Pets are a child’s best friend, not their siblings

Children get more satisfaction from relationships with their pets than with their brothers or sisters, according to new research from the University of Cambridge. Children also appear to get on even better with their animal companions than with siblings.

The research adds to increasing evidence that household pets may have a major influence on child development, and could have a positive impact on children's social skills and emotional well-being.

Pets are almost as common as siblings in western households, although there are relatively few studies on the importance of child-pet relationships.

''Anyone who has loved a childhood pet knows that we turn to them for companionship and disclosure, just like relationships between people," says Matt Cassells, a Gates Cambridge Scholar at the Department of Psychiatry, who led the study. "We wanted to know how strong these relationships are with pets relative to other close family ties. Ultimately this may enable us to understand how animals contribute to healthy child development"

This study, published in the Journal of Applied Developmental Psychology, was conducted in collaboration with the WALTHAM Centre for Pet Nutrition, part of Mars Petcare and co-funded by the Economic and Social Research Council as part of a larger study, led by Prof Claire Hughes at the University of Cambridge Centre for Family Research. Researchers surveyed 12 year old children from 77 families with one or more pets of any type and more than one child at home. Children reported strong relationships with their pets relative to their siblings, with lower levels of conflict and greater satisfaction in owners of dogs than other kinds of pets.

''Even though pets may not fully understand or respond verbally, the level of disclosure to pets was no less than to siblings," says Cassels. "The fact that pets cannot understand or talk back may even be a benefit as it means they are completely non-judgmental.

"While previous research has often found that boys report stronger relationships with their pets than girls do, we actually found the opposite. While boys and girls were equally satisfied with their pets, girls reported more disclosure, companionship, and conflict with their pet than did boys, perhaps indicating that girls may interact with their pets in more nuanced ways.''

"Evidence continues to grow showing that pets have positive benefits on human health and community cohesion," says Dr Nancy Gee, Human-Animal Interaction Research Manager at WALTHAM and a co-author of the study. "The social support that adolescents receive from pets may well support psychological well-being later in life but there is still more to learn about the long term impact of pets on children's development."

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DNA analysis of seawater detects 80% of fish species in just one day

Collecting water samples. (Image courtesy of Kobe University)

A Japanese research group has used a new technology that identifies multiple fish species populating local areas by analyzing DNA samples from seawater, and proved that this method is accurate and more effective than visual observation.

This research was carried out as part of the Japan Science and Technology Strategic Basic Research Programs by a group including Academic Researcher YAMAMOTO Satoshi (Kobe University Graduate School of Human Development and Environment), Associate Professor MASUDA Reiji (Kyoto University), Professor ARAKI Hitoshi (Hokkaido University), Professor KONDOH Michio (Ryukoku University), Project Assistant Professor MINAMOTO Toshifumi (Kobe University Graduate School of Human Development and Environment), and Adjunct Associate Professor MIYA Masaki (Head of Department of Ecology and Environmental Sciences, Natural History Museum and Institute, Chiba).

Until recently, marine surveys of fish species relied on diving or capturing methods that classified fish based on appearance. In addition to requiring a lot of manpower, these methods also depend upon specialist knowledge for fish classification. A new solution to the survey issue has recently drawn attention: environmental DNA metabarcoding, a method which can simultaneously detect multiple species. This method identifies the fish species through collection and analysis of DNA released by fish in seawater (environmental DNA, or eDNA). Until now, researchers could only gain limited confirmation of the effectiveness of this method because it had only been proven in areas with limited numbers of fish species. In places such as the Japan coast, home to many different fish species, data collected using traditional methods is limited. As the results could not be compared with previous data, the effectiveness of eDNA metabarcoding remained unconfirmed.

This research group used eDNA metabarcoding in Maizuru bay, Kyoto prefecture. After just one day of field surveys applying this method, they were able to detect 128 species of fish from the seawater samples. Over 60% of the species observed during 140 visual surveys spanning 14 years were included in these 128 varieties. Excluding fish varieties who only migrated to Maizuru bay in certain years, this rose to nearly an 80% match. They also detected fish species that could not be confirmed by visual observation. Researchers believe that this method is the first time they have been able to detect certain varieties of fish larvae that are hard to identify through visual observation.

These findings show that even in areas with many different fish species, eDNA metabarcoding enables researchers to survey fish in multiple areas during a short time period. This method has potential applications for monitoring the invasion of foreign species across large areas, surveys of expanding fish distribution, and use in hard to access areas such as the deep sea, subterranean lakes, dangerous polluted waters, and protected areas where collecting specimens is prohibited. The findings were published on January 12 inScientific Reports.

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Brain shape linked to personality differences

The shape of your brain can influence personality traits, according to a new study.

New research reveals the shape of our brain can provide surprising clues about how we behave and our risk of developing mental health disorders.

Florida State University College of Medicine Associate Professor Antonio Terracciano joined a team of researchers from the United States, United Kingdom and Italy to examine the connection between personality traits and brain structure. Their study, published in the journal Social Cognitive and Affective Neuroscience, looked at differences in the anatomy of the cortex (the outer layer of the brain) as indexed by three measures -- the thickness, area, and amount of folding in the cortex -- and how these measures related to the five major personality traits.

The traits include neuroticism, the tendency to be in a negative emotional state; extraversion, the tendency to be sociable and enthusiastic; openness, how open-minded a person is; agreeableness, a measure of altruism and cooperativeness; and conscientiousness, a measure of self-control and determination.

The study involved an imaging dataset from more than 500 individuals made publicly available by the Human Connectome Project, an ambitious effort by the National Institutes of Health to map neural pathways underlying human brain function.

"Evolution has shaped our brain anatomy in a way that maximizes its area and folding by reducing thickness of the cortex," said senior author Luca Passamonti from the Department of Clinical Neurosciences at the University of Cambridge. "It's like stretching and folding a rubber sheet -- this increases the surface area, but at the same time the sheet itself becomes thinner. We refer to this as the 'cortical stretching hypothesis.'"

