Plenty of habitat for bears in Europe

The map of Europe shows areas currently inhabited by brown bears (blue), areas that are suitable habitat for bears according to the new study, but which are currently not populated (green) and areas unsuitable as bear habitat (grey). Note that several potential bear habitats are geographically isolated and unlikely to become naturally recolonised.

Great opportunity for European brown bears: a new study spearheaded by the German Centre for Integrative Biodiversity Research (iDiv) and the Martin Luther University Halle-Wittenberg (MLU) shows that there are still many areas in Europe where bears are extinct but with suitable habitat for hosting the species. An effective management of the species, including a reduction of direct pressures by humans (like hunting), has the potential to help these animals come back in many of these areas, according to the head of the study. It is now important to plan the recovery of the species while taking measures to prevent conflicts.

Some 500 years ago, there were brown bears almost everywhere in Europe. However, in the following centuries they were wiped out in many places, including Germany. The reasons for the decline of bears were primarily habitat loss and hunting. Today, around 17,000 animals still live in Europe, distributed over ten populations and 22 countries. Some of these populations are at risk due to their relatively small size.

Excellent opportunity for species conservation

In recent years, the hunting of brown bears has been banned or restricted in Europe. In the future, bears could recolonise parts of Europe. A new study led by the German Centre for Integrative Biodiversity Research (iDiv) and Martin Luther University Halle-Wittenberg (MLU) reveals: there are still many areas in Europe where there are currently no bears, but which would, in principle, be suitable as habitat. Of an estimated amount of more than one million square kilometres of suitable habitat in Europe, about 37% is not populated; equivalent to an area of ??about 380,000 square kilometres. In Germany, there are 16,000 square kilometres of potential bear habitat. However, the probability of future recolonisation varies widely. E. g. in Germany, potential bear habitats outside the Alps are geographically isolated and unlikely for the bear to come back naturally.

"The fact that there is still suitable habitat for brown bears is a great opportunity for species conservation," says the head of the study Dr Néstor Fernández from the iDiv research centre and the University of Halle. Scientists are already seeing around 70% of Europe's populations recover, and it is likely that bears will return to some of the currently unoccupied areas. "In Germany, too, it is very likely that some areas will, sooner or later, be colonised by brown bears, especially in the Alpine region," says Fernández. So, there is reason to hope that bears will be native to Germany once more, 200 years after their extermination.

Pre-emptive action important

For many people this would probably be good news. "In recent years, the attitude of Europeans towards wildlife has changed a lot. Today, many people feel positive about the return of large mammals," says Fernández. Nevertheless, the fact that bear comeback can lead to conflicts with some human activities needs to be considered at an early stage. Such conflicts mostly arise when bears eat crops or damage beehives, and they also occasionally attack sheep. Direct attacks by bears on humans are, however, extremely rare; bears themselves generally steer clear of people.

The map developed by Fernández and his colleague Anne Scharf (Max Planck Institute for Ornithology) makes it possible to predict the areas into which bears could return. These maps can help policymakers identify potential areas of conflict early and counter these with specifically targeted measures. For example, compensation payments should be coupled with preventive measures being taken in advance, explains Fernández. Such preventive measures can be, for example, the construction of physical barriers such as closures for apiaries, electric fences, or the use of guard dogs to protect fields and grazing pastures, and increasing public awareness. A look at the map also makes it clear; bears do not stick to national borders. "That's why a common management policy for the brown bear and other wild animals at the European level would be desirable," says Fernández. At present, policies between member states regarding the protection and management of bears is very heterogeneous, and there is disparity in how compensation schemes are structured in different states.

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Scientists warn that proposed US-Mexico border wall threatens biodiversity, conservation

Amidst increased tensions over the US-Mexico border, a multinational group of over 2500 scientists have endorsed an article cautioning that a hardened barrier may produce devastating ecological effects while hampering binational conservation efforts. In the BioScience Viewpoint , a group led by Robert Peters, William J. Ripple, and Jennifer R. B. Miller call attention to ecological disturbances that could affect hundreds of terrestrial and aquatic species, notably including the Mexican gray wolf and Sonoran pronghorn.

The authors argue that the border wall will harm wildlife populations by fragmenting, degrading, and eliminating existing habitat, as well as by blocking species migration. "Our analysis shows that the border bisects the geographic ranges of 1506 native terrestrial and freshwater animal (n = 1077) and plant (n = 429) species," say the authors, noting that the number includes 62 species already listed as Critically Endangered, Endangered, or Vulnerable by the International Union for Conservation of Nature.

Further, the authors express concern that as a result of the 2005 Real ID Act, construction could proceed "without the necessary depth of environmental impact analysis, development of less-damaging alternative strategies, postconstruction environmental monitoring, mitigation, public input, and pursuit of legal remedies." Compounding the issue of forgone legal protections, Peters and colleagues warn that a border wall could threaten ongoing research and conservation programs, including those in binational habitat corridors and the 18% of borderlands that contain environmentally protected lands.

To mitigate the effects of the proposed wall, the authors make several urgent recommendations to the United States Congress and Department of Homeland Security; these include following existing environmental laws, taking action to mitigate ecological harm, and forgoing physical barriers in particularly sensitive areas. The article` also calls for the government to encourage scientific research in the borderlands, to inform and assist environmental evaluation and mitigation efforts. The authors conclude that "national security can and must be pursued with an approach that preserves our natural heritage."

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Bats harbor a gene swiped from an ancient Ebola-like virus -- here's how they may use it

The Ebola virus, captured by a CDC microbiologist in a colorized transmission electron microscope image. A study co-led by UB biologist Derek Taylor explores the evolutionary history and function of a gene “stolen” from an ancient, Ebola-like virus by an ancestor of modern bats.

Some 18 million years ago, an ancestor of mouse-eared bats "stole" genetic material from an ancient virus related to Ebola.

The swiped genetic sequence -- a gene called VP35 -- has remained largely intact in the bats despite the passage of time, with few changes since it was co-opted, a new study finds. The research also sheds light on the gene's possible function in bats, suggesting that it may play a role in regulating the immune system's response to threats.

