Culture

Social gadflies in an organization are the new superheroes of conservation, according to a study in this month's Nature Sustainability.

Conservation globally has received a boost from the United Nation's Sustainable Development Goals, placing new emphasis on, and opportunities for, support for the world's flora and fauna. Yet even as environmental non-governmental organizations (ENGOs) like The Nature Conservancy prepare to rise to the challenge, they face size issues. Specifically, their own size.

Many ENGOs are vast and international, making it challenging to put innovations into action. Bring in social scientists to figure out who best is positioned to push good ideas out and garner support. Organization-savvy researchers at Michigan State University (MSU) teamed up with Nature Conservancy researchers to test the system.

"We helped conceptualize how to analyze and leverage the social network administrative data for diffusion," said Ken Frank, MSU Foundation Professor of Sociometrics. "What we found were the people in an organization that are four times more likely to diffuse information." In other words, they struck organizational gold.

The group, led by Yuqing Liu, an MSU PhD student, and Yuta Masuda, a senior sustainable development and behavioral scientist at The Nature Conservancy, were focusing on people known as informal boundary spanners, those in an organization who may be more receptive to new information, and share it with co-workers regardless of what department they're in, or what project they work on. They span boundaries.

The Nature Conservancy had expanded Conservation by Design (CbD), its guiding science principles and strategic framework for its work across the globe. The new version ramped up an emphasis on connections between people and nature, opening the door to more systemic changes. It also posed a question on how best to get that information out effectively to its thousands of staff.

Using targeted emails inviting staff to take part in an online tutorial on one of CbD's core innovations, the team analyzed how informal boundary spanners and a randomly selected group of non-boundary spanners engaged with and shared the information with their colleagues. This led them to realize that informal boundary spanners are people who don't need to be told it's their job to share a cool piece of work information.

"Imagine you need 80 staff to volunteer in distributing information to their colleagues," Liu said. "You only need to ask 100 boundary spanners, 80 of them will just go ahead and share the innovation. But you will have to reach 400 non-IBS staff to have 80 people willingly spreading the information with their co-workers. This is a big difference when look at large scale."

In recognition of a complex and intertwined world, many global agendas are increasingly integrated. Many organizations are now tasked with incorporating, adapting, and adopting new ideas and tools to address ambitious policy problems. But resources are finite, and organizations are eager to do so efficiently and effectively.

Masuda said that a simple, but perhaps inefficient method, would be to mandate adoption. This study demonstrates how administrative systems can create an understanding of informal networks within organizations, and then be used to identify theoretically important actors.

"For organizational leaders, having information on the organizational network structure is like holding a roadmap of how new information can spread," he said. "Informal boundary spanners are like important local hubs scattered across the organization. Organizational leaders now have one more method to disseminate new ideas and tools."

A team of chemical and biomedical engineers from the Cockrell School of Engineering at The University of Texas at Austin, in collaboration with researchers from the University of Pennsylvania, have discovered that HIV-infected patients experience a dysfunction in a certain type of immune cell: the follicular helper T (Tfh) cell.

In a paper published today in Science Immunology, the authors outline how, through combining a sophisticated sequencing technique with a mass cytometry method (the measurement of cell characteristics), they discovered the Tfh cell dysfunction.

According to the latest figures from the World Health Organization, about 40 million people worldwide are living with HIV/AIDS. In the U.S., about 1 million are living with the virus, and 1 in 7 of those infected don't know it. Overall, the number of recorded cases has been in steady decline -- thanks to medical advances and greater public awareness. Still, major information gaps remain in our understanding of the fundamental nature of HIV, making every new insight important.

The UT Austin research team's finding is significant because the Tfh cells -- which are present in greater numbers in HIV-infected patients than in healthy individuals-- typically help fight off infection by communicating with other immune-supporting cells in the lymph nodes (the immune system's command center) about an impending viral attack. The researchers found that the Tfh cells present in those infected with HIV are not playing their usual part to defend against viral infections.

Led by UT Austin assistant professor Jenny Jiang in the Department of Biomedical Engineering, the research team combined techniques and approaches developed by Jiang and Laura Su, assistant professor of medicine in Penn's Perelman School of Medicine. Together, these technologies allowed the team to comprehensively profile T cells in the lymph node glands of HIV patients.

"These types of cells play a critical role during viral infections of any kind," Jiang said. "They communicate with other immune cells and provide instructions to B cells, for example, to produce virus-neutralizing antibodies that not only kill it off but also help prevent future infections."

Although the CD4+ T cell is notoriously depleted in patients infected with HIV, the population of Tfh cells is actually more elevated in the lymph nodes of those infected with HIV than it is in healthy individuals. This paradox is what makes further analysis of Tfh cell behavior by anyone studying HIV so vital.

Based on their central role in generating protective antibodies, it would be intuitive to assume that the increased presence of Tfh cells should result in greater resistance to infection. However, the researchers found this not to be the case, suggesting that Tfh cells in HIV patients are ineffective at sending signals to B cells to request help to fight off the infection.

