Science and Discovery News

Near-death experiences? Results of the world's largest medical study of the human mind and consciousness at time of death​

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The results of a four-year international study of 2060 cardiac arrest cases across 15 hospitals concludes the following. The themes relating to the experience of death appear far broader than what has been understood so far, or what has been described as so called near-death experiences. In some cases of cardiac arrest, memories of visual awareness compatible with so called out-of-body experiences may correspond with actual events. A higher proportion of people may have vivid death experiences, but do not recall them due to the effects of brain injury or sedative drugs on memory circuits. Widely used yet scientifically imprecise terms such as near-death and out-of-body experiences may not be sufficient to describe the actual experience of death.

Recollections in relation to death, so-called out-of-body experiences (OBEs) or near-death experiences (NDEs), are an often spoken about phenomenon which have frequently been considered hallucinatory or illusory in nature; however, objective studies on these experiences are limited.

In 2008, a large-scale study involving 2060 patients from 15 hospitals in the United Kingdom, United States and Austria was launched. The AWARE (AWAreness during REsuscitation) study, sponsored by the University of Southampton in the UK, examined the broad range of mental experiences in relation to death. Researchers also tested the validity of conscious experiences using objective markers for the first time in a large study to determine whether claims of awareness compatible with out-of-body experiences correspond with real or hallucinatory events.

Results of the study have been published in the journal Resuscitation.
Dr Sam Parnia, Assistant Professor of Critical Care Medicine and Director of Resuscitation Research at The State University of New York at Stony Brook, USA, and the study's lead author, explained: "Contrary to perception, death is not a specific moment but a potentially reversible process that occurs after any severe illness or accident causes the heart, lungs and brain to cease functioning. If attempts are made to reverse this process, it is referred to as 'cardiac arrest'; however, if these attempts do not succeed it is called 'death'. In this study we wanted to go beyond the emotionally charged yet poorly defined term of NDEs to explore objectively what happens when we die."

Thirty-nine per cent of patients who survived cardiac arrest and were able to undergo structured interviews described a perception of awareness, but interestingly did not have any explicit recall of events.

"This suggests more people may have mental activity initially but then lose their memories after recovery, either due to the effects of brain injury or sedative drugs on memory recall," explained Dr Parnia, who was an Honorary Research Fellow at the University of Southampton when he started the AWARE study.

Among those who reported a perception of awareness and completed further interviews, 46 per cent experienced a broad range of mental recollections in relation to death that were not compatible with the commonly used term of NDE's. These included fearful and persecutory experiences. Only 9 per cent had experiences compatible with NDEs and 2 per cent exhibited full awareness compatible with OBE's with explicit recall of 'seeing' and 'hearing' events.

One case was validated and timed using auditory stimuli during cardiac arrest. Dr Parnia concluded: "This is significant, since it has often been assumed that experiences in relation to death are likely hallucinations or illusions, occurring either before the heart stops or after the heart has been successfully restarted, but not an experience corresponding with 'real' events when the heart isn't beating. In this case, consciousness and awareness appeared to occur during a three-minute period when there was no heartbeat. This is paradoxical, since the brain typically ceases functioning within 20-30 seconds of the heart stopping and doesn't resume again until the heart has been restarted. Furthermore, the detailed recollections of visual awareness in this case were consistent with verified events.

"Thus, while it was not possible to absolutely prove the reality or meaning of patients' experiences and claims of awareness, (due to the very low incidence (2 per cent) of explicit recall of visual awareness or so called OBE's), it was impossible to disclaim them either and more work is needed in this area. Clearly, the recalled experience surrounding death now merits further genuine investigation without prejudice."

Further studies are also needed to explore whether awareness (explicit or implicit) may lead to long term adverse psychological outcomes including post-traumatic stress disorder.

Dr Jerry Nolan, Editor-in-Chief of Resuscitation, stated: "The AWARE study researchers are to be congratulated on the completion of a fascinating study that will open the door to more extensive research into what happens when we die."

Article Link​

 

Non-coding half of human genome unlocked with novel sequencing technique​

Texas A&M University biology doctoral student John C. Aldrich (left), working with associate professor of biology Dr. Keith A. Maggert (right), has developed an inexpensive, fluorescent-dye-based sequencing technique to monitor DNA-related dyanmics in heterochromatin -- a game-changing discovery that lays the groundwork to study the non-coding half of the human genome.​

Credit: Image courtesy of Texas A&M University







An obscure swatch of human DNA once thought to be nothing more than biological trash may actually offer a treasure trove of insight into complex genetic-related diseases such as cancer and diabetes, thanks to a novel sequencing technique developed by biologists at Texas A&M University.

The game-changing discovery was part of a study led by Texas A&M biology doctoral candidate John C. Aldrich and Dr. Keith A. Maggert, an associate professor in the Department of Biology, to measure variation in heterochromatin. This mysterious, tightly packed section of the vast, non-coding section of the human genome, widely dismissed by geneticists as "junk," previously was thought by scientists to have no discernable function at all.
In the course of his otherwise routine analysis of DNA in fruit flies, Aldrich was able to monitor dynamics of the heterochromatic sequence by modifying a technique called quantitative polymerase chain reaction (QPCR), a process used to amplify specific DNA sequences from a relatively small amount of starting material. He then added a fluorescent dye, allowing him to monitor the fruit-fly DNA changes and to observe any variations.
Aldrich's findings, published today in the online edition of the journal PLOS ONE, showed that differences in the heterochromatin exist, confirming that the junk DNA is not stagnant as researchers originally had believed and that mutations which could affect other parts of the genome are capable of occurring.