"We're using a multidisciplinary approach to understand the evolution, structure and function of a viral gene co-opted by a mammal," says Derek J. Taylor, PhD, an evolutionary biologist at the University at Buffalo. "From an evolutionary standpoint, it's rare that you can actually see a viral gene sequence like this that has remained intact in a mammalian host. Most of these things are eroded over time -- they get chopped up and shuffled around.

"But VP35 is highly conserved. It's similar in all the bats we looked at, and the bat versions remain very close to what you see in modern Ebola and Marburg viruses. This conservation suggests that the gene has been preserved for an important purpose."

In Ebola and Marburg viruses today, the VP35 gene carries instructions for building a protein that blocks the immune response of infected animals, enabling disease to take hold. When scientists used artificial synthesis to create bat VP35 proteins in the lab, these proteins also acted as immune suppressors, but they were less potent than viral VP35s.

The study answers some important questions, but many mysteries remain. For example: Is the VP35 gene active in mouse-eared bats? Do mouse-eared bats produce any VP35 proteins? If the bats do make VP35 proteins, why is this beneficial?

"Our study explores VP35 function, but further research is needed to determine the specific evolutionary benefit," Taylor says. "Why has this gene been conserved for so long? We don't quite know the answer, and it's possible that VP35 has some other function in bats that we haven't yet discovered."

The study will be published in the journal Cell Reports on July 24, with Megan R. Edwards, PhD, of Georgia State University as first author. The project was led by Christopher F. Basler, PhD, of Georgia State; Daisy W. Leung, PhD, of the Washington University School of Medicine; and Taylor, a professor of biological sciences in the UB College of Arts and Sciences.

Similarities -- and differences -- in bats and in deadly viruses

To understand VP35's evolutionary history, the team compared VP35 sequences in 15 bat species from the genus Myotis (the mouse-eared bats), and used these sequences to reconstruct the archaic version of the gene that was first acquired by the bats' forebear some 18 million years ago.

This analysis showed that VP35 was strikingly similar across all 15 modern bats, modern Ebola and Marburg viruses, and the reconstructed ancestral gene. In other words: VP35 has changed very little in viruses and mouse-eared bats in the last 18 million years. Bolstering this conclusion, researchers discovered that the structure of a Myotis VP35 protein and an Ebola VP35 protein were alike in many ways.

Despite these resemblances, bat and viral forms of VP35 differ in function. Lab tests showed that bat VP35 helps to suppress production of an infection-fighting immune protein called interferon beta, but less effectively than Ebola and Marburg VP35s.

"How could a bat use a viral gene that normally suppresses interferon? While we don't know the exact answer, interferon is associated with inflammation, and it turns out that turning off the inflammation response is an important aspect of immune system function -- prolonged inflammation can be harmful in mammals," Taylor says. "So one possibility is that bats recruited a viral anti-inflammation gene to enhance control of inflammation."

Genetic theft: How it happens and why it matters

The new study was inspired in part by Taylor's prior work on VP35 and other "stolen" viral genes. Known as non-retroviral integrated RNA viral sequences (NIRVs), these co-opted genetic snippets are accidentally inserted into the genomes of infected hosts when a virus like Ebola or Marburg hijacks a host's genetic machinery to replicate.

NIRVs are a gold mine of information. Taylor, one of the first scientists to study them, calls them "scars of infection" and likens them to a "viral fossil record": You can investigate them to learn many fascinating things about the co-evolution of viruses and hosts.

In prior research, Taylor and colleagues used NIRVs to show that filoviruses -- the family housing Ebola and Marburg -- are ancient. The scientists also discovered that several mammals harbor the VP35 NIRV, which was originally acquired from archaic filoviruses that shared a common ancestor with Ebola and Marburg. Species that have this NIRV range from bats to hamsters, voles and wallabies.

The new project builds on this work by exploring VP35's modern function and showing that the gene has been meticulously conserved through evolution in mouse-eared bats.

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Young galaxy's halo offers clues to its growth and evolution

This is an artist's concept showing the gaseous halo surrounding a galaxy, illuminated by a narrow band of ultraviolet light called Lyman alpha emission. BX418's gas halo is about ten times the size of the galaxy itself.

A team of astronomers has discovered a new way to unlock the mysteries of how the first galaxies formed and evolved.

In a study published today in Astrophysical Journal Letters, lead author Dawn Erb of the University of Wisconsin-Milwaukee and her team -- for the very first time -- used new capabilities at W. M. Keck Observatory on Maunakea, Hawaii to examine Q2343-BX418, a small, young galaxy located about 10 billion light years away from Earth.

This distant galaxy is an analog for younger galaxies that are too faint to study in detail, making it an ideal candidate for learning more about what galaxies looked like shortly after the birth of the universe.

BX418 is also attracting astronomers' attention because its gas halo is giving off a special type of light.

"In the last several years, we've learned that the gaseous halos surrounding galaxies glow with a particular ultraviolet wavelength called Lyman alpha emission. There are a lot of different theories about what produces this Lyman alpha emission in the halos of galaxies, but at least some of it is probably due to light that is originally produced by star formation in the galaxy being absorbed and re-emitted by gas in the halo," said Erb.

Erb's team, which includes Charles Steidel and Yuguang Chen of Caltech, used one of the observatory's newest instruments, the Keck Cosmic Web Imager (KCWI), to perform a detailed spectral analysis of BX418's gas halo; its properties could offer clues about the stars forming within the galaxy.

"Most of the ordinary matter in the universe isn't in the form of a star or a planet, but gas. And most of that gas exists not in galaxies, but around and between them," said Erb.

The halo is where gas enters and exits the system. The gas surrounding galaxies can fuel them; gas from within a galaxy can also escape into the halo. This inflow and outflow of gas influences the fate of stars.

"The inflow of new gas accreting into a galaxy provides fuel for new star formation, while outflows of gas limit a galaxy's ability to form stars by removing gas," says Erb.

"So, understanding the complex interactions happening in this gaseous halo is key to finding out how galaxies form stars and evolve."

This study is part of a large ongoing survey that Steidel has been leading for many years. Previously, Steidel's team studied BX418 using other instruments at Keck Observatory.

