Culture

The Sun is why we're here. It's also why Martians or Venusians are not.

When the Sun was just a baby four billion years ago, it went through violent outbursts of intense radiation, spewing scorching, high-energy clouds and particles across the solar system. These growing pains helped seed life on early Earth by igniting chemical reactions that kept Earth warm and wet. Yet, these solar tantrums also may have prevented life from emerging on other worlds by stripping them of atmospheres and zapping nourishing chemicals.

Just how destructive these primordial outbursts were to other worlds would have depended on how quickly the baby Sun rotated on its axis. The faster the Sun turned, the quicker it would have destroyed conditions for habitability.

This critical piece of the Sun's history, though, has bedeviled scientists, said Prabal Saxena, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Saxena studies how space weather, the variations in solar activity and other radiation conditions in space, interacts with the surfaces of planets and moons.

Now, he and other scientists are realizing that the Moon, where NASA will be sending astronauts by 2024, contains clues to the ancient mysteries of the Sun, which are crucial to understanding the development of life.

"We didn't know what the Sun looked like in its first billion years, and it's super important because it likely changed how Venus' atmosphere evolved and how quickly it lost water. It also probably changed how quickly Mars lost its atmosphere, and it changed the atmospheric chemistry of Earth," Saxena said.

The Sun-Moon Connection

Saxena stumbled into investigating the early Sun's rotation mystery while contemplating a seemingly unrelated one: Why, when the Moon and Earth are made of largely the same stuff, is there significantly less sodium and potassium in lunar regolith, or Moon soil, than in Earth soil?

This question, too, revealed through analyses of Apollo-era Moon samples and lunar meteorites found on Earth, has puzzled scientists for decades -- and it has challenged the leading theory of how the Moon formed.

Our natural satellite took shape, the theory goes, when a Mars-sized object smashed into Earth about 4.5 billion years ago. The force of this crash sent materials spewing into orbit, where they coalesced into the Moon.

"The Earth and Moon would have formed with similar materials, so the question is, why was the Moon depleted in these elements?" said Rosemary Killen, an planetary scientist at NASA Goddard who researches the effect of space weather on planetary atmospheres and exospheres.

The two scientists suspected that one big question informed the other -- that the history of the Sun is buried in the Moon's crust.

Killen's earlier work laid the foundation for the team's investigation. In 2012, she helped simulate the effect solar activity has on the amount of sodium and potassium that is either delivered to the Moon's surface or knocked off by a stream of charged particles from the Sun, known as the solar wind, or by powerful eruptions known as coronal mass ejections.

Saxena incorporated the mathematical relationship between a star's rotation rate and its flare activity. This insight was derived by scientists who studied the activity of thousands of stars discovered by NASA's Kepler space telescope: The faster a star spins, they found, the more violent its ejections. "As you learn about other stars and planets, especially stars like our Sun, you start to get a bigger picture of how the Sun evolved over time," Saxena said.

Using sophisticated computer models, Saxena, Killen and colleagues think they may have finally solved both mysteries. Their computer simulations, which they described on May 3 in the The Astrophysical Journal Letters, show that the early Sun rotated slower than 50% of baby stars. According to their estimates, within its first billion years, the Sun took at least 9 to 10 days to complete one rotation.

They determined this by simulating the evolution of our solar system under a slow, medium, and then a fast-rotating star. And they found that just one version -- the slow-rotating star -- was able to blast the right amount of charged particles into the Moon's surface to knock enough sodium and potassium into space over time to leave the amounts we see in Moon rocks today.

"Space weather was probably one of the major influences for how all the planets of the solar system evolved," Saxena said, "so any study of habitability of planets needs to consider it."

Life Under the Early Sun

The rotation rate of the early Sun is partly responsible for life on Earth. But for Venus and Mars -- both rocky planets similar to Earth -- it may have precluded it. (Mercury, the closest rocky planet to the Sun, never had a chance.)

Earth's atmosphere was once very different from the oxygen-dominated one we find today. When Earth formed 4.6 billion years ago, a thin envelope of hydrogen and helium clung to our molten planet. But outbursts from the young Sun stripped away that primordial haze within 200 million years.

As Earth's crust solidified, volcanoes gradually coughed up a new atmosphere, filling the air with carbon dioxide, water, and nitrogen. Over the next billion years, the earliest bacterial life consumed that carbon dioxide and, in exchange, released methane and oxygen into the atmosphere. Earth also developed a magnetic field, which helped protect it from the Sun, allowing our atmosphere to transform into the oxygen- and nitrogen-rich air we breathe today.

"We were lucky that Earth's atmosphere survived the terrible times," said Vladimir Airapetian, a senior Goddard heliophysicist and astrobiologist who studies how space weather affects the habitability of terrestrial planets. Airapetian worked with Saxena and Killen on the early Sun study.

Had our Sun been a fast rotator, it would have erupted with super flares 10 times stronger than any in recorded history, at least 10 times a day. Even Earth's magnetic field wouldn't have been enough to protect it. The Sun's blasts would have decimated the atmosphere, reducing air pressure so much that Earth wouldn't retain liquid water. "It could have been a much harsher environment," Saxena noted.