"We know that there is hidden variation there, like disease proclivities or things that are evolutionarily important, but we never knew how to study it," Maggert said. "We couldn't even do the simplest things because we didn't know if there was a little DNA or a lot of it.

"This work opens up the other non-coding half of the genome."

Maggert explains that chromosomes are located in the nuclei of all human cells, and the DNA material in these chromosomes is made up of coding and non-coding regions. The coding regions, known as genes, contain the information necessary for a cell to make proteins, but far less is known about the non-coding regions, beyond the fact that they are not directly related to making proteins.

"Believe it or not, people still get into arguments over the definition of a gene," Maggert said. "In my opinion, there are about 30,000 protein-coding genes. The rest of the DNA -- greater than 90 percent -- either controls those genes and therefore is technically part of them, or is within this mush that we study and, thanks to John, can now measure. The heterochromatin that we study definitely has effects, but it's not possible to think of it as discrete genes. So, we prefer to think of it as 30,000 protein-coding genes plus this one big, complex one that can orchestrate the other 30,000."
Although other methods of measuring DNA are technically available, Aldrich notes that, as of yet, none has proven to be as cost-effective nor time-efficient as his modified-QPCR-fluorescence technique.

"There's some sequencing technology that can also be used to do this, but it costs tens of thousands of dollars," Aldrich said. "This enables us to answer a very specific question right here in the lab."
The uncharted genome sequences have been a point of contention in scientific circles for more than a decade, according to Maggert, a Texas A&M faculty member since 2004. It had long been believed that the human genome -- the blueprint for humanity, individually and as a whole -- would be packed with complex genes with the potential to answer some of the most pressing questions in medical biology.

When human DNA was finally sequenced with the completion of the Human Genome Project in 2003, he says that perception changed. Based on those initial reports, researchers determined that only two percent of the genome (about 21,000 genes) represented coding DNA. Since then, numerous other studies have emerged debating the functionality, or lack thereof, of non-coding, so-called "junk DNA."

Now, thanks to Aldrich's and Maggert's investigation of heterochromatin, the groundwork has been laid to study the rest of the genome. Once all of it is understood, scientists may finally find the root causes and possibly treatments for many genetic ailments.

"There is so much talk about understanding the connection between genetics and disease and finding personalized therapies," Maggert said. "However, this topic is incomplete unless biologists can look at the entire genome. We still can't -- yet -- but at least now, we're a step closer."
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Article Link​

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NASA’s NuSTAR Telescope Discovers Shockingly Bright Dead Star
October 8, 2014





A rare and mighty pulsar (pink) can be seen at the center of the galaxy Messier 82 in this new multi-wavelength portrait. NASA's NuSTAR mission discovered the "pulse" of the pulsar — a type of dead star — using is high-energy X-ray vision.
Image Credit:
NASA/JPL-Caltech
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Astronomers have found a pulsating, dead star beaming with the energy of about 10 million suns. This is the brightest pulsar – a dense stellar remnant left over from a supernova explosion – ever recorded. The discovery was made with NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR.
"You might think of this pulsar as the 'Mighty Mouse' of stellar remnants," said Fiona Harrison, the NuSTAR principal investigator at the California Institute of Technology in Pasadena, California. "It has all the power of a black hole, but with much less mass."

The discovery appears in a new report in the Thursday Oct. 9 issue of the journal Nature.

The surprising find is helping astronomers better understand mysterious sources of blinding X-rays, called ultraluminous X-ray sources (ULXs). Until now, all ULXs were thought to be black holes. The new data from NuSTAR show at least one ULX, about 12 million light-years away in the galaxy Messier 82 (M82), is actually a pulsar.
"The pulsar appears to be eating the equivalent of a black hole diet," said Harrison. "This result will help us understand how black holes gorge and grow so quickly, which is an important event in the formation of galaxies and structures in the universe."

ULXs are generally thought to be black holes feeding off companion stars -- a process called accretion. They also are suspected to be the long-sought after "medium-size" black holes – missing links between smaller, stellar-size black holes and the gargantuan ones that dominate the hearts of most galaxies. But research into the true nature of ULXs continues toward more definitive answers.

NuSTAR did not initially set out to study the two ULXs in M82. Astronomers had been observing a recent supernova in the galaxy when they serendipitously noticed pulses of bright X-rays coming from the ULX known as M82 X-2. Black holes do not pulse, but pulsars do.
Pulsars belong to a class of stars called neutron stars. Like black holes, neutron stars are the burnt-out cores of exploded stars, but puny in mass by comparison. Pulsars send out beams of radiation ranging from radio waves to ultra-high-energy gamma rays. As the star spins, these beams intercept Earth like lighthouse beacons, producing a pulsed signal.

"We took it for granted that the powerful ULXs must be massive black holes," said lead study author Matteo Bachetti, of the University of Toulouse in France. "When we first saw the pulsations in the data, we thought they must be from another source."

NASA's Chandra X-ray Observatory and Swift satellite also have monitored M82 to study the same supernova, and confirmed the intense X-rays of M82 X-2 were coming from a pulsar.

"Having a diverse array of telescopes in space means that they can help each other out," said Paul Hertz, director of NASA's astrophysics division in Washington. "When one telescope makes a discovery, others with complementary capabilities can be called in to investigate it at different wavelengths."

