Scientists use parasite's internal clock to attack sleeping sickness

Trypanosoma brucei is a parasite that causes the deadly sleeping sickness. Scientists have determined the parasite has its own biological clock that makes it more vulnerable to medications in the afternoon.

The parasite that causes deadly sleeping sickness has its own biological clock that makes it more vulnerable to medications during the afternoon, according to international research that may help improve treatments for one of Africa's most lethal diseases.

The finding from the Peter O'Donnell Jr. Brain Institute could be especially beneficial for patients whose bodies can't handle side effects of toxic treatments used to eradicate the parasite. By knowing the optimal time to administer these medications - which can be fatal - doctors hope to reduce the duration and dosage of the treatment and save more lives.

"This research has opened a door," said Dr. Filipa Rijo-Ferreira, first author of the study from the O'Donnell Brain Institute at UT Southwestern Medical Center. "If the same therapeutic effect can be obtained with a lower dose, then it may be possible to reduce the mortality associated with the treatment."

Establishing that parasites have their own internal clock is a key step in finding new ways to treat a variety of parasitic conditions, from sleeping sickness to malaria. While many of these diseases are often not deadly, sleeping sickness has been among the most lethal.

The condition - known formally as African trypanosomiasis - is transmitted through the bite of the Tsetse fly and threatens tens of millions of people in sub-Saharan African countries. After entering the body, the parasite causes such symptoms as inverted sleeping cycles, fever, muscle weakness, and itching. It eventually invades the central nervous system and, depending on its type, can kill its host in anywhere from a few months to several years.

Control efforts have significantly reduced the number of cases over the last decade. However, an unknown number of people still die annually from sleeping sickness as scientists continue seeking a vaccine and alternative treatments to the arsenic-based medications that are occasionally fatal to patients.
Dr. Joseph S. Takahashi, who oversaw the collaborative study published in Nature

Microbiology with Dr. Luisa Figueiredo at the University of Lisbon in Portugal, said the finding will likely apply to all types of parasites and perhaps lead to improved treatment for their associated conditions.



"There have been many observations of the presence of daily patterns in parasites, but until now we didn't know if this was the result of an intrinsic molecular clock. In the future, we may consider biological rhythms when defining therapies to treat sleeping sickness and potentially other infections," said Dr. Takahashi, Chairman of Neuroscience at UT Southwestern, holder of the Loyd B. Sands Distinguished Chair in Neuroscience, and Investigator with the Howard Hughes Medical Institute.

Researchers from UT Southwestern and the Institute of Molecular Medicine at the University of Lisbon in Portugal made their finding after isolating the parasite - known as Trypanosoma brucei - in the lab and obtaining a type of genetic fingerprint to gauge its daily cycles independent of a host. They found the parasite has daily metabolic cycles that make it more vulnerable to treatments in the afternoon.

Scientists now hope to learn what drives the parasite's internal clock so they can target specific genes and disrupt its circadian rhythms. Much like humans struggle to cope when their sleep cycle is interrupted, scientists expect the parasite would become weaker if its cycle is disturbed.

"We know that in other organisms if we mutate their clock they are less adapted to the world," said Dr. Rijo-Ferreira, an HHMI Associate. "We're trying to jetlag these parasites, trying to make them less fit."

5 parasite diseases to watch for in the U.S.

While deadly sleeping sickness is primarily transmitted in rural regions of Africa, millions of people in the U.S. are exposed to other forms of parasitic diseases. Here are five such diseases the U.S. Centers for Disease Control and Prevention lists as public-health priorities.

Chagas: This disease is most commonly acquired through contact with the feces of an infected kissing bug, a blood-sucking insect. There may be swelling where the parasite enters the body, and in rare cases the disease results in life-threatening inflammation of the heart or brain. If untreated, infection is lifelong. CDC estimates about 300,000 people in the U.S. have the condition.

Toxoplasmosis: This condition is a leading cause of death related to food-borne illness in the U.S. More than 30 million Americans carry the parasite, though few show symptoms because their immune systems protect against the illness. People can become infected by eating undercooked, contaminated meat, and women who are infected during pregnancy sometimes pass the parasite to their unborn children. This transfer can result in a miscarriage, a stillborn child, eye disease, or unusual head size.



Toxocariasis: Caused by two species of roundworm and is typically spread through the feces of dogs and cats. Most infected people don't show symptoms, though in some cases the parasite can travel through parts of the body such as the liver, lungs, or central nervous system. The larvae can also travel to the eye and cause blindness. Each year about 70 people, mostly children, are blinded by the condition.

