Sunday, 6 July 2014
Friday, 4 July 2014
BAMBOO THE FASTEST GROWING PLANT ON EARTH.
Bamboo are members of the grass family.they are mostly found on tropical areas.its growth is far more faster than the other plants,in 24 hour period it grows upto 30 foot,its on record.they are 120 foot tall,hollow inside and in some of the species leaves grow only once in a period of 30 years,some species are also seen to grow leaves during period of 100 years
it doesn't require pesticides,insecticides or fertilizers.it fights global warming by taking 400% of the green house gases and produces 35% more oxygen than the standing tress and its biodegradable means biodegradable simply means to be consumed by microorganisms and return to compounds found in nature
it is widely used in furniture making and in some areas of the world its seem to edible
Thursday, 3 July 2014
First show off, then take-off: New specimen of Archaeopteryx reveals previously unknown features of the plumage
Date:
July 3, 2014
Source:
Ludwig-Maximilians-Universitaet Muenchen (LMU)
Summary:
Paleontologists are currently studying a new specimen of Archaeopteryx, which reveals previously unknown features of the plumage. The initial findings shed light on the original function of feathers and their recruitment for flight.
Paleontologists of Ludwig-Maximilians-Universitaet (LMU) in Munich are currently studying a new specimen of Archaeopteryx, which reveals previously unknown features of the plumage. The initial findings shed light on the original function of feathers and their recruitment for flight.
A century and a half after its discovery and a mere 150 million years or so since it took to the air, Archaeopteryx still has surprises in store: The eleventh specimen of the iconic "basal bird" so far discovered turns out to have the best preserved plumage of all, permitting detailed comparisons to be made with other feathered dinosaurs. The fossil is being subjected to a thorough examination by a team led by Dr. Oliver Rauhut, a paleontologist in the Department of Earth and Environmental Sciences at LMU Munich, who is also affiliated with the Bavarian State Collection for Paleontology and Geology in Munich. The first results of their analysis of the plumage are reported in the latest issue of Nature. The new data make a significant contribution to the ongoing debate over the evolution of feathers and its relationship to avian flight. They also imply that the links between feather development and the origin of flight are probably much more complex than has been assumed up to now.
"For the first time, it has become possible to examine the detailed structure of the feathers on the body, the tail and, above all, on the legs," says Oliver Rauhut. In the case of this new specimen, the feathers are, for the most part, preserved as impressions in the rock matrix. "Comparisons with other feathered predatory dinosaurs indicate that the plumage in the different regions of the body varied widely between these species. That suggests that primordial feathers did not evolve in connection with flight-related roles, but originated in other functional contexts," says Dr. Christian Foth of LMU and the Bavarian State Collection for Paleontology and Geology in Munich, first author on the new paper.
To keep warm and to catch the eye
Predatory dinosaurs (theropods) with body plumage are now known to predate Archaeopteryx, and their feathers probably provided thermal insulation. Advanced species of predatory dinosaurs and primitive birds with feathered forelimbs may have used them as balance organs when running, like ostriches do today. Moreover, feathers could have served useful functions in brooding, camouflage and display. Indeed, the feathers on the tail, wings and hind-limbs most probably fulfilled functions in display, although it is very likely that Archaeopteryx was also capable of flight. "Interestingly, the lateral feathers in the tail of Archaeopteryx had an aerodynamic form, and most probably played an important role in its aerial abilities," says Foth.
On the basis of their investigation of the plumage of the new fossil, the researchers have been able to clarify the taxonomical relationship between Archaeopteryx and other species of feathered dinosaur. Here, the diversity in form and distribution of the feather tracts is particularly striking. For instance, among dinosaurs that had feathers on their legs, many had long feathers extending to the toes, while others had shorter down-like plumage. "If feathers had evolved originally for flight, functional constraints should have restricted their range of variation. And in primitive birds we do see less variation in wing feathers than in those on the hind-limbs or the tail," explains Foth.
These observations imply that feathers acquired their aerodynamic functions secondarily: Once feathers had been invented, they could be co-opted for flight. "It is even possible that the ability to fly evolved more than once within the theropods," says Rauhut. "Since the feathers were already present, different groups of predatory dinosaurs and their descendants, the birds, could have exploited these structures in different ways." The new results also contradict the theory that powered avian flight evolved from earlier four-winged species that were able to glide.
Archaeopteryx represents a transitional form between reptiles and birds and is the best-known, and possibly the earliest, bird fossil. It proves that modern birds are directly descended from predatory dinosaurs, and are themselves essentially modern-day dinosaurs. The many new fossil species of feathered dinosaurs discovered in China in recent years have made it possible to place Archaeopteryx within a larger evolutionary context. However, when feathers first appeared and how often flight evolved are matters that are still under debate.
The eleventh known specimen of Archaeopteryx is still in private hands. Like all other examples of the genus, it was found in the Altmühl valley in Bavaria, which in Late Jurassic times lay in the northern tropics, and at the bottom of a shallow sea, as all Archaeopteryx fossils found so far have been recovered from limestone deposits.
