Category: Science News

{A new study led by the University of Minnesota shows that monkeys in captivity lose much of their native gut bacteria diversity and their gut bacteria ends up resembling those of humans. The results suggest that switching to a low-fiber, Western diet may have the power to deplete most normal primate gut microbes in favor of a less diverse set of bacteria.}

The study was published in the most recent issue of the Proceedings of the National Academy of Sciences (PNAS).

The microbiome (or gut bacteria) has been tied to a wide variety of medical conditions from autism to obesity. The lack of fiber in modern Western diets is often thought to cause harmful perturbations to the human gut microbiome. However, the causes and consequences of how the gut bacteria of humans changes as societies become modernized and westernized is still a mystery because there are too many variables when studying humans.

To better understand how changes in diet, lifestyle, and exposure to modern medicine affect primates’ guts, a team of researchers led by University of Minnesota computer science and engineering professor Dan Knights, veterinary medicine professor Tim Johnson, and veterinary medicine Ph.D. student Jonathan Clayton, used DNA sequencing to study the gut microbes of multiple non-human primates species in the wild and in captivity as a model for studying the effects of emigration and lifestyle changes.

The researchers studied two different species: the highly endangered red-shanked douc and the mantled howler monkey. The authors then compared the captive primate microbiomes to the microbiomes of their wild counterparts and to those of modern humans living in developing nations and in the United States.

What they found could be considered alarming. Not only did captive monkeys lose most of their natural wild gut bacteria, but they very consistently all acquired the same new and less diverse set of bacteria — the same bacteria living in our own modern human guts. Across several different zoos on three different continents, all captive primate microbiomes showed the same pattern of converging toward the modern human microbiome.

“We don’t know for certain that these new modern human microbes are bad, but on the other hand many studies are now showing that we evolved together with our resident microbes,” said Knights. “If that is the case, then it is likely not beneficial to swap them out for a totally different set.”

In the wild, each primate species had its own signature fingerprint of microbes. Yet in captivity, they all lost their distinctive microbes and ended up being dominated by the same bacteria that dominate our human guts — species of Bacteroides and Prevotella.

This, along with other analyses to rule out confounding factors like genetics, geography and antibiotic usage, suggested a simple explanation for why the captive primate guts looked more like human guts on the inside — they weren’t eating enough plants.

To test whether a partial loss of plant-derived dietary fiber would result in a partial loss of native gut microbes, the authors also collected fecal samples from a semi-captive population of red-shanked doucs who lived in a sanctuary and received about half of the normal variety of plants eaten by wild doucs. Interestingly, these semi-captive animals’ microbiomes fell right in between those of the wild and captive doucs, further supporting they hypothesis that lower plant consumption causes loss of microbial diversity.

By comparing DNA sequenced from primate stool samples to plant genomes the authors were able to actually measure the amount and diversity of plants being consumed by the captive and wild primates, and the difference was stark. Wild primate stool contained up to 40 percent plant DNA, while the captive primate stool contained almost none.

“We think this study underscores the link between fiber-rich diets and gut microbiome diversity,” Knights said.

This research was funded primarily by a variety of grants from the Morris Animal Foundation, University of Minnesota, Margot Marsh Biodiversity Foundation, Mohamed bin Zayed Species Conservation Fund, and a PharmacoNeuroImmunology Fellowship through the National Institutes of Health.

{Dogs have the ability to distinguish vocabulary words and the intonation of human speech through brain regions similar to those that humans use, a new study reports.}

Attila Andics et al. note that vocabulary learning “does not appear to be a uniquely human capacity that follows from the emergence of language, but rather a more ancient function that can be exploited to link arbitrary sound sequences to meanings.”

Words are the basic building blocks of human languages, but they are hardly ever found in nonhuman vocal communications. Intonation is another way that information is conveyed through speech, where, for example, praises tend to be conveyed with higher and more varying pitch. Humans understand speech through both vocabulary and intonation.

Here, Andics and colleagues explored whether dogs also depend on both mechanisms. Dogs were exposed to recordings of their trainers’ voices as the trainers spoke to them using multiple combinations of vocabulary and intonation, in both praising and neutral ways.

For example, trainers spoke praise words with a praising intonation, praise words with a neutral intonation, neutral words with a praising intonation, and neutral words with neutral intonation.

Researchers used fMRI to analyze the dogs’ brain activity as the animals listened to each combination. Their results reveal that, regardless of intonation, dogs process vocabulary, recognizing each word as distinct, and further, that they do so in a way similar to humans, using the left hemisphere of the brain.

Also like humans, the researchers found that dogs process intonation separately from vocabulary, in auditory regions in the right hemisphere of the brain. Lastly, and also like humans, the team found that the dogs relied on both word meaning and intonation when processing the reward value of utterances.

Thus, dogs seem to understand both human words and intonation. The authors note that it is possible that selective forces during domestication could have supported the emergence of the brain structure underlying this capability in dogs, but, such rapid evolution of speech-related hemispheric asymmetries is unlikely.

Humans, they say, are only unique in their ability to invent words.