Cysticercosis: Spread through ingesting larval cysts of a tapeworm, causing infections in the muscles, brain, or other tissue. People become infected when they drink water or eat food contaminated with tapeworm eggs, or if they put contaminated fingers in their mouths. Cysts in the brain or spinal cord commonly cause seizures or headaches. The condition may also cause life-threatening brain swelling or strokes. CDC estimates that at least 1,000 people are hospitalized each year with the more severe brain-related form of the disease.

Trichomoniasis The parasite that causes trichomoniasis is transferred from human to human during sex. About 3.7 million people in the U.S. have the condition, though most do not know they have it. Symptoms may include itching, burning, redness or soreness in the infected areas. The parasite can be eradicated through medications. Without treatment, the infection can last for months or years.

Source: Nature Microbiology - Provided by: UT Southwestern Medical Center

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

Model of Anorexia Created Using Stem Cells

Though often viewed as a non-biological disorder, new research suggests 50 to 75 percent of risk for AN may be heritable; with predisposition driven primarily by genetics and not, as sometimes presumed, by vanity, poor parenting or factors related to specific groups of individuals. NeuroscienceNews.com image is for illustrative purposes only.

Findings suggest a strong genetic factor could predispose people to anorexia and other eating disorders. Technique suggests novel gene may contribute to eating disorder.

An international research team, led by scientists at University of California San Diego School of Medicine, has created the first cellular model of anorexia nervosa (AN), reprogramming induced pluripotent stem cells (iPSCs) derived from adolescent females with the eating disorder.

Writing in the March 14th issue of Translational Psychiatry, the scientists said the resulting AN neurons — the disease in a dish — revealed a novel gene that appears to contribute to AN pathophysiology, buttressing the idea that AN has a strong genetic factor. The proof-of-concept approach, they said, provides a new tool to investigate the elusive and largely unknown molecular and cellular mechanisms underlying the disease.

“Anorexia is a very complicated, multifactorial neurodevelopmental disorder,” said Alysson Muotri, PhD, professor in the UC San Diego School of Medicine departments of Pediatrics and Cellular and Molecular Medicine, director of the UC San Diego Stem Cell Program and a member of the Sanford Consortium for Regenerative Medicine. “It has proved to be a very difficult disease to study, let alone treat. We don’t actually have good experimental models for eating disorders. In fact, there are no treatments to reverse AN symptoms.”



Primarily affecting young female adolescents between ages 15 and 19, AN is characterized by distorted body image and self-imposed food restriction to the point of emaciation or death. It has the highest mortality rate among psychiatric conditions. For females between 15 and 24 years old who suffer from AN, the mortality rate associated with the illness is 12 times higher than the death rate of all other causes of death.

Though often viewed as a non-biological disorder, new research suggests 50 to 75 percent of risk for AN may be heritable; with predisposition driven primarily by genetics and not, as sometimes presumed, by vanity, poor parenting or factors related to specific groups of individuals.

But little is actually known about the molecular, cellular or genetic elements or genesis of AN. In their study, Muotri and colleagues at UC San Diego and in Brazil, Australia and Thailand, took skin cells from four females with AN and four healthy controls, generated iPSCs (stem cells with the ability to become many types of cells) from these cells and induce these iPSCs to become neurons.



(Previously, Muotri and colleagues had created stem cell-derived neuronal models of autism and Williams syndrome, a rare genetic neurological condition.)

Then they performed unbiased comprehensive whole transcriptome and pathway analyses to determine not just which genes were being expressed or activated in AN neurons, but which genes or transcripts (bits of RNA used in cellular messaging) might be associated with causing or advancing the disease process.

No predicted differences in neurotransmitter levels were observed, the researchers said, but they did note disruption in the Tachykinin receptor 1 (TACR1) gene. Tachykinins are neuropeptides or proteins expressed throughout the nervous and immune systems, where they participate in many cellular and physiological processes and have been linked to multiple diseases, including chronic inflammation, cancer, infection and affective and addictive disorders.

The scientists posit that disruption of the tachykinin system may contribute to AN before other phenotypes or observed characteristics become obvious, but said further studies employing larger patient cohorts are necessary.