"Cortical stretching is a key evolutionary mechanism that enabled human brains to expand rapidly while still fitting into our skulls, which grew at a slower rate than the brain," Terracciano added. "Interestingly, this same process occurs as we develop and grow in the womb and throughout childhood, adolescence, and into adulthood: The thickness of the cortex tends to decrease while the area and folding increase."

In other research, Terracciano and others have shown that as people get older, neuroticism goes down -- people become better at handling emotions -- while conscientiousness and agreeableness go up -- people become progressively more responsible and less antagonistic.

The researchers found that high levels of neuroticism, which may predispose people to develop neuro-psychiatric disorders, were associated with increased thickness as well as reduced area and folding in some regions of the cortex, such as the prefrontal-temporal cortices.

In contrast, openness, which is a personality trait linked with curiosity, creativity, and a preference for variety and novelty, was associated with the opposite pattern: reduced thickness and an increase in area and folding in some prefrontal cortices.

Brains imaged as part of the Human Connectome Project all belonged to healthy individuals 22-36 years old with no history of neuro-psychiatric or other major medical problems. The relation between brain structure and personality traits in young and healthy people can change as people age and provide a reference frame for better understanding the brain structures in conditions such as autism, depression, or Alzheimer's disease.

"Linking how brain structure is related to basic personality traits is a crucial step to improving our understanding of the link between the brain morphology and particular mood, cognitive or behavioral disorders," Passamonti said. "We also need to have a better understanding of the relation between brain structure and function in healthy people to figure out what is different in people with neurological and psychiatric disorders."

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Rat-grown mouse pancreases help reverse diabetes in mice

Rat in which researchers were able to grow a mouse pancreas. Islets from the pancreases were transplanted into mice with diabetes. The transplants helped control the mice's blood sugar levels. (Courtesy of the Nakauchi lab)

Rat-grown mouse pancreases help reverse diabetes in mice, say researchers at Stanford, University of TokyoMouse pancreases grown in rats generate functional, insulin-producing cells that can reverse diabetes when transplanted into mice with the disease, according to researchers at the Stanford University School of Medicine and the Institute of Medical Science at the University of Tokyo.

The recipient animals required only days of immunosuppressive therapy to prevent rejection of the genetically matched rather than lifelong treatment.

The success of the interspecies transplantation suggests that a similar technique could one day be used to generate matched, transplantable human organs in large animals like pigs or sheep.

To conduct the work, the researchers implanted mouse pluripotent stem cells, which can become any cell in the body, into early rat embryos. The rats had been genetically engineered to be unable to develop their own pancreas and were thus forced to rely on the mouse cells for the development of the organ.

Once the rats were born and grown, the researchers transplanted the insulin-producing cells, which cluster together in groups called islets, from the rat-grown pancreases into mice genetically matched to the stem cells that formed the pancreas. These mice had been given a drug to cause them to develop diabetes.

"We found that the diabetic mice were able to normalize their blood glucose levels for over a year after the transplantation of as few as 100 of these islets," said Hiromitsu Nakauchi, MD, PhD, a professor of genetics at Stanford. "Furthermore, the recipient animals only needed treatment with immunosuppressive drugs for five days after transplantation, rather than the ongoing immunosuppression that would be needed for unmatched organs."

Nakauchi, who is a member of Stanford's Institute for Stem Cell Biology and Regenerative Medicine, is the senior author of a paper describing the findings, which will be published online Jan. 25 in Nature. Tomoyuki Yamaguchi, PhD, an associate professor of stem cell therapy, and researcher Hideyuki Sato, both from the University of Tokyo, share lead authorship of the paper.

Organs in short supply

About 76,000 people in the United States are currently waiting for an organ transplant, but organs are in short supply. Generating genetically matched human organs in large animals could relieve the shortage and release transplant recipients from the need for lifelong immunosuppression, the researchers say.

People suffering from diabetes could also benefit from this approach. Diabetes is a life-threating metabolic disease in which a person or animal is unable to either make or respond appropriately to insulin, which is a hormone that allows the body to regulate its blood sugar levels in response to meals or fasting. The disease affects hundreds of millions of people worldwide and is increasing in prevalence. The transplantation of functional islets from healthy pancreases has been shown to be a potentially viable option to treat diabetes in humans, as long as rejection can be avoided.

The researchers' current findings come on the heels of a previous study in which they grew rat pancreases in mice. Although the organs appeared functional, they were the size of a normal mouse pancreas rather than a larger rat pancreas. As a result, there were not enough functional islets in the smaller organs to successfully reverse diabetes in rats.

Mouse pancreases grown in rats

In the current study, the researchers swapped the animals' roles, growing mouse pancreases in rats engineered to lack the organ. The pancreases were able to successfully regulate the rats' blood sugar levels, indicating they were functioning normally. Rejection of the mouse pancreases by the rats' immune systems was uncommon because the mouse cells were injected into the rat embryo prior to the development of immune tolerance, which is a period during development when the immune system is trained to recognize its own tissues as "self." Most of these mouse-derived organs grew to the size expected for a rat pancreas, rendering enough individual islets for transplantation.

Next, the researchers transplanted 100 islets from the rat-grown pancreases back into mice with diabetes. Subsequently, these mice were able to successfully control their blood sugar levels for over 370 days, the researchers found.

Because the transplanted islets contained some contaminating rat cells, the researchers treated each recipient mouse with immunosuppressive drugs for five days after transplant. After this time, however, the immunosuppression was stopped.

After about 10 months, the researchers removed the islets from a subset of the mice for inspection.

"We examined them closely for the presence of any rat cells, but we found that the mouse's immune system had eliminated them," said Nakauchi. "This is very promising for our hope to transplant human organs grown in animals because it suggests that any contaminating animal cells could be eliminated by the patient's immune system after transplant."?

