Category: Science News

{A rare, severe form of pulmonary hypertension, which up until now, has only been classified as a human lung disease, has also been discovered in dogs according to a Michigan State University study.}

“Our research is the first to document the existence of pulmonary veno-occlusive disease, or PVOD, in dogs,” said Kurt Williams, the lead author of the study and an expert in respiratory pathology in MSU’s College of Veterinary Medicine. “PVOD is considered one of the most severe forms of pulmonary hypertension.”

The study is published in the journal Veterinary Pathology.

The number of pulmonary hypertension, or PH, cases reported in the United States is low, affecting 15 to 50 people per million each year. PVOD is diagnosed in only about 10 percent of PH cases where no other cause of the disease has been determined. Unfortunately, there are very few effective treatment options for PVOD and a lung transplant often becomes the best choice.

“PVOD might be more common in dogs than in people, but this has yet to be determined and needs to be looked at further,” Williams said.

Pulmonary hypertension develops because of abnormal blood vessels in the lungs, which makes it harder for the heart to push blood through and provide oxygen to the rest of the body. In cases of PVOD, the small veins in the lungs become blocked, increasing pressure in these blood vessels, and ultimately causing heart failure.

“The same process happens in canines,” Williams said. “These dogs also come in with similar symptoms as humans, yet because subtle changes in health may not be recognized as quickly in dogs, death can occur quickly once the animal is seen by a veterinarian.”

Symptoms include cough, increased rate of breathing, respiratory distress, loss of appetite and chronic fatigue. Fatal progression of the disease in humans can last up to two years.

“PVOD is a poorly understood disease not just because it’s so rare, but also because there’ve been no other animals known to have the disease,” Williams said. “Our finding changes things.”

Williams said that the discovery could be important for human medicine because the canine disease may serve as a model for human PVOD.

“It’s cases like this that help to remind us how important veterinary medicine is to medicine in general,” he said. “Our colleagues in the human medical community are becoming much more aware of the many diseases shared by our respective patients and how together we can learn from each other.”

{Eyewitnesses remember the faces of black suspects less accurately in drive-by shootings than they do in serial killings. Their memories are further skewed when the victims are women or white males, psychology researchers have found.}

Eyewitnesses remember the faces of black suspects less accurately in drive-by shootings than they do in serial killings.

Their memories are further skewed when the victims are women or white males, psychology researchers at UBC’s Okanagan campus have found.

“What this study shows is that the memory of an eyewitness is heavily influenced by the type of crime that was committed,” says Prof. Paul Davies. “In crimes such as drive-by shootings, typically associated with black males, eyewitnesses overwhelmingly remembered the black suspect’s face incorrectly.

“In crimes that were are more typically ‘white’, witnesses remembered the black suspect’s faces with a high degree of accuracy.”

In his study, four groups of participants were shown one of two staged videos with a black male leaving the scene of a multiple murder. One video was of a serial killing and the other was a drive-by shooting. The race and gender of the victims was shared with the members of some groups and not others.

Following the videos, photos of the suspect, where facial features such as skin color and breadth of nose and fullness of lips were electronically manipulated in a series of 100 frames, were shown to the witnesses. Witnesses were asked to stop on the frame that most accurately represented the suspect they saw in the video.

DNA evidence in initiatives such as the United States’ Innocence Project have been exonerating increasing numbers of people, mostly black men, who were imprisoned largely based on eyewitness testimony. This trend along with evidence that shows the fallibility of eyewitness memories may want to be considered in the Canadian justice system, says Davies.

“Eyewitness testimony is very compelling and may have the ability to sway a jury,” says Davies. “However, if we know that witnesses’ memories are inherently biased in the case of black male suspects, our justice system may want to take that into account to aid them in avoiding wrongful convictions.”

Davies study was recently published in the journal Social Psychological and Personality Science.

