New trick found for how cells stay organized

As time passes (left to right), RNA granules (green dots) segregate to the posterior of a newly fertilized C. elegans egg. Chromosomes are marked in red.

Organization is key to an efficient workplace, and cells are no exception to this rule. New evidence from Johns Hopkins researchers suggests that, in addition to membranes, cells have another way to keep their contents and activities separate: with ribbons of spinning proteins. A summary of their findings appears in the journal eLife.

Each cell is a busy warehouse of activity. To keep things orderly, protein workers are "assigned" to specific areas of the cell where other workers are collaborating on the same project. Most of the project areas, or organelles, in the cell are cordoned off by flexible membranes that let things in and out on an as-needed basis, but some organelles, like RNA granules, do not seem to have clear boundaries.

RNA granules float throughout the watery space inside the cell and are responsible for transporting, storing and controlling RNA -- DNA's chemical cousin -- which holds blueprints for proteins. Until now, researchers thought that the granules didn't have concrete edges to separate them from the space outside.

"Before, the thinking was that RNA granules were like oil in water," says Geraldine Seydoux, Ph.D., a Howard Hughes investigator and professor of molecular biology and genetics at the Johns Hopkins University School of Medicine. "Oil molecules create droplets because they are attracted to themselves, and so they are able to separate from surrounding water. Now we know that the separation of RNA granules from their watery surroundings is facilitated by a dynamic envelope that stabilizes them."

Seydoux and her team worked with Eric Betzig, Ph.D., of Janelia Farm, who uses a state-of-the-art microscope that can detect rapidly moving particles. That microscope was key to detecting the irregularly shaped protein "cages" that surround the granules because they are constantly orbiting. When the researchers identified the proteins that create the cages, they were further surprised to find that the proteins are predicted not to interact with RNA and are rarely folded as most proteins are.

Seydoux says there are many questions left open about the nature of these protein cages and the RNA granules they surround, but "it is quite exciting to have discovered a new way that cells organize their contents."

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Heart arrhythmias detected in deep-diving marine mammals

This is an image of a Weddell seal in Antarctica. Researchers studied the heart rates of seals during deep dives beneath the Antarctic sea ice.

A new study of dolphins and seals shows that despite their remarkable adaptations to aquatic life, exercising while holding their breath remains a physiological challenge for marine mammals. The study, published January 15 in Nature Communications, found a surprisingly high frequency of heart arrhythmias in bottlenose dolphins and Weddell seals during the deepest dives.

The normal dive response in marine mammals has long been understood to involve a marked reduction in heart rate (called bradycardia) and other physiological changes to conserve limited oxygen reserves while the air-breathing animals are underwater. How marine mammals cope with the exertion needed to pursue prey at depth has been unclear, however, since the normal physiological response to exercise is an increase in heart rate (called tachycardia). The new study shows that these conflicting signals to the heart can lead to cardiac arrhythmias, said lead author Terrie Williams, a professor of ecology and evolutionary biology at UC Santa Cruz.

"This study changes our understanding of bradycardia in marine mammals," Williams said. "The heart is receiving conflicting signals when the animals exercise intensely at depth, which often happens when they are starting their ascent. We're not seeing lethal arrhythmias, but it is putting the heart in an unsteady state that could make it vulnerable to problems."
Instead of a single level of reduced heart rate during dives, the researchers found that heart rates of diving animals varied with both depth and exercise intensity, sometimes alternating rapidly between periods of bradycardia and tachycardia. Cardiac arrhythmias occurred in more than 70 percent of deep dives.

"We tend to think of marine mammals as completely adapted to life in the water. However, in terms of the dive response and heart rate, it's not a perfect system," Williams said. "Even 50 million years of evolution hasn't been able to make that basic mammalian response impervious to problems."

The conflict between dive-induced bradycardia and exercise-induced tachycardia involves two different neural circuits that regulate heart rate, she said. The sympathetic nervous system stimulates the heart during exercise, whereas the parasympathetic nervous system controls the slowing of the heart rate during the dive response.