This most recent study using KCWI adds detail and clarity to the image of the galaxy and its gas halo that was not possible before; the instrument is specifically engineered to study wispy currents of faint gas that connect galaxies, known as the cosmic web.

"Our study was really enabled by the design and sensitivity of this new instrument. It's not just an ordinary spectrograph -- it's an integral field spectrograph, which means that it's a sort of combination camera and spectrograph, where you get a spectrum of every pixel in the image," said Erb.

The power of KCWI, combined with the Keck telescopes' location on Maunakea where viewing conditions are among the most pristine on Earth, provides some of the most detailed glimpses of the cosmos.

Erb's team used KCWI to take spectra of the Lyman alpha emission of BX418's halo. This allowed them to trace the gas, plot its velocity and spatial extent, then create a 3-D map showing the structure of the gas and its behavior.

The team's data suggests that the galaxy is surrounded by a roughly spherical outflow of gas and that there are significant variations in the density and velocity range of this gas.

Erb says this analysis is the first of its kind. Because it has only been tested on one galaxy, other galaxies need to be studied to see if these results are typical.

Now that the team has discovered a new way to learn about the properties of the gaseous halo, the hope is that further analysis of the data they collected and computer simulations modeling the processes will yield additional insights into the characteristics of the first galaxies in our universe.

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Unless we spot changes, most life experiences are fabricated from memories

Event Memory Retrieval and Comparison Theory proposes that current event features cue retrieval of recent related event representations. Both those representations and ongoing perceptual information inform predictions about upcoming event features. Changed features in upcoming events lead to prediction error and event model updating, whereas repeated features tend to lead to maintaining stable event models.

We may not be able to change recent events in our lives, but how well we remember them plays a key role in how our brains model what's happening in the present and predict what is likely to occur in the future, finds new research in the Journal of Experimental Psychology: General.

"Memory isn't for trying to remember," said Jeff Zacks, professor of psychology and brain sciences in Arts & Sciences at Washington University in St. Louis and an author of the study. "It's for doing better the next time."

The study, co-authored with Chris Wahlheim of the University of North Carolina at Greensboro (UNCG), brings together several emerging theories of brain function to suggest that the ability to detect changes plays a critical role in how we experience and learn from the world around us.

Known as "Event Memory Retrieval and Comparison Theory" or EMRC, the model builds on previous research by Zacks and colleagues that suggests the brain continually compares sensory input from ongoing experiences against working models of similar past events that it builds from related memories.

When real life does not match the "event model," prediction errors spike and change detection sets off a cascade of cognitive processing that rewires the brain to strengthen memories for both the older model events and the new experience, the theory contends.

"We provide evidence for a theoretical mechanism that explains how people update their memory representations to facilitate their processing of changes in everyday actions of others," Wahlheim said. "These findings may eventually illuminate how the processing of everyday changes influences how people guide their own actions."

In their current study, Zacks and Wahlheim tested the change detection model with experiments that take advantage of the well-documented fact that older adults often have increased difficulty in recalling details of recent events.

Groups of healthy older and younger adults were shown video clips of a woman acting out a series of routine, everyday activities, such as doing dishes or preparing to exercise. One week later, they were shown similar videos in which some event details had been changed.

"When viewers tracked the changes in these variation-on-a-theme videos, they had excellent memory for what happened on each day, but when they failed to notice a change, memory was horrible," Zacks said.

"These effects may account for some of the problems older adults experience with memory -- in these experiments, older adults were less able to track the changes, and this accounted for some of their lower memory performance."

Previous research by Zacks and others has shown that the brain breaks up the activities of daily life into a hierarchy of distinct smaller events or "chunks," and that our ability to identify transitions or "boundaries" between these chunks has consequences for how these experiences gets encoded in our memories.

For instance, just walking through a doorway, which the brain perceives as an "event boundary," has been shown to diminish our recollection for information being processed just before we entered the new room. Thus, we sometimes find ourselves forgetting the reason we entered a room in the first place.

This event-driven model of brain function, known as Event Segmentation Theory (EST), has been gaining credence over the last decade.

Zacks, the author of the book "Flicker: Your Brain on Movies," has used EST to explain how the brain processes fast-paced movie cuts and other film-making techniques that force viewers to process sensory input in ways evolution could never have predicted.

Event models may be based on previous personal experiences, but might also include perceptions gleaned from conversations with friends or similar situations portrayed in books, movies and television.

Thus, someone's "event model" for a future wedding day might be based on other weddings attended, past gatherings of family and friends and tidbits gleaned from repeat viewings of the movie, "My Big Fat Greek Wedding."

Event Memory Retrieval and Comparison Theory takes the event segmentation model a step further by introducing concepts from the "memory-for-change" framework, a theory put forth in recent research by Wahlheim and Larry Jacoby.

Jacoby is a prominent cognitive psychologist known for work on the interplay of consciously controlled versus more automatic influences of memory. He is now a professor emeritus of psychological & brain sciences at Washington University.

Wahlheim completed his PhD and postdoctoral training at Washington University, and now directs the Memory and Cognition Lab as an assistant professor at UNCG.

In recent research, Jacoby and Wahlheim exposed study participants to series of lists that included pairs of related words, including some lists where an originally presented word was paired with a new word.

While seeing the same "trigger" word associated with multiple word pairs has been shown to cause interference in the recall process, Jacoby and Wahlheim found that memory improved when participants both recognized the change during presentation and later remembered that the change had been recognized.

The memory-for-change framework suggests that noticing the change is critical to the creation of a memory trace that ties all these events together, strengthening our memory for the original pairing, the recognition of change and the new pairing.

The current study explores the memory-for-change phenomena in a more naturalistic scenario in which videos of daily activities replace paired-word lists. It also adds a chronological element by suggesting the videos represent activities filmed one week apart.

Findings suggest that establishing time-based connections improves recall because memory for a later event becomes embedded within a trace that includes reminding of an earlier event. Recent events embed earlier events, but not vice versa.

More broadly, these studies provide evidence that a major function of our memory is to help us retrieve relevant experiences and relate them to what is happening in the current environment.

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Warming alters predator-prey interactions in the Arctic

Wolf spiders are top predators in the tundra. They are becoming larger with the earlier snowmelt caused by Arctic warming, which could alter their predation effects on the ecosystem, according to new research from Washington University in St. Louis.