But the Sun rotated at an ideal pace for Earth, which thrived under the early star. Venus and Mars weren't so lucky. Venus was once covered in water oceans and may have been habitable. But due to many factors, including solar activity and the lack of an internally generated magnetic field, Venus lost its hydrogen -- a critical component of water. As a result, its oceans evaporated within its first 600 million years, according to estimates. The planet's atmosphere became thick with carbon dioxide, a heavy molecule that's harder to blow away. These forces led to a runaway greenhouse effect that keeps Venus a sizzling 864 degrees Fahrenheit (462 degrees Celsius), far too hot for life.

Mars, farther from the Sun than Earth is, would seem to be safer from stellar outbursts. Yet, it had less protection than did Earth. Due partly to the Red Planet's weak magnetic field and low gravity, the early Sun gradually was able to blow away its air and water. By about 3.7 billion years ago, the Martian atmosphere had become so thin that liquid water immediately evaporated into space. (Water still exists on the planet, frozen in the polar caps and in the soil.)

After influencing the course for life (or lack thereof) on the inner planets, the aging Sun gradually slowed its pace and continues to do so. Today, it revolves once every 27 days, three times slower than it did in its infancy. The slower spin renders it much less active, though the Sun still has violent outbursts occasionally.

Exploring the Moon, Witness of Solar System Evolution

To learn about the early Sun, Saxena said, you need to look no further than the Moon, one of the most well-preserved artifacts from the young solar system.

"The reason the Moon ends up being a really useful calibrator and window into the past is that it has no annoying atmosphere and no plate tectonics resurfacing the crust," he said. "So as a result, you can say, 'Hey, if solar particles or anything else hit it, the Moon's soil should show evidence of that.'"

Apollo samples and lunar meteorites are a great starting point for probing the early solar system, but they are only small pieces in a large and mysterious puzzle. The samples are from a small region near the lunar equator, and scientists can't tell with complete certainty where on the Moon the meteorites came from, which makes it hard to place them into geological context.

Since the South Pole is home to the permanently shadowed craters where we expect to find the best-preserved material on the Moon, including frozen water, NASA is aiming to send a human expedition to the region by 2024.

If astronauts can get samples of lunar soil from the Moon's southernmost region, it could offer more physical evidence of the baby Sun's rotation rate, said Airapetian, who suspects that solar particles would have been deflected by the Moon's erstwhile magnetic field 4 billion years ago and deposited at the poles: "So you would expect -- though we've never looked at it -- that the chemistry of that part of the Moon, the one exposed to the young Sun, would be much more altered than the equatorial regions. So there's a lot of science to be done there."

Certain groups of heart failure patients may see improved heart function with cardiac resynchronization therapy with defibrillator (CRT-D) if traditional implantable cardioverter defibrillator treatment does not work, according to research published today in the Journal of the American College of Cardiology.

There are three types of conduction disorders, and until now, most research on CRT therapy in heart failure patients has focused on the most common, called left bundle branch block (LBBB). This is a heart conduction abnormality seen on the electrocardiogram (EKG). In this condition, activation of the left ventricle of the heart is delayed, which causes the left ventricle to contract later than the right ventricle.

The new study focused on two less common conduction disorders: right bundle branch block (RBBB) and nonspecific intraventricular conduction delay (NICD)--together, often referred to as "non-LBBB"--to determine the benefit of CRT-D.

A CRT-D is a special device for heart failure patients who are also at high risk for sudden cardiac death. While functioning like a normal defibrillator (called an implantable cardioverter defibrillator, or ICD) to treat slow heart rhythms and life-threatening fast heart rhythms, a CRT-D device also delivers small electrical impulses to the left and right ventricles to help them contract at the same time. This helps the heart pump more efficiently.

"CRT is known to improve heart function in patients with LBBB, but until now we have not had enough evidence to support use of CRT in patients with either RBBB or NICD," said lead researcher Hiro Kawata, MD, PhD, of the Oregon Heart and Vascular Institute in Springfield. "Current guidelines state that when patients with heart failure and non-LBBB conduction disorder continue to suffer symptoms such as shortness of breath or fatigue even after medical therapy, CRT can be tried as a next step, even though there is a lack of evidence about its effectiveness in these patients. We wanted to find out whether CRT can help non-LBBB patients."

Kawata and colleagues evaluated data between 2010-2013 from the NCDR ICD Registry, the national standard for understanding patient selection, care and outcomes in patients receiving ICD therapy.

The researchers divided patients with RBBB and NICD into two groups according to the length of their QRS, or waves on an EKG that represent how long it takes to conduct electricity through the lower ventricle of the heart. A QRS longer than 120 milliseconds represents a conduction abnormality.

"In patients with LBBB, the longer the QRS, the more likely you are to respond to CRT," Kawata said. "We wanted to find out whether this was also true in patients with non-LBBB conduction disorders."

The study compared patients who had one of two types of defibrillator - either an CRT-D or an ICD.

Among 5,954 Medicare-aged patients with NICD or RBBB who were implanted with a defibrillator, the study found patients with NICD and a QRS of more than 150 milliseconds responded best to CRT-D. In these patients, CRT-D was associated with decreased risk of death, readmission to the hospital for any cause, as well as readmission for heart-related causes, compared with a similar group of patients implanted with ICD. Among patients with RBBB, CRT-D was not associated with better outcomes compared with ICD, regardless of the duration of their QRS.

"This means that if you have a patient with RBBB who is still suffering from heart failure symptoms after medical therapy, there is not enough data to support using CRT blindly," Kawata said. "But in NICD patients, we now know that those with a long QRS are likely to benefit from CRT."

He said more study is needed to establish whether certain RBBB patients might respond to CRT.