Importantly, the researchers also did not see any signs of tumor formation or other abnormalities caused by the pluripotent mouse stem cells that formed the islets. Tumor formation is often a concern when pluripotent stem cells are used in an animal due to the cells' remarkable developmental plasticity. The researchers believe the lack of any signs of cancer is likely due to the fact that the mouse pluripotent stem cells were guided to generate a pancreas within the developing rat embryo, rather than coaxed to develop into islet cells in the laboratory. The researchers are working on similar animal-to-animal experiments to generate kidneys, livers and lungs.

Although the findings provide proof-of-principle for future work, much research remains to be done. Ethical considerations are also important when human stem cells are transplanted into animal embryos, the researchers acknowledge.

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Deep learning algorithm does as well as dermatologists in identifying skin cancer

A dermatologist using a dermatoscope, a type of handheld microscope, to look at skin. Computer scientists at Stanford have created an artificially intelligent diagnosis algorithm for skin cancer that matched the performance of board-certified dermatologists. (Matt Young)

It's scary enough making a doctor's appointment to see if a strange mole could be cancerous. Imagine, then, that you were in that situation while also living far away from the nearest doctor, unable to take time off work and unsure you had the money to cover the cost of the visit. In a scenario like this, an option to receive a diagnosis through your smartphone could be lifesaving.

Universal access to health care was on the minds of computer scientists at Stanford when they set out to create an artificially intelligent diagnosis algorithm for skin cancer. They made a database of nearly 130,000 skin disease images and trained their algorithm to visually diagnose potential cancer. From the very first test, it performed with inspiring accuracy.

"We realized it was feasible, not just to do something well, but as well as a human dermatologist," said Sebastian Thrun, an adjunct professor in the Stanford Artificial Intelligence Laboratory. "That's when our thinking changed. That's when we said, 'Look, this is not just a class project for students, this is an opportunity to do something great for humanity.'"

The final product, the subject of a paper in the Jan. 25 issue of Nature, was tested against 21 board-certified dermatologists. In its diagnoses of skin lesions, which represented the most common and deadliest skin cancers, the algorithm matched the performance of dermatologists.

Why skin cancer

Every year there are about 5.4 million new cases of skin cancer in the United States, and while the five-year survival rate for melanoma detected in its earliest states is around 97 percent, that drops to approximately 14 percent if it's detected in its latest stages. Early detection could likely have an enormous impact on skin cancer outcomes.

Diagnosing skin cancer begins with a visual examination. A dermatologist usually looks at the suspicious lesion with the naked eye and with the aid of a dermatoscope, which is a handheld microscope that provides low-level magnification of the skin. If these methods are inconclusive or lead the dermatologist to believe the lesion is cancerous, a biopsy is the next step.

Bringing this algorithm into the examination process follows a trend in computing that combines visual processing with deep learning, a type of artificial intelligence modeled after neural networks in the brain. Deep learning has a decades-long history in computer science but it only recently has been applied to visual processing tasks, with great success. The essence of machine learning, including deep learning, is that a computer is trained to figure out a problem rather than having the answers programmed into it.

"We made a very powerful machine learning algorithm that learns from data," said Andre Esteva, co-lead author of the paper and a graduate student in the Thrun lab. "Instead of writing into computer code exactly what to look for, you let the algorithm figure it out."

The algorithm was fed each image as raw pixels with an associated disease label. Compared to other methods for training algorithms, this one requires very little processing or sorting of the images prior to classification, allowing the algorithm to work off a wider variety of data.

From cats and dogs to melanomas and carcinomas

Rather than building an algorithm from scratch, the researchers began with an algorithm developed by Google that was already trained to identify 1.28 million images from 1,000 object categories. While it was primed to be able to differentiate cats from dogs, the researchers needed it to know a malignant carcinoma from a benign seborrheic keratosis.

"There's no huge dataset of skin cancer that we can just train our algorithms on, so we had to make our own," said Brett Kuprel, co-lead author of the paper and a graduate student in the Thrun lab. "We gathered images from the internet and worked with the medical school to create a nice taxonomy out of data that was very messy -- the labels alone were in several languages, including German, Arabic and Latin."

After going through the necessary translations, the researchers collaborated with dermatologists at Stanford Medicine, as well as Helen M. Blau, professor of microbiology and immunology at Stanford and co-author of the paper. Together, this interdisciplinary team worked to classify the hodgepodge of internet images. Many of these, unlike those taken by medical professionals, were varied in terms of angle, zoom and lighting. In the end, they amassed about 130,000 images of skin lesions representing over 2,000 different diseases.

During testing, the researchers used only high-quality, biopsy-confirmed images provided by the University of Edinburgh and the International Skin Imaging Collaboration Project that represented the most common and deadliest skin cancers -- malignant carcinomas and malignant melanomas. The 21 dermatologists were asked whether, based on each image, they would proceed with biopsy or treatment, or reassure the patient. The researchers evaluated success by how well the dermatologists were able to correctly diagnose both cancerous and non-cancerous lesions in over 370 images.

The algorithm's performance was measured through the creation of a sensitivity-specificity curve, where sensitivity represented its ability to correctly identify malignant lesions and specificity represented its ability to correctly identify benign lesions. It was assessed through three key diagnostic tasks: keratinocyte carcinoma classification, melanoma classification, and melanoma classification when viewed using dermoscopy. In all three tasks, the algorithm matched the performance of the dermatologists with the area under the sensitivity-specificity curve amounting to at least 91 percent of the total area of the graph.

An added advantage of the algorithm is that, unlike a person, the algorithm can be made more or less sensitive, allowing the researchers to tune its response depending on what they want it to assess. This ability to alter the sensitivity hints at the depth and complexity of this algorithm. The underlying architecture of seemingly irrelevant photos -- including cats and dogs -- helps it better evaluate the skin lesion images.

Health care by smartphone

Although this algorithm currently exists on a computer, the team would like to make it smartphone compatible in the near future, bringing reliable skin cancer diagnoses to our fingertips.

"My main eureka moment was when I realized just how ubiquitous smartphones will be," said Esteva. "Everyone will have a supercomputer in their pockets with a number of sensors in it, including a camera. What if we could use it to visually screen for skin cancer? Or other ailments?"

