles of extrachromosomal DNA appear to be widespread in mammals

Small circles of extrachromosomal DNA appear to be widespread in mammals | Amazing Science | Scoop.it
A newly identified form of DNA—small circles of non-repetitive sequences—may be widespread in somatic cells of mice and humans, according to a study in this week’s issue of Science. These extrachromosomal bits of DNA, dubbed microDNA, may be the byproducts of microdeletions in chromosomes, meaning that cells all over the body may have their own constellation of missing pieces of DNA.

 

“It’s an intriguing finding,” said James Lupski, a geneticist at Baylor College of Medicine in Houston who did not participate in the research. Most DNA studies use cells drawn from blood, but that snapshot of a person’s genome may not be giving a complete picture, Lupski explained, if cells in other organs have their own set of chromosomal snippets missing.

 

But the findings do not surprise Sabine Mai, who studies genomic instability at the University of Manitoba. Extrachromosomal DNA is a well-studied phenomenon in cells ranging from plants to humans, she says. This research is just renaming an old phenomenon, previously referred to small polydispersed DNA. Small circles of DNA have been identified before, Mai says, though new deep sequencing techniques will allow for a “deeper characterization” of these extrachromosomal snippets.

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US NSF: Artificial worlds - research at the AlloSphere facility

US NSF: Artificial worlds - research at the AlloSphere facility | Amazing Science | Scoop.it

A fluid dynamic environment containing bio-generative algorithms representing plant and insect-like life-forms. The image was produced as part of the Artificial Nature project at the AlloSphere, one of the largest immersive scientific instruments in the world.

 

The National Science Foundation (NSF)-supported AlloSphere is located at the California NanoSystems Institute (CNSI) building at the University of California, Santa Barbara. The AlloSphere takes scientific data that is too small to see and hear and visually and sonically magnifies it to a human scale so researchers can better analyze the data and find new patterns. Over 20 researchers can stand in the center of the sphere and be collectively immersed in multi-dimensional information. The AlloSphere infrastructure was completed in March 2007 and it is a key part of the Digital Media Center located within the CNSI.

 

Applications for the AlloSphere include audiovisual technologies, abstract arts and art entertainment, "green" technology, computers and networking, education, nanotechnology, physics, materials science, geography and remote sensing, human perception, behavior and cognition, and medicine and telemedicine.

 

More info about the AlloSpere is here:

http://nsf.gov/discoveries/disc_summ.jsp?cntn_id=121535&org=NSF

 

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It’s not a leaf - it's a bug! Insect mimicry goes back to the Jurassic

It’s not a leaf - it's a bug! Insect mimicry goes back to the Jurassic | Amazing Science | Scoop.it
File this one under turning-lemons-into lemonade: instead of getting frustrated by the difficulty of keeping track of fossil specimens—or maybe in addition to getting frustrated—Yongjie Wang at the College of Life Sciences in Beijing parlayed the confusion into the identification of a new species. The confusion came because the extinct hangingfly looks almost exactly like an extinct ginkgo leaf. Researchers speculate that the bugs may have mimicked the leaves in order to escape predators, and may also have provided a protective function, preventing other bugs from eating real leaves nearby.

 

Wang is not the first fossil collector to get his leaf and wing specimens mixed up. Modern leaf-mimicking insects were described in the tropics in the late 1930s. Once it was determined that this was no mere coincidence—that the bugs had evolved to look like the leaves as a strategy to avoid predators—fossil hunters remembered the similarities they had seen in their specimens. They thought: if bugs are imitating leaves now, maybe they were also doing it back in the day.

 

The Jiulongshan Formation, a rock deposit in Northeastern China’s Inner Mongolia, is full of fossils dating from the late Middle Jurassic—roughly a hundred and seventy million years ago. Back then, there were many more types of both Mecoptera (the order of insects that includes hangingflies) and Ginkgoales than there are today.

 

Wang et al. found that when one hangingfly species extended its wings, one of these bugs, Juracimbrophlebia ginkgofolia, would look just like the multilobed leaf from a ginkgo tree that lived at the same time, Yimaia capituliformis. They report that these trees and others with similar leaves comprised 12.4 percent of the total number of plant species in the area, so they would provide great camouflage for the hangingflies.