{Using the oldest fossil micrometeorites — space dust — ever found, Monash University-led research has made a surprising discovery about the chemistry of Earth’s atmosphere 2.7 billion years ago.}

The findings of a new study published today in the journal Nature — led by Dr Andrew Tomkins and a team from the School of Earth, Atmosphere and Environment at Monash, along with scientists from the Australian Synchrotron and Imperial College, London — challenge the accepted view that Earth’s ancient atmosphere was oxygen-poor. The findings indicate instead that the ancient Earth’s upper atmosphere contained about the same amount of oxygen as today, and that a methane haze layer separated this oxygen-rich upper layer from the oxygen-starved lower atmosphere.

Dr Tomkins explained how the team extracted micrometeorites from samples of ancient limestone collected in the Pilbara region in Western Australia and examined them at the Monash Centre for Electron Microscopy (MCEM) and the Australian Synchrotron.

“Using cutting-edge microscopes we found that most of the micrometeorites had once been particles of metallic iron — common in meteorites — that had been turned into iron oxide minerals in the upper atmosphere, indicating higher concentrations of oxygen than expected,” Dr Tomkins said.

“This was an exciting result because it is the first time anyone has found a way to sample the chemistry of the ancient Earth’s upper atmosphere,” Dr Tomkins said.

Imperial College researcher Dr Matthew Genge — an expert in modern cosmic dust — performed calculations that showed oxygen concentrations in the upper atmosphere would need to be close to modern day levels to explain the observations.

“This was a surprise because it has been firmly established that the Earth’s lower atmosphere was very poor in oxygen 2.7 billion years ago; how the upper atmosphere could contain so much oxygen before the appearance of photosynthetic organisms was a real puzzle,” Dr Genge said.

Dr Tomkins explained that the new results suggest the Earth at this time may have had a layered atmosphere with little vertical mixing, and higher levels of oxygen in the upper atmosphere produced by the breakdown of CO 2 by ultraviolet light.

“A possible explanation for this layered atmosphere might have involved a methane haze layer at middle levels of the atmosphere. The methane in such a layer would absorb UV light, releasing heat and creating a warm zone in the atmosphere that would inhibit vertical mixing,” Dr Tomkins said.

“It is incredible to think that by studying fossilised particles of space dust the width of a human hair, we can gain new insights into the chemical makeup of Earth’s upper atmosphere, billions of years ago.” Dr Tomkins said.

Dr Tomkins outlined next steps in the research.

“The next stage of our research will be to extract micrometeorites from a series of rocks covering over a billion years of Earth’s history in order to learn more about changes in atmospheric chemistry and structure across geological time. We will focus particularly on the great oxidation event, which happened 2.4 billion years ago when there was a sudden jump in oxygen concentration in the lower atmosphere.”

{Australian archaeologists have discovered a piece of the world’s oldest axe in the remote Kimberley region of Western Australia.}

The axe fragment is about the size of a thumbnail and dates back to a Stone Age period of 45,000 to 49,000 years ago — at, or very soon after, the time humans arrived on the continent, and more than ten millennia earlier than any previous ground-edge axe discoveries.

The University of Sydney’s Professor Peter Hiscock is the lead and corresponding author of a new analysis of the fragment published in the journal Australian Archaeology. He said the axe revealed that the first Australians were technological innovators.

“Since there are no known axes in Southeast Asia during the Ice Age, this discovery shows us that when humans arrived in Australia they began to experiment with new technologies, inventing ways to exploit the resources they encountered in the new Australian landscape,” he said.

The axe fragment was initially excavated in the early 1990s by lead archaeologist Professor Sue O’Connor from the Australian National University (ANU)among a sequence of food scraps, tools, artwork and other artifacts from Carpenter’s Gap, a large rock shelter known to be one of the first sites occupied by modern humans.

“Nowhere else in the world do you get axes at this date. In Japan such axes appear about 35,000 years ago. But in most countries in the world they arrive with agriculture after 10,000 years ago,” Professor O’Connor said.

In 2014, as further study was being carried out on the objects dug out of the site, Professor Hiscock’s team discovered a small fragment of a polished axe, recovered from the oldest levels of the site.