The new findings have implications for efforts to understand stranding events involving deep-diving marine mammals such as beaked whales. The authors note that the behaviors associated with cardiac anomalies in this study (increased physical exertion, deep diving, and rapid ascent from depth) are the same as those involved in the flight response of beaked whales and blue whales exposed to shipping noise and mid-frequency sonars.

"This study is not saying that these deep-diving animals will die if they exercise hard at depth," Williams said. "Rather, it raises questions about what happens physiologically when extreme divers are disturbed during a dive, and it needs further investigation."

The study's findings may also be relevant in humans, she said. The mammalian dive response or dive reflex, though most pronounced in marine mammals, also occurs in humans and other terrestrial animals and is triggered when the face contacts cold water. A 2010 study of triathlons found that the swimming segment of cold water triathlons accounts for over 90 percent of race day deaths. "It may be that the same conflicting signals we saw in dolphins and seals are causing arrhythmias in some triathletes," Williams said. She is currently working with triathlon groups to help mitigate such problems during races.

To conduct the study, the researchers developed a monitoring device to record heart rate, swimming stroke frequency, depth, and time throughout the dives of trained bottlenose dolphins diving in pools or open water, as well as free-ranging Weddell seals swimming beneath the ice in McMurdo Sound, Antarctica. Williams said the animals typically used low-intensity swimming modes as much as possible during dives. When hunting fish beneath the ice, Weddell seals alternated between easy glides and short chases in pursuit of prey. This behavior appeared to enable the marine mammals to avoid cardiac conflicts and associated arrhythmias during hunting.

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Roller coaster geese: Insights into high altitude bird flight physiology and biomechanics

Tibet high altitude mountains.

Roller Coaster migratory flights of geese give unique insights into bird physiology and biomechanics at high altitudes.

An international team of scientists studying the migratory biology of bar-headed geese (Anser indicus), during their high altitude flights across the Tibetan plateau and Himalayan Mountains, have revealed how these birds cope with flying in the relatively low-density mountain atmosphere.

Dr. Charles Bishop of Bangor University led the study, along with colleagues Robin Spivey and Dr. Lucy Hawkes (now at University of Exeter), Professor Pat Butler from the University of Birmingham, Dr. Nyambayar Batbayar (Wildlife Science and Conservation Center of Mongolia), Dr. Graham Scott (McMaster University) and an international team from Canada, Australia, Germany and the USA. The study used custom-designed data loggers to monitor pressure-derived altitude, body accelerations and heart rate of geese during their southern migration from their breeding grounds in Mongolia to their wintering grounds in South-eastern Tibet or India.

Historically, it was commonly assumed that bar-headed geese would fly to high altitudes relatively easily and then remain there during their flights, possibly benefitting from a tailwind. Instead, the new study (published in Science 16th January 2015) shows that the geese perform a sort of roller coaster ride through the mountains, essentially tracking the underlying terrain even if this means repeatedly shedding hard-won altitude only to have to regain height later in the same or subsequent flight.

Why do they do this?

The birds adopt this roller coaster strategy as flying at progressively higher altitudes becomes more difficult, as the decreasing air density reduces the bird's ability to produce the lift and thrust required to maintain flight. The birds also face the problem of reduced oxygen availability as the atmospheric pressure falls from 100% at sea level (with oxygen content of 21%), to around 50% at 5500 m (equivalent to 10.5% oxygen at sea level) and near 33% at the top of Mt. Everest (equivalent to 7% oxygen at sea level).

"We have developed two independent models to estimate changes in the energy expenditure of birds during flight," said Robin Spivey (the Research Officer on the project and developer of the data logging equipment). "One based on changes in heart rate and one based on the vertical movements of the bird's body. These indicate that, as even horizontal flapping flight is relatively expensive at higher altitudes, it is generally more efficient to reduce the overall costs of flying by seeking higher-density air at lower altitudes."

The team was surprised to find that, very occasionally, bar-headed geese were flying in relatively strong updrafts of air. "During these moments, it seems likely that the bar-headed geese are flying on the windward side of a valley wall," said Prof. Pat Butler. "This would give them the best opportunity to obtaining assistance from wind that is deflected upwards by the ground (known as orographic lift), thus, providing additional rates of ascent with either a reduction in their energetic costs or at least no increase."