Wolf spiders are so abundant that they outweigh real wolves in the Alaskan Arctic by several orders of magnitude. Their sheer numbers make them one of the important predators on the tundra. They may also be important in buffering some effects of climate change.

Under warming conditions, arctic wolf spiders' tastes in prey might be changing, according to new research from Washington University in St. Louis, initiating a new cascade of food web interactions that could potentially alleviate some impacts of global warming.

The surprising result of this chain reaction is described in a new paper by Amanda Koltz, a postdoctoral researcher in biology in Arts & Sciences, published July 23 in the Proceedings of National Academy of Sciences.

The ways in which animals interact with each other will be affected by climate change, scientists generally agree. But few studies have explored the larger picture of how these changes will alter not just individual species, but concurrently impact all of the biological and physical interactions in a given environment.

"We often think about how warmer temperatures might strengthen or weaken interactions between predators and their prey," Koltz said. "But in this case we show that when warming alters those interactions, it can also lead to changes in ecosystem-level processes like decomposition rates."

Koltz and her team study wolf spiders. They are less than half an inch long, but in a warming future, they might be both larger and more prolific (so don't say we didn't warn you).

Wolf spiders don't make webs. This type of spider hunts on the ground and can eat almost anything smaller in size, from plant-eating bugs to other predators.

But they really love to eat Collembola -- the small arthropods commonly called springtails. It's this spider snack that connects them to the belowground environment. Springtails eat both decaying plants and fungus. And, in wet tundra, the fungus in the ground largely controls how quickly dead plant matter is decomposed and its nutrients released into the soil and air.

Arctic wolf spiders are thus said to have an "indirect" effect on decomposition. The spiders eat animals (springtails) that eat fungus; if more fungus-eaters get eaten, then fungus grows unchecked. When there is a lot more fungal activity, there is faster decomposition.

Decomposition is usually positive for plants, in that it releases more nutrients to the soil. Some of these nutrients, such as nitrogen, are sought-after fertilizers that enhance plant productivity. But decomposition is a double-edged sword for the environment. As microbes eat dead plants, they also respire carbon dioxide and methane -- powerful greenhouse gases.

Between one-third to one-half of the global pool of soil organic carbon is frozen in Arctic permafrost, currently locked away from decomposers but vulnerable to warming.

To test the effects of warming on the spider/fungus-eater/soil system, Koltz and her team installed a series of experimental enclosures in an area of arctic tundra in Northern Alaska over two summer seasons. These mini-ecosystems were 1.5 meters in diameter and separated all of the regular tundra inhabitants -- including belowground animals and fungus -- from their surroundings in a space where temperature and densities of spiders could be manipulated.

At the end of the study period, the scientists surveyed everything inside the enclosures. They counted springtails and mites, measured microbial biomass (fungus and bacteria), and tallied the other tiny animals that could either eat the springtails themselves or serve as alternative food sources for the wolf spiders.

What they discovered was surprising. At ambient temperatures, there were fewer springtails left in the high-spider-density plots, and decomposition of leaf litter had happened faster. This was expected since wolf spiders love to eat springtails. But in the warmed plots with high spider densities, the researchers found significantly more of the springtail prey, and less evidence of decomposition of the leaf litter in the soil.

What's going on here? The researchers believe that under warming conditions, the wolf spiders are developing a taste for different prey. Instead of springtails, they could be eating more of the intermediate predators, like smaller spiders.

That's good news for springtails -- and maybe for the climate, too.

In a warming future, if wolf spiders eat fewer springtails, such that the springtails are able to eat more microbes, then there may be less decomposition -- and less carbon released from the permafrost.

"The way that organisms interact with one another can influence important ecosystem functions like how much carbon stays fixed by plants, how quickly decomposition happens, and how nutrients are cycled within that ecosystem," Koltz said. "Controls on nutrient cycling in the Arctic are very important for us to understand, because this region plays a disproportionately large role in the global carbon cycle.

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Where Martian dust comes from

A portion of the Medusae Fossae Formation on Mars showing the effect of billions of years of erosion. The image was acquired by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter.

The dust that coats much of the surface of Mars originates largely from a single thousand-kilometer-long geological formation near the Red Planet's equator, scientists have found.

A study published in the journal Nature Communications found a chemical match between dust in the Martian atmosphere and the surface feature, called the Medusae Fossae Formation.

"Mars wouldn't be nearly this dusty if it wasn't for this one enormous deposit that is gradually eroding over time and polluting the planet, essentially," said co-author Kevin Lewis, an assistant professor of Earth and planetary science at the Johns Hopkins University.

In the film The Martian, a dust storm leads to a series of events that strands an astronaut played by actor Matt Damon. As in the movie, dust on Mars has caused problems for real missions, including the Spirit Mars exploration rover. The fine, powdery stuff can get into expensive instruments and obscure solar panels needed to power equipment.

On Earth, dust is separated from soft rock formations by forces of nature including wind, water, glaciers, volcanoes and meteor impacts. For more than 4 billion years, however, streams of water and moving glaciers have likely made but a small contribution to the global dust reservoir on Mars. While meteor craters are a common feature on the fourth planet from the sun, the fragments created by the impacts typically are bigger than the fine particles that comprise Martian dust.

"How does Mars make so much dust, because none of these processes are active on Mars?" said lead author Lujendra Ojha, a postdoctoral fellow in Lewis' lab. Although these factors may have played a role in the past, something else is to blame for the large swathes of dust surrounding Mars now, he said.

Ojha and the science team looked at the dust's chemical composition. Landers and rovers far apart on the planet have all reported surprisingly similar data about the dust. "Dust everywhere on the planet is enriched in sulfur and chlorine and it has this very distinct sulfur-to-chlorine ratio," Ojha said.

They also studied data captured by the spacecraft Mars Odyssey, which has orbited the planet since 2001. Ojha and his colleagues were able to pinpoint the MFF region as having an abundance of sulfur and chlorine, as well as a match to the ratio of sulfur to chlorine in Mars dust.

Earlier findings suggest that the MFF had a volcanic origin. Once 50 percent of the continental United States in size, the wind has eroded it, leaving behind an area that's now more like about 20 percent. Yet it is the largest known volcanic deposit in our solar system.