New studies of the fragment have revealed that it comes from an axe that had been shaped from basalt then polished by grinding it on another rock until it was very smooth.

The fragment came from the polished edge when it was later re-sharpened. The team believes the axe was most likely carried away to be used elsewhere, leaving the fragment behind.

“Polished stone axes were crucial tools in hunter-gatherer societies and were once the defining characteristic of the Neolithic phase of human life. But when were axes invented? This question has been pursued for decades, since archaeologists discovered that in Australia axes were older than in many other places. Now we have a discovery that appears to answer the question,” said Professor Hiscock.

Professor O’Connor said evidence suggests the technology was developed in Australia after people arrived around 50,000 years ago. “We know that they didn’t have axes where they came from. There are no axes in the islands to our north. They arrived in Australia and innovated axes,” she said.

Professor Hiscock said the ground-edge axe technology specifically arose as the dispersing humans adapted to their new regional landscapes.

“Although humans spread across Australia, axe technology did not spread with them. Axes were only made in the tropical north, perhaps suggesting two different colonizing groups or that the technology was abandoned as people spread into desert and sub-topical woodlands,” he said.

“These differences between northern Australia, where axes were always used, and southern Australia, where they were not, originated around the time of colonization and persisted until the last few thousand years when axes began to be made in most southern parts of mainland Australia.”

The team’s latest discoveries are published in this month’s issue of the journal Australian Archaeology.

{A step has been taken toward the possibility of tuning the strength of memory by manipulating one of the brain’s signaling memory mechanisms, a neurotransmitter called acetylcholine.}

Imagine if memory could be tuned in such a way where good memories are enhanced for those suffering from dementia or bad memories are wiped away for individuals with post-traumatic stress disorder. A Stony Brook University research team has taken a step toward the possibility of tuning the strength of memory by manipulating one of the brain’s natural mechanisms for signaling involved in memory, a neurotransmitter called acetylcholine. Their findings are published in the journal Neuron.

Brain mechanisms underlying memory are not well understood, but most scientists believe that the region of the brain most involved in emotional memory is the amygdala. Acetylcholine is delivered to the amygdala by cholinergic neurons that reside in the base of the brain. These same neurons appear to be affected early in cognitive decline. Previous research has suggested that cholinergic input to the amygdala appears to strengthen emotional memories.

“Memories of emotionally charged experiences are particularly strong, whether positive or negative experiences, and the goal of our research is to determine the mechanisms underlying the strengthening of memory,” said Lorna Role, PhD, Professor and Chair of the Department of Neurobiology and Behavior and Co-Director of the Neurosciences Institute at Stony Brook Medicine.

In the paper, titled “Cholinergic Signaling Controls Conditioned Fear Behaviors and Enhances Plasticity of Cortical-Amygdala Circuits,” Dr. Role and colleagues used a fear-based memory model in mice to test the underlying mechanism of memory because fear is a strong and emotionally charged experience.

The team used opto-genetics, a newer research method using light to control cells in living tissue, to stimulate specific populations of cholinergic neurons during the experiments.

Two of the team’s findings stand out. First, when they increased acetylcholine release in the amygdala during the formation of a traumatic memory, it greatly strengthened memory making the memory last more than twice as long as normal. Then, when they decreased acetylcholine signaling in the amygdala during a traumatic experience, one that normally produces a fear response, they could actually wipe out memory.

“This second finding was particularly surprising, as we essentially created fearless mice by manipulating acetylcholine circuits in the brain,” explained Dr. Role. “The findings provide the basis for research examining novel approaches to reverse post-traumatic stress disorder.”

The challenge of continued research is that cholinergic neurons remain difficult to study because they are intermingled with other types of neurons and are few in number compared to other types of neurons in the brain.

Because acetylcholine is a natural signaling mechanism and seemingly essential for memory, additional research will center on non-pharmacologic ways to manipulate or fine-tune memory.