The key to NuSTAR's discovery was its sensitivity to high-energy X-rays, as well as its ability to precisely measure the timing of the signals, which allowed astronomers to measure a pulse rate of 1.37 seconds. They also measured its energy output at the equivalent of 10 million suns, or 10 times more than that observed from other X-ray pulsars. This is a big punch for something about the mass of our sun and the size of Pasadena.

How is this puny, dead star radiating so fiercely? Astronomers are not sure, but they say it is likely due to a lavish feast of the cosmic kind. As is the case with black holes, the gravity of a neutron star can pull matter off companion stars. As the matter is dragged onto the neutron star, it heats up and glows with X-rays. If the pulsar is indeed feeding off surrounding matter, it is doing so at such an extreme rate to have theorists scratching their heads.

Astronomers are planning follow-up observations with NASA's NuSTAR, Swift and Chandra spacecraft to find an explanation for the pulsar’s bizarre behavior. The NuSTAR team also will look at more ULXs, meaning they could turn up more pulsars. At this point, it is not clear whether M82 X-2 is an oddball or if more ULXs beat with the pulse of dead stars. NuSTAR, a relatively small telescope, has thrown a big loop into the mystery of black holes.

“In the news recently, we have seen that another source of unusually bright X-rays in the M82 galaxy seems to be a medium-sized black hole," said astronomer Jeanette Gladstone of the University of Alberta, Canada, who is not affiliated with the study. "Now, we find that the second source of bright X-rays in M82 isn’t a black hole at all. This is going to challenge theorists and pave the way for a new understanding of the diversity of these fascinating objects."

More information about NuSTAR is online at:
http://www.nasa.gov/nustar
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Cells' powerhouses were once energy parasites: Study upends current theories of how mitochondria began
Date:
October 16, 2014
Source:
University of Virginia

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Summary:
Parasitic bacteria were the first cousins of the mitochondria that power cells in animals and plants -- and first acted as energy parasites in those cells before becoming beneficial, according to a new study.
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Artist's 3-D rendering of mitochondria (stock illustration).
Credit: © Mopic / Fotolia​

Parasitic bacteria were the first cousins of the mitochondria that power cells in animals and plants -- and first acted as energy parasites in those cells before becoming beneficial, according to a new University of Virginia study that used next-generation DNA sequencing technologies to decode the genomes of 18 bacteria that are close relatives of mitochondria.

The study appears this week in the online journal PLoS ONE, published by the Public Library of Science. It provides an alternative theory to two current theories of how simple bacterial cells were swallowed up by host cells and ultimately became mitochondria, the "powerhouse" organelles within virtually all eukaryotic cells -- animal and plant cells that contain a nucleus and other features. Mitochondria power the cells by providing them with adenosine triphosphate, or ATP, considered by biologists to be the energy currency of life.

The origin of mitochondria began about 2 billion years ago and is one of the seminal events in the evolutionary history of life. However, little is known about the circumstances surrounding its origin, and that question is considered an enigma in modern biology.
"We believe this study has the potential to change the way we think about the event that led to mitochondria," said U.Va. biologist Martin Wu, the study's lead author. "We are saying that the current theories -- all claiming that the relationship between the bacteria and the host cell at the very beginning of the symbiosis was mutually beneficial -- are likely wrong.

"Instead, we believe the relationship likely was antagonistic -- that the bacteria were parasitic and only later became beneficial to the host cell by switching the direction of the ATP transport."

The finding, Wu said, is a new insight into an event in the early history of life on Earth that ultimately led to the diverse eukaryotic life we see today. Without mitochondria to provide energy to the rest of a cell, there could not have evolved such amazing biodiversity, he said.

"We reconstructed the gene content of mitochondrial ancestors, by sequencing DNAs of its close relatives, and we predict it to be a parasite that actually stole energy in the form of ATP from its host -- completely opposite to the current role of mitochondria," Wu said.

In his study, Wu also identified many human genes that are derived from mitochondria -- identification of which has the potential to help understand the genetic basis of human mitochondrial dysfunction that may contribute to several diseases, including Alzheimer's disease, Parkinson's disease and diabetes, as well as aging-related diseases.
In addition to the basic essential role of mitochondria in the functioning of cells, the DNA of mitochondria is used by scientists for DNA forensics, genealogy and tracing human evolutionary history.

Story Source:
The above story is based on materials provided by University of Virginia. Note: Materials may be edited for content and length.
Journal Reference:
Zhang Wang, Martin Wu. Phylogenomic Reconstruction Indicates Mitochondrial Ancestor Was an Energy Parasite. PLOS ONE, 2014 DOI: 10.1371/journal.pone.0110685

Article Link​

 

Paralysed man walks again after cell transplant

Fergus Walsh By Fergus Walsh Medical correspondent

BBC Article Link​

A paralysed man has been able to walk again after a pioneering therapy that involved transplanting cells from his nasal cavity into his spinal cord.
Darek Fidyka, who was paralysed from the chest down in a knife attack in 2010, can now walk using a frame.

The treatment, a world first, was carried out by surgeons in Poland in collaboration with scientists in London.

I have waited 40 years for something like this”
Prof Wagih El Masri Consultant spinal injuries surgeon
Details of the research are published in the journal Cell Transplantation.
BBC One's Panorama programme had unique access to the project and spent a year charting the patient's rehabilitation.
Darek Fidyka, 40, from Poland, was paralysed after being stabbed repeatedly in the back in the 2010 attack.
He said walking again - with the support of a frame - was "an incredible feeling", adding: "When you can't feel almost half your body, you are helpless, but when it starts coming back it's like you were born again."
Prof Geoff Raisman, chair of neural regeneration at University College London's Institute of Neurology, led the UK research team.
He said what had been achieved was "more impressive than man walking on the moon".