"We believe Tfh cells behave differently when fighting chronic infections like HIV versus when fighting off acute infections like the common cold, potentially making them an easy target for HIV," Jiang said. "Our next step is to determine why the Tfh cell dysfunction occurs in HIV-infected patients, moving us one step closer to better understanding the virus."

Suspensions of live bacteria in a viscous liquid do not act as expected when spun at certain speeds and now a team of researchers know why the bacterial aggregation appears to explode when the spinning stops.

"We looked at the aggregation and manipulation of active matter -- live bacteria or artificial microswimmers -- and the depletion area surrounding them when droplets of bacteria are spun," said Igor Aronson, Huck Chair Professor of Biomedical Engineering, Chemistry and Mathematics, Penn State. "We were trying to understand how the depletion ring formed, but instead found that at higher speeds, when the spinning stopped, the aggregated bacteria explode like a nova."

The researchers placed a droplet containing mixtures of a viscous fluid and bacteria on a slide and dropped a tiny particle of nickel onto the droplet. Then the slide was turned over and the particle settled to the bottom of the drop. A spinning magnetic field created by four coils spins the particle. The spinning caused the bacteria to clump together around and under the spinning nickel particle. It also created a depletion ring around the bacteria where few if any bacteria were found. The spinning bacterial cluster and the depletion ring were visible.

Previous research used a liquid with fewer bacteria and spun the magnet at only 2 to 20 Hertz. To investigate the depletion ring, the researchers used 100 times more bacteria and spun the magnet at 100 to 400 Hertz. The system with these new parameters exhibited unusual and unexpected behavior, the researchers reported in a recent issue of Nature Communications. This behavior is only seen in active materials -- live bacteria or their synthetic analogs.

This behavior, while interesting in itself, might have implications for rotating equipment in environments where biofilms easily form.
"We often think that if something spins really fast there will be no bacterial film because the bacteria can't settle," said Aronson. "But this isn't true. This kind of bacterial accretion could be worse on spinning parts."

Another possible implication of this phenomenon might be in new diagnostic techniques to extract a few bacteria from suspensions.

Using both experiments and modeling, the researchers discovered that when the spinning nickel particle causes the bacteria to aggregate to a high enough density, other things are happening as well that cause what appears to be an explosion when the spinning stops.

"We did an analysis and found that if the accretion disk were perfectly round, it would just expand when the spinning stopped," said Aronson. "But because it is not perfect, the imperfect area gets propagated faster and it moves away from the center more rapidly. This makes the bacterial clump unstable and it appears to explode."

When bacteria are spinning they become orderly, arranging themselves in parallel streams. Although when looking down at what appears to be a dense disk of bacteria, the fluid motion itself is more complex. It flows out at the equator and in at the poles. Because the nickel particle that is causing the spinning is resting at the bottom of the liquid droplet that is a barrier, and the bacterial disk is rotating adjacent to the droplet surface, a stagnation zone forms. Once the spinning stops, the stagnation zone disappears and imperfections in the surface of the disk cause the rapid, non-uniform movement of bacteria away from the origin of rotation.

The researchers used mathematical models and a variety of experimental markers to see the behavior of the bacteria, including tomography and florescence. The model agreed with the experimental data.

"The behavior of these bacteria look like the explosion of a star going nova," said Aronson. "Of course, when a supernova explodes, the physics is very different."

Astrophysicists from the University of Surrey and the University of Edinburgh have created a new method to measure the amount of dark matter at the centre of tiny "dwarf" galaxies.

Dark matter makes up most of the mass of the Universe, yet it remains elusive. Depending on its properties, it can be densely concentrated at the centres of galaxies, or more smoothly distributed over larger scales. By comparing the distribution of dark matter in galaxies with detailed models, researchers can test or rule out different dark matter candidates.

The tightest constraints on dark matter come from the very smallest galaxies in the Universe, "dwarf galaxies". The smallest of these contain just a few thousand or tens of thousands of stars - so-called "ultra-faint" dwarfs. Such tiny galaxies, found orbiting close to the Milky Way, are made up almost entirely of dark matter. If the distribution of dark matter in these tiny galaxies could be mapped out it could provide new and exciting information about its nature. However, being entirely devoid of gas and containing very few stars, until recently there was no viable method for making this measurement.

In a study published by the Monthly Notices of the Royal Astronomical Society (MNRAS), a team of scientists from the University of Surrey have developed a new method to calculate the inner dark matter density of dwarf galaxies, even if they have no gas and very few stars. The key to the method is to make use of one or more dense star clusters orbiting close to the centre of the dwarf.

Star clusters are gravitationally bound collections of stars that orbit inside galaxies. Unlike galaxies, star clusters are so dense that their stars gravitationally scatter from one another causing them to slowly expand. The research team made the key new insight when they realised that the rate of this expansion depends on the gravitational field that the star cluster orbits in and, therefore, on the distribution of dark matter in the host galaxy. The team used a large suite of computer simulations to show how the structure of star clusters is sensitive to whether dark matter is densely packed at the centre of galaxies, or more smoothly distributed. The team then applied their method to the recently discovered "ultra-faint" dwarf galaxy, Eridanus II, finding much less dark matter in its centre than many models would have predicted.