“The long-term goal of our research is that we would like to find ways — potentially independent of drug administration — to enhance or diminish the strength of specific memories, the good ones, and diminish the bad ones,” summarized Dr. Role.

{New research has used bacteria to show that acquiring duplicate copies of genes can provide a ‘template’ allowing organisms to evolve novel traits from redundant copies of existing genes.}

The evolution of major novel traits — characteristics such as wings, flowers, horns or limbs — has long been known to play a key role in allowing organisms to exploit new opportunities in their surroundings.

What’s still up for debate, though, is how these important augmentations come about from a genetic point of view.

New research from an international team of evolutionary biologists, led by the University of Oxford, has used bacteria to show that acquiring duplicate copies of genes can provide a ‘template’ allowing organisms to develop new attributes from redundant copies of existing genes.

Gene duplication has been proposed as playing a key role in innovation since the 1970s, but these findings add important empirical evidence to support this theory.

The study, which involved collaboration with researchers from the University of Zurich, is published in the journal PLOS Genetics.

Professor Craig MacLean, a Wellcome Trust Research Fellow in the Department of Zoology at Oxford University, said: ‘The appearance of novel traits, such as wings and flowers, has played a key role in the evolution of biological diversity. However, it is usually difficult to understand the actual genetic changes that drive these evolutionary innovations.

‘We have taken advantage of a simple bacterial model system, where bacteria evolve the ability to eat new food sources, to overcome this obstacle.’

The researchers allowed 380 populations of Pseudomonas aeruginosa bacteria to evolve novel metabolic traits such as the ability to degrade new sugars. This gave the researchers the opportunity to witness evolution happening in real-time.

After 30 days of evolution, they sequenced the genomes of bacteria that had evolved novel metabolic traits. They found that mutations mainly affected genes involved in transcription and metabolism, and that novelty tended to evolve through mutations in pre-existing duplicated genes in the P. aeruginosa genome.

Duplication drives novelty because genetic redundancy provided by duplication allows bacteria to evolve new metabolic functions without compromising existing functions. These findings suggest that past duplication events might be important for future innovations.

Professor MacLean added: ‘The key insight of our study is that having redundant copies of genes provides bacteria with a template for evolving new traits without sacrificing existing traits. In other words, redundant genes allow bacteria to have their cake and eat it.

‘In higher organisms like animals and plants, duplicate genes arise from spontaneous duplication of existing genes. In contrast, bacteria tend to acquire duplicate genes from neighbouring bacterial cells through horizontal gene transfer, which is the bacterial equivalent of sex.

‘These findings provide important empirical evidence to support the role of gene duplication in evolutionary innovation, and they suggest that it may be possible to predict the ability of pathogenic bacteria to evolve clinically important traits, such as virulence and antibiotic resistance.’

{It happens only a little more than once a decade and the next chance to see it is Monday, May 9, 2016. Throughout the US, sky watchers can watch Mercury pass between Earth and the sun in a rare astronomical event known as a planetary transit. }

Three NASA satellites will be providing images of the transit and one of them will have a near-live feed.

It happens only a little more than once a decade and the next chance to see it is Monday, May 9, 2016. Throughout the U.S., sky watchers can watch Mercury pass between Earth and the sun in a rare astronomical event known as a planetary transit. Mercury will appear as a tiny black dot as it glides in front of the sun s blazing disk over a period of seven and a half hours. Three NASA satellites will be providing images of the transit and one of them will have a near-live feed.

Although Mercury zooms around the sun every 88 days, Earth, the sun and Mercury rarely align. And because Mercury orbits in a plane that is tilted from Earths orbit, it usually moves above or below our line of sight to the sun. As a result, Mercury transits occur only about 13 times a century.

Transits provide a great opportunity to study the way planets and stars move in space — information that has been used throughout the ages to better understand the solar system and which still helps scientists today calibrate their instruments. Three of NASA’s solar telescopes will watch the transit for just that reason.