"While implanting a CRT-D is relatively safe, it is not without risks," Kawata said.

CRT can cause complications, including infection, a pneumothorax (punctured lung) or cardiac perforation (perforated heart muscle), he said.

In an editorial accompanying the study, Michael Gold, MD, PhD, of the Medical University of South Carolina in Charleston, noted the results from this study provide important data indicating that not all non-LBBB types, or morphologies, are the same.

"The authors should be commended for providing more detailed analysis of the electrocardiogram and not simply using what is now the conventional LBBB vs non-LBBB morphologies," he said. "These findings will need to be confirmed with further studies, either from prospective trials or pooled data from previous randomized trials. However, importantly, the results of the present study challenge our convention of lumping CRT candidates into two categories."

Dogs have evolved new muscles around the eyes to better communicate with humans.

New research comparing the anatomy and behavior of dogs and wolves suggests dogs' facial anatomy has changed over thousands of years specifically to allow them to better communicate with humans.

In the first detailed analysis comparing the anatomy and behavior of dogs and wolves, researchers found that the facial musculature of both species was similar, except above the eyes. Dogs have a small muscle, which allows them to intensely raise their inner eyebrow, which wolves do not.

The authors suggest that the inner eyebrow raising movement triggers a nurturing response in humans because it makes the dogs' eyes appear larger, more infant like and also resembles a movement humans produce when they are sad.

The research team, led by comparative psychologist Dr Juliane Kaminski, at the University of Portsmouth, included a team of behavioural and anatomical experts in the UK and USA.

It is published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Dr Kaminski said: "The evidence is compelling that dogs developed a muscle to raise the inner eyebrow after they were domesticated from wolves.

"We also studied dogs' and wolves' behavior, and when exposed to a human for two minutes, dogs raised their inner eyebrows more and at higher intensities than wolves.

"The findings suggest that expressive eyebrows in dogs may be a result of humans unconscious preferences that influenced selection during domestication. When dogs make the movement, it seems to elicit a strong desire in humans to look after them. This would give dogs, that move their eyebrows more, a selection advantage over others and reinforce the 'puppy dog eyes' trait for future generations."

Dr Kaminski's previous research showed dogs moved their eyebrows significantly more when humans were looking at them compared to when they were not looking at them.

She said: "The AU101 movement is significant in the human-dog bond because it might elicit a caring response from humans but also might create the illusion of human-like communication."

Lead anatomist Professor Anne Burrows, at Duquesne University, Pittsburgh, USA, co-author of the paper, said: "To determine whether this eyebrow movement is a result of evolution, we compared the facial anatomy and behaviour of these two species and found the muscle that allows for the eyebrow raise in dogs was, in wolves, a scant, irregular cluster of fibres.

"The raised inner eyebrow movement in dogs is driven by a muscle which doesn't consistently exist in their closest living relative, the wolf.

"This is a striking difference for species separated only 33,000 years ago and we think that the remarkably fast facial muscular changes can be directly linked to dogs' enhanced social interaction with humans."

Dr Kaminski and co-author, evolutionary psychologist Professor Bridget Waller, also at the University of Portsmouth, previously mapped the facial muscular structure of dogs, naming the movement responsible for a raised inner eyebrow the Action Unit (AU) 101.

Professor Waller said: "This movement makes a dogs' eyes appear larger, giving them a childlike appearance. It could also mimic the facial movement humans make when they're sad.

"Our findings show how important faces can be in capturing our attention, and how powerful facial expression can be in social interaction."

Co-author and anatomist Adam Hartstone-Rose, at North Carolina State University, USA, said: "These muscles are so thin that you can literally see through them - and yet the movement that they allow seems to have such a powerful effect that it appears to have been under substantial evolutionary pressure. It is really remarkable that these simple differences in facial expression may have helped define the relationship between early dogs and humans."

Co-author Rui Diogo, an anatomist at Howard University, Washington DC, USA, said: "I must admit that I was surprised to see the results myself because the gross anatomy of muscles is normally very slow to change in evolution, and this happened very fast indeed, in just some dozens of thousands of years."

Soft tissue, including muscle, doesn't tend to survive in the fossil record, making the study of this type of evolution harder.

The only dog species in the study that did not have the muscle was the Siberian husky, which is among more ancient dog breeds.

An alternative reason for the human-dog bond could be that humans have a preference for other individuals which have whites in the eye and that intense AU 101 movements exposes the white part of the dogs eyes.

It is not known why or precisely when humans first brought wolves in from the cold and the evolution from wolf to dog began, but this research helps us understand some of the likely mechanisms underlying dog domestication.

Scientists at the University of York have revealed that there are two separate 'pathways' for seeing 3D motion in the human brain, which allow people to perform a wide range of tasks such as catching a ball or avoiding moving objects.

The new insight could help further understanding into how to alleviate the effects of lazy eye syndrome, as well as how industry could develop better 3D visual displays and virtual reality systems.

Much of what scientists know about 3D motion comes from comparing the 'stereoscopic' signals generated by a person's eyes, but the exact way the brain processes these signals has not been fully understood in the past.

Scientists at the Universities of York, St Andrews, and Bradford have now shown that there are two ways the brain can compute 3D signals, not just one as previously thought.

They found that 3D motion signals separate into two 'pathways' in the brain at an early stage of the image transmission between the eyes and the brain.