The new study showed that the wingbeat frequency of bar-headed geese gradually increased with altitude and reduced air density but was very precisely regulated during each flight and with a typical variation of only 0.6 flaps per second. Remarkably, heart rate was very highly correlated with wingbeat frequency but there is a very steep exponential relationship. For example, a small change in wingbeat frequency of +5% would result in a large elevation in heart rate of 19% and a massive 41% increase in estimated flight power.

Dr. Charles Bishop said: "It seems that geese must keep very fine control over their wingbeat cycles. As they flap faster they also move the wing further, i.e. with bigger amplitude. They are designed with a very high gearing linkage between the movement of the wing and the cardiac output or flow of blood from the heart. It is like riding a bike with an increasingly large cog for the pedals as you move faster and a relatively small cog on the back wheel. An increasing effort is required to move the bike pedal (or the bird's wing) at the same frequency, or even slightly faster, through each revolution but the back wheel (or the bird's heart) is rapidly increasing its activity and overall speed is increasing."

While previous studies show that these birds may be capable of flying over 7000 m, 98% of observations show them flying below 6,000 m. Dr. Lucy Hawkes said: "Our highest single records were of birds flying briefly at 7290 m and 6540 m and 7 of the highest 8 occurred during the night. Interestingly, flying at night means that the air is colder and denser and, again, would reduce the cost of flight compared to the daytime. "

By utilising a roller coaster flight strategy, along with the occasional benefits of orographic lift and flying at night, these birds can minimize the overall energetic cost of their migrations and adopt a risk averse strategy. "Bar-headed geese are heavier than most other bird species, yet their average heart rate for the journey from Mongolia to India was only 328 beats per minute," said Dr. Nyambayar Batbayar, "compared to values of around 450 bpm recorded in wind tunnels or on rare occasions in the wild. Bar-headed geese have found a way to cross the world's highest land massif while remaining well within their physiological capabilities."

How is this possible? "The physiology of bar-headed geese has evolved in a number of ways to extract oxygen from the thin air at high altitudes," said Dr. Graham Scott. "As a result, they are able to accomplish something that is impossible for most other birds."

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Emerald ash borer confirmed as threat to white fringetree

Emerald ash borer larva recovered from white fringetree. (A) Dorsal habitus. (B) Ventral habitus. (C) Dorsal view of head. (D) Ventral view of head.

The emerald ash borer (Agrilus planipennis), also known as EAB, is an invasive insect pest from Asia that has killed millions of trees in the United States and Canada and has caused billions of dollars of damage since it was discovered in 2002. Fortunately, its damage has been limited to ash trees -- or so we thought.

During the summer and fall of 2014, Dr. Don Cipollini, a professor at Wright State University, found evidence that the EAB can also attack white fringetree (Chionanthus virginicus), a species native to the southeastern United States that is planted ornamentally. His observations are described in an article published in the Journal of Economic Entomology called "White Fringetree as a Novel Larval Host for Emerald Ash Borer" (DOI: 10.1093/jee/tou026).

While examining white fringetrees in Yellow Springs, Ohio, Dr. Cipollini found external symptoms of emerald ash borer attacks, including the presence of adult exit holes, canopy dieback, bark splitting, and other deformities. After removing the bark from one of the trees, he found evidence that at least three generations of emerald ash borer larvae had used the tree, and he saw several live larvae that were actively feeding. In addition, he found a dead adult that has been confirmed as emerald ash borer. Additional white fringetrees exhibiting evidence of emerald ash borer attack were also found in Springfield and Dayton, Ohio.

"It appears that emerald ash borer is eating more than ash trees," Cipollini said. "It may have a wider host range than we ever thought in the first place, or it is adapting to utilize new hosts. This biological invasion is having drastic ecological and economic consequences, and you can't always predict what's going to happen."

The borers attack trees by laying eggs on the bark. The serpentine feeding galleries of the larvae inside the bark disrupt the flow of nutrients and water and starve the tree.