“But more to the point, this work helps make that possible,” said Muotri. “It’s a novel technological advance in the field of eating disorders, which impacts millions of people. These findings transform our ability to study how genetic variations alter brain molecular pathways and cellular networks to change risk of AN — and perhaps our ability to create new therapies.”
Source: NEUROSCIENCE NEWS

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

New MIT-developed System can make Webpages load 34 per cent Faster in any Browser

Students walk across the MIT campus, where the program was developed Joe Raedle/Getty Images

The 'Polaris' system could help counter the browser-slowing effects of complex webpages

Computer scientists at the world-famous Massachusetts Institute of Technology (MIT) have developed a system that can reliably make websites load 34 per cent faster.

As internet speeds have increased, websites have got more complex, leaving some pages sluggish and unresponsive. This is a problem for companies like Amazon, who say that for every one-second delay in loading time, their profits are cut by one per cent.
But a team of researchers, working at the university's Computer Science and Artificial Intelligence Laboratory, may have found the solution.



Named Polaris, the system cuts load-times by determining the best way to 'overlap' the downloading of different parts of a webpage.

When you visit a new page, your browser reaches across the internet to fetch 'objects' like pictures, videos, and HTML files. The browser then evaluates the objects and puts them on the page.

However, some objects are dependent on others, and browsers can't see all of these dependencies until they come across them.

Polaris works by tracking all of these relationships and dependencies between objects on the page and turning the information into a 'dependency graph' that can be interpreted by your browser.

Polaris essentially gives the browser a roadmap of the page, with all the details of the best and quickest way to load it.

PhD student Ravi Netravali, who worked on Polaris, explained: "It can take up to 100
milliseconds each time a browser has to cross a mobile network to fetch a piece of data."
"As pages increase in complexity, they often require multiple trips that create delays that really add up. Our approach minimizes the number of round trips so that we can substantially speed up a page's load-time."



The researchers tested Polaris across a range of network conditions on some of the world's most popular websites, and found it made them load an average of 34 per cent faster when compared to a normal browser.

Polaris could be used on any website and with unmodified browsers, and when tech companies like Google and Amazon are working hard to improve load-times, a similar system might appear on your device soon.

Source: Massachusetts Institute Of Technology, Computer Science

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

Scientists reach Back in Time to Discover some of the most Power-packed Galaxies

In the heart of an active galaxy, matter falling toward a supermassive black hole generates jets of particles traveling near the speed of light.Credit: NASA's Goddard Space Flight Center Scientific Visualization Studio

When the universe was young, a supermassive black hole heaved out a jet of particle-infused energy that raced through space at nearly the speed of light. Billions of years later, scientists has identified this black hole and four others similar to it that range in age from 1.4 billion to 1.9 billion years old.

When the universe was young, a supermassive black hole -- bloated to the bursting point with stupendous power -- heaved out a jet of particle-infused energy that raced through the vastness of space at nearly the speed of light.

Billions of years later, a trio of Clemson University scientists, led by College of Science astrophysicist Marco Ajello, has identified this black hole and four others similar to it that range in age from 1.4 billion to 1.9 billion years old. These objects emit copious gamma rays, light of the highest energy, that are billions of times more energetic than light that is visible to the human eye.

The previously known earliest gamma-ray blazars -- a type of galaxy whose intense emission is powered by extremely powerful relativistic jets launched by monstrous black holes -- were more than 2 billion years old. Currently, the universe is estimated to be approximately 14 billion years old.



"The discovery of these supermassive black holes, which launch jets that emit more energy in one second than our sun will produce in its entire lifetime, was the culmination of a yearlong research project," said Ajello, who has spent much of his career studying the evolution of distant galaxies. "Our next step is to increase our understanding of the mechanisms involved in the formation, development and activities of these amazing objects, which are the most powerful accelerators in the universe. We can't even come close to replicating such massive outputs of energy in our laboratories. The complexities we're attempting to unravel seem almost as mysterious as the black holes themselves."

Ajello conducted his research in conjunction with Clemson post-doc Vaidehi Paliya and Ph.D candidate Lea Marcotulli. The trio worked closely with the Fermi-Large Area Telescope collaboration, which is an international team of scientists that includes Roopesh Ojha, an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Maryland; and Dario Gasparrini of the Italian Space Agency.

The Clemson team's breakthroughs were made possible by recently juiced-up software on NASA's Fermi Gamma-ray Telescope. The refurbished software significantly boosted the orbiting telescope's sensitivity to a level that made these latest discoveries possible.



"People are calling it the cheapest refurbishment in history," Ajello said. "Normally, for the Hubble Space Telescope, NASA had to send someone up to space to physically make these kinds of improvements. But in this case, they were able to do it remotely from an Earth-bound location. And of equal importance, the improvements were retroactive, which meant that the previous six years of data were also entirely reprocessed. This helped provide us with the information we needed to complete the first step of our research and also to strive onward in the learning process."