Story Source:
The above story is based on materials provided by Ludwig-Maximilians-Universitaet Muenchen (LMU). Note: Materials may be edited for content and length.
Journal Reference:
- Christian Foth, Helmut Tischlinger, Oliver W. M. Rauhut. New specimen of Archaeopteryx provides insights into the evolution of pennaceous feathers.Nature, 2014; 511 (7507): 79 DOI: 10.1038/nature13467
Wednesday, 2 July 2014
Ocean on Saturn's moon Titan could be as salty as Earth's Dead Sea
Date:
July 2, 2014
Source:
NASA/Jet Propulsion Laboratory
Summary:
Scientists analyzing data from NASA's Cassini mission have firm evidence the ocean inside Saturn's largest moon, Titan, might be as salty as Earth's Dead Sea. The new results come from a study of gravity and topography data collected during Cassini's repeated flybys of Titan during the past 10 years. Using the Cassini data, researchers presented a model structure for Titan, resulting in an improved understanding of the structure of the moon's outer ice shell.
Scientists analyzing data from NASA's Cassini mission have firm evidence the ocean inside Saturn's largest moon, Titan, might be as salty as Earth's Dead Sea.
The new results come from a study of gravity and topography data collected during Cassini's repeated flybys of Titan during the past 10 years. Using the Cassini data, researchers presented a model structure for Titan, resulting in an improved understanding of the structure of the moon's outer ice shell. The findings are published in this week's edition of the journal Icarus.
"Titan continues to prove itself as an endlessly fascinating world, and with our long-lived Cassini spacecraft, we're unlocking new mysteries as fast as we solve old ones," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, who was not involved in the study.
Additional findings support previous indications the moon's icy shell is rigid and in the process of freezing solid. Researchers found that a relatively high density was required for Titan's ocean in order to explain the gravity data. This indicates the ocean is probably an extremely salty brine of water mixed with dissolved salts likely composed of sulfur, sodium and potassium. The density indicated for this brine would give the ocean a salt content roughly equal to the saltiest bodies of water on Earth.
"This is an extremely salty ocean by Earth standards," said the paper's lead author, Giuseppe Mitri of the University of Nantes in France. "Knowing this may change the way we view this ocean as a possible abode for present-day life, but conditions might have been very different there in the past."
Cassini data also indicate the thickness of Titan's ice crust varies slightly from place to place. The researchers said this can best be explained if the moon's outer shell is stiff, as would be the case if the ocean were slowly crystalizing and turning to ice. Otherwise, the moon's shape would tend to even itself out over time, like warm candle wax. This freezing process would have important implications for the habitability of Titan's ocean, as it would limit the ability of materials to exchange between the surface and the ocean.
A further consequence of a rigid ice shell, according to the study, is any outgassing of methane into Titan's atmosphere must happen at scattered "hot spots" -- like the hot spot on Earth that gave rise to the Hawaiian Island chain. Titan's methane does not appear to result from convection or plate tectonics recycling its ice shell.
How methane gets into the moon's atmosphere has long been of great interest to researchers, as molecules of this gas are broken apart by sunlight on short geological timescales. Titan's present atmosphere contains about five percent methane. This means some process, thought to be geological in nature, must be replenishing the gas. The study indicates that whatever process is responsible, the restoration of Titan's methane is localized and intermittent.
"Our work suggests looking for signs of methane outgassing will be difficult with Cassini, and may require a future mission that can find localized methane sources," said Jonathan Lunine, a scientist on the Cassini mission at Cornell University, Ithaca, New York, and one of the paper's co-authors. "As on Mars, this is a challenging task."
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate in Washington.
For more information about Cassini, visit:
Story Source:
The above story is based on materials provided by NASA/Jet Propulsion Laboratory.Note: Materials may be edited for content and length.
Journal Reference:
- Giuseppe Mitri, Rachele Meriggiola, Alex Hayes, Axel Lefevre, Gabriel Tobie, Antonio Genova, Jonathan I. Lunine, Howard Zebker. Shape, topography, gravity anomalies and tidal deformation of Titan. Icarus, 2014; 236: 169 DOI:10.1016/j.icarus.2014.03.018
Tuesday, 1 July 2014
IRAN'S INDIGENOUSLY BUILT STEALTH JET "THE VANQUISHER"
ANOTHER JOKE OR REALITY!
Iranian Defense
Minister Ahmad Vahidi says Iran’s new domestically-designed and
developed fighter jet, Qaher-313 (Conqueror-313), is ‘super advanced’
and capable of ‘evading radars.’
Speaking on the sidelines of its unveiling ceremony on Saturday,
Vahidi said the aircraft had a “very low radar cross section” and was
capable of conducting operations at low altitudes.
The Iranian defense minister noted that highly-advanced
materials and electro-ionic systems had been used in the structure of
Qaher-313, adding that the aircraft was capable of carrying advanced
armaments.
Qaher-313 can take off and land on short runways and it has easy maintenance, Vahidi said.