White fringetree, a relative of ash, is a deciduous shrub or small tree that can grow up to 30 feet tall. It has white flowers and a purple, olive-like fruit, and is growing in popularity as an ornamental. It is known for its relative lack of pest and disease problems, and until now has never been reported as a host to wood borers related to emerald ash borer.

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Lassa fever controls need to consider human-human transmission and role of super spreaders

One in five cases of Lassa fever -- a disease that kills around 5,000 people a year in West Africa -- could be due to human-to-human transmission, with a large proportion of these cases caused by 'super-spreaders', according to research published today in the journal PLOS Neglected Tropical Diseases.

Lassa fever is an acute viral haemorrhagic illness caused by Lassa virus. First identified in the village of Lassa, Nigeria, in 1969, the disease is thought to be transmitted to humans from contact with food or household items contaminated with rat urine or faeces. There have also been recorded cases of human-to-human transmission within hospital settings, but until now the risk -- or mode -- of transmission has not been clear. Understanding the different modes of transmission and how they are affected by factors such as people's interaction with their environment is crucial for understanding the link between Lassa and changes in the ecosystem, and has important implications for public health strategies.

"Given the many competing health priorities in West Africa -- exacerbated by the current Ebola epidemic -- it is essential that we know the relative risk of human-to-human transmission of other potentially deadly diseases, such as Lassa fever," says first author Dr Gianni Lo Iacono from the Department of Veterinary Medicine at the University of Cambridge. "That way, public health officials can decide where to focus their public health campaigns and how to prevent or respond to potential outbreaks."

The researchers, part of the Dynamic Drivers of Disease in Africa Consortium, used mathematical modelling to analyse data from outbreaks known to be due to human-to-human chains of transmission, and calculated the 'effective reproductive number'. This number represents the number of secondary infections from a typical infected individual -- for an outbreak to take hold, this number needs to be greater than one. They compared data from hundreds of Lassa infected patients from Kenema Government Hospital, in Sierra Leone, who could have been infected either by rodents or humans, with the data from human-to-human chains. By considering the effective reproductive numbers, they inferred the proportion of patients infected by humans rather than rodents.

The researchers estimated that around one in five cases (20%) of infection is caused by human-to-human transmission. However, the study also highlighted the disproportionate number of infections that could be traced back to a small number of people, whom the researchers describe as 'super-spreaders' -- rather than passing their infection on to just one other person (if at all), these individuals infected multiple others. It is not clear what makes them a super-spreader -- their physiology, the environment in which they live, their social interactions or probably a combination of these factors.

Dr Donald Grant, chief physician at the Lassa ward in Kenema Governmental Hospital and co-author of the research, said: "Simple messages to the local people could change their perceptions of risk and hopefully make the difference. For example, making people aware that the virus can remain in urine for several weeks during the recovery period, could promote improved hygienic practices.

"What's more, measures to target human-to-human spread of Lassa virus can be bundled in with prevention interventions for diseases with similar transmission routes, such as Ebola and even Hepatitis B."

Professor James Wood, Head of the Department of Veterinary Medicine and senior author on the study, says: "The idea of super-spreaders in infectious diseases is not new. We've known about them since the notorious case of 'Typhoid Mary' in the early twentieth century and they've been documented for other diseases including TB, measles and SARS.

"Although we don't understand what makes someone a 'super-spreader', it highlights the importance of strict hygiene measures in preventing infection. In the case of Lassa fever, we now know that whilst the chance of transmission between humans is much lower than it is from rodents, it is still a very real risk."

Further progress has been hampered by the Ebola outbreak, which has resulted in the death of key collaborators in Kenema Hospital, which was used to nurse Ebola patients, in particular Dr Sheik Humarr Khan, who played such a key role in establishing and furthering the Lassa fever research programme.

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Are all rattlesnakes created equal? No, maybe not

If you're one of the unfortunate few to be bitten by a venomous snake, having access to effective antivenom to combat the swelling, pain and tissue damage to these bites is critical.

But new research by a team of biologists at Florida State University has revealed that creating antivenom is a bit tricky. That's because the type of venom a snake produces can change according to where it lives.