Using Fermi data, Ajello and Paliya began with a catalog of 1.4 million quasars, which are
galaxies that harbor at their centers active supermassive black holes. Over the course of a year, they narrowed their search to 1,100 objects. Of these, five were finally determined to be newly discovered gamma-ray blazars that were the farthest away -- and youngest -- ever identified.

"After using our filters and other devices, we were left with about 1,100 sources. And then we did the diagnostics for all of these and were able to narrow them down to 25 to 30 sources," Paliya said. "But we still had to confirm that what we had detected was scientifically authentic. So we performed a number of other simulations and were able to derive properties such as black hole mass and jet power. Ultimately, we confirmed that these five sources were guaranteed to be gamma-ray blazars, with the farthest one being about 1.4 billion years old from the beginning of time."



Marcotulli, who joined Ajello's group as a Ph.D student in 2016, has been studying the blazars' mechanisms by using images and data delivered from another orbiting NASA telescope, the Nuclear Spectroscopic Telescope Array (NuSTAR). At first, Marcotulli's role was to understand the emission mechanism of gamma-ray blazars closer to us. Now she is turning her attention toward the most distant objects in a quest to understand what makes them so powerful.

"We're trying to understand the full spectrum of the energy distribution of these objects by using physical models," Marcotulli said. "We are currently able to model what's happening far more accurately than previously devised, and eventually we'll be able to better understand what processes are occurring in the jets and which particles are radiating all the energy that we see. Are they electrons? or protons? How are they interacting with surrounding photons? All these parameters are not fully understood right now. But every day we are deepening our understanding."



All galaxies have black holes at their centers -- some actively feeding on the matter surrounding them, others lying relatively dormant. Our own galaxy has at its center a super-sized black hole that is currently dormant. Ajello said that only one of every 10 black holes in today's universe are active. But when the universe was much younger, it was closer to a 50-50 ratio.

The supermassive black holes at the center of the five newly discovered blazar galaxies are among the largest types of black holes ever observed, on the order of hundreds of thousands to billions of times the mass of our own sun. And their accompanying accretion disks -- rotating swirls of matter that orbit the black holes -- emit more than two trillion times the energy output of our sun.

One of the most surprising elements of Ajello's research is how quickly -- by cosmic measures -- these supersized black holes must have grown in only 1.4 billion years. In terms of our current knowledge of how black holes grow, 1.4 billion years is barely enough time for a black hole to reach the mass of the ones discovered by Ajello's team.

"How did these incomprehensibly enormous and energy-laden black holes form so quickly?" Ajello said. "Is it because one black hole ate a lot all the time for a very long time? Or maybe because it bumped into other black holes and merged into one? To be honest, we have no observations supporting either argument. There are mechanisms at work that we have yet to unravel. Puzzles that we have yet to solve. When we do eventually solve them, we will learn amazing things about how the universe was born, how it grew into what it has become, and what the distant future might hold as the universe continues to progress toward old age."
Source: Materials provided by Clemson University

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

Scientists reveal new Super-Fast form of Computer that 'Grows as it Computes'

DNA double helix. Credit: public domain

Researchers from The University of Manchester have shown it is possible to build a new super-fast form of computer that "grows as it computes".

Professor Ross D King and his team have demonstrated for the first time the feasibility of engineering a nondeterministic universal Turing machine (NUTM), and their research is to be published in the prestigious Journal of the Royal Society Interface.

The theoretical properties of such a computing machine, including its exponential boost in speed over electronic and quantum computers, have been well understood for many years – but the Manchester breakthrough demonstrates that it is actually possible to physically create a NUTM using DNA molecules.

"Imagine a computer is searching a maze and comes to a choice point, one path leading left, the other right," explained Professor King, from Manchester's School of Computer Science. "Electronic computers need to choose which path to follow first.



"But our new computer doesn't need to choose, for it can replicate itself and follow both paths at the same time, thus finding the answer faster.

"This 'magical' property is possible because the computer's processors are made of DNA rather than silicon chips. All electronic computers have a fixed number of chips.
"Our computer's ability to grow as it computes makes it faster than any other form of computer, and enables the solution of many computational problems previously considered impossible.
"Quantum computers are an exciting other form of computer, and they can also follow both paths in a maze, but only if the maze has certain symmetries, which greatly limits their use.