{Lucy, the most famous fossil of a human ancestor, probably died after falling from a tree, according to a new study. Researchers have found that the injury Lucy sustained was consistent with a four-part proximal humerus fracture, caused by a fall from considerable height when the conscious victim stretched out an arm in an attempt to break the fall.}

Lucy, the most famous fossil of a human ancestor, probably died after falling from a tree, according to a study appearing in Nature led by researchers at The University of Texas at Austin.

Lucy, a 3.18-million-year-old specimen of Australopithecus afarensis — or “southern ape of Afar” — is among the oldest, most complete skeletons of any adult, erect-walking human ancestor. Since her discovery in the Afar region of Ethiopia in 1974 by Arizona State University anthropologist Donald Johanson and graduate student Tom Gray, Lucy — a terrestrial biped — has been at the center of a vigorous debate about whether this ancient species also spent time in the trees.

“It is ironic that the fossil at the center of a debate about the role of arborealism in human evolution likely died from injuries suffered from a fall out of a tree,” said lead author John Kappelman, a UT Austin anthropology and geological sciences professor.

Kappelman first studied Lucy during her U.S. museum tour in 2008, when the fossil detoured to the High-Resolution X-ray Computed Tomography Facility (UTCT) in the UT Jackson School of Geosciences — a machine designed to scan through materials as solid as a rock and at a higher resolution than medical CT. For 10 days, Kappelman and geological sciences professor Richard Ketcham carefully scanned all of her 40-percent-complete skeleton to create a digital archive of more than 35,000 CT slices.

“Lucy is precious. There’s only one Lucy, and you want to study her as much as possible,” Ketcham said. “CT is nondestructive. So you can see what is inside, the internal details and arrangement of the internal bones.”

Studying Lucy and her scans, Kappelman noticed something unusual: The end of the right humerus was fractured in a manner not normally seen in fossils, preserving a series of sharp, clean breaks with tiny bone fragments and slivers still in place.

“This compressive fracture results when the hand hits the ground during a fall, impacting the elements of the shoulder against one another to create a unique signature on the humerus,” said Kappelman, who consulted Dr. Stephen Pearce, an orthopedic surgeon at Austin Bone and Joint Clinic, using a modern human-scale, 3-D printed model of Lucy.

Pearce confirmed: The injury was consistent with a four-part proximal humerus fracture, caused by a fall from considerable height when the conscious victim stretched out an arm in an attempt to break the fall.

Kappelman observed similar but less severe fractures at the left shoulder and other compressive fractures throughout Lucy’s skeleton including a pilon fracture of the right ankle, a fractured left knee and pelvis, and even more subtle evidence such as a fractured first rib — “a hallmark of severe trauma” — all consistent with fractures caused by a fall. Without any evidence of healing, Kappelman concluded the breaks occurred perimortem, or near the time of death.

The question remained: How could Lucy have achieved the height necessary to produce such a high velocity fall and forceful impact? Kappelman argued that because of her small size — about 3 feet 6 inches and 60 pounds — Lucy probably foraged and sought nightly refuge in trees.

In comparing her with chimpanzees, Kappelman suggested Lucy probably fell from a height of more than 40 feet, hitting the ground at more than 35 miles per hour. Based on the pattern of breaks, Kappelman hypothesized that she landed feet-first before bracing herself with her arms when falling forward, and “death followed swiftly.”

“When the extent of Lucy’s multiple injuries first came into focus, her image popped into my mind’s eye, and I felt a jump of empathy across time and space,” Kappelman said. “Lucy was no longer simply a box of bones but in death became a real individual: a small, broken body lying helpless at the bottom of a tree.”

Kappelman conjectured that because Lucy was both terrestrial and arboreal, features that permitted her to move efficiently on the ground may have compromised her ability to climb trees, predisposing her species to more frequent falls. Using fracture patterns when present, future research may tell a more complete story of how ancient species lived and died.

In addition to the study, the Ethiopian National Museum provided access to a set of 3-D files of Lucy’s shoulder and knee for the public to download and print so that they can evaluate the hypothesis for themselves.

“This is the first time 3-D files have been released for any Ethiopian fossil hominin, and the Ethiopian officials are to be commended,” Kappelman said. “Lucy is leading the charge for the open sharing of digital data.”

{For a large part of human prehistory, people around the world practised trepanation: a crude surgical procedure that involves forming a hole in the skull of a living person by either drilling, cutting or scraping away layers of bone with a sharp implement.}

To date, thousands of skulls bearing signs of trepanation have been unearthed at archaeological sites across the world.

But despite its apparent importance, scientists are still not completely agreed on why our ancestors performed trepanation.

Anthropological accounts of 20th-Century trepanations in Africa and Polynesia suggest that, in these cases at least, trepanation was performed to treat pain – for instance, the pain caused by skull trauma or neurological disease.

Trepanation may also have had a similar purpose in prehistory. Many trepanned skulls show signs of cranial injuries or neurological diseases, often in the same region of the skull where the trepanation hole was made.

But as well as being used to treat medical conditions, researchers have long suspected that ancient humans performed trepanation for a quite different reason: ritual.

The earliest clear evidence of trepanation dates to approximately 7,000 years ago. It was practised in places as diverse as Ancient Greece, North and South America, Africa, Polynesia and the Far East. People probably developed the practice independently in several locations.