 

J. ginkgofolia were big bugs, with weak legs and wings, which is perhaps why they developed this mimetic strategy to avoid detection. Y. capituliformis were extinct by the Cretaceous, a hundred and sixty-six million years ago, and J. ginkgofolia seems to have been gone by then as well. The hangingflies that survived to the present day never resembled ginkgo leaves as much as those that died out—with the ginkgos largely dying off, that may be why they are the ones still hanging around.

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100M-Year-Old Non-Coding DNA Regions Identified in Four Plants

100M-Year-Old Non-Coding DNA Regions Identified in Four Plants | Amazing Science | Scoop.it

A computational analysis of the genomes of the papaya, poplar, grape, and a small flowering plant called Arabidopsis thaliana, has identified hundreds of 100-million-year-old non-coding DNA sequences shared between these plants.

 

These conserved non-coding sequences, discovered by an international group of biologists, are not genes, but are located in the promoters upstream of genes and are around 100 DNA base pairs in length. As the papaya, poplar, grape and Arabidopsis have evolved separately for around 100 million years, the fact that these DNA regions have been conserved suggests they play an important role in the plants’ development and functioning.

 

“We know that certain genes are conserved between species – but we also see that sequences outside of genes are conserved,” said senior author Dr. Sascha Ott of the University of Warwick’s Systems Biology Center. “The regions outside genes that we have discovered have been kept for millions and millions of years across four species. There must be a reason for this – if something has been around for so long it is probably useful in some way. We believe it may be because these regions have a very important role to play in how the plant develops and functions.”

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Telomerase Gene Therapy Extends Mouse Lifespan by 24%

Telomerase Gene Therapy Extends Mouse Lifespan by 24% | Amazing Science | Scoop.it
Inducing cells to express telomerase, the enzyme which is supposed to slow down the metabolic clock, has enabled researchers boost the lifespan of mouse by 24% with a single treatment.

 

The gene therapy acts on specific genes and is applied in adult life, not from the embryonic stage. Researchers at the Spanish National Cancer Research Center (CNIO) have demonstrated that the mouse lifespan can be extended by the application of one treatment acting directly on the animal’s genes in adult life. The therapy has been found to be safe and effective in mice.

 

Adult and aged mice were treated with the gene therapy, delivering a rejuvenating effect. On average, the mice lived 24% longer. The older mice lived 13% longer. The therapy produces an appreciable improvement on the animal’s health and delayed the onset of age-related diseases.

 

The genes were treated with a DNA-modified virus. The viral genes were replaced by those of the telomerase enzyme, which plays a key role in aging. Telomerase repairs the extreme ends of chromosomes, and slows the cells and therefore the body’s biological clock.

 

There is a potential to develop a telomerase-based anti-aging gene therapy that won’t increase the risk of cancer. Telomeres are the caps that protect the end of chromosomes, but each time the cell divides, the telomeres get shorter until they lose all functionality. The cell then stops dividing or dies. Telomerase prevents telomeres from shortening or even rebuilding them.

 

In most cells, telomerase is only active before birth. The cells of adult organisms contain no telomerase. There are some exceptions such as adult stem cells and cancer cells, which divide limitlessly and could be immortal.

 

The risk of cancer tumor promotion is a risk that has set back telomerase-based anti-aging therapies. The kind of virus employed to carry the telomerase gene to the cells is very important. The viruses used is in this study have been successfully used in gene therapy treatment of hemophilia and eye disease. They are non-replicating viruses derived from others that are non-pathogenic in humans.

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The incredible origami house that can change shape depending on the weather

The incredible origami house that can change shape depending on the weather | Amazing Science | Scoop.it

This new incredible folding house is able to, in the words of its creators, 'metamorphosize' into eight different configurations to adapt to seasonal, meteorological and even astronomical conditions. For example, in the summer plan, bedroom one faces east and watches the sun rise as its inhabitants wake up. It can then rotate so that the user is constantly in sunlight, while the house generates energy through its solar panels. The revolutionary home is based on the work of an early 20th Century mathematician who discovered a way to dissect a square and rearrange its parts into an equilateral triangle.