UK research team leader Prof Geoff Raisman: Paralysis treatment "has vast potential"
The treatment used olfactory ensheathing cells (OECs) - specialist cells that form part of the sense of smell.

OECs act as pathway cells that enable nerve fibres in the olfactory system to be continually renewed.
In the first of two operations, surgeons removed one of the patient's olfactory bulbs and grew the cells in culture.

Two weeks later they transplanted the OECs into the spinal cord, which had been cut through in the knife attack apart from a thin strip of scar tissue on the right. They had just a drop of material to work with - about 500,000 cells.

About 100 micro-injections of OECs were made above and below the injury.
Four thin strips of nerve tissue were taken from the patient's ankle and placed across an 8mm (0.3in) gap on the left side of the cord.

The scientists believe the OECs provided a pathway to enable fibres above and below the injury to reconnect, using the nerve grafts to bridge the gap in the cord.​

How the injury was treated
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Spinal graphic

1) One of the patient's two olfactory bulbs was removed and the olfactory ensheathing cells (OECs) were grown in culture
2) 100 micro injections of OECs were made above and below the damaged area of the spinal cord
3) Four strips of nerve tissue were placed across an 8mm gap in the spinal cord. The scientists believe the OECs acted as a pathway to stimulate the spinal cord cells to regenerate, using the nerve grafts as a bridge to cross the severed cord

Before the treatment, Mr Fidyka had been paralysed for nearly two years and had shown no sign of recovery despite many months of intensive physiotherapy.
This programme of exercise - five hours per day, five days a week - has continued after the transplant at the Akson Neuro-Rehabilitation Center in Wroclaw.
Mr Fidyka first noticed that the treatment had been successful after about three months, when his left thigh began putting on muscle.
Six months after surgery, Mr Fidyka was able to take his first tentative steps along parallel bars, using leg braces and the support of a physiotherapist.
Two years after the treatment, he can now walk outside the rehabilitation centre using a frame.
He has also recovered some bladder and bowel sensation and sexual function.
Dr Pawel Tabakow, consultant neurosurgeon at Wroclaw University Hospital, who led the Polish research team, said: "It's amazing to see how regeneration of the spinal cord, something that was thought impossible for many years, is becoming a reality."

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Darek undergoing physiotherapy Mr Fidyka undergoes five hours of physiotherapy a day
Mr Fidyka still tires quickly when walking, but said: "I think it's realistic that one day I will become independent.
"What I have learned is that you must never give up but keep fighting, because some door will open in life."
The groundbreaking research was supported by the Nicholls Spinal Injury Foundation (NSIF) and the UK Stem Cell Foundation (UKSCF)
UKSCF was set up in 2007 to speed up progress of promising stem cell research - the charity has to date contributed ￡2.5m
NSIF was set up by chef David Nicholls after his son Daniel was paralysed from the arms down in a swimming accident in 2003.
To date the charity has given £1m to fund the research in London and a further £240,000 for the work in Poland.

The breakthrough
A key difference with Mr Fidyka was that the scientists were able use the patient's olfactory bulb, which is the richest source of olfactory ensheathing cells.
This meant there was no danger of rejection, so no need for immunosuppressive drugs used in conventional transplants.
Most of the repair of Mr Fidyka's spinal cord was done on the left side, where there was an 8mm gap.
He has since regained muscle mass and movement mostly on that side.

Scientists believe this is evidence that the recovery is due to regeneration, as signals from the brain controlling muscles in the left leg travel down the left side of the spinal cord.

MRI scans suggest that the gap in the cord has closed up following the treatment.
None of those involved in the research want to profit from it.

Prof Geoff Raisman said: "It would be my proudest boast if I could say that no patient had had to pay one penny for any of the information we have found."
NSIF said if there were any patents arising, it would acquire them so as to make the technique freely available.

The sense of smell and spinal repair

Generic image of a person smelling​

The complex neural circuitry responsible for our sense of smell is the only part of the nervous system that regenerates throughout adult life.
It is this ability that scientists have tried to exploit in stimulating repair in the spinal cord.

Every time we breathe, molecules carrying different odours in the air come into contact with nerve cells in the nose.
These transmit messages to our olfactory bulbs - at the very top of the nasal cavity, sitting at the base of the brain.
The nerve cells are being continually damaged and must be replaced.

This process of regeneration is made possible by olfactory ensheathing cells (OECs), which provide a pathway for the fibres to grow back.

Mr Nicholls said: "When Dan had his accident I made him a promise that, one day, he would walk again. I set up the charity to raise funds purely for research into repairing the spinal cord. The results with Darek show we are making significant progress towards that goal."

Prof Wagih El Masri said: "Although the clinical neurological recovery is to date modest, this intervention has resulted in findings of compelling scientific significance."
The consultant spinal injuries surgeon, who has treated thousands of patients in the UK, added: "I have waited 40 years for something like this."
All those involved in the research are keen not to raise false hopes in patients and stress that the success will need to be repeated to show definitively whether it can stimulate spinal cord regeneration.

The scientists hope to treat another 10 patients, in Poland and Britain over the coming years, although that will depend on the research receiving funding.
Dr Tabakow said: "Our team in Poland would be prepared to consider patients from anywhere in the world who are suitable for this therapy. They are likely to have had a knife wound injury where the spinal cord has been cleanly severed.
Sir Richard Sykes, chair of the UK Stem Cell Foundation, said: "The first patient is an inspirational and important step, which brings years of laboratory research towards the clinical testbed."