Dr Alex Wade from the University of York's Department of Psychology, said: "We know that we have two signals from our visual system that helps the brain compute 3D motion - one is a fast signal and one is a slow signal.

"This helps us in a number of ways, with our hand-eye coordination for example, or so that we don't fall over navigating around objects. What we didn't know was what the brain did with these signals to allow us to understand what is going on in front of our eyes and react appropriately.

"Using brain imaging technology we were able to see that two 3D motion signals are separated out into two distinct pathways in the brain, allowing information to be extracted simultaneously and indicating to the visual system that it is encountering a 3D moving object."

The research team had previously shown that people with lazy eye syndrome might still be able to see 'fast' 3D motion signals, despite them having very poor 3D vision in general. Now that scientists understand how this pathway works, there is the potential to build tests to measure and monitor therapies aimed at curing the condition.

Dr Milena Kaestner, who conducted the work as part of her PhD at the University of York, said: "We were also surprised to see a link between 3D motion signals and how the brain receives information about colour. We now believe that colour might be more important in this type of visual processing than we previously thought.

"The visual pathways for colour have been thought to be independent of signals about motion and depth, but the research suggests that there could be a connection in the brain between these three visual properties."

Dr Julie Harris, from St Andrews University, said: "Knowing more about our visual system, and particularly how motion, depth and colour could all be connected in the brain, could help in a number of research areas into what happens when these pathways go wrong, resulting in visual disturbances that impact negatively on people's quality of life."

The research is published in the journal Proceedings of the National Academy of Sciences (PNAS).

Virginia Tech biochemist Brandon Jutras has discovered the cellular component that contributes to Lyme arthritis, a debilitating and extremely painful condition that is the most common late stage symptom of Lyme disease.

Jutras found that as the Lyme-causing bacteria Borrelia burgdorferi multiplies, it sheds a cellular component called peptidoglycan that elicits a unique inflammatory response in the body.

"This discovery will help researchers improve diagnostic tests and may lead to new treatment options for patients suffering with Lyme arthritis," said Jutras, the lead author on the study. "This is an important finding, and we think that it has major implications for many manifestations of Lyme disease, not just Lyme arthritis."

Reported incidences of Lyme disease, the most reported vector-borne disease in the country, have increased by more than 6,000 percent in the past 15 years in the state of Virginia. The Centers for Disease Control estimates that approximately 300,000 people are diagnosed with Lyme disease annually in the United States. Scientists predict that the number of people who become infected with Lyme will increase as our climate continues to change.

Jutras -- an assistant professor of biochemistry in the College of Agriculture and Life Sciences and an affiliated faculty member of the Fralin Life Sciences Institute -- and his collaborators recently published their findings in the Proceedings of the National Academy of Sciences.

The PNAS paper was four years in the making, and Jutras began this research during his post-doctoral fellowship in the lab of Christine Jacobs-Wagner, a Howard Hughes Medical Institute Investigator and professor at Yale University.

"Nowadays, nothing significant in science is accomplished without collaboration," Jutras said. Co-authors on this paper ranged from bench scientists to medical doctors and practicing physicians. Allen Steere, a Harvard doctor who originally identified Lyme disease in the 1970s, assisted Jutras with his research and provided access to patient samples.

This research may provide a new way to diagnose Lyme disease and Lyme arthritis for patients with vague symptoms based on the presence of the cellular component called peptidoglycan in synovial fluid.

The team found peptidoglycan is a major contributor to Lyme arthritis in late-stage Lyme disease patients. Peptidoglycan is an essential component of bacterial cell walls. All bacteria have some form of peptidoglycan, but the form found in the bacteria that causes Lyme, Borrelia burgdorferi, has a unique chemical structure. When the bacteria multiply, they shed peptidoglycan into the extracellular environment, because its genome does not have the appropriate proteins to recycle it back into the cell.

"We can actually detect peptidoglycan in the synovial fluid of the affected, inflamed joints of patients that have all the symptoms of Lyme arthritis but no longer have an obvious, active infection," Jutras said.

Peptidoglycan elicits an inflammatory response and the molecule persists in the synovial fluid, which means that our bodies continue to respond, without mounting a counter response.

Receptors in our immune system sense bacterial products and, depending on the individual's genetic predispositions, may determine how strongly a patient's body reacts to peptidoglycan.

The next phase of Jutras' work is to use methods to destroy the peptidoglycan, or intervene to prevent a response, which could get rid of Lyme disease symptoms. Jutras predicts that with either therapy patients would start recovering sooner.

Clinical samples included in this study were obtained from patients that had confirmed cases of Lyme disease under the guidelines of the CDC, but virtually all did not respond to oral and/or intravenous antibiotic treatment. The presence of peptidoglycan in these patients' synovial fluids may explain why some people experience symptoms of late stage Lyme disease in the absence of an obvious infection. In this case, the usual antibiotic treatments for Lyme disease would no longer be helpful, but this discovery might provide avenues for new treatments.

Members of the Jacobs-Wagner lab purified the peptidoglycan and removed all other bacterial components and asked: Is peptidoglycan all on its own capable of causing arthritis in a mouse model?

Within 24 hours post-injection, mice presented with dramatic joint inflammation, indicating that peptidoglycan can cause arthritis.

Jutras is continuing his research at Virginia Tech on peptidoglycan by more thoroughly studying its chemical composition to determine how it is able to persist in the human body. This will also help further the understanding of how this bacterial product contributes to other manifestations of Lyme disease.