The team believes it will be relatively easy to transition the algorithm to mobile devices but there still needs to be further testing in a real-world clinical setting.

"Advances in computer-aided classification of benign versus malignant skin lesions could greatly assist dermatologists in improved diagnosis for challenging lesions and provide better management options for patients," said Susan Swetter, professor of dermatology and director of the Pigmented Lesion and Melanoma Program at the Stanford Cancer Institute, and co-author of the paper. "However, rigorous prospective validation of the algorithm is necessary before it can be implemented in clinical practice, by practitioners and patients alike."

Even in light of the challenges ahead, the researchers are hopeful that deep learning could someday contribute to visual diagnosis in many medical fields.

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Bursts of methane may have warmed early Mars

The presence of water on ancient Mars is a paradox. There's plenty of geographical evidence that rivers periodically flowed across the planet's surface. Yet in the time period when these waters are supposed to have run -- three to four billion years ago -- Mars should have been too cold to support liquid water.

So how did it stay so warm?

Researchers from the Harvard John A. Paulson School of Engineering and Applied Science (SEAS) suggest that early Mars may have been warmed intermittently by a powerful greenhouse effect. In a paper published in Geophysical Research Letters, researchers found that interactions between methane, carbon dioxide and hydrogen in the early Martian atmosphere may have created warm periods when the planet could support liquid water on the surface.

"Early Mars is unique in the sense that it's the one planetary environment, outside Earth, where we can say with confidence that there were at least episodic periods where life could have flourished," said Robin Wordsworth, assistant professor of environmental science and engineering at SEAS, and first author of the paper. "If we understand how early Mars operated, it could tell us something about the potential for finding life on other planets outside the solar system."

Four billion years ago, the Sun was about 30 percent fainter than today and significantly less solar radiation -- a.k.a. heat -- reached the Martian surface. The scant radiation that did reach the planet was trapped by the atmosphere, resulting in warm, wet periods. For decades, researchers have struggled to model exactly how the planet was insulated.

The obvious culprit is CO₂. Carbon dioxide makes up 95 percent of today's Martian atmosphere and is the most well-known and abundant greenhouse gas on Earth.

But CO₂ alone does not account for Mars' early temperatures.

"You can do climate calculations where you add CO₂ and build up to hundreds of times the present day atmospheric pressure on Mars and you still never get to temperatures that are even close to the melting point," said Wordsworth.

There must have been something else in Mars' atmosphere that contributed to a greenhouse effect.

The atmospheres of rocky planets lose lighter gases, such as hydrogen, to space over time. (In fact, the oxidation that gives Mars its distinctive hue is a direct result of the loss of hydrogen.)

Wordsworth and his collaborators looked to these long-lost gases -- known as reducing gases -- to provide a possible explanation for Mars' early climate. In particular, the team looked at methane, which today is not abundant in the Martian atmosphere. Billions of years ago, however, geological processes could have been releasing significantly more methane into the atmosphere. This methane would have been slowly converted to hydrogen and other gases, in a process similar to that occurring today on Saturn's moon, Titan.

To understand how this early Martian atmosphere may have behaved, the team needed to understand the fundamental properties of these molecules.

"When you're looking at exotic atmospheres, you can't compare them to Earth's atmosphere," said Wordsworth. "You have to start from first principles. So we looked at what happens when methane, hydrogen and carbon dioxide collide and how they interact with photons. We found that this combination results in very strong absorption of radiation."

Carl Sagan first speculated that hydrogen warming could have been important on early Mars back in 1977, but this is the first time scientists have been able to calculate its greenhouse effect accurately. It is also the first time that methane has been shown to be an effective greenhouse gas on early Mars.

"This research shows that the warming effects of both methane and hydrogen have been underestimated by a significant amount," said Wordsworth. "We discovered that methane and hydrogen, and their interaction with carbon dioxide, were much better at warming early Mars than had previously been believed."

The researchers hope that future missions to Mars will shed light on the geological processes that produced methane billions of years ago.

"One of the reasons early Mars is so fascinating is that life needs complex chemistry to emerge," said Wordsworth. "These episodes of reducing gas emission followed by planetary oxidation could have created favorable conditions for life on Mars."

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How plant cells regulate growth shown for the first time

The meristem. The photo was taken using confocal microscopy. (Arun Sampathkumar and Yassin Refahi)

Researchers have managed to show how the cells in a plant, a multicellular organism, determine their size and regulate their growth over time. The findings overturn previous theories in the field and are potentially significant for the future of agriculture and forestry -- as it reveals more about one of the factors which determine the size of plants and fruits.

"We have looked at how the cells in a multicellular organism regulate their size and this is the first time it has been done. We can show that the mechanism which leads to the maintenance of the cell size over generations is a combination of what has been found in yeast and bacteria," explains Henrik Jönsson, who specialises in computational biology and biological physics at Lund University in Sweden.

Similar studies have previously only been conducted on single cell organisms, such as bacteria and yeast. Now Henrik Jönsson, together with colleagues in the US and UK, has studied the apical meristem of a plant, thale cress (Arabidopsis thaliana). The researchers investigated cell division in this stem cell niche and succeeded in mapping how the cells determine their size and adjust their growth so that cell size is homogeneous over time.

Cells in single-cell systems such as bacteria and yeast do not change size over time. Yeast cells divide when they reach a critical size, whereas bacteria such as E. coli increase by a constant volume between cell divisions. In the latter case, small cells become larger, and large cells relatively smaller in the next generation. This means that the cells end up the same size when considered over several generations.

The researchers have worked on developing a method that follows growth and cell division within the living plant, using what is known as confocal microscopy. New fluorescent markers and a new microscopy protocol have been developed. In addition, new computational algorithms identify, segment and track cells over time.

"This has allowed us to quantify cell size and growth with a higher resolution than anyone managed previously. We have also developed mathematical models for analyzing hypotheses about various rules which could determine cell size," says Henrik Jönsson.