Archaeologists have turned up some of the best evidence for ritual trepanation ever discovered

Trepanation had been abandoned by most cultures by the end of the Middle Ages, but the practice was still being carried out in a few isolated parts of Africa and Polynesia until the early 1900s.

Since the very first scientific studies on trepanation were published in the 19th Century, scholars have continued to argue that ancient humans sometimes performed trepanation to allow the passage of spirits into or out of the body, or as part of an initiation rite.

However, convincing evidence is hard to come by. It is almost impossible to completely rule out the possibility that a trepanation was carried out for medical reasons, because some brain conditions leave no trace on the skull.

However, in a small corner of Russia archaeologists have turned up some of the best evidence for ritual trepanation ever discovered.

The story begins in 1997. Archaeologists were excavating a prehistoric burial site close to the city of Rostov-on-Don in the far south of Russia, near the northern reaches of the Black Sea.

The site contained the skeletal remains of 35 humans, distributed among 20 separate graves. Based on the style of the burials, the archaeologists knew that they dated to between approximately 5,000 and 3,000 BC, a period known as the Chalcolithic or “Copper Age”.

Less than 1% of all recorded trepanations are located above the obelion point
One of the graves contained the skeletons of five adults – two women and three men – together with an infant aged between one and two years, and a girl in her mid-teens.

Finding multiple skeletons in the same prehistoric grave is not particularly unusual. But what had been done to their skulls was: the two women, two of the men and the teenage girl had all been trepanned.

Each of their skulls contained a single hole, several centimetres wide and roughly ellipsoidal in shape, with signs of scraping around the edges. The skull of the third man contained a depression which also showed evidence of having been carved, but not an actual hole. Only the infant’s skull was unblemished.

The job of analysing the contents of the grave fell to Elena Batieva, an anthropologist now at the Southern Federal University in Rostov-on-Don, Russia. She immediately recognised the holes as trepanations, and she soon realised that these trepanations were unusual.

They had all been made in almost exactly the same location: a point on the skull called the “obelion”. The obelion is on the top of the skull and towards the rear, roughly where a high ponytail might be gathered.

Opening the skull in this location would have risked major haemorrhage and death
Less than 1% of all recorded trepanations are located above the obelion point. What’s more, Batieva knew that such trepanations were even less common in ancient Russia. As far as she was aware at the time, there was just one other recorded case of an obelion trepanation: a skull unearthed in 1974 at an archaeological site remarkably close to the one she was excavating.

Clearly, finding even one obelion trepanation is remarkable. But Batieva was looking at five, all of them buried in the same grave. This was, and is, unprecedented.
There is a good reason why obelion trepanation is uncommon: it is very dangerous.

The obelion point is located directly above the superior sagittal sinus, where blood from the brain collects before flowing into the brain’s main outgoing veins. Opening the skull in this location would have risked major haemorrhage and death.

This suggests the Copper Age inhabitants of Russia must have had good reason to perform such trepanation procedures. Yet none of the skulls showed any signs of having suffered any injury or illness, before or after the trepanation had been performed.

Among the 137 skulls, they found nine with conspicuous holes

In other words, it appeared as if all of these people were trepanned while they were completely healthy. Was their trepanation evidence of some sort of ritual?

It was an intriguing possibility. However, Batieva had to give up the trail. She had many more skeletons to analyse from all over southern Russia, and could not afford to get sidetracked by just a few skulls, however enigmatic.

Before she gave up, Batieva decided to search through Russia’s unpublished archaeological records, in case any more strange obelion trepanations had been discovered but not reported.

Surprisingly, she got two hits. The skulls of two young women with obelion trepanations had been discovered years earlier: one in 1980 and another in 1992.

Each one had been unearthed less than 31 miles (50km) from Rostov-on-Don, and neither showed any signs of having been trepanned for a medical reason.

This gave Batieva a grand total of eight unusual skulls, all clustered in a small region of southern Russia and potentially all of about the same age. A decade later, even more came to light.

In 2011, an international team of archaeologists was analysing 137 human skeletons. They had recently been excavated from three separate Copper Age burial sites in a mountainous part of southern Russia called Kabardino-Balkaria, around 310 miles (500km) south-east of Rostov-on-Don, close to the modern-day border with Georgia.
The archaeologists had not set out to discover trepanations. They were there to learn about the general health of the prehistoric inhabitants of the region. But among the 137 skulls, they found nine with conspicuous holes.

Southern Russia may have been a centre for ritual trepanation

Five of them were standard examples of trepanation. The holes had been made in a variety of different locations around the front and side of the skull, and all of the skulls showed signs of having suffered a physical trauma, suggesting that the trepanations had been performed to treat the effects of the injuries.

But none of the other four trepanned skulls showed any signs of damage or disease. What’s more, all four had been trepanned exactly above the obelion point.

Quite by chance one of the researchers – Julia Gresky, a German anthropologist – had already read Batieva’s paper describing the unusual trepanations from the Rostov-on-Don region.

Now Gresky, Batieva and other archaeologists have teamed up to describe all 12 of the obelion trepanations from Southern Russia. Their study was published in April 2016 in the American Journal of Physical Anthropology.

The 12 skulls would have been remarkable discoveries wherever they had been found. But the fact that they were all discovered in the same tiny corner of Russia meant that a connection seemed likely. If there was no link, the odds that a batch of such rare trepanations would turn up exclusively in southern Russia would have been exceedingly low.