"To fully develop future treatments that benefit the 3 million paralysed globally will need continued investment for wide scale clinical trials,"

The researchers




Prof Raisman has spent more than 40 years studying how to repair the spinal cord.
In animal studies he showed that OECs injected into the rat spinal cord could reverse paralysis.
In 2005, Prof Raisman was approached by a Polish neurosurgeon who had begun researching how to apply the technique in humans.




Dr Tabakow carried out an initial trial involving three paralysed patients who each had a small amount of OECs injected in their damaged spinal cords.
While none showed any significant improvement, the main purpose of the study was achieved, showing that the treatment was safe.

 

Seeing dinosaur feathers in a new light​

Date:
October 30, 2014

Source:
Universität Bonn
Article Link
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Summary:
Why were dinosaurs covered in a cloak of feathers long before the early bird species Archaeopteryx first attempted flight? Researchers postulate that these ancient reptiles had a highly developed ability to discern color. Their hypothesis: The evolution of feathers made dinosaurs more colorful, which in turn had a profoundly positive impact on communication, the selection of mates and on dinosaurs’ procreation.

Feathers close up (stock image). The researchers' hypothesis:
The evolution of feathers made dinosaurs more colorful,
which in turn had a profoundly positive impact on communication,
the selection of mates and on dinosaurs' procreation.
Credit: © thawats / Fotolia​

Why were dinosaurs covered in a cloak of feathers long before the early bird species Archaeopteryx first attempted flight? Researchers from the University of Bonn and the University of Göttingen attempt to answer precisely that question in their article "Beyond the Rainbow" in the latest issue of the journal Science. The research team postulates that these ancient reptiles had a highly developed ability to discern color. Their hypothesis: The evolution of feathers made dinosaurs more colorful, which in turn had a profoundly positive impact on communication, the selection of mates and on dinosaurs' procreation.

The suggestion that birds and dinosaurs are close relatives dates back to the 19th century, the time when the father of evolutionary theory, Charles Darwin, was hard at work. But it took over 130 years for the first real proof to come to light with numerous discoveries of the remains of feathered dinosaurs, primarily in fossil sites in China. Thanks to these fossil finds, we now know that birds descend from a branch of medium-sized predatory dinosaurs, the so-called theropods. Tyrannosaurus rex and also velociraptors, made famous by the film Jurassic Park, are representative of these two-legged meat eaters. Just like later birds, these predatory dinosaurs had feathers -- long before Archaeopteryx lifted itself off the ground. But why was this, particularly when dinosaurs could not fly?


Dinosaurs' color vision

"Up until now, the evolution of feathers was mainly considered to be an adaptation related to flight or to warm-bloodedness, seasoned with a few speculations about display capabilities" says the article's first author, Marie-Claire Koschowitz of the Steinmann Institute for Geology, Mineralogy and Paleontology at the University of Bonn. "I was never really convinced by any of these theories. There has to be some particularly important feature attached to feathers that makes them so unique and caused them to spread so rapidly amongst the ancestors of the birds we know today," explains Koschowitz. She now suggests that this feature is found in dinosaurs' color vision. After analyzing dinosaurs' genetic relationships to reptiles and birds, the researcher determined that dinosaurs not only possessed the three color receptors for red, green and blue that the human eye possesses, but that they, like their closest living relatives, crocodiles and birds, were probably also able to see extremely short-wave and ultraviolet light by means of an additional receptor. "Based on the phylogenetic relationships and the presence of tetrachromacy in recent tetrapods it is most likely that the stem species-of all terrestrial vertebrates had photo receptors to detect blue, green, red and uv," says Dr. Christian Fischer of the University of Göttingen.
This makes the world much more colorful for most animals than it is for human beings and other mammals. Mammals generally have rather poor color vision or even no color vision at all because they tended to be nocturnal during the early stages of their evolution. In contrast, numerous studies on the social behavior and choice of mates among reptiles and birds, which are active during the day, have shown that information transmitted via color exerts an enormous influence on those animals' ability to communicate and procreate successfully.


Feathers allowed for more visible signals than did fur

We know from dinosaur fossil finds that the precursors to feathers resembled hairs similar to mammals' fur. They served primarily to protect the smaller predatory dinosaurs -- which would eventually give rise to birds -- from losing too much body heat. The problem with these hair-like forerunners of feathers and with fur is that neither allow for much color, but tend instead to come in basic patterns of brown and yellow tones as well as in black and white. Large flat feathers solved this shortcoming by providing for the display of color and heat insulation at the same time. Their broad surface area, created by interlocked strands of keratin, allows for the constant refraction of light, which consequently produces what is referred to as structural coloration. This refraction of light is absolutely necessary to produce colors such as blue and green, the effect of metallic-like shimmering or even colors in the UV spectrum. "Feathers enable a much more noticeable optical signaling than fur would allow. Iridescent birds of paradise and hummingbirds are just two among a wealth of examples," explains Koschowitz.

This work means we must see the evolution of feathers in a whole new light. They provided for a nearly infinite variety of colors and patterns while simultaneously providing heat insulation. Prof. Dr. Martin Sander of the University of Bonn's Steinmann Institute summarizes the implications of this development: "This allowed dinosaurs to not only show off their colorful feathery attire, but to be warm-blooded animals at the same time -- something mammals never managed."