Recently, the researchers showed that the size of the meristem is significant for the number of stem cells present. Now they are pursuing their research by investigating whether, and if so, how the size of the meristem affects the size of the plant itself. Henrik Jönsson describes this as a multidisciplinary method which will lead to biology becoming comprehensible on a much more detailed level than previously possible.

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Astronomers find seven dwarf-galaxy groups, the building blocks of massive galaxies

Dwarf galaxies, nuggets of stars and gas 100 to 1,000 times smaller than the Milky Way, are thought to be the building blocks of massive galaxies. Evidence for groups of merging dwarf galaxies, however, has been lacking, until now.

Using data from the Sloan Digital Sky Survey (SDSS) and various optical telescopes, a team of astronomers has discovered seven distinct groups of dwarf galaxies with just the right starting conditions to eventually merge and form larger galaxies, including spiral galaxies like the Milky Way. This discovery offers compelling evidence that the mature galaxies we see in the universe today were formed when smaller galaxies merged many billions of years ago.

"We know that to make a large galaxy, the universe has to bring together many smaller galaxies," said Sabrina Stierwalt an astronomer with the National Radio Astronomy Observatory (NRAO) and University of Virginia in Charlottesville. "For the first time, we have found examples of the first steps in this process -- entire populations of dwarf galaxies that are all bound together in the same general neighborhoods."

Stierwalt and her team began their search by poring over SDSS data looking for pairs of interacting dwarf galaxies. The astronomers then examined the images to find specific pairs that appeared to be part of even larger assemblages of similar galaxies.

The researchers then used the Magellan telescope in Chile, the Apache Point Observatory in New Mexico, and the Gemini telescope in Hawaii to confirm that the apparent clusters are not just on the same line of sight but are also approximately the same distance from Earth, indicating they are gravitationally bound together.

This discovery of long-sought groups of tiny galaxies is reported online in the journal Nature Astronomy.

"We hope this discovery will enable future studies of groups of dwarf galaxies and offer insights into the formation of galaxies like the Milky Way," concluded Stierwalt.

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Microscopic submarines for your stomach

Tiny "submarines" that speed independently through the stomach, use gastric acid for fuel (while rapidly neutralizing it), and release their cargo precisely at the desired pH: Though it may sound like science fiction, this is a new method for treating stomach diseases with acid-sensitive drugs introduced by scientists in the journal Angewandte Chemie. The technique is based on proton-driven micromotors with a pH-dependent polymer coating that can be loaded with drugs.

Though our gastric acid is useful for digestion and protection from pathogens, it can be destructive to orally administered, pH-sensitive pharmaceuticals, including protein-based drugs or some antibiotics. A coating resistant to gastric juices is sufficient to protect substances intended to work in the intestines. However, if a drug needs to be activated in the stomach, for instance to treat stomach ulcers or Helicobacter pylori bacteria infection, it is usually combined with proton pump inhibitors to block production of acid. When used over longer periods, these can cause some side effects in patients, including headaches, diarrhea, fatigue, and in some severe cases, anxiety, depression, or rhabdomyolysis (a muscle disease).

With their micromotors, a team led by Liangfang Zhang and Joseph Wang at the University of California, San Diego (La Jolla, USA) has introduced a novel approach for the neutralization of gastric acid that avoids side-effects and simultaneously acts as a drug transport mechanism that releases its cargo only when the required pH is reached.

To make the motors, 20 ?m magnesium spheres are coated with a nanolayer of gold and then a pH sensitive polymer into which the drug is embedded. Because the spheres lie on a glass support during the coating process, a small spot on the magnesium core remains uncoated. At this spot, an electrochemical reaction occurs, consuming protons and forming magnesium ions and releasing tiny bubbles of hydrogen gas. The bubbles propel the motors. This motion results in effective mixing of the liquid. This causes the reaction to proceed rapidly. Less than 20 minutes after administering the motors, the stomach environment reaches a neutral pH value. Once this is reached, the polymer dissolves and releases the payload. In addition, the propulsion increases penetration of the microtransporter into the gastric mucosa, which increases the amount of time that the drug is retained in the stomach. The micromotors are biocompatible and safe to use in the stomach. Stomach function is not affected and the normal pH value is re-established within 24 hours.

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Strength of hair inspires new materials for body armor

In a new study, researchers at the University of California San Diego investigate why hair is incredibly strong and resistant to breaking. The findings could lead to the development of new materials for body armor and help cosmetic manufacturers create better hair care products.

Hair has a strength to weight ratio comparable to steel. It can be stretched up to one and a half times its original length before breaking. "We wanted to understand the mechanism behind this extraordinary property," said Yang (Daniel) Yu, a nanoengineering Ph.D. student at UC San Diego and the first author of the study.

"Nature creates a variety of interesting materials and architectures in very ingenious ways. We're interested in understanding the correlation between the structure and the properties of biological materials to develop synthetic materials and designs -- based on nature -- that have better performance than existing ones," said Marc Meyers, a professor of mechanical engineering at the UC San Diego Jacobs School of Engineering and the lead author of the study.

In a study published online in Dec. in the journalMaterials Science and Engineering C, researchers examined at the nanoscale level how a strand of human hair behaves when it is deformed, or stretched. The team found that hair behaves differently depending on how fast or slow it is stretched. The faster hair is stretched, the stronger it is. "Think of a highly viscous substance like honey," Meyers explained. "If you deform it fast it becomes stiff, but if you deform it slowly it readily pours."

Hair consists of two main parts -- the cortex, which is made up of parallel fibrils, and the matrix, which has an amorphous (random) structure. The matrix is sensitive to the speed at which hair is deformed, while the cortex is not. The combination of these two components, Yu explained, is what gives hair the ability to withstand high stress and strain.

And as hair is stretched, its structure changes in a particular way. At the nanoscale, the cortex fibrils in hair are each made up of thousands of coiled spiral-shaped chains of molecules called alpha helix chains. As hair is deformed, the alpha helix chains uncoil and become pleated sheet structures known as beta sheets. This structural change allows hair to handle up a large amount deformation without breaking.