"We are interested in understanding everything associated with how patients respond, how we can prevent that response, and how we could possibly intervene with blocking therapies or therapies that eliminate the molecule entirely," Jutras said.

To understand our brains, scientists need to know their components. This theme underlies a growing effort in neuroscience to define the different building blocks of the brain -- its cells.

With the mouse's 80 million neurons and our 86 billion, sorting through those delicate, microscopic building blocks is no small feat. A new study from the Allen Institute for Brain Science, which was published today in the journal Nature Neuroscience, describes a large profile of mouse neuron types based on two important characteristics of the cells: their 3D shape and their electrical behavior.

The study, which yielded the largest dataset of its kind from the adult laboratory mouse to date, is part of a larger effort at the Allen Institute to discover the brain's "periodic table" through large-scale explorations of brain cell types. The researchers hope a better understanding of cell types in a healthy mammalian brain will lay the foundation for uncovering the cell types that underlie human brain disorders and diseases.

If you think of the classical periodic table, chemical elements can be described and sorted in a number of ways: their mass, their chemical properties, whether they are metal or not. Neuroscientists are faced with a similar challenge. A given neuron will have many different personality traits that distinguish it from other neuron types: its shape, its behavior, the unique set of genes it switches on, its location in the brain, the other types of cells it interacts with.

How do you define a cell type?

To understand what a single cell type does, researchers need to explore all these attributes, said Hongkui Zeng, Ph.D., Executive Director of Structured Science at the Allen Institute for Brain Science, a division of the Allen Institute, and senior author on the study.

"A cell type is a group of cells that have similar functional properties to each other, but we don't understand what all those properties are," Zeng said. "We shouldn't just be looking at a single feature; we need to look at as many features of the cells as possible and ask whether they are consistent with each other."

In the study, the research team sorted through neurons from the visual processing part of the mouse brain to find a few dozen different brain cell types, carefully analyzing close to 2,000 neurons' electrical activity and their detailed 3D shape (also known as morphology) of nearly 500 of those same cells. The researchers also saw that these new cell type categories line up with categories from a complementary study published last year. In that earlier study, Allen Institute researchers used gene expression, or the list of genes that are switched on in any one cell, to sort nearly 24,000 brain cells into different types.

The fact that different features yield similar cell type groups gives the researchers confidence that they're on the right track in their categorization, said Staci Sorensen, Ph.D., a neuroscientist who leads the morphology team at the Allen Institute for Brain Science and is a lead author on the study along with Nathan Gouwens, Ph.D., and Jim Berg, Ph.D. "If we get alignment across multiple properties of a cell, then we can feel more confident that we have a biologically meaningful cell type," Sorensen said.

Why shape and activity matter

Their activity and shape also give the researchers clues about what the individual cells are doing in the larger context of neural circuits in the brain. Electrical signaling using pulses, so-called spikes or action potentials, is the near universal idiom of the way neurons communicate with each ones. Different neurons are tuned to send and receive different patterns of such spikes.

Understanding those signals helps researchers reconstruct how these neurons might connect to others in a circuit. And their shape gives a clue as well.

"A cell's shape is a proxy for how it's connected to other cells," said Gouwens, a computational neuroscientist at the Allen Institute. "We care about how cells are connected to each other because that's how they form circuits to process information."

Data for the community

The researchers hope that these publicly available data -- along with the data about brain cell types' gene expression, all of which are part of the Allen Cell Types database -- will enable deeper exploration into specific cell types in health and disease. If a research team is interested in a specific disease-related gene in the brain, for example, they can see which cell types have that gene switched on, or expressed, and then explore the shape and activity of those neurons to form new hypotheses about how the gene might act -- and what might go wrong in disease if the gene is mutated or missing.

"They can form a hypothesis as to how the gene dysfunction might change that cell type, how it might lead to specific effects," said Berg, a neuroscientist at the Allen Institute for Brain Science who leads the team that measures neurons' electrical activity. "It takes a lot of numbers to get that coverage so that people can trust the data, but I think we're finally at that phase."

An unbiased approach

To study a neuron's morphology, researchers need to first identify a single cell amidst the tangled mess of other neurons and supporting cells in the mouse brain and then inject that one cell with a special dye-containing probe to stain it in its entirety within a slice of brain. The team used mice that were engineered at the Allen Institute to carry genes that make certain neurons glow bright colors under the microscope, letting the researchers more easily pick out individual neurons. The researchers then used those same microscopic probes to read out the cells' electrical activity by studying their responses to different types of electrical input.

Because these experiments are so labor-intensive, research groups typically explore one or a handful of cell types at a time, which are often selected based on a specific question. The Allen Institute team, however, wanted to tackle the problem in a broad, unbiased fashion, studying cells under the same experimental conditions and from the same region of the brain so they can be more easily compared to each other.

"Instead of having a list of cell types already in mind and then putting the cells into those categories, we're letting the categories emerge from the data," Gouwens said. "We're trying to be fairly broad and then see what shape the data have."

PHILADELPHIA - The human immune system relies on a delicate balance of finely tuned cell types that keep germs and cancerous cells in check. In cancer and chronic infections this balance can be disrupted, resulting in immune system dysfunction or "exhaustion." An important protein called TOX, which varies in amount in different immune cell types, controls the identity of the cells that become exhausted, according to researchers in the Perelman School of Medicine at the University of Pennsylvania. With this knowledge, investigators now have a way to accurately identify immune cells that are exhausted in a tumor or site of an infection, which could allow clinicians to improve the effectiveness of patients' immune response to cancer treatments by reinvigorating exhausted T cells. This work is published this week in Nature.