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Radiation effects could be mitigated by ingestion of Ex-Rad pills (targeting p53-induced apoptosis)

Radiation effects could be mitigated by ingestion of Ex-Rad pills (targeting p53-induced apoptosis) | Amazing Science | Scoop.it
Onconova Therapeutics, with assistance from the Department of Defence, have developed a new drug called Ex-Rad that increases the likelihood that you'll survive if you are exposed to a potentially lethal dose of radiation. You can take it before or after exposure, intravenously or via pill. Studies with mice have shown that mice who got a the drug and were exposed to a lethal dose of gamma radiation had a higher survival rate than mice who did not receive Ex-Rad. Human tests did not use radiation, but showed that the drug was not harmful and had no side effects.

Researchers also conducted experiments with cell cultures to try and figure out how Ex-Rad works. It seems to alter how cells deal with DNA damage and suppresses a specific protein (p53) that triggers cell death.

This is one of those "science-fiction predicted it" stories thanks to the Fallout video game franchise. Fallout players have been gulping pills for years to reduce their level of radioactivity and protect against high radiation levels. The drug that protects you from radiation is Fallout is even named Rad-X.
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Quantum correlations with no causal order

Quantum correlations with no causal order | Amazing Science | Scoop.it
Causality is one of the oldest and most important concepts of Physics. Even recently, at the beginning of the XX century, with the invention of Special Relativity, this concept was in some sense rediscovered. As in a relativistic framework the events can change their temporal order a great effort was made in order to preserve causality in the theory.

There is a general consensus in the scientific community about this concept: For all scientific theories, even for all the theories that will come in the future, causality should be preserved. If causal relations are broken an important number of paradoxes and counter-intuitive results arise. You could even go back in time and kill your grandgrandfather!

In quantum mechanics the discovery of entangled states, that are states with correlations than can act immediately even in they are separated by a distance of millions of light years, challenged this concept. The solution for preserving causality was to accept that quantum systems are intrinsically random and no theory can give a complete description of them.
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A randomised controlled trial of bumetanide in the treatment of autism in children

A randomised controlled trial of bumetanide in the treatment of autism in children | Amazing Science | Scoop.it
Gamma aminobutyric acid (GABA)-mediated synapses and the oscillations they orchestrate are altered in autism. GABA-acting benzodiazepines exert in some patients with autism paradoxical effects, raising the possibility that like in epilepsies, GABA excites neurons because of elevated intracellular concentrations of chloride. Following a successful pilot study, an international group of researchers has now performed a double-blind clinical trial using the diuretic, chloride-importer antagonist bumetanide that reduces intracellular chloride reinforcing GABAergic inhibition. Sixty children with autism or Asperger syndrome (3–11 years old) received for 3 months placebo or bumetanide (1 mg daily), followed by 1-month wash out. Determination of the severity of autism was made with video films at day 0 (D0) and D90 by blind, independent evaluators. Bumetanide reduced significantly the Childhood Autism Rating Scale (CARS) (D90−D0; P<0.004 treated vs placebo), Clinical Global Impressions (P<0.017 treated vs placebo) and Autism Diagnostic Observation Schedule values when the most severe cases (CARS values above the mean±s.d.; n=9) were removed (Wilcoxon test: P-value=0.031; Student’s t-test: P-value=0.017). Side effects were restricted to an occasional mild hypokalaemia (3.0–3.5 mM l−1 K+) that was treated with supplemental potassium. In a companion study, chronic bumetanide treatment significantly improved accuracy in facial emotional labelling, and increased brain activation in areas involved in social and emotional perception (Hadjikhani et al., submitted). Therefore, bumetanide is a promising novel therapeutic agent to treat autism. Larger trials are warranted to better determine the population best suited for this treatment.
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Augmented immune cells force leukaemia into remission

Augmented immune cells force leukaemia into remission | Amazing Science | Scoop.it
Genetically engineered white blood cells have been shown to have a strong impact on leukaemia after just three months.

Thirteen people with a form of the cancer called multiple myeloma were treated with genetically engineered T-cells, and all improved. "The fact we got a response in all 13, you can't get better than that," says James Noble, CEO of Adaptimmune in Abingdon, UK, which developed the treatment.