This structural transformation is partially reversible. When hair is stretched under a small amount of strain, it can recover its original shape. Stretch it further, the structural transformation becomes irreversible. "This is the first time evidence for this transformation has been discovered," Yu said.

"Hair is such a common material with many fascinating properties," said Bin Wang, a UC San Diego PhD alumna and co-author on the paper. Wang is now at the Shenzhen Institutes of Advanced Technology in China continuing research on hair.

The team also conducted stretching tests on hair at different humidity levels and temperatures. At higher humidity levels, hair can withstand up to 70 to 80 percent deformation before breaking. Water essentially "softens" hair -- it enters the matrix and breaks the sulfur bonds connecting the filaments inside a strand of hair. Researchers also found that hair starts to undergo permanent damage at 60 degrees Celsius (140 degrees Fahrenheit). Beyond this temperature, hair breaks faster at lower stress and strain.

"Since I was a child I always wondered why hair is so strong. Now I know why," said Wen Yang, a former postdoctoral researcher in Meyers' research group and co-author on the paper.

The team is currently conducting further studies on the effects of water on the properties of human hair. Moving forward, the team is investigating the detailed mechanism of how washing hair causes it to return to its original shape.

Full paper: "Structure and mechanical behavior of human hair." Authors of the study are: Yang Yu, Wen Yang, Bin Wang and Marc André Meyers, all of UC San Diego.

This research is supported by a Multi-University Research Initiative grant through the Air Force Office of Science Research (AFOSR-FA9550-15-1-1-0009).

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New species of moth named in honor of Donald Trump ahead of his swearing-in as president

This is a close up of the head of the holotype of the new species Neopalpa donaldtrumpi. (Dr. Vazrick Nazari / CC-BY 4.0)

Days before Donald J. Trump steps forward on the Inaugural platform in Washington to assume the role of the 45th President of the United States of America, evolutionary biologist and systematist Dr. Vazrick Nazari named a new species in his honour. The author, whose publication can be found in the open access journal ZooKeys, hopes that the fame around the new moth will successfully point to the critical need for further conservation efforts for fragile areas such as the habitat of the new species.

While going through material borrowed from the Bohart Museum of Entomology, University of California, Davis, Dr. Vazrick Nazari stumbled across a few specimens that did not match any previously known species. Following thorough analysis of these moths, as well as material from other institutions, the scientist confirmed he had discovered the second species of a genus of twirler moths.

While both species in the genus share a habitat, stretching across the states of California, USA, and Baja California, Mexico, one can easily tell them apart. The new moth, officially described as Neopalpa donaldtrumpi, stands out with yellowish-white scales present on the head in adults. In fact, it was in these scales that the author found an amusing reference to Mr. Trump's hairstyle and turned it into an additional justification for its name.

Donald Trump's flying namesake is announced only a month following the recently described species of basslet named after predecessor President Barack Obama, also published inZooKeys. The fish is only known from coral reefs in the Papahānaumokuākea Marine National Monument, Northwestern Hawaii, a nature reserve which the 44th President of the United States of America expanded to become the largest protected marine area in the world.

Being a substantially urbanized and populated area, the habitat of N. donaldtrumpi is also under serious threat.

"The discovery of this distinct micro-moth in the densely populated and otherwise zoologically well-studied southern California underscores the importance of conservation of the fragile habitats that still contain undescribed and threatened species, and highlights the paucity of interest in species-level taxonomy of smaller faunal elements in North America," says discoverer Dr. Vazrick Nazari. "By naming this species after the 45th President of the United States, I hope to bring some public attention to, and interest in, the importance of alpha-taxonomy in better understanding the neglected micro-fauna component of the North American biodiversity."

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Maternal micronutrients, nurturing environment boost child development

Mothers who take multi-micronutrient supplements during pregnancy can add the equivalent of up to one full year of schooling to a child's cognitive abilities at age 9-12, says a new study.

Other essential ingredients in the recipe for smarter kids include early life nurturing, happy moms, and educated parents, according to the research conducted in Indonesia.

As well, the study finds that a child's nurturing environment is more strongly correlated than biological factors to brain development and general intellectual ability, declarative memory, procedural memory, executive function, academic achievement, fine motor dexterity, and socio-emotional health.

Funded by the Government of Canada through Grand Challenges Canada's Saving Brains program, the study appears January 16, 2017 in the journal, Lancet Global Health.

The research was conducted by international group of researchers from Indonesia (Summit Institute of Development, the study leader, and the Center for Research on Language and Culture, University of Mataram), the United States (Harvard T.H. Chan School of Public Health, the University of California, Davis, and Georgetown University) the United Kingdom (University of Lancaster) and Australia (Deakin University).

Between 2012 and 2014, the researchers tested extensively almost 3,000 Indonesian school children, then 9 to 12 years old, whose mothers had participated in an earlier study into the effects of consuming either multiple micronutrient (MMN) supplements or standard iron-folic acid (IFA) supplements during pregnancy.

In the earlier "Supplementation with Multiple Micronutrients Intervention Trial" (SUMMIT), conducted between 2001 and 2004, half of the 31,290 participating Indonesian mothers consumed MMN supplements; the other half received IFA supplements. The MMN supplements were similar to the pre-natal multivitamin supplements consumed by many women in Canada, the United States, and other countries during pregnancy.

The latest follow-up study revealed impressive long-term benefits to children whose mothers took MMN supplements, including better "procedural memory" equivalent to the increase in score typical after an additional half-year of schooling.

The procedural memory is tied to the learning of new skills and the processing of established perceptual, motor, and cognitive skills. Procedural memory is important for a child's academic performance and daily life, and is tied to activities such as driving, typing, reading, arithmetic, reading, speaking and understanding language, and learning sequences, rules, and categories.

Children of anemic mothers in the MMN group scored substantially higher in general intellectual ability, a difference comparable to the increase associated with an additional full year of schooling.

What further impressed and surprised the researchers: The strength of the relationship between cognitive abilities and early life social and environmental conditions.