"The discovery of TOX as the key regulator of exhausted T cells now allows us to envision immunotherapies that target, or engineer, TOX to reverse or prevent exhaustion and improve immunity to infections or cancer," said senior author E. John Wherry, PhD, chair of the department of Pharmacology and director of the Penn Institute of Immunology.

The T cells the team studied come in three varieties and rely on efficient and coordinated transitions between different identities. Following initial activation by specific proteins, immature T cells replicate and undergo an orchestrated program of molecular rewiring to become effector T cells (TEFF), which produce inflammatory cytokines that kill offending cancer and germ cells.

If an infection or tumor is cleared, most of the TEFF pool dies, but a subset persists. This set undergoes more rewiring and forms long-lived, self-renewing memory T cells (TMEM) capable of mounting a rapid recall response should an invader be detected a second time. However, during chronic infections or with cancer, when T cell stimulation is drawn out, this program of T cell differentiation is diverted and the cells becoming ineffective against the tumor or infection--instead, they become exhausted. But, these exhausted T cells (TEX) are not totally useless. In fact, they may keep low-level germ or tumor presence in the body in check.

In this battle, Wherry likens TEX to an infantry that performs the day in and day out work of containing minor assaults, such as long-term infection by the herpes virus. On the other end of the spectrum, TEFFs are like calling in the Navy SEALs.

"They get the job of containment done, and quickly, by whipping up a cytokine storm, but there is the collateral damage of an overactive inflammatory response," Wherry said. TEX are not strong enough to cause an increased inflammatory response, and in some cases, may strike a necessary balance between partially containing an infection or tumor without causing excessive damage to the host.

The longer TOX is expressed in a T cell the more permanent the TEX identity becomes. The level of TOX in a T cell dictates how an infection or tumor is contained by controlling the number of TEFF versus TEX cells. High and sustained induction of TOX results in the permanent existence of TEX, but the consequences of a restrained ability to fight invaders can be the persistence or progression of disease.

The team also showed that TOX shapes cell identity by making the spools on which genes are wound in the nucleus more or less available to be translated into proteins. This ability of TOX to shape the structure of a cell's genome via its epigenome also provides insight into why changing TEX into TEFF has been difficult with other therapies. Epigenetic changes help "lock" cells into their permanent identity, but these new findings may allow researchers to change that for future immunotherapies.

Most fishing communities from North Carolina to Maine are projected to face declining fishing options unless they adapt to climate change by catching different species or fishing in different areas, according to a study in the journal Nature Climate Change.

Some Maine fishing communities were at greatest risk of losing their current fishing options, according to the study by Rutgers and other scientists.

"Some communities like Portland, Maine, are on track to lose out, while others like Mattituck, New York, or Sandwich, Massachusetts, may do better as waters warm," said senior author Malin Pinsky, an associate professor in the Department of Ecology, Evolution, and Natural Resources at Rutgers University-New Brunswick. "Adapting to climate change for many communities will require fundamentally new approaches to fishing. Change has become the new normal."

Fishing has been the economic and cultural lifeblood for many coastal towns and cities along the Northeast coast, in some cases for hundreds of years, Pinsky said. But climate change is expected to have a major impact on the distribution, abundance and diversity of marine species worldwide, the study notes.

The researchers, including Kevin St. Martin, an associate professor in the Department of Geography at Rutgers-New Brunswick, studied how climate change will likely affect the fishing opportunities for 85 communities in New England and the Mid-Atlantic. They used 13 global climate models to project how ocean temperatures are likely to change, then examined ocean temperatures and types of bottom habitat to determine where important commercial fisheries species are likely to move. They also looked at whether the species caught by fishing communities are likely to become more or less abundant in the ocean regions where they typically fish.

While fish species may shift as the climate changes, fishers often have limits on where they can fish based on local ecological knowledge, vessel size or gear type, the distance to fishing areas, management or conservation measures and, in some cases, traditional fishing territories.

For 24 of 33 species studied, habitat was projected to improve in some Northeast regions and deteriorate in others by 2040 to 2050. For example, monkfish habitat was expected to expand in the Gulf of Maine but become less suitable throughout the Mid-Atlantic Bight, including waters off the New Jersey coast, according to the study.

Sixty-four of the 85 communities are projected to face increased risk (fewer fish resources due to changes in habitat) by 2050, suggesting declines in fishing options if current practices continue. Communities of small trawlers in Maine faced the most risk because of their historical dependence on species, such as Atlantic cod and witch flounder, that are expected to lose suitable habitats.

For communities, adaptation will likely require shifting where fishing vessels go to follow their target species or focusing on "winner" species versus losers, the study says.

BATON ROUGE, LOUISIANA, June 17, 2019--Getting an excellent rabbiteye blueberry harvest requires helpful pollinators--particularly native southeastern blueberry bees--although growers can bring in managed honey bees to do the job, according to Agricultural Research Service (ARS) scientists.

This is especially true for commercial rabbiteye blueberry producers in Mississippi and Louisiana. With sufficient pollinators, they have been able to increase the percentage of flowers setting fruit from 10-30 percent to 70 percent or more. A mature rabbiteye blueberry bush can produce as much as 15 pounds of berries.