Cancers often develop because T-cells have lost their ability to target tumour cells, which they normally destroy. To retune that targeting, a team led by Aaron Rapoport at the University of Maryland in Baltimore engineered T-cell genes that coded for a receptor on the cell's surface. They extracted T-cells from each person, then inserted the engineered genes into these cells and re-injected them.

The souped-up cells were better able to recognise proteins called NY-ESO-1 and LAGE-1, found on myeloma cells but not healthy ones. All 13 people also had the standard treatment for multiple myeloma, which boosts white blood cell count. Three months after the injection, 10 of the 13 were in remission or very close to it – a 77 per cent response rate – and the others showed drastic reduction in their cancer.
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Plants Grow Fine Without Gravity. Potential of Growing Crops in Space and Other Planets

Plants Grow Fine Without Gravity. Potential of Growing Crops in Space and Other Planets | Amazing Science | Scoop.it
Turns out plants grow just fine on the International Space Station. When researchers sent plants to the International Space Station in 2010, the flora wasn't meant to be decorative. Instead, the seeds of these small, white flowers—called Arabidopsis thaliana—were the subject of an experiment to study how plant roots developed in a weightless environment.

Gravity is an important influence on root growth, but the scientists found that their space plants didn't need it to flourish. The research team from the University of Florida in Gainesville thinks this ability is related to a plant's inherent ability to orient itself as it grows. Seeds germinated on the International Space Station sprouted roots that behaved like they would on Earth—growing away from the seed to seek nutrients and water in exactly the same pattern observed with gravity.

Since the flowers were orbiting some 220 miles (350 kilometers) above the Earth at the time, the NASA-funded experiment suggests that plants still retain an earthy instinct when they don't have gravity as a guide.

"The role of gravity in plant growth and development in terrestrial environments is well understood," said plant geneticist and study co-author Anna-Lisa Paul, with the University of Florida in Gainesville. "What is less well understood is how plants respond when you remove gravity.
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mdashf's curator insight, December 14, 2012 3:49 PM

Gravity ain't responsible for how fauna grows?

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New optical tweezers trap specimens just a few nanometers wide

New optical tweezers trap specimens just a few nanometers wide | Amazing Science | Scoop.it
A technique known as optical trapping uses beams of light as tweezers to hold and manipulate tiny particles. Stanford researchers have found a new way to trap particles smaller than 10 nanometers — and potentially down to just a few atoms in size — which until now have escaped light’s grasp. This new technique allows for studying individual proteins and unraveling them.

To grasp and move microscopic objects, such as bacteria and the components of living cells, scientists can harness the power of concentrated light to manipulate them without ever physically touching them. Now, doctoral student Amr Saleh and Assistant Professor Jennifer Dionne, researchers at the Stanford School of Engineering, have designed an innovative light aperture that allows them to optically trap smaller objects than ever before — potentially just a few atoms in size.

The process of optical trapping — or optical tweezing, as it is often known — involves sculpting a beam of light into a narrow point that produces a strong electromagnetic field. The beam attracts tiny objects and traps them in place, just like a pair of tweezers.

Unfortunately, there are natural limits to the technique. The process breaks down for objects significantly smaller than the wavelength of light. Therefore, optical tweezers cannot grasp super-small objects like individual proteins, which are only a couple of nanometers in diameter.

Saleh and Dionne have shown theoretically that light passed through their novel aperture would stably trap objects as small as 2 nanometers. Saleh is now building a working prototype of the microscopic device.

Dionne says that the most promising method of moving tiny particles with light relies on plasmonics, a technology that takes advantage of the optical and electronic properties of metals. A strong conductor like silver or gold holds its electrons weakly, giving them freedom to move around near the metal’s surface.

When light waves interact with these mobile electrons, they move in what Dionne describes as “a very well-defined, intricate dance,” scattering and sculpting the light into electromagnetic waves called plasmon-polaritons. These oscillations have a very short wavelength compared to visible light, enabling them to trap small specimens more tightly.

Dionne and Saleh applied plasmonic principles to design a new aperture that focuses light more effectively. The aperture is structured much like the coaxial cables that transmit television signals, Saleh said. A nanoscale tube of silver is coated in a thin layer of silicon dioxide, and those two layers are wrapped in a second outer layer of silver. When light shines through the silicon dioxide ring, it creates plasmons at the interface where the silver and silicon dioxide meet. The plasmons travel along aperture and emerge on the other end as a powerful, concentrated beam of light.