Mark Marges, a Florida State doctoral student in Professor Darin Rokyta's laboratory, led a research study that examined the venom of 65 eastern diamondback rattlesnakes and 49 eastern coral snakes from all over the state of Florida to determine whether snake venoms varied by geography.

In the rattlesnakes, geography mattered.

The venom from an eastern diamondback rattlesnake in the Florida panhandle is very different than the venom from a rattlesnake 500 miles south in the Everglades, and this has huge implications for snakebite treatment.

"So if you use just southern venoms when making the antivenom, it would be ineffective against some of the more common toxins found in northern diamondback rattlesnakes," said Florida State University doctoral student Mark Margres.

The research is published in the journal Genetics.

In the rattlesnakes, they found significant variation linked to geography. But, in the coral snakes, they found the venom to be identical no matter where the snakes were found.

"This can tell us a bit of the history and evolutionary patterns of the snakes," said Kenny Wray, a post-doctoral research associate in Rokyta's lab. "This suggests that the coral snakes may be recent invaders to the region and haven't had time to evolve different venoms in different areas."

This information also will help with the development of coral snake antivenom, because scientists now know there is uniformity in coral snake venom. According to a 2012 estimate by the Center for Disease Control, 7,000 to 8,000 people in the United States are bitten by venomous snakes every year.

Not only are there medical implications, this information is also important for conservation purposes.

The eastern diamondback rattlesnake is being considered for federal protection under the Endangered Species Act. But, if the snakes are removed from one geographic area, they will be irrevocably deleted sfrom the ecosystem altogether.

"If we lose some of these populations, we lose a whole venom type," Rokyta said. "That really changes conservation."

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DNA 'smart glue' could someday be used to build tissues, organs

DNA glue holds together this 3-D printed gel, a precursor step to building tissues.

DNA molecules provide the "source code" for life in humans, plants, animals and some microbes. But now researchers report an initial study showing that the strands can also act as a glue to hold together 3-D-printed materials that could someday be used to grow tissues and organs in the lab. This first-of-its-kind demonstration of the inexpensive process is described in the brand-new journal ACS Biomaterials Science & Engineering.

 Andrew Ellington and colleagues explain that although researchers have used nucleic acids such as DNA to assemble objects, most of these are nano-sized -- so tiny that humans can't see them with the naked eye. Making them into larger, visible objects is cost-prohibitive. Current methods also do not allow for much control or flexibility in the types of materials that are created. Overcoming these challenges could potentially have a big payoff -- the ability to make tissues to repair injuries or even to create organs for the thousands of patients in need of organ transplants. With this in mind, Ellington's group set out to create a larger, more affordable material held together with DNA.

The researchers developed DNA-coated nanoparticles made of either polystyrene or polyacrylamide. DNA binding adhered these inexpensive nanoparticles to each other, forming gel-like materials that they could extrude from a 3-D printer. The materials were easy to see and could be manipulated without a microscope. The DNA adhesive also allowed the researchers to control how these gels came together. They showed that human cells could grow in the gels, which is the first step toward the ultimate goal of using the materials as scaffolds for growing tissues.

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Tiny plant fossils a window into Earth's landscape millions of years ago

This is a 49 million-year-old epidermal phytolith from a fossil soil horizon of the Las Flores Formation. Its curvy and large shape indicate the plant it came from grew in shady conditions. Scale bar = 10 micrometers.

Minuscule, fossilized pieces of plants could tell a detailed story of what the Earth looked like 50 million years ago.

An international team led by the University of Washington has discovered a way to determine the tree cover and density of trees, shrubs and bushes in locations over time based on clues in the cells of plant fossils preserved in rocks and soil. Tree density directly affects precipitation, erosion, animal behavior and a host of other factors in the natural world. Quantifying vegetation structure throughout time could shed light on how the Earth's ecosystems changed over millions of years.

"Knowing an area's vegetation structure and the arrangement of leaves on the Earth's surface is key for understanding the terrestrial ecosystem. It's the context in which all land-based organisms live, but we didn't have a way to measure it until now," said lead author Regan Dunn, a paleontologist at the UW's Burke Museum of Natural History and Culture. Dunn completed this work as a UW doctoral student in the lab of Caroline Strömberg, the Estella B. Leopold associate professor in biology and curator of paleobotany at the Burke Museum.