Gresky, Bateiva and their colleagues argue that, while this idea is difficult to prove, the clustering of these unusual trepanations suggests that southern Russia may have been a centre for ritual trepanation.

The owners of the other skulls seem to have survived their operations

Maria Mednikova of the Russian Academy of Sciences in Moscow is an expert on Russian trepanation. She believes that trepanations in specific, dangerous areas of the cranium may have been performed to achieve “transformations” of some kind. She suggests that, by trepanning in these places, people thought they could acquire unique skills that ordinary members of society did not have.

We can only speculate as to why these 12 apparently healthy people were trepanned in such an unusual and dangerous way. But thanks to the trepanation holes themselves, we can infer a surprising amount about the fate of the people after they received their trepanation.

One of the 12 skulls belonged to a woman under the age of 25, who had been buried at one of the sites near Rostov-on-Don. It showed no signs of healing, suggesting that she died during her trepanation or shortly afterwards.

However, the owners of the other skulls seem to have survived their operations. Their skulls showed bone healing around the edges of the trepanation holes – although the bone never completely re-grew over the holes.

Three of the 12 skulls showed only slight signs of healing around the trepanation hole, suggesting that their owners only survived between two and eight weeks after the operation. Two of these individuals were women between 20 and 35 years of age. The third was an elderly person between 50 and 70 years old, whose sex could not be determined.

The other eight skulls showed more advanced healing. Based on what we know about bone healing today, these individuals probably survived for at least four years after their operations.

It appeared as if all of these people were trepanned while they were completely healthy

These eight survivors included all five of the people from the mass grave near Rostov-on-Don, whose bizarrely-trepanned skulls first attracted Batieva’s attention almost 20 years ago.

The two men, two women and one adolescent girl had all survived with their obelion holes for years. The girl, who based on her skeleton was between 14 and 16 years old, must have been trepanned when she was no older than 12, and possibly much younger.

It is still possible that these 12 people were suffering from diseases or head injuries.

In that case, the trepanning operation may have worked for at least eight of them.

But it is also possible that Batieva and her colleagues are right, and these people were trepanned for a ritual purpose. If that is true, we can only guess at what benefits they received – or believed they had received – throughout the rest of their lives.

{Plans to cut airline CO2 using greener jet fuels made from waste wood have been dismissed as a “pipe dream” by environmentalists.}

Several high octane, waste-based biofuels are being tested by airlines as a way of curbing CO2.

UN officials are set to endorse these fuels as a key part of global plans to stabilise aviation emissions by 2020.

But critics say the plans are unrealistic and airlines are not taking the issue seriously.

{{Contested airspace}}

One of the big failures of the Paris climate agreement, adopted in December 2015, is that it doesn’t cover emissions from shipping or aviation.

The scale and impact of carbon from the booming airline business is heavily contested. The industry points out that in 2015 only 2% of human emissions of CO2 came from aircraft.

Environmentalists point out that this doesn’t include the warming impact of contrails or other gases and aerosols. They believe the true impact is about 5%.

Earlier this year, the International Civil Aviation Authority (ICAO), the UN body that regulates this sector, produced a report that predicted a three-fold increase in emissions from airplanes by 2050 if nothing is done to restrict carbon.

ICAO has developed a long term plan that it says will ensure that, by the middle of the century, aviation emissions will be half of what they were in 2005.

One of the key parts of that plan is green jet fuel.

Since Virgin Atlantic flew the first flight powered partly by biofuel in 2008, there have been dozens of tests with many different types of alternative jet fuels, often made from oil seed crops or animal fats.

But in the US earlier this year, the Federal Aviation Authority gave the go-ahead to a new fuel making process that some people believe will be a game changer for greener flying.

The new biofuel is made from a type of alcohol called isobutanol, which occurs naturally in the fermentation process and can be found in many items including bread and scotch whiskey.

{{Pine scented soup}}

At a large, warm and sweet smelling industrial facility in St Joseph’s, Missouri, fermenting tanks three stories tall contain a swirling mixture of wood pulp, water and enzymes.

The engineers here call the liquid, a “broth”, and it’s from pine-scented soup that isobutanol is extracted.

“It’s like making a hot toddy, it has a bit of an alcoholic smell to it but you can still smell the undertones of the pine feedstock in the fermentation,” said Andrew Hawkins from Gevo, the company that has been licensed to make jet fuel using this new method.

The enzymes are used to extract the sugars from the pine. Genetically modified yeast then deliver the isobutanol from the sugars. By this stage, the smell of pine has long departed and the clear liquid remaining has the breathtaking whiff of a high-octane fuel.

One more refining step, at another facility, is required to complete the process.

What’s making airlines excited about using isobutanol based fuel is the fact that it is much more powerful than ethanol, the current biofuel of choice for transport.

Another attraction is that unlike, ethanol, jet fuel made from isobutanol can be carried and mixed in the same pipes and fuel trucks as petroleum products.

By using forest residue, supporters believe the new fuel can make a real and sustainable difference to airline carbon emissions as trees soak up CO2 as they grow and it is only the waste from their harvesting that’s used in production.

“We are short cutting mother nature and sucking carbon directly out of the atmosphere, that maybe yesterday’s plane put into the atmosphere,” Andrew Hawkins told BBC News.