The newly-unveiled Iranian military aircraft is said to be similar
to the US-built F/A-18, although its appearance is like F-5E/F Tiger II.
The new single-seat bomber has been manufactured based on state-of-the-art technologies and modern defense achievements.
In recent years, Iran has made great achievements in its defense sector and gained self-sufficiency in essential military hardware and defense systems.
Azarakhsh (Lightning) is Iran’s first domestically-manufactured combat jet.
Saeqeh (Thunderbolt) fighter jet is a follow-up aircraft, derived from Azarakhsh. Iran unveiled its first squadron of Saeqeh fighter bombers in an air show in September 2010.
3-D printed wrist splints for arthritis sufferers
Date:
July 1, 2014
Source:
University of Loughborough
Summary:
A computer software concept has been developed that will enable clinicians with no experience in Computer Aided Design (CAD) to design and make custom-made 3D printed wrist splints for rheumatoid arthritis sufferers. The 3D printed splints are not only more comfortable and attractive but potentially cheaper than the current ones that are 'ugly, bulky, and can make a patients arm sweat'.
A Loughborough University lecturer has developed a computer software concept that will enable clinicians with no experience in Computer Aided Design (CAD) to design and make custom-made 3D printed wrist splints for rheumatoid arthritis sufferers.
Dr Abby Paterson, from the Design School, said: "I wanted to give clinicians the ability to make splints they have not been able to make before. They can improve the aesthetics, the fit, and integrate extra bits of functionality they couldn't do before as a result of our Additive Manufacturing facilities here at Loughborough University. Thanks to our Objet Connex machine, we can integrate multiple materials in a single splint such as rubber-like integral hinges or cushioning features but, more importantly, the specialised software prototype we've developed will enable clinicians to design these splints for their patients."
The 3D printed splints are not only more comfortable and attractive but potentially cheaper than the current ones that are 'ugly, bulky, and can make a patients arm sweat'. As a result patients do not use them as often as they should.
The splints, which provide joint protection, rest, and promote pain relief,could be a major boost for sufferers of rheumatoid arthritis, the second most common type of arthritis in the UK which affects more than 400,000 people.
The splints are made by scanning a patient's arm in the 'appropriate position'. A 3D model splint is then designed based on the scan to generate a computer model.
The 3D printer can then produce as many splints as are needed at the touch of a button. They can be any colour, feature multiple materials, have a lattice design to aid ventilation and any type of fastening the patient requires.
The 3D CAD software prototype was shown to certified splinting practitioners, such as occupational therapists and physiotherapists.
Dr Paterson said: "The practitioners were very excited by new, novel ideas to expand the possibilities available to them, such as integrated rubber borders for increased comfort."
The 3D CAD software prototype is the product of Dr Paterson's PhD and development work is still needed on the software and materials.
Dr Paterson was supervised during her PhD by Dr Richard Bibb and Dr Ian Campbell. Dr Bibb came up with the idea for bespoke wrist splints in the late 1990's.
Dr Bibb and Dr Paterson are currently pursuing opportunities to perform a 'thorough cost analysis' of providing the service.
Dr Bibb says the 3D splints could be cheaper than the current ones because the design and manufacture stages have been separated. He believes they will be cost-effective for the NHS while the 'sky's the limit' in the private sector.
Dr Bibb, Reader in Medical Applications of Design in the Design School, said: "We are in the development phase. The research has proved that this is desirable and the clinicians want it. We know there's lots of potential."
Story Source:
The above story is based on materials provided by University of Loughborough.Note: Materials may be edited for content and length.
Muscle-powered bio-bots walk on command
Date:
July 1, 2014
Source:
University of Illinois at Urbana-Champaign
Summary:
A new generation of miniature biological robots is flexing its muscle. Engineers have demonstrated a class of walking 'bio-bots' powered by muscle cells and controlled with electrical pulses, giving researchers unprecedented command over their function.
A new generation of miniature biological robots is flexing its muscle. Engineers at the University of Illinois at Urbana-Champaign demonstrated a class of walking "bio-bots" powered by muscle cells and controlled with electrical pulses, giving researchers unprecedented command over their function. The group published its work in the online early edition of Proceedings of the National Academy of Sciences.
"Biological actuation driven by cells is a fundamental need for any kind of biological machine you want to build," said study leader Rashid Bashir, Abel Bliss Professor and head of bioengineering at the U. of I. "We're trying to integrate these principles of engineering with biology in a way that can be used to design and develop biological machines and systems for environmental and medical applications. Biology is tremendously powerful, and if we can somehow learn to harness its advantages for useful applications, it could bring about a lot of great things."
Bashir's group has been a pioneer in designing and building bio-bots, less than a centimeter in size, made of flexible 3-D printed hydrogels and living cells. Previously, the group demonstrated bio-bots that "walk" on their own, powered by beating heart cells from rats. However, heart cells constantly contract, denying researchers control over the bot's motion. This makes it difficult to use heart cells to engineer a bio-bot that can be turned on and off, sped up or slowed down.