The findings are published Jan. 16 in the journal Science.

The team focused its fieldwork on several sites in Patagonia, Argentina, which have some of the best-preserved fossils in the world and together represent 38 million years of ecosystem history (49-11 million years ago). Paleontologists have for years painstakingly collected fossils from these sites, and worked to precisely determine their ages using radiometric dating. The new study builds on this growing body of knowledge.

In Patagonia and other places, scientists have some idea based on ancient plant remains such as fossilized pollen and leaves what species of plants were alive at given periods in Earth's history. For example, the team's previous work documented vegetation composition for this area of Patagonia. But there hasn't been a way to precisely quantify vegetation openness, aside from general speculations of open or bare habitats, as opposed to closed or tree-covered habitats.

"Now we have a tool to go and look at a lot of different important intervals in our history where we don't know what happened to the structure of vegetation," said Dunn, citing the period just after the mass extinction that killed off the dinosaurs.

"The significance of this work cannot be understated," said co-author Strömberg. "Vegetation structure links all aspects of modern ecosystems, from soil moisture to primary productivity to global climate. Using this method, we can finally quantify in detail how Earth's plant and animal communities have responded to climate change over millions of years, which is vital for forecasting how ecosystems will change under predicted future climate scenarios."

Work by other scientists has shown that the cells found in a plant's outermost layer, called the epidermis, change in size and shape depending on how much sun the plant is exposed to while its leaves develop. For example, the cells of a leaf that grow in deeper shade will be larger and curvier than the cells of leaves that develop in less covered areas.

Dunn and collaborators found that these cell patterns, indicating growth in shade or sun, similarly show up in some plant fossils. When a plant's leaves fall to the ground and decompose, tiny silica particles inside the plants called phytoliths remain as part of the soil layer. The phytoliths were found to perfectly mimic the cell shapes and sizes that indicate whether or not the plant grew in a shady or open area.

The researchers decided to check their hypothesis that fossilized cells could tell a more complete story of vegetation structure by testing it in a modern setting: Costa Rica.

Dunn took soil samples from sites in Costa Rica that varied from covered rainforests to grassy savannahs to woody shrub lands. She also took photos looking directly up at the tree canopy (or lack thereof) at each site, noting the total vegetation coverage.

Back in the lab, she extracted the phytoliths from each soil sample and measured them under the microscope. When compared with tree coverage estimated from the corresponding photos, Dunn and co-authors found that the curves and sizes of the cells directly related to the amount of shade in their environments. The researchers characterized the amount of shade as "leaf area index," which is a standard way of measuring vegetation over a specific area.

Testing this relationship between leaf area index and plant cell structures in modern environments allowed the team to develop an equation that can be used to predict vegetation openness at any time in the past, provided there are preserved plant fossils.

"Leaf area index is a well-known variable for ecologists, climate scientists and modelers, but no one's ever been able to imagine how you could reconstruct tree coverage in the past -- and now we can," said co-author Richard Madden of the University of Chicago. "We should be able to reconstruct leaf area index by using all kinds of fossil plant preservation, not just phytoliths. Once that is demonstrated, then the places in the world where we can reconstruct this will increase."

When Dunn and co-authors applied their method to 40-million-year-old phytoliths from Patagonia, they found something surprising -- habitats lost dense tree cover and opened up much earlier than previously thought based on other paleobotanic studies. This is significant because the decline in vegetation cover occurred during the same period as cooling ocean temperatures and the evolution of animals with the type of teeth that feed in open, dusty habitats.

The research team plans to test the relationship between vegetation coverage and plant cell structure in other regions around the world. They also hope to find other types of plant fossils that hold the same information at the cellular level as do phytoliths.

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Prolonging lifespan: Researchers create 'Methuselah fly' by selecting best cells

A deceased Drosophila melanogaster.

A team of researchers at the University of Bern has managed to considerably prolong the lifespan of flies by activating a gene which destroys unhealthy cells. The results could also open new possibilities in human anti aging research.