Biological factors such as maternal nutritional status during pregnancy, low infant birth weight, premature birth, poor infant physical growth and nutritional status at follow-up were not as strongly linked to cognitive ability as the socio-environmental factors assessed during the study: home environment, maternal depression, parental education and socio-economic status.

This suggests that current public health programs focused only on biological factors may not sufficiently enhance child cognition, and that programs addressing socio-environmental factors are essential to achieve thriving populations, according to the study.

In Indonesia's West Nusa Tenggara province, where the study was carried out, officials are already taking action in light of the research results.

Says Provincial Secretary General Dr. Rosiady Sayuti: "The findings led us to create, with the Summit Institute of Development and colleagues, the inter-sectoral Golden Generation Program to enhance social interventions to foster early childhood development."

Adds Dr. Nurhandini Eka Dewi, Head of the Provincial Health Office of West Nusa Tenggara: "We are procuring multiple micronutrients and scaling-up the Golden Generation Program for family nurturing. These will inform efforts to scale the work nationally."

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For first time ever, x-ray imaging captures material defect process

From blacksmiths forging iron to artisans blowing glass, humans have for centuries been changing the properties of materials to build better tools -- from iron horseshoes and swords to glass jars and medicine vials.

In modern life, new materials are created to improve today's items, such as stronger steel for skyscrapers and more reliable semiconductors for cell phones.

Now, researchers at the Department of Energy's (DOE) Argonne National Laboratory have discovered a new approach to detail the formation of these material changes at the atomic scale and in near-real time, an important step that could assist in engineering better and stronger new materials.

In a study published Jan. 16 in Nature Materials, researchers at Argonne's Advanced Photon Source, a DOE Office of Science User Facility, reveal they have captured -- for the first time ever -- images of the creation of structural defects in palladium when the metal is exposed to hydrogen.

This imaging capability will help researchers validate models that predict the behavior of materials and how they form defects. Defect engineering is the practice of intentionally creating defects within a material in order to change the material's properties. This knowledge is key to engineering better, stronger and more reliable materials for buildings, semiconductors, batteries, technological devices and many other items and tools.

"Defect engineering is based on the idea that you can take something you already know the properties of and, by putting in defects or imperfections, engineer things with improved properties," said Argonne scholar Andrew Ulvestad, one of the authors of the study. "The practice applies not only to metals but any material that has a crystal structure, like those found in solar cells and battery cathodes."

Defect engineering is used to optimize material design across a variety of fields, but it is most commonly associated with the development of semiconductors. Semiconductor materials, like silicon, are used as electrical components; they form the foundation for most of our modern day electronics, including laptops and mobile phones.

In a process known as "doping," manufacturers create defects in these materials by adding impurities in order to manipulate their electrical properties for various technological uses.

While manufacturers know they can change the properties of various materials to get the attributes they want, the processes that govern these changes are not always clear.

To increase the understanding of such processes, Argonne researchers focused specifically on defects forming on the nanoscale. Defects, interfaces and fluctuations at this very small level can provide critical insight into the functionalities of materials, such as their thermal, electronic and mechanical properties, on a larger scale.

To capture the formation of defects, the Argonne team took a nanostructured sample of palladium and injected, or infused, it with hydrogen at high-pressure. At the same time, they exposed the sample to powerful X-rays at the Advanced Photon Source.

Upon hitting the palladium crystal, the X-rays scattered, and their dispersion pattern was captured by a detector and used to calculate the changes in the position of atoms within the palladium structure. Essentially, this process enabled researchers to "see" deformations within the material.

"In some ways, we got the one-in-a-million shot, because defects occurring within the crystal don't always happen due to the complex nature of the process," said Argonne physicist Ross Harder, another author in the study.

The changes shown in the scans exemplify the numerous ways in which defects can alter the properties of materials and how they respond to external stimuli. For instance, the defects that formed altered the pressures at which palladium could store and release hydrogen, knowledge that could be useful for hydrogen storage, sensing and purification applications, the researchers said.

Defect engineering approaches are already being used to study other systems, including battery cathode nanoparticles. However, the study led by Ulvestad and Harder is the first to capture the formation of defects as they are happening.

"What we've done is create a roadmap for other researchers. We've shown them a way to model this system and systems that have similar dynamics," Ulvestad said.

The study, titled "Three-dimensional imaging of dislocation dynamics during the hydriding phase transformation," is published in Nature Materials.

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First humans arrived in North America a lot earlier than believed

This horse mandible from Cave 2 shows a number of cut marks on the lingual surface. They indicate that the animal's tongue was cut out with a stone tool. (Image courtesy of Université de Montréal)

The timing of the first entry of humans into North America across the Bering Strait has now been set back 10,000 years.

This has been demonstrated beyond a shadow of a doubt by Ariane Burke, a professor in Université de Montréal's Department of Anthropology, and her doctoral student Lauriane Bourgeon, with the contribution of Dr. Thomas Higham, Deputy Director of Oxford University's Radiocarbon Accelerator Unit.

The earliest settlement date of North America, until now estimated at 14,000 years Before Present (BP) according to the earliest dated archaeological sites, is now estimated at 24,000 BP, at the height of the last ice age or Last Glacial Maximum.

The researchers made their discovery using artifacts from the Bluefish Caves, located on the banks of the Bluefish River in northern Yukon near the Alaska border. The site was excavated by archaeologist Jacques Cinq-Mars between 1977 and 1987. Based on radiocarbon dating of animal bones, the researcher made the bold hypothesis that human settlement in the region dated as far back as 30,000 BP.

In the absence of other sites of similar age, Cinq-Mars' hypothesis remained highly controversial in the scientific community. Moreover, there was no evidence that the presence of horse, mammoth, bison and caribou bones in the Bluefish Caves was due to human activity.

To set the record straight, Bourgeon examined the approximate 36,000 bone fragments culled from the site and preserved at the Canadian Museum of History in Gatineau -- an enormous undertaking that took her two years to complete. Comprehensive analysis of certain pieces at UdeM's Ecomorphology and Paleoanthropology Laboratory revealed undeniable traces of human activity in 15 bones. Around 20 other fragments also showed probable traces of the same type of activity.