The May 9 Mercury transit will occur between about 7:12 a.m. and 2:42 p.m. EDT. Mercury is too small to see without magnification, but it can be seen with a telescope or binoculars. These must be outfitted with a solar filter as you can’t safely look at the sun directly. Without the correct solar filter looking direction at the sun can cause serious irreversible eye damage.

Astronomers get excited when any two things come close to each other in the heavens said Louis Mayo, program manager at NASA s Goddard Space Flight Center in Greenbelt, Maryland. This is a big deal for us.

Mercury transits have been key to helping astronomers throughout history: In 1631, astronomers first observed a Mercury transit. Those observations allowed astronomers to measure the apparent size of Mercury s disk, as well as help them estimate the distance from Earth to the sun.

Back in 1631, astronomers were only doing visual observations on very small telescopes by today s standards said Mayo.

Since then, technological advancements have allowed us to study the sun and planetary transits in greater detail. In return, transits allow us to test our spacecraft and instruments.

Scientists for the Solar and Heliospheric Observatory, or SOHO (jointly operated by NASA and ESA, the European Space Agency), and NASA s Solar Dynamics Observatory, or SDO, will work in tandem to study the May 9 transit. The Hinode solar mission will also observe the event. Hinode is a collaboration between the space agencies of Japan, the United States, the United Kingdom and Europe led by the Japan Aerospace Exploration Agency.

SOHO launched in December 1995 with 12 instruments to study the sun from the deep solar core all the way out to the sun’s effects on the rest of the solar system. Two of these instruments the Extreme ultraviolet Imaging Telescope and the Michelson Doppler Imager will be brought back into full operation to take measurements during the transit after five years of quiescence.

For one thing, the SOHO will measure the sun s rotation axis using images captured by the spacecraft.

Instruments on board SDO and SOHO use different spectral lines, different wavelengths and they have slightly different optical properties to study solar oscillations, said SOHO Project Scientist Joseph Gurman. “Transit measurements will help us better determine the solar rotation axis.”

Such data is another piece of a long line of observations, which together help us understand how the sun changes over hours, days, years and decades.

It used to be hard to observe transits, Gurman said. If you were in a place that had bad weather, for example, you missed your chance and had to wait for the next one. These instruments help us make our observations, despite any earthly obstacles.

SDO will be able to use the transit to help with instrument alignment. Because scientists know so precisely where Mercury should be in relationship to the sun, they can use it as a marker to fine tune exactly how their instruments should be pointed.

The transit can also be used to help calibrate space instruments. The utter darkness of the planet provides an opportunity to study effects on the observations of stray light within the instrument. The backside of Mercury should appear black as it moves across the face of the sun. But because instruments scatter some light, Mercury will look slightly illuminated.

“It’s like getting a cataract, you see stars or halos around bright lights as though you are looking through a misty windshield,” said SDO Project Scientist Dean Pesnell.We have the same problem with our instruments.

Scientists run software on the images to try and mitigate the effect and check whether it can remove all of the scattered light.

For those of us down on the ground, it is worth trying to find a local astronomy club with a solar telescope to see if you can witness this rare event. Alternatively, a near-live feed of SDO images will be available at http://www.nasa.gov/transit.

{All-cause mortality is higher for those who eat meat, particularly red or processed meat, on a daily basis, a review of large-scale studies involving more than 1.5 million people has found.}

A review of large-scale studies involving more than 1.5 million people found all-cause mortality is higher for those who eat meat, particularly red or processed meat, on a daily basis. Conducted by physicians from Mayo Clinic in Arizona, “Is Meat Killing Us?” was published today in the Journal of the American Osteopathic Association.

The authors analyzed six studies that evaluated the effects of meat and vegetarian diets on mortality with a goal of giving primary care physicians evidence-based guidance about whether they should discourage patients from eating meat. Their recommendation: physicians should advise patients to limit animal products when possible and consume more plants than meat.