"As DNA molecules are very small a desktop computer could potentially utilize more processors than all the electronic computers in the world combined - and therefore outperform the world's current fastest supercomputer, while consuming a tiny fraction of its energy."



The University of Manchester is famous for its connection with Alan Turing - the founder of computer science - and for creating the first stored memory electronic computer.

"This new research builds on both these pioneering foundations," added Professor King.
Alan Turing's greatest achievement was inventing the concept of a universal Turing machine (UTM) - a computer that can be programmed to compute anything any other computer can compute. Electronic computers are a form of UTM, but no quantum UTM has yet been built.

DNA computing is the performing of computations using biological molecules rather than traditional silicon chips. In DNA computing, information is represented using the four-character genetic alphabet - A [adenine], G [guanine], C [cytosine], and T [thymine] - rather than the binary alphabet, which is a series of 1s and 0s used by traditional computers.

Provided by: University of Manchester

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

Scientists engineer animals with ancient genes to test causes of evolution

A transgenic fruit fly engineered to carry the alcohol dehydrogenase gene as it existed about 4 million years ago. Thousands of these 'ancestralized' flies were bred and studied for their ability to metabolize alcohol and to survive on an.

Scientists at the University of Chicago have created the first genetically modified animals containing reconstructed ancient genes, which they used to test the evolutionary effects of genetic changes that happened in the deep past on the animals' biology and fitness.

The research, published early online in Nature Ecology & Evolution on Jan. 13, is a major step forward for efforts to study the genetic basis of adaptation and evolution. The specific findings, involving the fruit fly's ability to break down alcohol in rotting fruit, overturn a widely-held hypothesis about the molecular causes of one of evolutionary biology's classic cases of adaptation.



"One of the major goals of modern evolutionary biology is to identify the genes that caused species to adapt to new environments, but it's been hard to do that directly, because we've had no way to test the effects of ancient genes on animal biology," said Mo Siddiq, a graduate student in the Department of Ecology and Evolution at the University of Chicago, one of the study's lead scientists.

"We realized we could overcome this problem by combining two recently developed methods—statistical reconstruction of ancient gene sequences and engineering of transgenic animals," he said.

Until recently, most studies of molecular adaptation have analyzed gene sequences to identify "signatures of selection"—patterns suggesting that a gene changed so quickly during its evolution that selection is likely to have been the cause. The evidence from this approach is only circumstantial, however, because genes can evolve quickly for many reasons, such as chance, fluctuations in population size, or selection for functions unrelated to the environmental conditions to which the organism is thought to have adapted.

Siddiq and his advisor, Joe Thornton, PhD, professor of ecology and evolution and human genetics at the University of Chicago, wanted to directly test the effects of a gene's evolution on adaptation. Thornton has pioneered methods for reconstructing ancestral genes—statistically determining their sequences from large databases of present-day sequences, then synthesizing them and experimentally studying their molecular properties in the laboratory. This strategy has yielded major insights into the mechanisms by which biochemical functions evolve.

Thornton and Siddiq reasoned that by combining ancestral gene reconstruction with techniques for engineering transgenic animals, they could study how genetic changes that occurred in the deep past affected whole organisms-their development, physiology, and even their fitness.



"This strategy of engineering 'ancestralized animals' could be applied to many evolutionary questions," Thornton said. "For the first test case, we chose a classic example of adaptation-how fruit flies evolved the ability to survive the high alcohol concentrations found in rotting fruit. We found that the accepted wisdom about the molecular causes of the flies' evolution is simply wrong."

The fruit fly Drosophila melanogaster is one of the most studied organisms in genetics and evolution. In the wild, D. melanogaster lives in alcohol-rich rotting fruit, tolerating far higher alcohol concentrations than its closest relatives, which live on other food sources. Twenty-five years ago at the University of Chicago, biologists Martin Kreitman and John McDonald invented a new statistical method for finding signatures of selection, which remains to this day one of the most widely used methods in molecular evolution. They demonstrated it on the alcohol dehydrogenase (Adh) gene—the gene for the enzyme that breaks down alcohol inside cells—from this group of flies. Adh had a strong signature of selection, and it was already known that D. melanogaster flies break down alcohol faster than their relatives. So, the idea that the Adh enzyme was the cause of the fruit fly's adaptation to ethanol became the first accepted case of a specific gene that mediated adaptive evolution of a species.

Siddiq and Thornton realized that this hypothesis could be tested directly using the new technologies. Siddiq first inferred the sequences of ancient Adh genes from just before and just after D. melanogaster evolved its ethanol tolerance, some two to four million years ago. He synthesized these genes biochemically, expressed them, and used biochemical methods to measure their ability to break down alcohol in a test tube.