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Direct brain interface between humans​

Date:
November 5, 2014

Source:
University of Washington
Article Link​

Summary:
Researchers have successfully replicated a direct brain-to-brain connection between pairs of people as part of a scientific study following the team's initial demonstration a year ago. In the newly published study, which involved six people, researchers were able to transmit the signals from one person's brain over the Internet and use these signals to control the hand motions of another person within a split second of sending that signal.

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In this photo, UW students Darby Losey, left, and Jose Ceballos are positioned in two different buildings on campus as they would be during a brain-to-brain interface demonstration. The sender, left, thinks about firing a cannon at various points throughout a computer game. That signal is sent over the Web directly to the brain of the receiver, right, whose hand hits a touchpad to fire the cannon.Mary Levin, U of Wash.

Credit: Image courtesy of University of Washington​

Sometimes, words just complicate things. What if our brains could communicate directly with each other, bypassing the need for language?

University of Washington researchers have successfully replicated a direct brain-to-brain connection between pairs of people as part of a scientific study following the team's initial demonstration a year ago. In the newly published study, which involved six people, researchers were able to transmit the signals from one person's brain over the Internet and use these signals to control the hand motions of another person within a split second of sending that signal.

At the time of the first experiment in August 2013, the UW team was the first to demonstrate two human brains communicating in this way. The researchers then tested their brain-to-brain interface in a more comprehensive study, published Nov. 5 in the journal PLOS ONE.

"The new study brings our brain-to-brain interfacing paradigm from an initial demonstration to something that is closer to a deliverable technology," said co-author Andrea Stocco, a research assistant professor of psychology and a researcher at UW's Institute for Learning & Brain Sciences. "Now we have replicated our methods and know that they can work reliably with walk-in participants."

Collaborator Rajesh Rao, a UW associate professor of computer science and engineering, is the lead author on this work.

The research team combined two kinds of noninvasive instruments and fine-tuned software to connect two human brains in real time. The process is fairly straightforward. One participant is hooked to an electroencephalography machine that reads brain activity and sends electrical pulses via the Web to the second participant, who is wearing a swim cap with a transcranial magnetic stimulation coil placed near the part of the brain that controls hand movements.

Using this setup, one person can send a command to move the hand of the other by simply thinking about that hand movement.

The UW study involved three pairs of participants. Each pair included a sender and a receiver with different roles and constraints. They sat in separate buildings on campus about a half mile apart and were unable to interact with each other in any way -- except for the link between their brains.

Each sender was in front of a computer game in which he or she had to defend a city by firing a cannon and intercepting rockets launched by a pirate ship. But because the senders could not physically interact with the game, the only way they could defend the city was by thinking about moving their hand to fire the cannon.

Across campus, each receiver sat wearing headphones in a dark room -- with no ability to see the computer game -- with the right hand positioned over the only touchpad that could actually fire the cannon. If the brain-to-brain interface was successful, the receiver's hand would twitch, pressing the touchpad and firing the cannon that was displayed on the sender's computer screen across campus.

Researchers found that accuracy varied among the pairs, ranging from 25 to 83 percent. Misses mostly were due to a sender failing to accurately execute the thought to send the "fire" command. The researchers also were able to quantify the exact amount of information that was transferred between the two brains.

Another research team from the company Starlab in Barcelona, Spain, recently published results in the same journal showing direct communication between two human brains, but that study only tested one sender brain instead of different pairs of study participants and was conducted offline instead of in real time over the Web.
Now, with a new $1 million grant from the W.M. Keck Foundation, the UW research team is taking the work a step further in an attempt to decode and transmit more complex brain processes.

With the new funding, the research team will expand the types of information that can be transferred from brain to brain, including more complex visual and psychological phenomena such as concepts, thoughts and rules.

They're also exploring how to influence brain waves that correspond with alertness or sleepiness. Eventually, for example, the brain of a sleepy airplane pilot dozing off at the controls could stimulate the copilot's brain to become more alert.

The project could also eventually lead to "brain tutoring," in which knowledge is transferred directly from the brain of a teacher to a student.

"Imagine someone who's a brilliant scientist but not a brilliant teacher. Complex knowledge is hard to explain -- we're limited by language," said co-author Chantel Prat, a faculty member at the Institute for Learning & Brain Sciences and a UW assistant professor of psychology.

Other UW co-authors are Joseph Wu of computer science and engineering; Devapratim Sarma and Tiffany Youngquist of bioengineering; and Matthew Bryan, formerly of the UW.

The research published in PLOS ONE was initially funded by the U.S. Army Research Office and the UW, with additional support from the Keck Foundation.

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Story Source:
The above story is based on materials provided by University of Washington. The original article was written by Michelle Ma. Note: Materials may be edited for content and length.

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Journal Reference:

1. Rajesh P. N. Rao, Andrea Stocco, Matthew Bryan, Devapratim Sarma, Tiffany M. Youngquist, Joseph Wu, Chantel S. Prat. A Direct Brain-to-Brain Interface in Humans. PLoS ONE, 2014; 9 (11): e111332 DOI: 10.1371/journal.pone.0111332

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The female nose always knows: Do women have more olfactory neurons?​

Date:
November 5, 2014

Source:
Publicase Comunicação Científica
Article Link​

Summary:
Using a new method called isotropic fractionator, a group of researchers has found biological evidence that may explain the superior olfactory abilities that women have over men.

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The olfactory bulb transmits information from the nose to the brain.
Credit: Roberto Lent​

Individuals show great diversity in their ability to identify scents and odors. More importantly, males and females greatly differ in their perceptual evaluation of odors, with women outperforming men on many kinds of smell tests.