Wind-carved ridges known as yardangs are the remnants of erosion. By calculating how much of the MFF has been lost over the past 3 billion years, the scientists could approximate the current quantity of dust on Mars, enough to form a 2 to 12 meters thick global layer.

Dust particles can also affect Martian climate by absorbing solar radiation, resulting in lower temperatures at the ground level and higher ones in the atmosphere. This temperature contrast can create stronger winds, leading to more dust being lifted from the surface.

While seasonal dust storms happen every Martian year (twice as long as an Earth year), global dust storms can form about every 10 or so years.

Read more at Science Daily

Empathetic dogs lend a helping paw

Many dogs are ready to lend a helping paw if needed.

Many dogs show empathy if their owner is in distress and will also try to help rescue them. This is according to Emily M. Sanford, formerly of Macalester College and now at Johns Hopkins University in the US. She is the lead author of a study in Springer's journal Learning & Behavior that tested whether there is truth in the notion that dogs have a prosocial and empathetic nature. Interesting to note, the study found that dogs specially trained for visitations as therapy dogs are just as likely to help as other dogs.

In one of their experiments, Sanford and her colleagues instructed the owners of 34 dogs to either give distressed cries or to hum while sitting behind a see-through closed door. Sixteen of these dogs were registered therapy dogs. The researchers watched what the dogs did, and also measured their heart rate variability to see how they physically reacted to the situation. In another part of the experiment, the researchers examined how these same dogs gazed at their owners to measure the strength of their relationship.

Dogs that heard distress calls were no more likely to open a door than dogs that heard someone humming. However, they opened the door much faster if their owner was crying. Based on their physiological and behavioral responses, dogs who opened the door were, in fact, less stressed than they were during baseline measurements, indicating that those who could suppress their own distress were the ones who could jump into action.

The study therefore provides evidence that dogs not only feel empathy towards people, but in some cases also act on this empathy. This happens especially when they are able to suppress their own feelings of distress and can focus on those of the human involved. According to Sanford, this is similar to what is seen when children need to help others. They are only able to do so when they can suppress their own feelings of personal distress.

"It appears that adopting another's emotional state through emotional contagion alone is not sufficient to motivate an empathetic helping response; otherwise, the most stressed dogs could have also opened the door," explains co-author Julia Meyers-Manor of Ripon College in the US. "The extent of this empathetic response and under what conditions it can be elicited deserve further investigation, especially as it can improve our understanding of the shared evolutionary history of humans and dogs."

Contrary to expectation, the sixteen therapy dogs in the study performed as well as the other dogs when tested on opening the door. According to Meyers-Manor this may be because registered therapy dogs, despite what people may think, do not possess traits that make them more attentive or responsive to human emotional states. She says that therapy dog certification tests involve skills based more on obedience rather than on human-animal bonding.

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Paleontologists discover largest dinosaur foot ever

Photograph from the excavations in 1998, with the brachiosaur foot bones below a tail of a Camarasaurus. University of Kansas expedition crew member as a scale.

The Black Hills region of the United States is famous today for tourist attractions like Deadwood and Mount Rushmore, but around 150 million years ago it was home to one of the largest dinosaurs known. This dinosaur was a member of the sauropod family with long necks and tails. These giant plant-eating dinosaurs like Brontosaurus and Diplodocus were the largest land animals that ever lived on this planet.

The foot described in a new scientific paper recently published in the open-access journal PeerJ -- the Journal of Life and Environmental Sciences was excavated in 1998 by an expedition from the University of Kansas, with Anthony Maltese, lead author of the study, as member of the crew. As he writes, it was immediately apparent that the foot, nearly a meter wide, was from an extremely large animal -- so the specimen was nicknamed "Bigfoot."

Now, after detailed preparation and study, Maltese and his international team of researchers from the USA, Switzerland, and Germany identified it as belonging to an animal very closely related to Brachiosaurus, famous for its appearance in the 1993 film Jurassic Park.

Anthony Maltese, Emanuel Tschopp, Femke Holwerda, and David Burnham used 3D scanning and detailed measurements to compare Bigfoot to sauropod feet from numerous species. Their research confirmed that this foot was unusually large. According to Holwerda, a Dutch PhD student at the Ludwig Maximilians University of Munich, Germany, comparisons with other sauropod feet showed that Bigfoot was clearly the largest dinosaur foot discovered to date.

It also confirmed that brachiosaurs inhabited a huge area from eastern Utah to northwestern Wyoming, 150 million years ago. "This is surprising," says Tschopp, a Swiss paleontologist working at the American Museum of Natural History in New York, "many other sauropod dinosaurs seem to have inhabited smaller areas during that time."

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Scientists generate key life event in artificial mouse 'embryo' created from stem cells

Synthetic embryo-like structure made of three stem cells types in yellow, pink and green.

The creation of artificial embryos has moved a step forward after an international team of researchers used mouse stem cells to produce artificial embryo-like structures capable of 'gastrulation', a key step in the life of any embryo.

The team, led by Professor Magdalena Zernicka-Goetz at the University of Cambridge, previously created a much simpler structure resembling a mouse embryo in culture, using two types of stem cells -- the body's 'master cells' -- and a 3D scaffold on which they can grow.

Now, in a study published today in Nature Cell Biology, Professor Zernicka-Goetz and colleagues have developed the embryo-like structures further, using not just two but three types of stem cells which let them reconstruct a process known as gastrulation, an essential step in which the embryonic cells being self-organising into the correct structure for an embryo to form.

Once a mammalian egg has been fertilised by a sperm, it divides multiple times to generate a small, free-floating ball comprising three types of stem cells. At the stage of development known as the 'blastocyst' stage, the particular stem cells that will eventually make the future body -- the embryonic stem cells (ESCs) -- cluster together inside the embryo towards one end. The other two types of stem cell in the blastocyst are the extra-embryonic trophoblast stem cells (TSCs), which will form the placenta, and primitive endoderm stem cells (PESCs) that will form the yolk sac, ensuring that the fetus's organs develop properly and providing essential nutrients.