The Stanford device is not the first plasmonic trap, but it promises to trap the smallest specimens recorded to date. Saleh and Dionne have theoretically shown that their design can trap particles as small as 2 nanometers. With further improvements, their design could even be used to optically trap molecules even smaller.

Dionne said she would first like to trap a single protein, and try to unravel its twisted structure using visible light alone. Dionne points out that the beam of light could also be used to exert a strong pulling force on stem cells, which has been shown to change how the these important building blocks differentiate into various kinds of cells. Saleh, on the other hand, is particularly excited about moving and stacking tiny particles to explore their attractive forces and create new, “bottom-up” materials and devices.
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New '4-D' transistor is preview of future computers

New '4-D' transistor is preview of future computers | Amazing Science | Scoop.it
A new type of transistor shaped like a Christmas tree has arrived just in time for the holidays, but the prototype won't be nestled under the tree along with the other gifts.

 

"It's a preview of things to come in the semiconductor industry," said Peide "Peter" Ye, a professor of electrical and computer engineering at Purdue University. Researchers from Purdue and Harvard universities created the transistor, which is made from a material that could replace silicon within a decade. Each transistor contains three tiny nanowires made not of silicon, like conventional transistors, but from a material called indium-gallium-arsenide. The three nanowires are progressively smaller, yielding a tapered cross section resembling a Christmas tree.

 

The research builds on previous work in which the team created a 3-D structure instead of conventional flat transistors. The approach could enable engineers to build faster, more compact and efficient integrated circuits and lighter laptops that generate less heat than today's. New findings show how to improve the device performance by linking the transistors vertically in parallel. "A one-story house can hold so many people, but more floors, more people, and it's the same thing with transistors," Ye said. "Stacking them results in more current and much faster operation for high-speed computing. This adds a whole new dimension, so I call them 4-D." 

 

Transistors contain critical components called gates, which enable the devices to switch on and off and to direct the flow of electrical current. Smaller gates make faster operation possible. In today's 3-D silicon transistors, the length of these gates is about 22 nanometers, or billionths of a meter.

 

The 3-D design is critical because gate lengths of 22 nanometers and smaller do not work well in a flat transistor architecture. Engineers are working to develop transistors that use even smaller gate lengths; 14 nanometers are expected by 2015, and 10 nanometers by 2018.

 

However, size reductions beyond 10 nanometers and additional performance improvements are likely not possible using silicon, meaning new materials will be needed to continue progress, Ye said.

 

Creating smaller transistors also will require finding a new type of insulating, or "dielectric" layer that allows the gate to switch off. As gate lengths shrink smaller than 14 nanometers, the dielectric used in conventional transistors fails to perform properly and is said to "leak" electrical charge when the transistor is turned off.

 

Nanowires in the new transistors are coated with a different type of composite insulator, a 4-nanometer-thick layer of lanthanum aluminate with an ultrathin, half-nanometer layer of aluminum oxide. The new ultrathin dielectric allowed researchers to create transistors made of indium-gallium- arsenide with 20-nanometer gates, which is a milestone, Ye said.

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Augmented Vision: A plethora of wearable displays coming our way

Augmented Vision: A plethora of wearable displays coming our way | Amazing Science | Scoop.it

Most augmented reality glasses incorporate a tiny projector in one arm of the spectacles. The picture is then reflected from the side into the centre of the lenses, which are etched with a reflective pattern that then beams the image into the eye. That means the image is directly incorporated into what the wearer see when looking directly ahead – unlike Google’s current incarnation of Google Glass, which puts a small video screen in the bottom right-hand corner of the right eye. That requires the wearer to look down to focus on it, taking their attention away from the view ahead.

 

In this review, many different augmented reality vision devices are shown and their features explained. Welcome to the new world of 2013!

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What We Still Don't Know: "Are We Real?" A mind-boggling journey to post-human life

Series from Channel 4 featuring Sir Martin Rees.

 

There is a fundamental chasm in our understanding of ourselves, the universe, and everything. To solve this, Sir Martin takes us on a mind-boggling journey through multiple universes to post-biological life. On the way we learn of the disturbing possibility that we could be the product of someone elses experiment.