"Series of straight, V-shaped lines on the surface of the bones were made by stone tools used to skin animals," said Burke. "These are indisputable cut-marks created by humans."

Bourgeon submitted the bones to further radiocarbon dating. The oldest fragment, a horse mandible showing the marks of a stone tool apparently used to remove the tongue, was radiocarbon-dated at 19,650 years, which is equivalent to between 23,000 and 24,000 cal BP (calibrated years Before Present).

"Our discovery confirms previous analyses and demonstrates that this is the earliest known site of human settlement in Canada," said Burke. It shows that Eastern Beringia was inhabited during the last ice age."

Beringia is a vast region stretching from the Mackenzie River in the Northwest Territories to the Lena River in Russia. According to Burke, studies in population genetics have shown that a group of a few thousand individuals lived in isolation from the rest of the world in Beringia 15,000 to 24,000 years ago.

"Our discovery confirms the 'Beringian standstill [or genetic isolation] hypothesis,'" she said, "Genetic isolation would have corresponded to geographical isolation. During the Last Glacial Maximum, Beringia was isolated from the rest of North America by glaciers and steppes too inhospitable for human occupation to the West. It was potentially a place of refuge."

The Beringians of Bluefish Caves were therefore among the ancestors of people who, at the end of the last ice age, colonized the entire continent along the coast to South America.

The results of Lauriane Bourgeon's doctoral research were published in the January 6 edition of PLoS One under the title "Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada." The article is co-authored by Professor Burke and by Dr. Thomas Higham of Oxford University's Radiocarbon Accelerator Unit, in the U.K.

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New study refutes how fruit flies developed their tolerance for alcohol

The common fruit fly, the tiny insect drawn to your beer or wine, has evolved to have an impressive tolerance for alcohol.

More than two decades ago, in one of the first papers using gene sequences to find signatures of natural selection, scientists hypothesized that a molecular change in an enzyme gave theDrosophila melanogaster fruit fly species its superior ability to metabolize alcohol. Scientists concluded that the change they found in the Alcohol dehydrogenase (ADH) protein could be the adaptation that allowed D. melanogaster to colonize ethanol-rich habitats in rotting fruit better than its nearly identical relative,Drosophila simulans.

It seemed a logical conclusion that the gene sequence changes that altered amino acids in an enzyme that breaks down alcohol would be the mechanism of natural selection.

However, the authors of a new paper published online Jan. 13 by Nature Ecology and Evolutionsay they have now refuted that hypothesis.

Their findings indicate that intuition and signatures of selection in gene sequence may not be enough for scientists to conclusively solve the puzzles of molecular evolution. Tests also are needed to check how the changes function in organisms.

Using genetic engineering, scientists resurrected the fruit flies' ADH protein from ancestral species to compare whether the amino acid changes that have occurred in D. melanogaster's ADH enzyme actually improved the fruit flies' ability to tolerate alcohol. The answer, conclusively, was "no."

"This paper takes advantage of modern molecular biology and genetic approaches to test some of those hypotheses," said University of Nebraska-Lincoln biologist Kristi L. Montooth, a fruit fly expert who co-authored the new study. "It doesn't dispute that this species has a high ethanol tolerance. But it suggests that the molecular changes that have led to that high tolerance are not in this protein. They must be in other genes in the genome."

The search for new pathways in fruit flies could offer new clues about alcohol tolerance in humans, Montooth added.

Montooth and University of Chicago researcher Mohammad A. Siddiq conducted experiments with living transgenetic flies in her Lincoln laboratory during October 2015. They found the ADH amino acid changes made no discernible difference in the species' ability to survive while being fed increasingly heavy doses of alcohol. The flies had been genetically engineered by University of Wisconsin researcher David Loehlin so that their only genetic difference was in the ADH protein sequence.

The experiments with living fruit flies supported the findings of other experiments investigating the enzyme's biochemistry.

With molecular evolution, scientists seek to identify the specific molecular changes underlying the trait changes that shape the evolutionary family tree.

"We're generating so much sequence data right now, from so many species, that it's relatively straightforward to look for signatures of selection in genes and to find good candidates for adaptations," Montooth said. "But those are just candidates. You have to functionally test them if you want to say those are the variants favored by natural selection."

Siddiq and Montooth began working together in 2008 after Siddiq took the freshman biology course Montooth taught while on faculty at Indiana University. He began working in her laboratory and co-authored research with her while he was an undergraduate student.

"Despite now being in my fifth year of graduate school, I'm still publishing papers with the professor that I met on my first day of college," Siddiq said.

Siddiq, who is the study's first author, is now pursuing a doctoral degree at the University of Chicago, where he is studying with co-author Joseph W. Thornton, a professor who studies the molecular mechanisms of evolution. David W. Loehlin, a post-doctoral researcher at the University of Wisconsin-Madison, also participated in the study, creating the transgenic flies used in the experiments.

He came to Lincoln to work with Montooth on the fruit fly study, he said, because of her experience and expertise in evolutionary physiology and because of her influence on his career.

"I took her introductory biology class (as a college freshman) and loved it because her passion for evolution and its role as a unifying principle in biology really came through," Siddiq said. "My appreciation for studying traits not only in the test tube, but in the level of organisms, comes from the experiments I did during my undergraduate years."

The new study is the first demonstration of an approach combining ancestral sequence reconstruction with the making of transgenic organisms to directly test hypotheses at multiple biological levels, Siddiq said. It's a broadly applicable approach that in theory could be used with other organisms that lend themselves to transgenic engineering.

"One of the neat things about this paper is that it looks at the effects of this gene's mutations at the level of how the enzyme functions in the test tube, how it functions in the fly and then the consequences for how the fly deals with ethanol," Montooth said. "It's looking at effects of mutations across different levels of biological organization. Each of the co-authors played a role by investigating a different level of organization."

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