In March 2017, Professor Zernicka-Goetz and colleagues published a study that described how, using a combination of genetically-modified mouse ESCs and TSCs, together with a 3D 'jelly' scaffold known as an extracellular matrix, they were able to grow a structure capable of assembling itself and whose development and architecture very closely resembled the natural embryo. There was a remarkable degree of communication between the two types of stem cell: in a sense, the cells were telling each other where in the embryo to place themselves.

However, a key step in the life of the embryo -- gastrulation, described by the eminent biologist Lewis Wolpert as "truly the most important time in your life" -- was missing. Gastrulation is the point at which the embryo transforms from being a single layer to three layers: an inner layer (endoderm), middle layer (mesoderm) and outer layer (endoderm), determining which tissues or organs the cells will then develop into.

"Proper gastrulation in normal development is only possible if you have all three types of stem cell. In order to reconstruct this complex dance, we had to add the missing third stem cell," says Professor Zernicka-Goetz. "By replacing the jelly that we used in earlier experiments with this third type of stem cell, we were able to generate structures whose development was astonishingly successful."

By adding the PESCs, the team was able to see their 'embryo' undergo gastrulation, organising itself into the three body layers that all animals have. The timing, architecture and patterns of gene activity reflected that of natural embryo development.

"Our artificial embryos underwent the most important event in life in the culture dish," adds Professor Zernicka-Goetz. "They are now extremely close to real embryos. To develop further, they would have to implant into the body of the mother or an artificial placenta."

The researchers say they should now be in a position to better understand how the three stem cell types interact to enable the embryo to develop, by experimentally altering biological pathways in one cell type and seeing how this affects the behaviour of one, or both, of the other cell types.

"We can also now try to apply this to the equivalent human stem cell types and so study the very earliest events in human embryo development without actually having to use natural human embryos," says Professor Zernicka-Goetz.

By applying these studies side-by-side, it should be possible to learn a great deal about the fundamental aspects of the first stages of mammalian development. In fact, such comparisons should enable scientists to study events that happen beyond day 14 in human pregnancies, but without using 14-day-old human embryos; UK law permits embryos to be studied in the laboratory only up to this period.

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New insights into plants' conquest of land

The Earth is filled with diverse and remarkable plant forms from the tallest redwoods that pierce forest canopies, to the smallest mosses that blanket the ground underfoot.

However, these striking forms came from much simpler origins. The ancestors of land plants were string-like (2D), aquatic green algae that looked very different from the three-dimensional (3D), upright stems and leaves of plants we are familiar with today.

Now, researchers at the University of Bristol have revealed exciting insights into how land plants evolved these 3D forms that were crucial for their advancement onto land.

The research, published today in the journal Current Biology, led by Dr Jill Harrison from the University's School of Biological Sciences, and collaborators, found that small proteins known as CLAVATA peptides, control the growth and division of cells at the very tips of plants, which generate organs such as the shoots and leaves.

CLAVATA is a peptide and receptor based signalling system. The peptide moves to the receptor to set the cell division planes.

However, when the researchers looked for CLAVATA molecules in the aquatic algae ancestors, they could not find them.

This showed that CLAVATA proteins evolved just as the first plants moved onto land.

Using mosses to exemplify the 2D to 3D growth transition, the researchers showed that CLAVATA protein rotate cell divisions at the tips of plant stems enabling growth in multiple directions.

Dr Harrison, a Royal Society University Research Fellow, said: "The CLAVATA genes were found to be specific to land plants to regulate their unique 3D growth patterns and so it looks like these genes were instrumental in enabling plants to get going on land.

"After this fundamental change in cell division patterns, plants could now develop many different forms, enabling them to dominate almost every environment on Earth, and so this work reveals a key role for these small proteins in plants' conquest of land."

From Science Daily

Archaeologists identify ancient North American mounds using new image analysis technique

Four shell ring features identified using the object-based image analysis (OBIA) algorithm. The ring on the top right has been confirmed as a shell ring site.

Researchers at Binghamton University, State University at New York have used a new image-based analysis technique to identify once-hidden North American mounds, which could reveal valuable information about pre-contact Native Americans.

"Across the East Coast of the United States, some of the most visible forms for pre-contact Native American material culture can be found in the form of large earthen and shell mounds," said Binghamton University anthropologist Carl Lipo. "Mounds and shell rings contain valuable information about the way in which past people lived in North America. As habitation sites, they can show us the kinds of foods that were eaten, the way in which the community lived, and how the community interacted with neighbors and their local environments.

In areas that are deeply wooded or consist of bayous and swamps, there exist mounds that have eluded more than 150 years of archaeological survey and research. Due to vegetation, these kinds of environments make seeing more than a couple of dozen feet difficult, and even large mounds can be hidden from view, even when one systematically walks on the terrain.

The use of satellites and new kinds of aerial sensors such as LiDAR (light detection and ranging) have transformed the way archaeologists can gather data about the archaeological record, said Lipo. Now scientists can study landscapes from images and peer through the forest canopy to look at the ground. LiDAR has been particularly effective at showing the characteristic rises in topography that mark the presence of mounds. The challenge to archaeologists, however, is to manage such a vast array of new data that are available for study. Object based image analysis (OBIA) allows archaeologists to configure a program to automatically detect features of interest. OBIA is a computer-based approach to use data from satellite images and aerial sensors to look for shapes and combinations of features that match objects of interest. Unlike traditional satellite image analyses that looks at combinations of light wavelengths, OBIA adds characteristics of shape to the search algorithm, allowing archaeologists to more easily distinguish cultural from natural phenomena.

Lipo's team systematically identified over 160 previously undetected mound features using LiDAR data from Beaufort County, S.C., and an OBIA approach. The result improves the overall knowledge of settlement patterns by providing systematic knowledge about past landscapes, said Lipo.

"Through the use of OBIA, archaeologists can now repeatedly generate data about the archaeological record and find historic and pre-contact sites over massive areas that would be cost-prohibitive using pedestrian survey. We can now also peer beneath the dense canopy of trees to see things that are otherwise obscured. In areas like coast South Carolina, with large swaths of shallow bays, inlets and bayous that are covered in forest, OBIA offers us our first look at this hidden landscape."