“This data reinforces what we have known for so long — your diet has great potential to harm or heal,” said Brookshield Laurent, DO, assistant professor of family medicine and clinical sciences at New York Institute of Technology College of Osteopathic Medicine. “This clinical-based evidence can assist physicians in counseling patients about the important role diet plays, leading to improved preventive care, a key consideration in the osteopathic philosophy of medicine.”

While findings for U.S. and European populations differed somewhat, the data found the steepest rise in mortality at the smallest increases of intake of total red meat. That 2014 study followed more than one million people over 5.5 to 28 years and considered the association of processed meat (such as bacon, sausage, salami, hot dogs and ham), as well as unprocessed red meat (including uncured, unsalted beef, pork, lamb or game).

A 2014 meta-analysis examined associations with mortality from cardiovascular disease and ischemic heart disease. In that study of more than 1.5 million people, researchers found only processed meat significantly increase the risk for all-cause mortality.

Combined, the findings of these studies are statistically significant in their similarity, the reviewers noted. Further, a 2003 review of more than 500,000 participants found a decreased risk of 25 percent to nearly 50 percent of all-cause mortality for very low meat intake compared with higher meat intake.

They also found a 3.6-year increase in life expectancy for those on a vegetarian diet for more than 17 years, as compared to short-term vegetarians.

{While studying worm infections, scientists have discovered a surprising ability of the immune system. The strange discovery has significant implications for our understanding of how the immune system responds to infections.}

In order to fight invading pathogens, the immune system uses “outposts” throughout the body, called lymph nodes. These are small, centimeter-long organs that filter fluids, get rid of waste materials, and trap pathogens, e.g. bacteria or viruses. Lymph nodes are packed with immune cells, and are know to grow in size, or ‘swell’, when they detect invading pathogens. But now, EPFL scientists have unexpectedly discovered that lymph nodes also contain more immune cells when the host is infected with a more complex invader: an intestinal worm. The discovery is published in Cell Reports , and has significant implications for our understanding of how the immune system responds to infections.

The discovery was made by the lab of Nicola Harris at EPFL. Her postdoc and first author Lalit Kumar Dubey noticed that the lymph nodes of mice that had been infected with the intestinal worm Heligmosomoides polygyrus bakeri had massively grown in size. This worm is an excellent tool for studying how the worm interacts with its host, and is therefore used as a standard throughout labs working in the field.

Lymph nodes have microscopic compartments called “follicles,” where they store a specific type of immune cells, the B-cells. Stored in the follicles, B-cells pump out antibodies into the bloodstream to attack invading pathogens.

The researchers found that the mouse lymph nodes were actually producing more follicles, suggesting they were producing more B-cells in response to the worm infection. Of course, this is not a simple event. Like many biological processes, it involves an entire sequence of molecular signals that result in the formation of new cells and tissue.

The EPFL scientists were able to reconstruct the molecular sequence, which is fairly complex: when the mouse is infected with the intestinal worm, a “cytokine” molecule is produced. This cytokine then stimulates B-cells in the lymph nodes to produce a molecule called a lymphotoxin. The lymphotoxin then interacts with the cells that form the foundation of the actual lymph node — the so-called “stromal cells.” The stromal cells then produce another cytokine, which stimulates the production of new follicles in the lymph node.

Until now, formation of new B-cell follicles in the lymph nodes was thought to only happen just after birth. This study provides the first detailed evidence to show that this phenomenon can take place in an adult mammal. The researchers also showed that formation of new follicles is important for fighting infection as it encourages the production of more antibodies.

Unlike bacterial or viral infections, worm infections are enormously complex. “Worms are large creatures that produce a host of their own molecules upon infection,” says Nicola Harris. “Some of these molecules stimulate the host’s immune system while some others suppress it. The field is investigating every one of these molecules, but it is slow work.”

It must be noted that the new production of B-cell follicles has only been confirmed in worm infections. “We are currently looking at this effect with bacterial infections in mice,” says Nicola Harris. “Nonetheless, we are pursuing a deeper understanding of this process to see if it is involved in producing adequate antibodies in response to vaccines.”