The new bio-bots are powered by a strip of skeletal muscle cells that can be triggered by an electric pulse. This gives the researchers a simple way to control the bio-bots and opens the possibilities for other forward design principles, so engineers can customize bio-bots for specific applications.
"Skeletal muscles cells are very attractive because you can pace them using external signals," Bashir said. "For example, you would use skeletal muscle when designing a device that you wanted to start functioning when it senses a chemical or when it received a certain signal. To us, it's part of a design toolbox. We want to have different options that could be used by engineers to design these things."
The design is inspired by the muscle-tendon-bone complex found in nature. There is a backbone of 3-D printed hydrogel, strong enough to give the bio-bot structure but flexible enough to bend like a joint. Two posts serve to anchor a strip of muscle to the backbone, like tendons attach muscle to bone, but the posts also act as feet for the bio-bot.
A bot's speed can be controlled by adjusting the frequency of the electric pulses. A higher frequency causes the muscle to contract faster, thus speeding up the bio-bot's progress as seen in this video.
"It's only natural that we would start from a bio-mimetic design principle, such as the native organization of the musculoskeletal system, as a jumping-off point," said graduate student Caroline Cvetkovic, co-first author of the paper. "This work represents an important first step in the development and control of biological machines that can be stimulated, trained, or programmed to do work. It's exciting to think that this system could eventually evolve into a generation of biological machines that could aid in drug delivery, surgical robotics, 'smart' implants, or mobile environmental analyzers, among countless other applications."
Next, the researchers will work to gain even greater control over the bio-bots' motion, like integrating neurons so the bio-bots can be steered in different directions with light or chemical gradients. On the engineering side, they hope to design a hydrogel backbone that allows the bio-bot to move in different directions based on different signals. Thanks to 3-D printing, engineers can explore different shapes and designs quickly. Bashir and colleagues even plan to integrate a unit into undergraduate lab curriculum so that students can design different kinds of bio-bots.
"The goal of 'building with biology' is not a new one -- tissue engineering researchers have been working for many years to reverse engineer native tissue and organs, and this is very promising for medical applications," said graduate student Ritu Raman, co-first author of the paper. "But why stop there? We can go beyond this by using the dynamic abilities of cells to self-organize and respond to environmental cues to forward engineer non-natural biological machines and systems.
"The idea of doing forward engineering with these cell-based structures is very exciting," Bashir said. "Our goal is for these devices to be used as autonomous sensors. We want it to sense a specific chemical and move towards it, then release agents to neutralize the toxin, for example. Being in control of the actuation is a big step forward toward that goal."
The National Science Foundation supported this work through a Science and Technology Center (Emergent Behavior of Integrated Cellular Systems) grant, in collaboration with the Massachusetts Institute of Technology, the Georgia Institute of Technology and other partner institutions. Mechanical science and engineering professor Taher Saif was also a co-author. Bashir also is affiliated with the Micro and Nanotechnology Laboratory, the department of electrical and computer engineering and of mechanical science and engineering, Frederick Seitz Materials Research Laboratory and the Institute for Genomic Biology at the U. of I.
Story Source:
The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.
Journal Reference:
- C. Cvetkovic, R. Raman, V. Chan, B. J. Williams, M. Tolish, P. Bajaj, M. S. Sakar, H. H. Asada, M. T. A. Saif, R. Bashir. Three-dimensionally printed biological machines powered by skeletal muscle. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1401577111
NOISE POLLUTION VERY DANGEROUS TO HEALTH!
Traffic noise is the second biggest environmental problem in the EU, according to WHO. After air pollution, noise is affecting health the most. But legislation regarding noise pollution is insufficient. A new report shows how negative health effects of noise can be reduced. Several means are easiest to apply in dense cities.
Most of us are not aware that cars today produce as much noise on the outside as they did 40 years ago. However, heavy vehicles have become somewhat quieter. The number of people exposed to noise pollution in our cities remains high. Traffic noise is today linked to stress-related health problems such as stroke and heart disease.
"In recent years, the scientific basis for assessment has broadened considerably. But the legislation to protect residents of unhealthy noise levels is completely inadequate," says Tor Kihlman, Professor Emeritus of Applied Acoustics at Chalmers.
Last fall, Tor Kihlman and Wolfgang Kropp initiated a meeting between international experts from the automotive industry, universities and government agencies in Innsbruck to discuss technical possibilities to achieve better urban environments. A summary report from the meeting is now available, see below.
IT CAUSES.
- STROKE
- ANNOYANCE
- DEPRESSION
- CARDIAC HYPERTENSION
- STRESS
- DIABETES
- HEART ATTACK
- SLEEP DISTURBANCE
- SPEECH INTERFERENCE
No simple technical solution exists for solving the traffic noise problem -- neither at the source nor for preventing noise from reaching ears. In order to achieve improvements, concerted actions from everyone involved are required, but such coordination of actions is lacking today. The division of responsibilities is unclear, says Tor Kihlman.