The results were surprising: the genetic changes that occurred during the evolution of D. melanogaster had no detectable effect on the protein's function.
Working with collaborators David Loehlin at the University of Wisconsin and Kristi

Montooth at the University of Nebraska, Siddiq then created and characterized transgenic flies containing the reconstructed ancestral forms of Adh. They bred thousands of these "ancestralized" flies, tested how quickly they could break down alcohol, and how well the larvae and adult flies survived when raised on food with high alcohol content. Surprisingly, the transgenic flies carrying the more recent Adh were no better at metabolizing alcohol than flies carrying the more ancient form of Adh. Even more strikingly, they were no better able to grow or survive on increasing alcohol concentrations. Thus, none of the predictions of the classic version of the story were fulfilled. There is no doubt that D. melanogaster did adapt to high-alcohol food sources during its evolution, but not because of changes in the Adh enzyme.

"The Adh story was accepted because the ecology, physiology, and the statistical signature of selection all pointed in the same direction. But three lines of circumstantial evidence don't make an airtight case," Thornton said. "That's why we wanted to test the hypothesis directly, now that we finally have the means to do so."

Siddiq and Thornton hope that the strategy of making ancestralized transgenic will become the gold standard in the field to decisively determine the historical changes in genes to their changes on organisms' biology and fitness.

For his part, Kreitman, who is still a professor of ecology and evolution at UChicago, has been supportive of the new research, helping advise Siddiq on the project and sharing his vast knowledge about molecular evolution and Drosophila genetics.



"From the beginning, Marty was excited about our experiments, and he was just as supportive when our results overturned well-known conclusions based on his past work," Siddiq said. "I think that's extremely inspiring."

Source: University of Chicago, Medical Center

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

Harvard scientists think they've pinpointed the physical source of consciousness

Scientists have struggled for millennial understand human consciousness - the awareness of one's existence. Despite advances in neuroscience, we still don't really know where it comes from, and how it arises.

But researchers think they might have finally figured out its physical origins, after pinpointing a network of three specific regions in the brain that appear to be crucial to consciousness.

It's a pretty huge deal for our understanding of what it means to be human, and it could also help researchers find new treatments for patients in vegetative states.



"For the first time, we have found a connection between the brainstem region involved in arousal and regions involved in awareness, two prerequisites for consciousness," said lead researcher Michael Fox from the Beth Israel Deaconess Medical Centre at Harvard Medical School.

"A lot of pieces of evidence all came together to point to this network playing a role in human consciousness."

Consciousness is generally thought of as being comprised of two critical components - arousal and awareness.

Researchers had already shown that arousal is likely regulated by the brainstem- the portion of the brain that links up with the spinal cord - seeing as it regulates when we sleep and wake, and our heart rate and breathing.

Awareness has been more elusive. Researchers have long though that it resides somewhere in the cortex - the outer layer of the brain - but no one has been able to pinpoint where.

Now the Harvard team has identified not only the specific brainstem region linked to arousal, but also two cortex regions, that all appear to work together to form consciousness.

To figure this out, the team analyzed 36 patients in hospital with brainstem lesions - 12 of them were in a coma (unconscious) and 24 were defined as being conscious.



The researchers then mapped their brainstems to figure out if there was one particular region that could explain why some patients had maintained consciousness despite their injuries, while others had become comatose.

What they found was one small area of the brainstem - known as the rostral dorsolateral pontine tegmentum - that was significantly associated with coma. Ten out of the 12 unconscious patients had damage in this area, while just one out of the 24 conscious patients did.

That suggests that this tiny region of the brainstem is important for consciousness, but it's not the full story.

To figure out which other parts of the brain were fully connected to this region, the team looked at a brain map - or connectome - of a healthy human brain, which shows all the different connections that we know of so far in our brains (you can see a connectome in the image at the top of this story).

They identified two areas in the cortex that were linked up to the rostral dorsolateral pontine tegmentum, and were most likely to play a role in regulating consciousness. One was in the left, ventral, anterior insula (AI), and the other was in the pregenual anterior cingulate cortex (pACC).

Both of these regions have been linked by previous studies to arousal and awareness, but this is the first time they've been connected to the brainstem.

The team double-checked their work by looking at fMRI scans of 45 patients in comas or vegetative states, and showed that all of them had the network between these three regions disrupted.