Fully pollinated berries also are bigger and mature earlier than fruit from inadequately pollinated flowers. So, bee-pollinated flowers produce fruit that bring a premium in the marketplace.

"We looked at multiple species of bees to see which did the best job of pollinating rabbiteye blueberries. We tested managed honey bees, native bumble bee species, southeastern blueberry bees and carpenter bees," explained research entomologist Robert Danka with the ARS Honey Bee Breeding, Genetics, and Physiology Research Laboratory in Baton Rouge, Louisiana, who co-led the study.

Of these bees, only the southeastern blueberry bee and the honey bee significantly increased fruit set, according to Danka "And the native southeastern blueberry bee did the best job," he said.

But the only way for commercial growers to have enough southeastern blueberry bees to provide a superior level of pollination is to provide habitat on the edges of their fields that encourages their population to grow.

"What commercial growers can do is provide woodlands near the edges of their fields because that's where southeastern blueberry bees prefer to nest. They are ground-dwelling bees that like shade and leaf litter but don't like wet or soil heavy with organic material," explained research entomologist Blair Sampson with the ARS Thad Cochran Southern Horticultural Laboratory in Poplarville, Mississippi.

A small grower with 1-3 acres of blueberries can probably get by solely with the pollination of native bees, especially if they have encouraged them with attractive habitat. But a grower with fields of 25 acres and more should probably consider supplementing by bringing in honey bee colonies, Sampson pointed out.

Complicating the matter is that some southeastern blueberry bees' population vary greatly from year to year, depending on rain and other weather conditions while other populations were reliably present every year in the study.

"A farmer who sees that during the first few days of bloom they are not getting prolific visits from the native bees should probably arrange to bring in some honey bee colonies. But even that may not guarantee ample pollination, because there is no way to be sure honey bees will stay on blueberries if there is something else in bloom that is more attractive to them," Sampson added.

"After all, rabbiteye blueberries are native North American bushes and honey bees are not natives so there was no co-evolved adaptation between these species."

Bottom Line: Adults who had pediatric-onset of multiple sclerosis (MS) before they were 18 were more likely to have greater cognitive consequences than patients who developed MS as adults. This study used Swedish registry data and included 5,704 patients with MS (300 of whom had pediatric-onset of the disease), and it compared test scores reflective of information-processing efficiency. Researchers report scores were lower, and declined faster, among patients with pediatric-onset MS compared to patients with adult-onset MS. Additionally, patients with pediatric-onset MS were more likely to experience cognitive impairment. Study limitations include misclassification of patients because the date of MS onset was largely based on self-reported symptoms.

High-flying careers in the airline industry don't mean sky-high salaries for women, according to new research by Swansea University.

The gender pay gap within airlines is often attributed to the fact that men frequently carry out high technically skilled jobs such as pilots and mechanics, whereas women commonly work in customer service roles like cabin crew.

The gender pay gap is a key focus of a new paper, Women in Aviation, written by Geraint Harvey, Joceleyn Finniear and Mrinalini Greedharry, academics at Swansea University's School of Management that has just been published in Research in Transportation Business and Management.

They argue that "the gendered nature of work in the industry means women commonly occupy lower skilled and less structurally important jobs, and as a consequence are more likely to experience insecurity in their work".

The paper acknowledges that the duties carried out by cabin crew and other customer- facing roles - jobs often done by female staff - require a high degree of emotional labour, a skill not valued in the same way as the technical skill of a pilot.

Nonetheless, a key finding of the study is that a gender pay gap exists for cabin crew after controlling for contract type.

Analysing data from a comprehensive study undertaken in 2014 with support of the European Commission by Geraint Harvey and Peter Turnbull, from Bristol University, the School of Management team contrasted the salaries of male and female cabin crew from Italy, Norway, Sweden and the UK.

Their findings show that UK airlines are lagging behind some of their continental counterparts in terms of pay equality.

The analysis revealed little difference between the percentage of male and female cabin crew who reported a guaranteed income of €1,400 or more per month in Sweden and Norway, but a statistically significant difference in the UK.

The team found also found "a statistically significant difference between the gross monthly income of male and female cabin crew in the UK with less than one quarter of female respondents stating a gross monthly income of €2,000 or more in contrast to over half of the male respondents".

The researchers discovered many of the staff were in the difficult position of having to endure the work-related pressures of a full-time role because part-time working wasn't financially feasible.

They also found work insecurity caused by the rearrangement of shifts at short notice could have a detrimental effect on work-life balance and family commitments.

The paper reported: "A high proportion of female respondents (44.1 per cent) stated that they were usually given less than 24 hours' notice for changes to their roster, while a further third (34.3 per cent) state they were usually given between 24 and 48 hours notification of a change."

In analysing the terms and conditions of male and female workers in the industry and finding a deterioration for both groups, the academics concluded it is not so much a case that women do less well than men but that both groups are doing badly with women faring even worse.

The myth that modern wheat varieties are more heavily reliant on pesticides and fertilisers is debunked by new research published in Nature Plants today.

Lead author on the paper, Dr Kai Voss-Fels, a research fellow at The University of Queensland, said modern wheat cropping varieties actually out-perform older varieties in both optimum and harsh growing conditions.

"There is a view that intensive selection and breeding which has produced the high-yielding wheat cultivars used in modern cropping systems has also made modern wheat less resilient and more dependent on chemicals to thrive," said Dr Voss-Fels.