Immortality has long been a dream for humans. For example, in many ancient mythologies, immortality is one of the traits that distinguishes humans from the gods. More recently, biological research has tried to prolong human lifespan using model organisms such as mice or flies. Researchers at the Institute of Cell Biology from the University of Bern in Switzerland, led by Eduardo Moreno, have developed a new method to extend lifespan of flies based on improved selection of the best cells within the body. Their work appeared in the journal Cell.

"Our bodies are composed of several trillion cells," explains Moreno, "and during aging those cells accumulate random errors due to stress or external insults, like UV-light from the sun." But those errors do not affect all cells at the same time and with the same intensity: "Because some cells are more affected than others, we reasoned that selecting the less affected cells and eliminating the damaged ones could be a good strategy to maintain tissue health and therefore delay aging and prolong lifespan."

A cellular quality control mechanism

To test their hypothesis, the researchers used Drosophila melanogaster flies. The first challenge was to find out which cells within the organs of Drosophila were healthier. Morenos team identified a gene which was activated in less healthy cells. They called the gene ahuizotl (azot) after a mythological Aztec creature selectively targeting fishing boats to protect the fish population of lakes, because the function of the gene was also to selectively target less healthy or less fit cells to protect the integrity and health of the organs like the brain or the gut.

Normally, there are two copies of this gene in each cell. By inserting a third copy, the researchers were able to select better cells more efficiently. The consequences of this improved cell quality control mechanism were, according to Moreno, "very exciting": The flies appeared to maintain tissue health better, aged slower and had longer lifespans. "Our flies had median lifespans 50 to 60 percent longer than normal flies," said Christa Rhiner, one of the authors of the study.

Could azot also slow down the human aging process?

However, the potential of the results goes beyond creating Methuselah flies, the researchers say: Because the gene azot is conserved in humans, this opens the possibility that selecting the healthier or fitter cells within organs could in the future be used as an anti aging mechanism. For example, it could prevent neuro- and tissue degeneration produced in our bodies over time.

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Huge 3-D displays without 3-D glasses

Billboards of the future could show astonishing 3D effects, thanks to a new technology developed in Austria.

A new invention opens the door to a new generation of outdoor displays. Different pictures can be seen at different angles, creating 3D effects without the need for 3D glasses.

Public screenings have become an important part of major sports events. In the future, we will be able to enjoy them in 3D, thanks to a new invention from Austrian scientists. A sophisticated laser system sends laser beams into different directions. Therefore, different pictures are visible from different angles. The angular resolution is so fine that the left eye is presented a different picture than the right one, creating a 3D effect.

In 2013, the young start-up company TriLite Technologies had the idea to develop this new kind of display, which sends beams of light directly to the viewers' eyes. The highly interdisciplinary project was carried out together with the Vienna University of Technology.

Together, TriLite and TU Vienna have created the first prototype. Currently it only has a modest resolution of five pixels by three, but it clearly shows that the system works. "We are creating a second prototype, which will display colour pictures with a higher resolution. But the crucial point is that the individual laser pixels work. Scaling it up to a display with many pixels is not a problem," says Jörg Reitterer (TriLite Technologies and PhD-student in the team of Professor Ulrich Schmid at the Vienna University of Technology).

Every single 3D-Pixel (also called "Trixel") consists of lasers and a moveable mirror. "The mirror directs the laser beams across the field of vision, from left to right. During that movement the laser intensity is modulated so that different laser flashes are sent into different directions," says Ulrich Schmid. To experience the 3D effect, the viewer must be positioned in a certain distance range from the screen. If the distance is too large, both eyes receive the same image and only a normal 2D picture can be seen. The range in which the 3D effect can be experienced can be tuned according to the local requirements.

Hundreds of Images at Once

3D movies in the cinema only show two different pictures -- one for each eye. The newly developed display, however, can present hundreds of pictures. Walking by the display, one can get a view of the displayed object from different sides, just like passing a real object. For this, however, a new video format is required, which has already been developed by the researchers. "Today's 3D cinema movies can be converted into our 3D format, but we expect that new footage will be created especially for our displays -- perhaps with a much larger number of cameras," says Franz Fiedler, CTO of TriLite Technologies.