Sex differences in olfactory detection may play a role in differentiated social behaviors and may be connected to one's perception of smell, which is naturally linked to associated experiences and emotions. Thus, women's olfactory superiority has been suggested to be cognitive or emotional, rather than perceptual.

Previous studies investigating the biological roots of greater olfactory sensitivity in women have used imaging methods that allow gross measures of brain structures. The results of such studies have been controversial, leaving unanswered the question of whether differences in olfactory sensitivity have biological roots or whether they represent a mere by-product of social and cognitive differences between genders.

The isotropic fractionator, a fast and reliable technique previously developed by a group of researchers at Federal University of Rio de Janeiro, measures the absolute number of cells in a given brain structure such as the olfactory bulb, which is the first brain region to receive olfactory information captured by the nostrils.

Using this technique, a group of researchers led by Prof. Roberto Lent from the Institute of Biomedical Sciences at the Federal University of Rio de Janeiro and the National Institute of Translational Neuroscience, Ministry of Science and Technology in Brazil, has finally found biological evidence in the brains of men and women that may explain the olfactory difference between genders.

The group examined post-mortem brains from seven men and 11 women who were all over the age of 55 at the time of death. All individuals were neurologically healthy and none worked in professions requiring exceptional olfactory abilities, such as coffee-tasting or professional cooking. By calculating the number of cells in the olfactory bulbs of these individuals, the group (that also included researchers from the University of São Paulo, the University of California, San Francisco, and the Albert Einstein Hospital in São Paulo) discovered that women have on average 43% more cells than men in this brain structure. Counting neurons specifically, the difference reached almost 50% more in women than men.

The question remains whether this higher cell number accounts for the differences in olfactory sensitivity between sexes. "Generally speaking, says Prof. Lent, larger brains with larger numbers of neurons correlate with the functional complexity provided by these brains. Thus, it makes sense to think that more neurons in the female olfactory bulbs would provide women with higher olfactory sensitivity."

The fact that few cells are added to our brains throughout life suggests that women are already born with these extra cells. But why do women's brains have this pre-wired ability? What mechanisms are responsible for this higher number of cells in their olfactory bulbs? Some believe this olfactory ability is essential for reproductive behaviors such as pair bonding and kin recognition.

If this holds true, then superior olfactory ability is an essential trait that has been inherited and then maintained throughout evolution, an idea expressed by Romanian playwright Eugene Ionesco when he said "a nose that can see is worth two that sniff."

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Story Source:
The above story is based on materials provided by Publicase Comunicação Científica. Note: Materials may be edited for content and length.

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Journal Reference:

1. Ana V. Oliveira-Pinto, Raquel M. Santos, Renan A. Coutinho, Lays M. Oliveira, Gláucia B. Santos, Ana T. L. Alho, Renata E. P. Leite, José M. Farfel, Claudia K. Suemoto, Lea T. Grinberg, Carlos A. Pasqualucci, Wilson Jacob-Filho, Roberto Lent. Sexual Dimorphism in the Human Olfactory Bulb: Females Have More Neurons and Glial Cells than Males. PLoS ONE, 2014; 9 (11): e111733 DOI: 10.1371/journal.pone.0111733

 

In This Image, Two Photons Interact. Here's Why It's Groundbreaking.​

Article Link
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Normally, photons want nothing to do with one another. Light waves just pass through each other like ghosts. But now, for the first time ever, scientists at the University of Vienna have coaxed a strong interaction between two single photons. It's an achievement that opens up radical new possibilities for a number of quantum technologies.
Above: In an optical fiber — about half as thick as a human hair — light can be seen running around its axis. In this case the light can not escape along the fiber because the diameter decreases to both sides. (University of Vienna)

Photons normally pass right through other beams of light. Indeed, light is this funky mixture of classical and quantum phenomenon, exhibiting properties of both waves and particles. This is great for engineers who wish to exploit these anti-social attributes, allowing them to create such things as optical fibre cables that stretch for miles. But it's a constraint if you want to transmit information through secure quantum channels, or for building optical gates. This latest breakthrough could change that.
A team of researchers at the University of Vienna created a strong interaction between two photons by using an ultra-thin glass fibre. The interaction was so strong that the phase of the photons was altered by 180 degrees.


"It is like a pendulum, which should actually swing to the left, but due to coupling with a second pendulum, it is swinging to the right. There cannot be a more extreme change in the pendulum's oscillation", noted study co-author Arno Rauschenbeutel in a statement. "We achieve the strongest possible interaction with the smallest possible intensity of light."

The light in a fiber is coupled to a bottle-shaped resonator. (University of Vienna)​

To make it happen, the photon was sent on a rather unconventional journey. An ultra-thin glass fibre was joined to a tiny bottle-like optical resonator so that light could enter into the resonator, twist about in circles, and then return to the glass fibre. It was this detour through the resonator that inverted the phase of the photon. And in fact, a wave crest appeared where a wave trough was expected.

But when the researchers added a single rubidium atom to the resonator, the system changed dramatically. Because of the atom, hardly any light entered into the resonator and the oscillation phase of the photon remained unchanged. Essentially, the addition of the atom got both photons to talk to each other.
As far as quantum mechanics is concerned, the two photons are indistinguishable. As noted by the University of Vienna release:

They have to be considered as a joint wave-like object, which is located in the resonator and in the glass fibre at the same time. Therefore, one cannot tell which photon has been absorbed and which one has passed. When both hit the resonator at the same time, they thus experience a joint phase shift of 180 degrees. Hence, two simultaneous photons that interact show a completely different behaviour than single photons.