“We then create sugars via these trees and then turn that back into fuel.”

{{A question of cost?}}

Gevo say they are planning to increase production to around 1 million gallons this year.

The company believe they can reduce the cost of production to around $3 a gallon – but that is still around $1.80 more than the current market price of petroleum based jet fuel.

Isobutanol made from corn is now being been used in test flights by Alaska Airlines in blends of up to 30% with regular fuel.

But whether they are made from wood waste or corn, the financial cost of these new fuels are likely to prove a major problem according to environmentalists.

“They are far too expensive, and they are not delivering the emissions reductions that would justify the investment,” said Bill Hemmings of campaign group Transport & Environment.

“The new fuels are two or three times the cost of existing jet fuels, no-one in their right mind would pay that price. People continue to bang that drum about new biofuels, but they are not going to deliver. It’s all fairytale stuff.”

Attempts to regulate airline emissions have proved very difficult as countries haven’t been able to agree on the ways of measurement and responsibility. For example, if an airplane owned by a Middle Eastern airline flies from a poor African country to a poor Asian destination, who should “own” these emissions?

ICAO believe they have found a way forward that would allow airlines to offset emissions in the future by purchasing credits from certified reduction schemes, such as tree planting.

But their long-term goal of halving the level of 2005 emissions by 2050 depends on a rapid uptake of green fuels.

Critics say that this is impossible – it would require around 170 large scale bio-refineries to be built every year between 2020 and 2050, at a cost of up to $60bn a year.

{{Flying gorillas?}}

As well as biofuels, UN officials meeting in Montreal in September will also announce tougher standards for new aircraft designs to curb CO2 that will come into force in 2028. Green campaigners say this approach is “incredibly weak”.

They say that around 15% of aircraft flying today perform better than these future criteria.

Real change, they argue, won’t come through these vague international efforts. They believe that the key to solving the problem lies in the US.

“The US is the 800 pound gorilla of carbon pollution in the sky,” said Vera Pardee a lawyer with the Centre for Biological Diversity.

“More than 30% of all international carbon pollution comes from the United States.

“It is the duty of the US to get us out of this problem. If the US Environmental Protection Agency were to adopt meaningful standards then the international community will follow.

“The airplane manufacturers are not stupid, they need to meet the demands of their markets, when a regulation goes into effect for one of their major markets, that will be the catalyst to cause emissions to finally be handled correctly and come down.”

{When someone uses the phrase “sleeping like a baby,” it’s obvious that they don’t really know how babies sleep. Many babies, especially newborns, are lousy sleepers, waking up every few hours to rustle around, cry and eat. For creatures who sleep up to 18 hours per 24-hour period, newborns are exhausting. }

That means that bone-tired parents are often desperate to get their babies to sleep so they can rest too. A study published in the September Pediatrics captured this nightly struggle in the homes of 162 Pennsylvanian families. And the results revealed something disturbing: Despite knowing that they were being videotaped, many parents didn’t put their babies into a safe sleeping spot.

The risk of sleep-related infant deaths, including those caused by strangulation or sudden infant death syndrome, goes up when babies are put in unsafe sleeping positions or near suffocation hazards. Babies should be on their back on a firm mattress free of any objects. But that wasn’t the case for the majority of babies in the study, says Ian Paul, a pediatrician at Penn State.

As a parent to three, Paul is sympathetic to the difficulties of soothing babies to sleep. “The first few months are really exhausting,” he says. But as a pediatrician, he also sees the risks of ignoring safe sleep guidelines. “Parents need to realize that these risks are real and might happen to them.”

The videos taken for the study revealed that at 1 month of age, nearly all of the babies were put onto a sleep surface that had a loose or ill-advised item. Some of those objects aren’t surprising: Loose blankets, pillows, stuffed animals, crib bumpers and a SIDS monitor turned up in babies’ sleep areas. “The fact that almost every baby had loose bedding in the crib was disturbing,” Paul says. Stranger objects, such as cords, electrical wires and even a pet, were also observed.

Some of these items, such as sleep positioners and the soft bumpers that run around crib rails, are sold at baby stores. “If they’re selling it, parents think it is safe,” Paul says. “That’s just not the case.” Despite public health messages, babies are still suffocating on bumpers or getting trapped between bumpers and their mattress. There are no federal rules against crib bumpers, but several areas have banned them.

The study also spotted lots of bed hopping. Often, babies would start the night in a safe crib, but by the morning, they’d be in a more dangerous place, such as a bed full of pillows with a parent. The nightly shifts usually went from safe to unsafe as tired parents moved their babies around, Paul and colleagues found.

Paul recommends that parents create a safe place right next to their own beds for their babies to sleep, such as a bassinet or playpen. By designing their environment to encourage good habits at night, tired parents may be more likely to put the baby into a safe spot.

{New research has been published on the emotional bonds between mothers and adolescent daughters. The study examined how well mother-daughter pairs were able to manage rapid transitions between emotional states and the so-called “emotional rollercoaster” of adolescence.}

Queen’s University researchers Tom Hollenstein and Jessica Lougheed have published new research on the emotional bonds between mothers and adolescent daughters. The study examined how well mother-daughter pairs were able to manage rapid transitions between emotional states and the so-called “emotional rollercoaster” of adolescence.