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Rhythmic Changes in Gene Activation Power the Circadian Clock

Rhythmic Changes in Gene Activation Power the Circadian Clock | Amazing Science | Scoop.it

Daily rhythms underlie most of the fundamental functions of mammals, from sleep-wake cycles to metabolic processes in the liver. The circadian clock has evolved in response to daily changes of temperature and light in the environment. At the root of circadian rhythms are daily fluctuations in gene expression, which occur in part through the process of transcription—the creation of RNA from sequences of DNA. Although past studies have uncovered how changes in transcription states relate to irreversible processes, for example when cells become more specialized, much less is known about how transcription fluctuates in synch with recurring cycles.

 

New insights into the dynamic nature of transcription are provided in a study led by Nouria Hernandez of the University of Lausanne and Felix Naef of the Ecole Polytechnique Fédérale de Lausanne. Their findings reveal the kinetics by which genes are activated in a rhythmic manner as well as the remarkable impact of daily cycles across the genome.

 

In the above-mentioned study, Hernandez and Naef used a combination of experimental and computational methods to study genome-wide transcriptional changes in the mouse liver, and how these changes relate to mRNA levels. They discovered that transcription in the liver occurs predominantly in morning and evening waves. These waves were accompanied by the rhythmic recruitment of RNA polymerase II (Pol II) — an enzyme that catalyzes transcription — to DNA strands. In addition, there were rhythmic changes in the modifications of histones — proteins that act as a scaffold for DNA and help to regulate gene expression. These rhythmic changes in transcription were driven primarily by the recruitment of Pol II to DNA.

 

The researchers also identified three classes of genes: One class showed both rhythmic transcription and mRNA fluctuations, a second class showed rhythmic transcription but flat mRNA levels, and a third class showed constant transcription but rhythmic mRNA fluctuations. The latter finding — that the levels of some mRNAs oscillated even when transcription remained constant — suggests that transcription alone does not regulate all rhythmic changes in mRNA levels. Instead, other processes, such as daily fluctuations in the rate of mRNA degradation, influence the accumulation of mRNA. These results indicate that molecular events taking place after transcription play a greater role in regulating daily fluctuations in mRNA levels than previously thought.

 

Taken together, the study reveals that many functions in the liver, such as lipid and carbohydrate metabolism as well as detoxification, are under the control of rhythmic changes in transcription. The findings could lead to insights into how the daily cycle influences genomic responses to food intake, eventually paving the way to the development of novel treatment strategies for diabetes and other metabolic diseases.


Via Sakis Koukouvis
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Deborah Verran's curator insight, December 13, 2012 4:27 AM

This report of basic science research reveals that many metabolic functions of the liver appear to be rhythmically controlled. It seems that even your liver may need a rest at night!

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The very first stars may have turned on when the universe was only 750 million years old

The very first stars may have turned on when the universe was only 750 million years old | Amazing Science | Scoop.it

As far back in time as astronomers have been able to see, the universe has had some trace of heavy elements, such as carbon and oxygen. These elements, originally churned from the explosion of massive stars, formed the building blocks for planetary bodies, and eventually for life on Earth.

 

Now researchers at MIT, the California Institute of Technology, and the University of California at San Diego have peered far back in time, to the era of the first stars and galaxies, and found matter with no discernible trace of heavy elements. To make this measurement, the team analyzed light from the most distant known quasar, a galactic nucleus more than 13 billion light-years from Earth. These quasar observations provide a snapshot of our universe during its infancy, a mere 750 million years after the initial explosion that created the universe. Analysis of the quasar's light spectrum provided no evidence of heavy elements in the surrounding gaseous cloud—a finding that suggests the quasar dates to an era nearing that of the universe's first stars. "The first stars will form in different spots in the universe … it's not like they flashed on at the same time," says Robert Simcoe, an associate professor of physics at MIT. "But this is the time that it starts getting interesting."

 

Based on numerous theoretical models, most scientists agree on a general sequence of events during the universe's early development: Nearly 14 billion years ago, an immense explosion, now known as the Big Bang, threw off massive amounts of matter and energy, creating a rapidly expanding universe. In the minutes following the explosion, protons and neutrons collided in nuclear fusion reactions to form hydrogen and helium. Eventually, the universe cooled to a point where fusion stopped generating these basic elements, leaving hydrogen as the dominant constituent of the universe. Heavier elements, such as carbon and oxygen, would not form until the first stars appeared.