This resulted in the creation of a "maximally entangled photon state" — a state that's required in quantum optics, quantum teleportation, and for the creation of light-transistors which could be used for quantum computing.

All this said, the system wasn't perfect. The noise rate was at 50%, which is a far cry from what's required in a quantum computer. But it's a remarkable achievement nonetheless, one that, if it can be refined, could result in scalable quantum computers.

Read the entire study at Nature Photonics: "Nonlinear π phase shift for single fibre-guided photons interacting with a single resonator-enhanced atom".

 

Scientists Have Finally Found The First Real Reason We Need To Sleep​

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• Jennifer Wels​

• Oct. 17, 2013, 2:00 PM​

We know we need to sleep. We know our brains and bodies work better after sleep. But what we didn't know, until now, was why.
Scientists have just reported the first major mechanical reason our brains need to sleep — certain cleaning mechanisms in the brain work better when we shut the brain down. Just like how dump trucks take to the city streets during the pre-dawn hours because there's less traffic, our brain's cleaners also work best when there's less going on.

"This study shows that the brain has different functional states when asleep and when awake," study researcher Maiken Nedergaard, of the University of Rochester said in a statement. "In fact, the restorative nature of sleep appears to be the result of the active clearance of the by-products of neural activity that accumulate during wakefulness."

We've known that our brains consolidate memories during sleep and perform other important functions. There are also benefits to the body during sleep — resting allows our muscles, bones, and organs to repair themselves. It also keeps our immune system healthy.

We know that sleep has all of these benefits, but until now we didn't know any of the specific changes that bring about these sleep benefits.

Charles Czeisler, a sleep researcher at Harvard Medical School in Boston, told Science Magazine's Emily Underwood that this is the "first direct experimental evidence at the molecular level" for why we need to sleep.

The paper was published in the journal Science on Oct. 17.

Toxic cells
All of our cells accumulate waste while they are working, and these waste products can be toxic. If they aren't removed they can build up and kill our cells. Throughout the rest of the body the lymphatic system washes these waste products away, but the brain is cut off from these actions because of the blood-brain barrier.

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J. Iliff and M. Nedergaard, STM, 2012The purple areas are the channels through which brain fluid flows, and the green areas are the glial cells that control the flow of fluid through them.​

The team just discovered the brain's unique trash disposal system last year — the find was published in the journal Science Translational Medicine on Aug. 15, 2012. It works like a plumbing system.

The brain itself is bathed in a special clear liquid called cerebrospinal fluid, which doesn't mix with the blood and lymph system of the rest of the body. In the study from last year, they found that this fluid travels through special channels and washes the brain out.

There are two types of cells in the brain — the neurons that send signals and the glial that keep them healthy. They found that these glial cells seem to create these cleaning channels around the neurons.

It washes away toxic proteins and removes them from the brain's circulatory system. They are transferred to the general circulatory system, where the liver can remove them.

Sleeping mice

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Xie, et. al, Science, 2013.When mice sleep, fluid-filled channels (pale blue) between neurons expand and flush out waste.

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By studying this newfound pathway in mice trained to sleep on a microscope, the researchers found that this system was 10 times more active during sleep than it was while the mice were awake.

They injected the mice with colored toxic proteins to see the system at work — when the mice were sleeping, these toxic proteins were removed from the brain twice as quickly as when they were awake.

In the new study, they found that while the brain is sleeping, the neurons shrink by about 60% and the channels between these cells grow and fill with fluid. The glial cells then activate their pumping system to push the brain's cerebrospinal fluid through these extra spaces and flush out the area around the neurons.

When we wake, these channels squeeze shut again as the cells plump up, and the cerebrospinal fluid is once again found mostly around the surface of the brain, not deep inside it. While awake, this washing process acts at only about 5% of its performance during sleep.

All of this fluid movement is energy intensive, which is why the researchers think it can only happen effectively during sleep. Normally, all of our brain's energy is busy doing normal brain activities that support every thing we do — all of our movements, our thoughts, creating memories, and analyzing the signals that come in through our senses. By shutting these processes down, our brains are able to switch into cleaning mode.

Understanding sleep
The toxins that this pathway removes are the kind responsible for neurodegenerative diseases like Alzheimer's. Understanding this pathway not only helps us understand our need for sleep, and possibly control it better with drugs that turn it on and off, but could also lead to new ways to treat and prevent these diseases.

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Alz.orgThe buildup of toxic waste proteins causes brain cells to die in Alzheimer's disease.

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In a Perspectives article in Science Magazine about the study, Suzana Herculano-Houzel, a brain researcher at the Universidade Federal do Rio de Janeiro, even suggested that this build up of toxins is what turns on our need to sleep and makes us sleepy.

The mice in the study were woken up after 60 minutes of sleep, so we don't yet know how the amount or kind of sleep humans get affects the washing process.
While it sounds counter-intuitive, this could even explain why some small-brained animals need more sleep than large-brained animals. For example, bats sleep up to 20 hours a day, while elephants sleep four. Why? Because bigger brains have more space to store these toxins before they build up to dangerous levels and need to be flushed.
Understanding how "brain structure and function changes in the two different states (sleep-wake) suggests that we can start to think about how we can manipulate the two states," Nedergaard told Business Insider in an email. Manipulations could include ways to put this cleaning system into "hyperdrive" so we could sleep less, but that's way in the future.

businessinsider.com/the-first-real-reason-we-need-to-sleep-2013-10#ixzz3IeG7FBrP​