“This study reflects a growing need to examine how typically developing adolescents — those without a diagnosis of any major mental health issue — learn to manage their emotions,” says Dr. Lougheed, co-principal investigator on the study and now a post-doctoral researcher at Pennsylvania State University. “Being able to effectively manage emotions in different kinds of emotional contexts — called ’emotion regulation’ — is a crucial part of healthy development.”

The researchers examined how mother-daughter pairs were able to manage transitions between emotional states. Ninety-six typically developing adolescent females and their mothers responded individually to a questionnaire consisting of questions on relationship quality, “internalizing” of symptoms such as anxiety and depression, and demographics. The pairs then answered a questionnaire on times when they felt happy, worried, proud, frustrated, and grateful toward each other and took part in a series of three-minute conversations about those emotional experiences. The videotaped sessions were played back and coded based on the emotions mothers and daughters expressed during the conversations.

As expected, pairs with low flexibility — those who displayed difficulty transitioning from one state to another — reported lower relationship quality and higher levels of maternal symptoms. Those who showed moderate levels of flexibility showed higher relationship quality and lower maternal symptoms. However, those with the highest degree of flexibility showed no associations with relationship quality or symptoms — suggesting that a moderate degree of flexibility is optimal for a strong and healthy relationship.

“We have speculated, but never tested the hypothesis, that flexibility is sort of an inverted-U function in terms that a certain amount is just right, but too much and you become disorganized and leaning towards a lack of coherence,” says Dr. Hollenstein, co-principal investigator on the study and Dr. Lougheed’s dissertation supervisor.

In addition, the study found that the degree of flexibility demonstrated was consistently related to the mothers’ depression and anxiety symptoms, though not with the symptoms reported by their daughters. Dr. Lougheed states this finding is a good reminder that adolescence is not just a time of development for youth, but a developmental transition for parents as well.

“The adolescent developmental period is an important transition for parents and adolescents alike,” says Dr. Lougheed. “Generally speaking, parents and teens who are able to ‘go with the flow’ of new emotional experiences in their relationship will likely be show better well-being in other ways as well.”

{Pale Red Dot campaign reveals Earth-mass world in orbit around Proxima Centauri.}

Astronomers have found clear evidence of a planet orbiting the closest star to Earth, Proxima Centauri. The long-sought world, designated Proxima b, orbits its cool red parent star every 11 days and has a temperature suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth and is the closest exoplanet to us — and it may also be the closest possible abode for life outside the Solar System.

Astronomers using ESO telescopes and other facilities have found clear evidence of a planet orbiting the closest star to Earth, Proxima Centauri. The long-sought world, designated Proxima b, orbits its cool red parent star every 11 days and has a temperature suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth and is the closest exoplanet to us — and it may also be the closest possible abode for life outside the Solar System. A paper describing this milestone finding will be published in the journal Nature on 25 August 2016.

Just over four light-years from the Solar System lies a red dwarf star that has been named Proxima Centauri as it is the closest star to Earth apart from the Sun. This cool star in the constellation of Centaurus is too faint to be seen with the unaided eye and lies near to the much brighter pair of stars known as Alpha Centauri AB.

During the first half of 2016 Proxima Centauri was regularly observed with the HARPS spectrograph on the ESO 3.6-metre telescope at La Silla in Chile and simultaneously monitored by other telescopes around the world [1]. This was the Pale Red Dot campaign, in which a team of astronomers led by Guillem Anglada-Escudé, from Queen Mary University of London, was looking for the tiny back and forth wobble of the star that would be caused by the gravitational pull of a possible orbiting planet [2].

As this was a topic with very wide public interest, the progress of the campaign between mid-January and April 2016 was shared publicly as it happened on the Pale Red Dot website and via social media. The reports were accompanied by numerous outreach articles written by specialists around the world.

Guillem Anglada-Escudé explains the background to this unique search: “The first hints of a possible planet were spotted back in 2013, but the detection was not convincing. Since then we have worked hard to get further observations off the ground with help from ESO and others. The recent Pale Red Dot campaign has been about two years in the planning.”

The Pale Red Dot data, when combined with earlier observations made at ESO observatories and elsewhere, revealed the clear signal of a truly exciting result. At times Proxima Centauri is approaching Earth at about 5 kilometres per hour — normal human walking pace — and at times receding at the same speed. This regular pattern of changing radial velocities repeats with a period of 11.2 days. Careful analysis of the resulting tiny Doppler shifts showed that they indicated the presence of a planet with a mass at least 1.3 times that of the Earth, orbiting about 7 million kilometres from Proxima Centauri — only 5% of the Earth-Sun distance [3].

Guillem Anglada-Escudé comments on the excitement of the last few months: “I kept checking the consistency of the signal every single day during the 60 nights of the Pale Red Dot campaign. The first 10 were promising, the first 20 were consistent with expectations, and at 30 days the result was pretty much definitive, so we started drafting the paper!”

Red dwarfs like Proxima Centauri are active stars and can vary in ways that would mimic the presence of a planet. To exclude this possibility the team also monitored the changing brightness of the star very carefully during the campaign using the ASH2 telescope at the San Pedro de Atacama Celestial Explorations Observatory in Chile and the Las Cumbres Observatory telescope network. Radial velocity data taken when the star was flaring were excluded from the final analysis.