It's a pretty exciting first step, but the researchers acknowledge that they now need to verify their find across a larger group of patients.

Independent teams will also need to confirm their results before we can say for sure that these three regions are the physical source of consciousness in our brains.



In the meantime, the research will hopefully lead to new treatment options for patients in comas, and vegetative states which might have otherwise healthy brains but simply can't regain consciousness.

"This is most relevant if we can use these networks as a target for brain stimulation for people with disorders of consciousness," said Fox.

"If we zero in on the regions and network involved, can we someday wake someone up who is in a persistent vegetative state? That’s the ultimate question."
The research has been published in Neurology
Source: Fiona MacDonald

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

Scientists find evidence for Alternate Theory of How Life Arose

A new study led by scientists at The Scripps Research Institute (TSRI) offers a twist on a popular theory for how life on Earth began about four billion years ago.

The study questions the "RNA world" hypothesis, a theory for how RNA molecules evolved to create proteins and DNA. Instead, the new research offers evidence for a world where RNA and DNA evolved simultaneously.

"Even if you believe in a RNA-only world, you have to believe in something that existed with RNA to help it move forward," said Ramanarayanan Krishnamurthy, associate professor of chemistry at TSRI and senior author of the new study. "Why not think of RNA and DNA rising together, rather than trying to convert RNA to DNA by means of some fantastic chemistry at a prebiotic stage?"

The study was published recently in the journal Angewandte Chemie.

A Look Back in Time
Researchers have explored the RNA world hypothesis for more than 30 years. The idea behind this theory is that a series of chemical reactions led to the formation of self-replicating RNA molecules. RNA then evolved to create proteins and enzymes that resembled early versions of what makes up life today. Eventually, these enzymes helped RNA produce DNA, which led to complex organisms.

On the surface, RNA and DNA molecules look similar, with DNA forming a ladder-like structure (with nucleobase pairs as the rungs and sugar molecule backbones as the sides) and RNA forming what looks like just one side of a ladder.



If the RNA world theory is accurate, some researchers believe there would have been many cases where RNA nucleotides were mixed with DNA backbones, creating "heterogeneous" strands. If stable, these blended "chimeras" would have been an intermediate step in the transition to DNA.

Problems with Instability
However, the new study shows a significant loss of stability when RNA and DNA share the same backbone. The chimeras do not stay together as well as pure RNA or pure DNA, which would compromise their ability to hold genetic information and replicate.

"We were surprised to see a very deep drop in what we would call the 'thermal stability,'" said Krishnamurthy, who in addition to his position at TSRI has joint appointments with the National Science Foundation (NSF)-National Aeronautics and Space Administration (NASA) Center for Chemical Evolution and the Simons Collaboration on the Origins of Life. This instability appeared to be due to a difference in the DNA sugar molecule structure versus the RNA sugar molecule.

The finding supported previous research from Nobel laureate and Harvard University Chemistry and Chemical Biology Professor Jack Szostak that showed a loss of (nucleotide-binding aptamer) function when RNA mixed with DNA.



Because of this instability, chimeras in the RNA world would have likely died off in favor of more stable RNA molecules. This reflects what scientists see in cells today: If RNA nucleobases mistakenly join a DNA strand, sophisticated enzymes will rush to fix the mistake. Evolution has led to a system that favors more stable, "homogeneous" molecules.

These sophisticated enzymes were probably not around at the time of RNA and DNA's early evolution, so these substitutions may have had a crippling effect on the molecules' ability to replicate and function. "The transition from RNA to DNA would not have been easy without mechanisms to keep them separate," said Krishnamurthy.

Considering a Second Theory
This realization led the scientists to consider an alternate theory: RNA and DNA may have arisen in tandem.

Krishnamurthy emphasized that his lab is not the first to propose this theory, but the findings on chimeric instability give scientists new evidence to consider.
If the two evolved at the same time, DNA could have established its own homogeneous system early on. RNA could have still evolved to produce DNA, but that may have occurred after it first met DNA and got to know its raw materials.

Krishnamurthy added that scientists will never know exactly how life began (barring the invention of a time machine), but by considering circumstances of early evolution, scientists can gain insights into the fundamentals of biology.



In addition to Krishnamurthy, authors of the study "RNA-DNA Chimeras in the Context of an RNA-world Transition to an RNA/DNA-world," were Jesse V. Gavette (first author) and Matthias Stoop of TSRI and the NSF-NASA Center for Chemical Evolution; and Nicholas V. Hud of the Georgia Institute of Technology and the NSF-NASA Center for Chemical Evolution.