Having demonstrated the effectiveness for using OBIA in conditions of dense vegetation and after optimizing our processing, Lipo and his team are expanding their efforts to include much-larger areas.

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Curing breast cancer but at what cost? Patients report heavy financial toll

As treatment for early stage breast cancer becomes less extensive and more precise, a new concern is surfacing: Cancer takes an enormous toll financially on many people.

A new study led by researchers at the University of Michigan Rogel Cancer Center finds many patients are concerned about the financial impact of their diagnosis and treatment, and that they feel their doctor's offices are not helping with these concerns.

"We have made a lot of progress in breast cancer treatment, which is wonderful. But this study shows we are only part of the way to our goal. We must now turn our efforts to confronting the financial devastation many patients face," says lead study author Reshma Jagsi, M.D., D.Phil., deputy chair and professor of radiation oncology at Michigan Medicine.

Researchers surveyed about 2,500 patients treated for early stage breast cancer and 845 treating surgeons, medical oncologists and radiation oncologists. The study is published in Cancer, a peer-reviewed journal of the American Cancer Society.

About 38 percent of women were at least somewhat worried about finances because of their breast cancer treatment, and some experienced extensive hardships. Overall, 14 percent of patients reported losing more than 10 percent of their household income, and 17 percent spent more than 10 percent of their household income on out-of-pocket medical expenses.

The financial burden varied significantly by race and ethnicity, with African-American and Latina women experiencing more concerns, including debt from treatment, losing their home, having utilities turned off for unpaid bills and cutting back on spending for food.

Among physicians, many reported engagement and concern about the costs and financial burden related to the treatments they recommended. Half of all medical oncologists and 43 percent radiation oncologists said someone in their practice often or always discusses financial burden with patients. Only 16 percent of surgeons did.

But of those patients worried about their finances, 73 percent said their doctor's office did not help. The mismatch suggests the need to improve communication around financial hardship. The researchers stress the importance of physicians or their staff assessing all patients for financial issues and ensuring the communication is effective and clear.

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Neurons can carry more than one signal at a time

Neurons

Back in the early days of telecommunications, engineers devised a clever way to send multiple telephone calls through a single wire at the same time. Called time-division multiplexing, this technique rapidly switches between sending pieces of each message.

New research from Duke University shows that neurons in the brain may be capable of a similar strategy.

In an experiment examining how monkeys respond to sound, a team of neuroscientists and statisticians found that a single neuron can encode information from two different sounds by switching between the signal associated with one sound and the signal associated with the other sound.

"The question we asked is, how do neurons preserve information about two different stimuli in the world at one time?" said Jennifer Groh, professor in the department of psychology and neuroscience, and in the department of neurobiology at Duke.

"We found that there are periods of time when a given neuron responds to one stimulus, and other periods of time where it responds to the other," Groh said. "They seem to be able to alternate between each one."

The results may explain how the brain processes complex information from the world around us, and may also provide insight into some of our perceptual and cognitive limitations. The results appeared July 13 in Nature Communications.

To make the discovery, Groh and her team collaborated with Surya Tokdar, associate professor of statistical science at Duke, to develop and apply several new methods of analysis to their experimental data.

Most studies of single neuron behavior investigate only one stimulus at a time, looking at how an individual neuron responds when the subject is played a single note or shown a single image.

But reality is rarely so simple. Our brains are capable of processing multiple stimuli at once -- such as listening to a friend at a party with music playing in the background, or picking out the buzz of a cicada from a symphony of trilling insects.

"It is not obvious how you go from single neurons encoding single objects, to neurons encoding multiple objects," said Valeria Caruso, a research scientist in Duke's department of psychology and neuroscience. "We wanted to provide an intermediate step, looking at how neurons encode small groups of objects."

To complicate matters, single-neuron studies have shown that many sensory neurons are broadly tuned, meaning each is capable of responding to sounds at a range of different frequencies. For example, the same neurons triggered by your friend's voice may also be triggered by the notes of your favorite tunes.

"If I am a neuron and I'm able to respond to both an image of a pillow and the couch it is resting on, how does the brain infer that both the pillow and the couch are present?" Groh said.

In the experiment, the researchers sat monkeys in a darkened room and trained them to look in the direction of sounds that they heard. The researchers played either one sound or two sounds, with each sound at a different frequency and coming from different locations.

When the researchers played two sounds together, the monkeys looked first in the direction of one sound, and then in the direction of the other sound, indicating that the monkeys recognized the existence of two distinct sounds.

To find out how the monkeys' brains encoded both sounds simultaneously, the team used electrodes in the inferior colliculus, a key point in the brain's auditory pathway, to measure the small spikes in the local electric field caused by neurons firing.

The researchers investigated the response of single neurons to both individual sounds and to combined sounds. The standard practice in the field is to count how many spikes occur over a period of time and compute the average of a number of trials, Groh said. But this method obscures any fluctuations in activity that might indicate the neurons are switching back and forth between different stimuli.

The team applied a combination of advanced statistical methods, including a new method called a Dynamic Admixture Point Process model developed by Tokdar and his team, to extract more detailed patterns from the data.

They found that a single neuron could respond to one sound with one firing rate, and a second sound with a different firing rate. When both sounds were played simultaneously, it appeared to fluctuate between the two firing rates. Sometimes the fluctuations were fast enough that the neurons switched within a half second of the presentation of the sound, and in other cases the switching was slower.

The team repeated the statistical analysis on data from experiments conducted by Winrich Freiwald, a professor of neurosciences and behavior at The Rockefeller University. In these experiments, Freiwald investigated the firing rates of single neurons in a visual area of the cortex in response to images of one face or two faces. The analysis revealed the same switching pattern when two faces were present.

These findings provide clues to other circumstances where the brain has to do more than one thing at a time with a limited set of neurons. For example, our working memory -- the number of things we can hold in our minds at one time -- is constrained to around five to seven items. While these experiments do not directly test working memory, the researchers think further studies may help explain these restrictions.

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Billion-year-old lake deposit yields clues to Earth's ancient biosphere

Earth view

A sample of ancient oxygen, teased out of a 1.4 billion-year-old evaporative lake deposit in Ontario, provides fresh evidence of what the Earth's atmosphere and biosphere were like during the interval leading up to the emergence of animal life.