Although Proxima b orbits much closer to its star than Mercury does to the Sun in the Solar System, the star itself is far fainter than the Sun. As a result Proxima b lies well within the habitable zone around the star and has an estimated surface temperature that would allow the presence of liquid water. Despite the temperate orbit of Proxima b, the conditions on the surface may be strongly affected by the ultraviolet and X-ray flares from the star — far more intense than the Earth experiences from the Sun [4].

Two separate papers discuss the habitability of Proxima b and its climate. They find that the existence of liquid water on the planet today cannot be ruled out and, in such case, it may be present over the surface of the planet only in the sunniest regions, either in an area in the hemisphere of the planet facing the star (synchronous rotation) or in a tropical belt (3:2 resonance rotation). Proxima b’s rotation, the strong radiation from its star and the formation history of the planet makes its climate quite different from that of the Earth, and it is unlikely that Proxima b has seasons.

This discovery will be the beginning of extensive further observations, both with current instruments [5] and with the next generation of giant telescopes such as the European Extremely Large Telescope (E-ELT). Proxima b will be a prime target for the hunt for evidence of life elsewhere in the Universe. Indeed, the Alpha Centauri system is also the target of humankind’s first attempt to travel to another star system, the StarShot project.

Guillem Anglada-Escudé concludes: “Many exoplanets have been found and many more will be found, but searching for the closest potential Earth-analogue and succeeding has been the experience of a lifetime for all of us. Many people’s stories and efforts have converged on this discovery. The result is also a tribute to all of them. The search for life on Proxima b comes next…”

Notes

[1] Besides data from the recent Pale Red Dot campaign, the paper incorporates contributions from scientists who have been observing Proxima Centauri for many years. These include members of the original UVES/ESO M-dwarf programme (Martin Kürster and Michael Endl), and exoplanet search pioneers such as R. Paul Butler. Public observations from the HARPS/Geneva team obtained over many years were also included.

[2] The name Pale Red Dot reflects Carl Sagan’s famous reference to the Earth as a pale blue dot. As Proxima Centauri is a red dwarf star it will bathe its orbiting planet in a pale red glow.

[3] The detection reported today has been technically possible for the last 10 years. In fact, signals with smaller amplitudes have been detected previously. However, stars are not smooth balls of gas and Proxima Centauri is an active star. The robust detection of Proxima b has only been possible after reaching a detailed understanding of how the star changes on timescales from minutes to a decade, and monitoring its brightness with photometric telescopes.

[4] The actual suitability of this kind of planet to support water and Earth-like life is a matter of intense but mostly theoretical debate. Major concerns that count against the presence of life are related to the closeness of the star. For example gravitational forces probably lock the same side of the planet in perpetual daylight, while the other side is in perpetual night. The planet’s atmosphere might also slowly be evaporating or have more complex chemistry than Earth’s due to stronger ultraviolet and X-ray radiation, especially during the first billion years of the star’s life. However, none of the arguments has been proven conclusively and they are unlikely to be settled without direct observational evidence and characterisation of the planet’s atmosphere. Similar factors apply to the planets recently found around TRAPPIST-1.

[5] Some methods to study a planet’s atmosphere depend on it passing in front of its star and the starlight passing through the atmosphere on its way to Earth. Currently there is no evidence that Proxima b transits across the disc of its parent star, and the chances of this happening seem small, but further observations to check this possibility are in progress.

{{More information}}

This research is presented in a paper entitled “A terrestrial planet candidate in a temperate orbit around Proxima Centauri,” by G. Anglada-Escudé et al., to appear in the journal Nature on 25 August 2016.

{It’s steady improvement, researchers say, and markedly better than mental health of the young.}

While even the best wines eventually peak and turn to vinegar, a new study by researchers at University of California, San Diego School of Medicine suggests a paradoxical trend in the mental health of aging adults: They seem to consistently get better over time.

“Their improved sense of psychological well-being was linear and substantial,” said senior author Dilip Jeste, MD, Distinguished Professor of Psychiatry and Neurosciences and director of the Center on Healthy Aging at UC San Diego. “Participants reported that they felt better about themselves and their lives year upon year, decade after decade.”

The findings are published in the August 2016 issue of the Journal of Clinical Psychiatry.

Conversely, Jeste and colleagues noted high levels of perceived stress and symptoms of depression and anxiety among adults in their 20s and 30s participating in the study. “This ‘fountain of youth’ period is associated with far worse levels of psychological well-being than any other period of adulthood,” he said.

Conventional notions of aging have largely described it as an ongoing process of physical and cognitive decline, with little discussion about mental health except in the context of decline. It has been broadly assumed that the mental health of older people mirrors their worsening physical and cognitive function.

But Jeste, who has long studied the phenomenon as the Estelle and Edgar Levi Chair in Aging and director of the Sam and Rose Stein Institute for Research on Aging, both at UC San Diego, said actual research, though limited, produces mixed findings.

“Some investigators have reported a U-shaped curve of well-being across the lifespan, with declines from early adulthood to middle age followed by an improvement in later adulthood. The nadir of mental health in this model occurs during middle age, roughly 45 to 55. However, we did not find such a mid-life dip in well-being.”