"Many of the needed measures are ideal for implementation in dense cities. They are often in line with what is required to tackle climate change. Here are double benefits to point to," says Tor Kihlman, mentioning three examples: the procurement of quiet public transport, reduced speed, and the usage of buildings as as effective noise barriers, through good urban planning.
The new report describes the first steps needed, politically, for society to move towards substantially reduced health effects caused by traffic noise.
"The problems with traffic noise from roads cannot be satisfactory resolved by only taking actions at the source of the noise, not with foreseeable technology. Therefore, the report is also covering planning and construction measures. But today's methods of measuring and describing the noise emissions are neither sufficient nor adequate from the exposed citizens' point of view, says Tor Kihlman.
Monday, 30 June 2014
Noninvasive brain control: New light-sensitive protein enables simpler, more powerful optogenetics
Date:
June 29, 2014
Source:
Massachusetts Institute of Technology
Summary:
Engineers have now developed the first light-sensitive molecule that enables neurons to be silenced noninvasively, using a light source outside the skull. This noninvasive approach could pave the way to using optogenetics in human patients to treat epilepsy and other neurological disorders.
Optogenetics, a technology that allows scientists to control brain activity by shining light on neurons, relies on light-sensitive proteins that can suppress or stimulate electrical signals within cells. This technique requires a light source to be implanted in the brain, where it can reach the cells to be controlled.
MIT engineers have now developed the first light-sensitive molecule that enables neurons to be silenced noninvasively, using a light source outside the skull. This makes it possible to do long-term studies without an implanted light source. The protein, known as Jaws, also allows a larger volume of tissue to be influenced at once.
This noninvasive approach could pave the way to using optogenetics in human patients to treat epilepsy and other neurological disorders, the researchers say, although much more testing and development is needed. Led by Ed Boyden, an associate professor of biological engineering and brain and cognitive sciences at MIT, the researchers described the protein in the June 29 issue of Nature Neuroscience.
Optogenetics, a technique developed over the past 15 years, has become a common laboratory tool for shutting off or stimulating specific types of neurons in the brain, allowing neuroscientists to learn much more about their functions.
The neurons to be studied must be genetically engineered to produce light-sensitive proteins known as opsins, which are channels or pumps that influence electrical activity by controlling the flow of ions in or out of cells. Researchers then insert a light source, such as an optical fiber, into the brain to control the selected neurons.
Such implants can be difficult to insert, however, and can be incompatible with many kinds of experiments, such as studies of development, during which the brain changes size, or of neurodegenerative disorders, during which the implant can interact with brain physiology. In addition, it is difficult to perform long-term studies of chronic diseases with these implants.
Mining nature's diversity
To find a better alternative, Boyden, graduate student Amy Chuong, and colleagues turned to the natural world. Many microbes and other organisms use opsins to detect light and react to their environment. Most of the natural opsins now used for optogenetics respond best to blue or green light.
Boyden's team had previously identified two light-sensitive chloride ion pumps that respond to red light, which can penetrate deeper into living tissue. However, these molecules, found in the bacteria Haloarcula marismortui and Haloarcula vallismortis, did not induce a strong enough photocurrent -- an electric current in response to light -- to be useful in controlling neuron activity.
Chuong set out to improve the photocurrent by looking for relatives of these proteins and testing their electrical activity. She then engineered one of these relatives by making many different mutants. The result of this screen, Jaws, retained its red-light sensitivity but had a much stronger photocurrent -- enough to shut down neural activity.
"This exemplifies how the genomic diversity of the natural world can yield powerful reagents that can be of use in biology and neuroscience," says Boyden, who is a member of MIT's Media Lab and the McGovern Institute for Brain Research.
Using this opsin, the researchers were able to shut down neuronal activity in the mouse brain with a light source outside the animal's head. The suppression occurred as deep as 3 millimeters in the brain, and was just as effective as that of existing silencers that rely on other colors of light delivered via conventional invasive illumination.
A key advantage to this opsin is that it could enable optogenetic studies of animals with larger brains, says Garret Stuber, an assistant professor of psychiatry and cell biology and physiology at the University of North Carolina at Chapel Hill.
"In animals with larger brains, people have had difficulty getting behavior effects with optogenetics, and one possible reason is that not enough of the tissue is being inhibited," he says. "This could potentially alleviate that."
Restoring vision
Working with researchers at the Friedrich Miescher Institute for Biomedical Research in Switzerland, the MIT team also tested Jaws's ability to restore the light sensitivity of retinal cells called cones. In people with a disease called retinitis pigmentosa, cones slowly atrophy, eventually causing blindness.
Friedrich Miescher Institute scientists Botond Roska and Volker Busskamp have previously shown that some vision can be restored in mice by engineering those cone cells to express light-sensitive proteins. In the new paper, Roska and Busskamp tested the Jaws protein in the mouse retina and found that it more closely resembled the eye's natural opsins and offered a greater range of light sensitivity, making it potentially more useful for treating retinitis pigmentosa.