Compared to a movie screen, the display is very vivid. Therefore it can be used outdoors, even in bright sunlight. This is not only interesting for 3D-presentations but also for targeted advertisements. Electronic Billboards could display different ads, seen from different angles. "Maybe someone wants to appeal specifically to the customers leaving the shop across the street, and a different ad is shown to the people waiting at the bus stop," says Ferdinand Saint-Julien, CEO of TriLite Technologies. Technologically, this would not be a problem.

Entering the market

"We are very happy that the project was so successful in such a short period of time," says Ulrich Schmid. It took only three years to get from the first designs to a working prototype. The technology has now been patented and presented in several scientific publications. The second prototype should be finished by the middle of the year, the commercial launch is scheduled for 2016.

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New sulfate-breathing species discovered beneath ocean crust: Third of Earth's biomass in largely uncharted environment

Two miles below the surface of the ocean, researchers have discovered new microbes that "breathe" sulfate.

The microbes, which have yet to be classified and named, exist in massive undersea aquifers -- networks of channels in porous rock beneath the ocean where water continually churns. About one-third of Earth's biomass is thought to exist in this largely uncharted environment.

"It was surprising to find new bugs, but when we go to warmer, relatively old and isolated fluids, we find a unique microbial community," said Alberto Robador, postdoctoral researcher at the USC Dornsife College of Letters, Arts and Sciences and lead author of a paper on the new findings that will be published by the open-access journal Frontiers in Microbiology on Jan. 14.

Sulfate is a compound of sulfur and oxygen that occurs naturally in seawater. It is used commercially in everything from car batteries to bath salts and can be aerosolized by the burning of fossil fuels, increasing the acidity of the atmosphere.

Microbes that breathe sulfate -- that is, gain energy by reacting sulfate with organic (carbon-containing) compounds -- are thought to be some of the oldest types of organisms on Earth. Other species of sulfate-breathing microbes can be found in marshes and hydrothermal vents.

Microbes beneath the ocean's crust, however, are incredibly tricky to sample.

Researchers from USC and the University of Hawaii took their samples from the Juan de Fuca Ridge (off the coast of Washington state), where previous teams had placed underwater laboratories, drilled into the ocean floor. To place the labs, they lowered a drill through two miles of ocean and bored through several hundred feet of ocean sediment and into the rock where the aquifer flows.

"Trying to take a sample of aquifer water without contaminating it with regular ocean water presented a huge challenge," said Jan Amend, professor at USC Dornsife and director of the Center for Dark Energy Biosphere Investigations (C-DEBI), which helped fund the research.

To solve this problem, C-DEBI created Circulation Obviation Retrofit Kit (CORK) observatories. The moniker was basically dreamed up to fit the term "CORK" because these devices create a seal at the seafloor, like a cork in a bottle, allowing scientists to deploy instruments and sampling devices down a borehole while keeping ocean water out.

Samples were then shuttled to the surface by remote-controlled undersea vehicles or "elevators" -- balloons that drop ballast and float samples gently up to the waiting scientists.

Like the microbes on the forest floor that break down leaf litter and dead organisms, the microbes in the ocean also break down organic -- that is, carbon-based -- material like dead fish and algae. Unlike their counterparts, however, the microbes beneath the ocean crust often lack the oxygen that is used on land to effect the necessary chemical reaction.

Instead, these microbes can use sulfate to break down carbon from decaying biological material that sinks to the sea bottom and makes its way into the crustal aquifer, producing carbon dioxide.

Learning how these new microbes function will be important to getting a more accurate, quantified understanding of the overall global carbon cycle -- a natural cycling of carbon through the environment in which it is consumed by plants, exhaled by animals and enters the ocean via the atmosphere. This cycle is currently being disrupted by human-made carbon dioxide emissions.

"This is the first direct account of microbial activity in these type of environments," Robador said, "and shows the potential of these organisms to respire organic carbon."

The research was funded by the National Science Foundation (C-DEBI award OCE0939564, MCB0604014, 1207880 and 1207874) and the NASA Astrobiology Institute.

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