The reasons for these differences in results aren’t obvious. There is measurement variation across studies, with different researchers emphasizing different indicators that, ultimately, produce different conclusions. Nonetheless, the commonality is in finding improved well-being in the second half of life. Jeste emphasized that this study was not restricted to psychological well-being, but included “mental health,” which is broader in definition and also includes satisfaction with life, and low levels of perceived stress, anxiety, and depression.

Most epidemiologic studies report lower prevalence of all mental illnesses in older adults, except for dementias. “Some cognitive decline over time is inevitable,” said Jeste, “but its effect is clearly not uniform and in many people, not clinically significant — at least in terms of impacting their sense of well-being and enjoyment of life.”

In the latest study, Jeste and colleagues examined the physical health, cognitive function, and other measures of mental health in 1,546 adults, ages 21 to 100 years, living in San Diego County, who were selected using random digit dialing. Participants were almost evenly split by gender, stratified by age decade, with an oversampling of adults over age 75.

The linear nature of the findings was surprising, said Jeste, particularly in magnitude. The oldest cohort had mental health scores significantly better than the youngest cohort, though the former’s physical and cognitive function was measurably poorer than the latter’s.

The reasons for improved positive mental health in old age are not clear. Some previous research has shown older adults become more adept at coping with stressful changes. They learn, said Jeste, “not to sweat out the little things. And a lot of previously big things become little.” However, another important explanation may be increased wisdom with age. A number of studies have shown that older individuals tend to be more skilled at emotional regulation and complex social decision-making. They also experience and retain fewer negative emotions and memories. These are all collective elements of wisdom, as defined by the researchers.

Michael L. Thomas, PhD, first author of the paper and assistant research scientist in psychiatry at UC San Diego School of Medicine, cautioned that “like many other investigations of this type, it was a cross-sectional study, and thus a snapshot of data. Also, there may have been a survivor bias — i.e., less healthy adults do not survive into old age.” Yet, he also pointed out that older adults in this study were physically more disabled than younger ones — so this was not a sample of super-normal healthy adults.

Jeste expressed concern that the rates of psychological distress and mental illness in younger persons seem to be rising. “Inadequate attention has been paid to mental health issues that continue or get exacerbated post-adolescence. We need to understand mechanisms underlying better mental health in older age in spite of more physical ailments. That would help develop broad-based interventions to promote mental health in all age groups, including youth.”

{Researchers from the Universities of Groningen (Netherlands) and Pennsylvania have discovered a piece in the puzzle of how sleep deprivation negatively affects memory.}

For the first time, a study in mice, to be published in the journal eLife, shows that five hours of sleep deprivation leads to a loss of connectivity between neurons in the hippocampus, a region of the brain associated with learning and memory.

“It’s clear that sleep plays an important role in memory — we know that taking naps helps us retain important memories. But how sleep deprivation impairs hippocampal function and memory is less obvious,” says first author Robbert Havekes, PhD, Assistant Professor at the Groningen Institute for Evolutionary Life Sciences.

It has been proposed that changes in the connectivity between synapses — structures that allow neurons to pass signals to each other — can affect memory. To study this further, the researchers examined the impact of brief periods of sleep loss on the structure of dendrites, the branching extensions of nerve cells along which impulses are received from other synaptic cells, in the mouse brain.

They first used the Golgi silver-staining method to visualize the length of dendrites and number of dendritic spines in the mouse hippocampus following five hours of sleep deprivation, a period of sleep loss that is known to impair memory consolidation. Their analyses indicated that sleep deprivation significantly reduces the length and spine density of the dendrites belonging to the neurons in the CA1 region of the hippocampus.

They repeated the sleep-loss experiment, but left the mice to sleep undisturbed for three hours afterwards. This period was chosen based on the scientists’ previous work showing that three hours is sufficient to restore deficits caused by lack of sleep. The effects of the five-hour sleep deprivation in the mice were reversed so that their dendritic structures were similar to those observed in the mice that had slept.

The researchers then investigated what was happening during sleep deprivation at the molecular level. “We were curious about whether the structural changes in the hippocampus might be related to increased activity of the protein cofilin, since this can cause shrinkage and loss of dendritic spines,” Havekes says.

“Our further studies revealed that the molecular mechanisms underlying the negative effects of sleep loss do in fact target cofilin. Blocking this protein in hippocampal neurons of sleep-deprived mice not only prevented the loss of neuronal connectivity, but also made the memory processes resilient to sleep loss. The sleep-deprived mice learned as well as non-sleep deprived subjects.”

Ted Abel, PhD, Brush Family Professor of Biology at the University of Pennsylvania and senior author of the study, explains: “Lack of sleep is a common problem in our 24/7 modern society and it has severe consequences for health, overall wellbeing, and brain function.

“Despite decades of research, the reasons why sleep loss negatively impacts brain function have remained unknown. Our novel description of a pathway through which sleep deprivation impacts memory consolidation highlights the importance of the neuronal cell network’s ability to adapt to sleep loss. What is perhaps most striking is that these neuronal connections are restored with several hours of recovery sleep. Thus, when subjects have a chance to catch up on much-needed sleep, they are rapidly remodeling their brain.”