This type of noninvasive approach to optogenetics could also represent a step toward developing optogenetic treatments for diseases such as epilepsy, which could be controlled by shutting off misfiring neurons that cause seizures, Boyden says. "Since these molecules come from species other than humans, many studies must be done to evaluate their safety and efficacy in the context of treatment," he says.
Boyden's lab is working with many other research groups to further test the Jaws opsin for other applications. The team is also seeking new light-sensitive proteins and is working on high-throughput screening approaches that could speed up the development of such proteins.
The research at MIT was funded by Jerry and Marge Burnett, the Defense Advanced Research Projects Agency, the Human Frontiers Science Program, the IET A. F. Harvey Prize, the Janet and Sheldon Razin '59 Fellowship of the MIT McGovern Institute, the New York Stem Cell Foundation-Robertson Investigator Award, the National Institutes of Health, the National Science Foundation, and the Wallace H. Coulter Foundation.
Story Source:
The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Anne Trafton. Note: Materials may be edited for content and length.
In human evolution, changes in skin's barrier set northern Europeans apart
Date:
June 30, 2014
Source:
University of California, San Francisco (UCSF)
Summary:
The popular idea that northern Europeans developed light skin to absorb more UV light so they could make more vitamin D -- vital for healthy bones and immune function -- is questioned by researchers in a new study. Ramping up the skin’s capacity to capture UV light to make vitamin D is indeed important, however, researchers concluded in their study that changes in the skin’s function as a barrier to the elements made a greater contribution than alterations in skin pigment in the ability of northern Europeans to make vitamin D.
The popular idea that Northern Europeans developed light skin to absorb more UV light so they could make more vitamin D – vital for healthy bones and immune function – is questioned by UC San Francisco researchers in a new study published online in the journal Evolutionary Biology
Ramping up the skin’s capacity to capture UV light to make vitamin D is indeed important, according to a team led by Peter Elias, MD, a UCSF professor of dermatology. However, Elias and colleagues concluded in their study that changes in the skin’s function as a barrier to the elements made a greater contribution than alterations in skin pigment in the ability of Northern Europeans to make vitamin D.
Elias’ team concluded that genetic mutations compromising the skin’s ability to serve as a barrier allowed fair-skinned Northern Europeans to populate latitudes where too little ultraviolet B (UVB) light for vitamin D production penetrates the atmosphere.
Among scientists studying human evolution, it has been almost universally assumed that the need to make more vitamin D at Northern latitudes drove genetic mutations that reduce production of the pigment melanin, the main determinant of skin tone, according to Elias.
“At the higher latitudes of Great Britain, Scandinavia and the Baltic States, as well as Northern Germany and France, very little UVB light reaches the Earth, and it’s the key wavelength required by the skin for vitamin D generation,” Elias said.
“While is seems logical that the loss of the pigment melanin would serve as a compensatory mechanism, allowing for more irradiation of the skin surface and therefore more vitamin D production, this hypothesis is flawed for many reasons,” he continued. “For example, recent studies show that dark-skinned humans make vitamin D after sun exposure as efficiently as lightly-pigmented humans, and osteoporosis – which can be a sign of vitamin D deficiency – is less common, rather than more common, in darkly-pigmented humans.”
Furthermore, evidence for a south to north gradient in the prevalence of melanin mutations is weaker than for this alternative explanation explored by Elias and colleagues.
In earlier research, Elias began studying the role of skin as a barrier to water loss. He recently has focused on a specific skin-barrier protein called filaggrin, which is broken down into a molecule called urocanic acid – the most potent absorber of UVB light in the skin, according to Elias. “It’s certainly more important than melanin in lightly-pigmented skin,” he said.
In their new study, the researchers identified a strikingly higher prevalence of inborn mutations in the filaggrin gene among Northern European populations. Up to 10 percent of normal individuals carried mutations in the filaggrin gene in these northern nations, in contrast to much lower mutation rates in southern European, Asian and African populations.
Moreover, higher filaggrin mutation rates, which result in a loss of urocanic acid, correlated with higher vitamin D levels in the blood. Latitude-dependent variations in melanin genes are not similarly associated with vitamin D levels, according to Elias. This evidence suggests that changes in the skin barrier played a role in Northern European’s evolutionary adaptation to Northern latitudes, the study concluded.
Yet, there was an evolutionary tradeoff for these barrier-weakening filaggrin mutations, Elias said. Mutation bearers have a tendency for very dry skin, and are vulnerable to atopic dermatitis, asthma and food allergies. But these diseases have appeared only recently, and did not become a problem until humans began to live in densely populated urban environments, Elias said.
The Elias lab has shown that pigmented skin provides a better skin barrier, which he says was critically important for protection against dehydration and infections among ancestral humans living in sub-Saharan Africa. But the need for pigment to provide this extra protection waned as modern human populations migrated northward over the past 60,000 years or so, Elias said, while the need to absorb UVB light became greater, particularly for those humans who migrated to the far North behind retreating glaciers less than 10,000 years ago.