The findings, published in the journal Nature, represent the oldest measurement of atmospheric oxygen isotopes by nearly a billion years. The results support previous research suggesting that oxygen levels in the air during this time in Earth history were a tiny fraction of what they are today due to a much less productive biosphere.

"It has been suggested for many decades now that the composition of the atmosphere has significantly varied through time," says Peter Crockford, who led the study as a PhD student at McGill University. "We provide unambiguous evidence that it was indeed much different 1.4 billion years ago."

The study provides the oldest gauge yet of what earth scientists refer to as "primary production," in which micro-organisms at the base of the food chain -- algae, cyanobacteria, and the like -- produce organic matter from carbon dioxide and pour oxygen into the air.

A smaller biosphere

"This study shows that primary production 1.4 billion years ago was much less than today," says senior co-author Boswell Wing, who helped supervise Crockford's work at McGill. "This means that the size of the global biosphere had to be smaller, and likely just didn't yield enough food -- organic carbon -- to support a lot of complex macroscopic life," says Wing, now an associate professor of geological sciences at University of Colorado at Boulder.

To come up with these findings, Crockford teamed up with colleagues from Yale University, University of California Riverside, and Lakehead University in Thunder Bay, Ontario, who had collected pristine samples of ancient salts, known as sulfates, found in a sedimentary rock formation north of Lake Superior. Crockford shuttled the samples to Louisiana State University, where he worked closely with co-authors Huiming Bao, Justin Hayles, and Yongbo Peng, whose lab is one of a handful in the world using a specialized mass-spectrometry technique capable of probing such materials for rare oxygen isotopes within sulfates.

The work also sheds new light on a stretch of Earth's history known as the "boring billion" because it yielded little apparent biological or environmental change.

"Subdued primary productivity during the mid-Proterozoic era -- roughly 2 billion to 800 million years ago -- has long been implied, but no hard data had been generated to lend strong support to this idea," notes Galen Halverson, a co-author of the study and associate professor of earth and planetary sciences at McGill. "That left open the possibility that there was another explanation for why the middle Proterozoic ocean was so uninteresting, in terms of the production and deposit of organic carbon." Crockford's data "provide the direct evidence that this boring carbon cycle was due to low primary productivity."

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Sea pickles are adapting to the Pacific Northwest

Portland, Oregon,-based muralist Esteban Camacho, the artist-in-residence during this summer's research cruise off the Pacific Northwest Coast, displays a large pyrosome found offshore, where the animals, known popularly as sea pickles, appear to be adapting to cool water after moving northward from warmer waters off the California coast.

Tubular colonial jellies known as pyrosomes that arrived in 2014 along North America's Pacific Northwest Coast appear to be adapting to cooler water and may become permanent residents.

That, a five-member research team concludes in a study in the journal Ecology, could mean a continued nuisance for regional fishing operations and changes to energy flows that could alter long-existing near-shore food webs.

"These animals may be able to survive in colder water than we previously thought possible, but what might really be contributing to their continued presence is that the food source off of our coast is right for them," said study co-author Kelly Sutherland, a marine biologist at the University of Oregon.

UO graduate student Hilarie Sorensen, the study's other lead author, helped document the invasion by these "sea pickles," as pyrosomes are commonly called, during a research cruise in 2017. That prompted a deeper exploration.

Marine biologist Aaron Galloway was a third UO scientist on the research team. All three are with the Oregon Institute of Marine Biology at Charleston.

"The last few years have been relatively warm," said Sutherland, who also is with the UO's Clark Honors College and Institute of Ecology and Evolution. "The warmth on the surface tends to keep colder, denser, nutrient-rich water from reaching the surface; it's an oil-and-water kind of situation."

"These relatively nutrient-poor conditions lead to smaller prey particles that pyrosomes can capitalize on," Sorensen said. "This could be systemic of larger changes in the ecosystem."

Pyrosomes are made up of small, multicellular organisms, linked into a tunic to form a colony shaped like a tube. They are filter feeders that use cilia -- tiny, hairlike projections -- to draw plankton into their mucous filters. The ones seen off Oregon in 2017 ranged in size from about an inch to more than 2 feet long.

In their new paper, the researchers noted that pyrosomes -- a name refers to their fiery bioluminescence -- are "one of the least-studied planktonic grazers in spite of their widespread distribution and ecological significance."

Researchers in Sutherland's lab have been involved in recent efforts to understand filter-feeders.

Until 2014, the creatures were common in warmer waters south of California's Cape Mendocino. They possibly then began moving up the coast into the Pacific Northwest as part of a multi-year "warm blob" that was followed by a strong El Nino in 2016, the researchers noted.

During a research cruise in February, pyrosomes were found amassed in large numbers at three separate locations, six, 15 and 28 miles offshore from Newport, Oregon, where the water temperature was about 50 degrees Fahrenheit. The jellies were found at the base of the surface layer at a depth of about 130 feet.

Fish, sea turtles and sea birds are among predators that have been seen feeding on the sea pickles along the Pacific Northwest coast. In the Gulf of Mexico and off the British Columbia coast, anemones, sea urchins and crabs have been observed eating them.

Their continuing presence and their capacity to reach bloom proportions, the researchers wrote, suggests that pyrosomes may be thriving in colder waters and could become more permanent residents in the California current, which extends from near Baja, California, to off southern British Columbia.

Summer 2017 was difficult for the Pacific Northwest fishing industry as both live and dying sea pickles were captured in large numbers by trawling nets, requiring time-consuming sorting and removal. Potentially, Sutherland said, some fishing operations could face relocation.

Large-scale aggregations of sea pickles can potentially restructure energy flows by their removal of photosynthetic plankton through consumption at higher levels of the ocean food web, subsequent fecal pellet production and sinking as they die off, the researchers noted in their conclusion.

Other study co-authors were Olivia Blondheim of Drew University in Madison, New Jersey, and Richard Brodeur of the National Oceanic and Atmospheric Administration's Northwest Fisheries Science Center at Oregon State University. Blondheim was supported by NOAA's Ernest F. Hollings Scholarship Program while a 2017 summer intern with Brodeur and Sutherland.

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