"However, the data unequivocally shows that modern wheat varieties out-perform older varieties, even under conditions of reduced amounts of fertilisers, fungicides and water," he said.

"We also found that genetic diversity within the often-criticised modern wheat gene pool is rich enough to generate a further 23 per cent increase in yields."

Dr Voss-Fels said the findings might surprise some farmers and environmentalists.

"Quite a few people will be taken aback by just how tough modern wheat varieties proved to be, even in harsh growing conditions, such as drought, and using less chemical inputs."

Dr Voss-Fels said the findings could have potentially important implications for raising the productivity of organic cropping systems.
"It's been widely assumed that the older wheat cultivars are more robust and resilient but it's actually the modern cultivars that perform best in optimum and sub-optimum conditions."

Wheat is the world's most important food crop.

However, with global wheat yields reduced due to droughts in recent years and more climate risk anticipated in the future, the hardiness of modern wheat varieties is an issue of global significance.

The study is believed to provide the most detailed description of the consequences of intensive breeding and genetic selection for high grain yield and associated traits in European wheat over the past 50 years.

It was led by Professor Rod Snowdon of the Justus-Liebig-University Gießen (JLU), who is also an honorary Professor at UQ, in collaboration with seven other German universities.

The genetic analysis was undertaken at QAAFI under the leadership of Professor Ben Hayes.

The first part of the study involved testing 200 wheat varieties that have been essential to agriculture in Western Europe in the past 50 years.

Performance was compared between those varieties in side-by-side field trials under high, medium and low chemical input conditions.
The second part of the study was undertaken at QAAFI, to match the performance differences with the different varieties' genetic make-up.

"This genetic information allows us to take the discovery to the next level," Dr Voss-Fels says.

"We can use artificial intelligence (AI) algorithms to predict the optimal crosses needed to bring together the most favourable segments as fast as possible."

New research from Northwestern University finds that balanced professional networks are more important than individual talent when it comes to high-risk decision making.

The study, published today, June 14, in Nature Communications, is the first longitudinal study to prove several key tenants of structural balance theory (SBT), which provides an analytical framework to characterize how relationships change over time. SBT consists of four primary rules for relationships among individuals:

A friend of a friend is a friend

A friend of an enemy is an enemy

An enemy of an enemy is a friend

An enemy of a friend is an enemy

When all of these conditions are met, a network is said to be balanced. Through a two-year study of day traders, the researchers found that: (A) workers gravitate toward a state of balance in their relationships; and (B) performance improves when there is a high level of balance.

"This data shows that companies reap the benefits when conflict among employees is reduced," said corresponding author Brian Uzzi, the Richard L. Thomas Professor of Leadership and Organizational Change in Northwestern's Kellogg School of Management. "There are certain types of conflict that can't resolve themselves. This work can help managers identify those conflicts and actively step in to resolve them, ultimately leading to better performance."

From 2007 to 2009, researchers analyzed day traders' instant messages to determine the relationships among traders and compared those relationships to performance data for individual traders, controlling for factors including market volatility and work days. They found that the traders with the highest level of balance in their networks also made the best trades, regardless of the objective level of talent of any individual trader.

"We suspect that conflict in networks monopolizes some portion of workers' mental energy," Uzzi said. "Resolving that conflict frees up mental energy to make better decisions and perform at a higher level."

The findings of this study apply to individuals who engage in extensive high-risk decision making, particularly in situations where polarization is common, such as politics or in the military.

Further research is needed to determine whether the same rules hold in other work situations, such as creative and innovative endeavors.

Sleep patterns can predict the accumulation of Alzheimer’s pathology proteins later in life, according to a new study of older men and women published in JNeurosci. These findings could lead to new sleep-based early diagnosis and prevention measures in the treatment of Alzheimer’s disease.

Alzheimer's disease is associated with disrupted sleep and the accumulation of tau and proteins in the brain, which can emerge long before characteristic memory impairments appear. Two types of hippocampal sleep waves, slow oscillations and sleep spindles, are synced in young individuals, but have been shown to become uncoordinated in old age.

Matthew Walker, Joseph Winer, and colleagues at the University of California, Berkeley found a decrease in slow oscillations/sleep spindle synchronization was associated with higher tau, while reduced slow-wave-activity amplitude was associated with higher β-amyloid levels.

The researchers also found that a decrease in sleep quantity throughout aging, from the 50s through 70s, was associated with higher levels of β-amyloid and tau later in life. This means that changes in brain activity during sleep and sleep quantity during these time frames could serve as a warning sign for Alzheimer's disease, allowing for early preventive care.

High blood pressure may affect conditions such as Alzheimer's disease by interfering with the brain's waste management system, according to new research in rats published in JNeurosci. Maintaining blood vessel health could therefore help stave off cognitive decline.

Hypertension causes stiffening and elasticity loss in blood vessels, which hinders clearance of waste molecules from the brain. Using a rat model of hypertension, Maiken Negergaard and colleagues at the University of Copenhagen and Yale School of Medicine studied how the condition affects the movement of cerebrospinal fluid into and interstitial fluid out of brain cells.

The researchers tracked the flow of cerebrospinal fluid and found that the hypertensive rats exhibited larger ventricles, decreased brain volume, and impaired fluid transport. They concluded that hypertension interferes with the clearance of macromolecules from the brain, such as the Alzheimer's pathology protein β-amyloid. Treatments targeting hypertension could in turn reduce β-amyloid buildup and delay the onset of Alzheimer's disease.