The data from the new study do not explain why Northern Europeans lost melanin. If the need to make more vitamin D did not drive pigment loss, what did? Elias speculates that, “Once human populations migrated northward, away from the tropical onslaught of UVB, pigment was gradually lost in service of metabolic conservation. The body will not waste precious energy and proteins to make proteins that it no longer needs.”
For the Evolutionary Biology study, labeled a “synthesis paper” by the journal, Elias and co-author Jacob P. Thyssen, MD, a professor at the University of Copenhagen, mapped the mutation data and measured the correlations with blood levels of vitamin D. Labs throughout the world identified the mutations. Daniel Bikle, MD, PhD, a UCSF professor of medicine, provided expertise on vitamin D metabolism.
Story Source:
The above story is based on materials provided by University of California, San Francisco (UCSF). The original article was written by Jeffrey Norris. Note: Materials may be edited for content and length.
Journal Reference:
- Jacob P. Thyssen, Daniel D. Bikle, Peter M. Elias. Evidence That Loss-of-Function Filaggrin Gene Mutations Evolved in Northern Europeans to Favor Intracutaneous Vitamin D3 Production. Evolutionary Biology, 2014; DOI:10.1007/s11692-014-9282-7
Potentially habitable Earth-like planet discovered; May have similar temperatures to our planet
Date:
June 30, 2014
Source:
University of New South Wales
Summary:
A potentially habitable Earth-like planet that is only 16 light years away has been discovered. The "super-Earth" planet, GJ 832 c, takes 16 days to orbit its red-dwarf star, GJ 832, and has a mass at least five times that of Earth. It receives about the same average stellar energy as Earth does and may have similar temperatures to our planet. These characteristics put it among the top three most Earth-like planets.
AUNSW-led team of researchers has discovered a potentially habitable Earth-like planet that is only 16 light years away.
The "super-Earth" planet, GJ 832 c, takes 16 days to orbit its red-dwarf star, GJ 832, and has a mass at least five times that of Earth.
It receives about the same average stellar energy as Earth does, because red dwarfs shine more dimly than our Sun, and may have similar temperatures to our planet.
These characteristics put it among the top three most Earth-like planets, according to the Earth Similarity Index developed by scientists at the University of Puerto Rica in Arecibo.
The international team, led by Dr Robert Wittenmyer in the UNSW School of Physics, report their finding of the planet online ahead of publication in theAstrophysical Journal.
Team member and Head of UNSW's Exoplanetary Science research group, Professor Chris Tinney, says that if the planet has a similar atmosphere to Earth it may be possible for life to survive, although seasonal shifts would be extreme.
"However, given the large mass of the planet, it seems likely that it would possess a massive atmosphere, which may well render the planet inhospitable. A denser atmosphere would trap heat and could make it more like a super-Venus and too hot for life," says Professor Tinney.
The planet was discovered from its gravitational pull on its parent star, which causes the star to wobble slightly. Members of the Anglo-Australian Planet Search team used the Anglo-Australian Telescope to make observations of the planet.
Their data were combined with observations from the 6.5m Magellan Telescope and the European Southern Observatory 3.6m telescope (both in Chile) to make this new discovery.
This team had previously found, in 2009, that the star has a cold Jupiter-like planet with a near-circular orbit of about nine years, called Gliese GJ b.
"With an outer giant planet and an interior potentially rocky planet, this planetary system can be thought of as a miniature version of our Solar System," says Professor Tinney.
On the Earth Similarity Index, or ESI, the highest ranking exoplanet is Gliese 667C c, which is about 23 light years away. It has an ESI of 0.84 compared to Earth's maximum score of 1.0
Next on the list is Kepler-62 e with an ESI of 0.83, although it is much further away -- about 1,200 light years distant. And the new planet -- the closest at just 16 light years away -- comes in third with an ESI of 0.81.
For comparison, the Milky Way is about 100,000 light years across.
The team includes researchers from Australia, the UK, Finland, the US, Italy and Chile.
Story Source:
The above story is based on materials provided by University of New South Wales.Note: Materials may be edited for content and length.
Sunday, 29 June 2014
Monkeys also believe in winning streaks
Date:
June 29, 2014
Source:
University of Rochester
Summary:
Humans have a well-documented tendency to see winning and losing streaks in situations that, in fact, are random. But scientists disagree about whether the “hot-hand bias” is a cultural artifact picked up in childhood or a predisposition deeply ingrained in the structure of our cognitive architecture.
Humans have a well-documented tendency to see winning and losing streaks in situations that, in fact, are random. But scientists disagree about whether the "hot-hand bias" is a cultural artifact picked up in childhood or a predisposition deeply ingrained in the structure of our cognitive architecture.
Now in the first study in non-human primates of this systematic error in decision making, researchers find that monkeys also share our unfounded belief in winning and losing streaks. The results suggests that the penchant to see patterns that actually don't exist may be inherited -- an evolutionary adaptation that may have provided our ancestors a selective advantage when foraging for food in the wild, according to lead author Tommy Blanchard, a doctoral candidate in brain and cognitive sciences at the University of Rochester.