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A Breakthrough Against Leukemia Using Altered T-Cells

A Breakthrough Against Leukemia Using Altered T-Cells | Amazing Science | Scoop.it

Emma Whitehead, 7, has been in full remission for months after scientists used a disabled form of H.I.V. to reprogram her immune system to kill cancer cells. Emma had been ill with acute lymphoblastic leukemia since 2010, when she was 5, said her parents, Kari and Tom. She is their only child. She is among just a dozen patients with advanced leukemia to have received the experimental treatment, which was developed at the University of Pennsylvania. Similar approaches are also being tried at other centers, including the National Cancer Institute and Memorial Sloan-Kettering Cancer Center in New York.

 

“Our goal is to have a cure, but we can’t say that word,” said Dr. Carl June, who leads the research team at the University of Pennsylvania. He hopes the new treatment will eventually replace bone-marrow transplantation, an even more arduous, risky and expensive procedure that is now the last hope when other treatments fail in leukemia and related diseases.

 

Three adults with chronic leukemia treated at the University of Pennsylvania have also had complete remissions, with no signs of disease; two of them have been well for more than two years, said Dr. David Porter. Four adults improved but did not have full remissions, and one was treated too recently to evaluate. A child improved and then relapsed. In two adults, the treatment did not work at all. The Pennsylvania researchers were presenting their results on Sunday and Monday in Atlanta at a meeting of the American Society of Hematology.

 

Despite the mixed results, cancer experts not involved with the research say it has tremendous promise, because even in this early phase of testing it has worked in seemingly hopeless cases. “I think this is a major breakthrough,” said Dr. Ivan Borrello, a cancer expert and associate professor of medicine at the Johns Hopkins University School of Medicine.

 

The University of Pennsylvania team seems to have hit all the targets at once. Inside the patients, the T-cells modified by the researchers multiplied to 1,000 to 10,000 times the number infused, wiped out the cancer and then gradually diminished, leaving a population of “memory” cells that can quickly proliferate again if needed. The researchers said they were not sure which parts of their strategy made it work — special cell-culturing techniques, the use of HIV1 to carry new genes into the T-cells, or the particular pieces of DNA that they selected to reprogram the T-cells.

 

The concept of doctoring T-cells genetically was first developed in the 1980s by Dr. Zelig Eshhar at the Weizmann Institute of Science in Rehovot, Israel. It involves adding gene sequences from different sources to enable the T-cells to produce what researchers call chimeric antigen receptors, or CARs — protein complexes that transform the cells into “serial killers.”

 

Chronic lymphocytic leukemia is a cancer of B-cells, the part of the immune system that normally produces antibodies to fight infection. All B-cells, whether healthy or leukemic, have on their surfaces a protein called CD19. To treat patients with the disease, the researchers hoped to reprogram their T-cells to find CD19 and attack B-cells carrying it.

 

But which gene sequences should be used to reprogram the T-cells, from which sources? And how do you insert them? Various research groups have used different methods. Viruses are often used as carriers (or vectors) to insert DNA into other cells because that kind of genetic sabotage is exactly what viruses normally specialize in doing. To modify their patients’ T-cells, researchers tried a daring approach: they used a disabled form of HIV1 as the vector in gene therapy for cancer patients (the virus has been used in other diseases). The AIDS virus is a natural for this kind of treatment, because it evolved to invade T-cells. The idea of putting any form of the AIDS virus into people sounds a bit frightening, but the virus used here was considered no longer harmful. Other researchers had altered and disabled the virus by adding DNA from humans, mice and cows, and from a virus that infects woodchucks and another that infects cows.

 

To administer the treatment, the researchers collected as many of the patients’ T-cells as they could by passing their blood through a machine that removed the cells and returned the other blood components back into the patients’ veins. The T-cells were exposed to the vector, which transformed them genetically, and then were frozen. Meanwhile, the patients were given chemotherapy to deplete any remaining T-cells, because the native T-cells might impede the growth of the altered ones. Finally, the T-cells were infused back into the patients.

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