This is a computer graphic of an RNA molecule. Credit: Richard Feldmann/Wikipedia

Source:
Jesse V. Gavette ,Provided by: The Scripps Research Institute

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.

Scientists discovered mysterious Alien Organism

This astonishing picture of an “organism” found in space has baffled scientists who think it is a “seed” sent to Earth by aliens.

The never-before seen image shows a microscopic metal globe spewing out biological material feared to be an infectious agent.

Though the origin or purpose of the mysterious sphere is uncertain, experts say it could contain genetic material - the precursor to life.

They sensationally claim it could have been designed by an intelligent species to “seed” and propagate alien life on Earth.

It is the first time anything like this has been seen and points not only to the existence of extra-terrestrial life, but to complex and civilized beings watching our planet.



It follows findings that DNA capable of inserting itself into living creatures and replicating can exist in harsh space conditions.

A tiny ‘plasmid’, a circular strand of DNA used in genetic engineering, was sent into space from Sweden in 2011 on the exterior of a TEXUS-49 rocket.

After enduring 1,000C heat it was found to still be intact and with its biological properties when it returned to Earth.

Professor Chandra Wickramasinghe director of the Buckingham Centre for Astrobiology at the University of Buckingham in England said it is further proof of alien life.

However the latest finding, by Professor Milton Wainwright and his team from the University of Sheffield and the University of Buckingham Centre for Astrobiology, could reveal a much more sinister purpose.

Conjuring images as warned by H.G Wells in his 1898 novel War of the Worlds - it could have been deliberately engineered and sent to Earth to infect the planet.



Professor Wainwright said the structure is made from the metals titanium and vanadium with a “gooey” biological liquid oozing from its center.

He said there are several theories as to where it came from, the first being it is a complete microorganism programmed to propagate alien life on Earth.

“It is a ball about the width of a human hair, which has filamentous life on the outside and a gooey biological material oozing from its center,” he said.

“We were stunned when X-ray analysis showed that the sphere is made up mainly of titanium, with a trace of vanadium.

“One theory is it was sent to Earth by some unknown civilization in order to continue seeding the planet with life.

“This seeming piece of science fiction, called “directed panspermia” would probably not be taken seriously by any scientist were it not for the fact that it was very seriously suggested by the Nobel Prize winner of DNA fame, Sir Francis Crick.

“Unless of course we can find details of the civilization that is supposed to have sent it in this respect it is probably an unprovable theory.”

Professor Wainwright and his team found the object in dust and particulate matter collected from the stratosphere.



He sent balloons 27km into the sky to collect debris from space and isolated several particles he claims are proof of life in space.

It comes as the mysterious “ghost particle”, also found by Professor Wainwright was revealed and follows the revelation last year of the astonishing “Dragon Particle” the first of its kind to point towards proof of life in space.

Professor Wainwright said the curious orb landed on the sampler balloon it left a tiny impact crater proving it could not have gently fallen from close by.

He said: “On hitting the stratosphere sampler the sphere made an impact crater, a minute version of the huge impact crater on Earth caused by the asteroid said to have killed off the dinosaurs.

“This impact crater proves that the sphere was incoming to Earth from space, an organism coming from Earth would not be travelling fast enough when it fell back to Earth to cause such damage.

“This seems never before to have been found on Earth.”

He said one theory is the object was released deliberately to infect the human race with life-threatening diseases, another is that it travelled millions of miles on a comet.


He said: “For the moment, we are content to say that the life-containing titanium sphere came from space, possibly from a comet.



“NASA is currently sending a balloon into the stratosphere to look for life.

“Hopefully they will get the same results as we have, whether or not they acknowledge what the team have found, or claim the discovery for themselves remains to be seen.”
The findings come as scientists in the UK and Japan launch the ISPA (Institute for the Study of Panspermia and Astroeconomics) which seeks to prove life on Earth originated from Space.

Professor Wickramasinghe, director for research at the institute has long-maintained biological material including bacteria and viruses are constantly raining down from the skies.

He said: “Mainstream science and institutions have fought against theories which expound these beliefs but now evidence from meteorites, from samples of bacteria from space and from space observation is making resistance more difficult.

“Proving that the Earth is in a constant exchange of matter with the larger cosmos would have implications not only in terms of our identity, but could also give us insight into alien viruses which may be important for our group identity, evolution and survival itself.”



Source: Nathan Rao

YOUR INPUT IS MUCH APPRECIATED! LEAVE YOUR COMMENT BELOW.