The cognitive bias may be difficult to override even in situations that are truly random. This inborn tendency to feel that we are on a roll or in a slump may help explain why gambling can be so alluring and why the stock market is so prone to wild swings, said coauthor Benjamin Hayden, assistant professor brain and cognitive sciences at the University of Rochester.
Hayden, Blanchard, and Andreas Wilke, an assistant professor of psychology at Clarkson University, reported their findings in the July issue of the Journal of Experimental Psychology: Animal Learning and Cognition.
To measure whether monkeys actually believe in winning streaks, the researchers had to create a computerized game that was so captivating monkeys would want to play for hours. "Luckily, monkeys love to gamble," said Blanchard. So the team devised a fast-paced task in which each monkey could choose right or left and receive a reward when they guessed correctly.
The researchers created three types of play, two with clear patterns (the correct answer tended to repeat on one side or to alternate from side to side) and a third in which the lucky pick was completely random. Where clear patterns existed, the three rhesus monkeys in the study quickly guessed the correct sequence. But in the random scenarios, the monkeys continued to make choices as if they expected a "streak." In other words, even when rewards were random, the monkeys favored one side.
The monkeys showed the hot-hand bias consistently over weeks of play and an average of 1,244 trials per condition. "They had lots and lots of opportunities to get over this bias, to learn and change, and yet they continued to show the same tendency," said Blanchard.
So why do monkeys and humans share this false belief in a run of luck even when faced over and over with evidence that the results are random? The authors speculate that the distribution of food in the wild, which is not random, may be the culprit. "If you find a nice juicy beetle on the underside of a log, this is pretty good evidence that there might be a beetle in a similar location nearby, because beetles, like most food sources, tend to live near each other," explained Hayden.
Evolution has also primed our brains to look for patterns, added Hayden. "We have this incredible drive to see patterns in the world, and we also have this incredible drive to learn. I think it's very related to why we like music, and why we like to do crossword puzzles, Sudoku, and things like that. If there's a pattern there, we're on top of it. And if there may or may not be a pattern there, that's even more interesting."
Understanding the hot-hand bias could inform treatment for gambling addiction and provide insights for investors, said Hayden. "If a belief in winning streaks is hardwired, then we may want to look for more rigorous retaining for individuals who cannot control their gambling. And investors should keep in mind that humans have an inherited bias to believe that if a stock goes up one day, it will continue to go up."
The results also could provide nuance to our understanding of free will, said Blanchard, who was drawn to the study of decision making during prior graduate training in philosophy. "Biases in our decision-making mechanisms, like this bias towards belief in winning and losing streaks, say something really deep about what sorts of creatures we are. We often like to think we make decisions based only on the information we're conscious of. But we're not always aware of why we make certain decisions or believe certain things.
"We're a complex mix of biases and heuristics and statistical reasoning. When you put it all together, that's how you get sophisticated behavior. We don't know where a lot of these biases come from, but this study -- and others like it -- suggest many of them are due to cognitive mechanisms we share with our primate relatives," said Blanchard.
This research was supported by grants from the National Science Foundation and the Brain and Behavior Research Foundation to Hayden.
Story Source:
The above story is based on materials provided by University of Rochester. Note: Materials may be edited for content and length.
Journal Reference:
- Tommy C. Blanchard, Andreas Wilke, Benjamin Y. Hayden. Hot-hand bias in rhesus monkeys.. Journal of Experimental Psychology: Animal Learning and Cognition, 2014; 40 (3): 280 DOI: 10.1037/xan0000033
Saturday, 28 June 2014
PAKISTAN EXCEEDS AFRICAN COUNTRIES IN POLIO CASES!
GOVERNMENT OF PAKISTAN FINALLY MADE A DECISION THAT PAKISTANI CITIZENS TO CARRY POLIO CERTIFICATE FOR INTERNATIONAL TRAVEL,STATEMENT FROM WHO AND MINISTRY OF HEALTH SERVICES STARTING IN JUNE,
Earlier in May, the WHO’s International Health Regulatory Emergency Committee had recommended pre-travel condition on Pakistanis to curb the transmission of polio virus across the globe.it happened due to claims of syria and israel that polio keeps spreading still due to pakistan's failed government.
Are you polio certified?
With Pakistani travellers required to carry polio certification, here is how you can get yours before you board your flight.
• People traveling out of Pakistan can get vaccinated against polio from major public hospital at city, district and provincial level as well as from DHO offices, airports, seaports, cross-boarder check points of neighboring countries.
• They can get their polio certificate signed by any designated senior official (BPS-19) at these hospitals, airport and departments.
• The polio certificate issued to any one and vaccination done will be valid for one year.
• A person who has planned his foreign trip earlier can get vaccinated four week before to the actual date of traveling or incase of urgency, can get it done at the airport.
Till the printing of the template that is compliant with IHR Annex VII, the certificate can be issued on plain paper with the required stamps from health officials.