Dr Filippo Contenta from the University of Surrey and lead author of the study said: "We have developed a new tool to uncover the nature of dark matter and already the results are exciting. Eridanus II, one of the smallest galaxies known, has less dark matter in its centre than expected. If similar results are found for a larger sample of galaxies, this could have wide-ranging implications for the nature of dark matter."

Professor Mark Gieles, Professor of Astrophysics at the University of Surrey and Principal Investigator of the European Research Council (ERC) project that funded the project, added: "We started this ERC project with the hope that we could use star clusters to learn about dark matter so it is very exciting that it worked."

Professor Justin Read, a co-author on the study from the University of Surrey, added: "It is challenging to understand our results for Eridanus II if dark matter comprises a weakly interacting 'cold' particle -- the currently-favoured model for dark matter. One possibility is that the dark matter at the very centre of Eridanus II was "heated up" by violent star formation, as suggested by some recent numerical models. More tantalising, however, is the possibility is that dark matter is more complex than we have assumed to date."

Dr Jorge Peñarrubia from the University of Edinburgh's School of Physics and Astronomy said: "These findings lend a fascinating insight into the distribution of dark matter in the most dark matter dominated galaxies in the Universe, and there is great potential for what this new method might uncover in the future."

Researchers at Harvard Medical School, the University of California, San Francisco, and the University of Georgia have described how the protein that allows strep and staph bacteria to stick to human cells is prepared and packaged. The research, which could facilitate the development of new antibiotics, will appear in the April 6 issue of the Journal of Biological Chemistry.

All bacteria have a standard secretion system that allows them to export different types of proteins outside of their cells. An important class of extracellular molecules produced by pathogenic bacteria are adhesins, proteins that enable bacteria to adhere to host cells. For unknown reasons, the SRR (serine-rich-repeat) adhesins of Staphylococcus and Streptococcus bacteria - pathogens that can be involved in serious infections such as bacterial meningitis, bacterial pneumonia and pericarditis - are transported through a secretion pathway that is similar to the standard system, but dedicated solely to adhesin.

It would be as if a warehouse that processes many types of goods were to have a separate set of doors and forklifts for just one of its wares. Tom Rapoport, a professor at Harvard Medical School who oversaw the new study, wanted to understand what exactly these dedicated molecular supply chains were doing.

"I was intrigued by the fact that there is a second secretion system in some bacteria that is separate from the canonical secretion system and is just dedicated to the secretion of one protein," Rapoport said. "There is a whole machinery, and it's only doing one thing."

Yu Chen, at the time a postdoctoral research associate in Rapoport's lab, led the investigation. She found that, in order to be transported, the adhesin protein needed to be modified with specific sugars by three enzymes acting in a specific sequence. These sugar modifications stabilize the protein and enhance its stickiness to target cells. Furthermore, the experiments showed that two proteins in the adhesin-specific pathway, whose function had previously been mysterious, seemed to be able to bind to these sugars, presumably enabling them to carry the adhesin to the cell membrane where adhesin's dedicated exit channel is located.

The complexity of the adhesin transport system necessitated collaboration with research teams at UCSF, Harvard Medical School, and the University of Georgia. Members of Paul Sullam's lab at UCSF provided the clinical perspective, members of Maofu Liao's lab at Harvard characterized the targeting complex by electron microscopy, and members of Parastoo Azadi's lab at Georgia analyzed the sugar modifications.

"It's a complicated system because it involves protein modification, chaperone activity and membrane targeting, so we encountered a lot of challenges," Chen said. "This (study) is a great example of how collaboration across labs in the scientific community advances human knowledge."

The reason that these bacteria use this separate export pathway for adhesins remains elusive. But because this pathway is unique to strep and staph bacteria, the new understanding of its components could help researchers develop highly targeted antibiotics to treat infections caused by these bacteria in the future.

"You could imagine that you could develop novel antibiotics that could target this pathway," Rapoport said. "(They) would be very specific for pathogenic bacteria."

Frankfurt am Main/ Germany, April 5, 2018. For the first time, scientists of the German Senckenberg Biodiversity and Climate Research Center, Goethe University and the University of Lund in Sweden have deciphered the complete genome of the blue whale and three other rorquals. These insights now allow tracking the evolutionary history of the worlds' largest animal and its relatives in unprecedented detail. Surprisingly, the genomes show that rorquals have been hybridizing during their evolutionary history. In addition, rorquals seem to have separated into different species in the absence of geographical barriers. This phenomenon, called sympatric speciation, is very rare in animals. The study has just been published in Science Advances.

Blue whales are the giants of the sea. With up to 30 meters (100 feet) long and weighing up to 175 tons, they are the largest animals that ever evolved on earth; larger even than dinosaurs. Short of becoming extinct due to whaling by the end of the 80s, currently the populations of the gentle giants are slowly recovering. Now new research highlights that the evolution of these extraordinary animals and other rorquals was also anything but ordinary.

A research team led by Professor Axel Janke, evolutionary geneticist at the Senckenberg Biodiversity and Climate Research Center and Goethe University, has found that the rorquals, including the blue whale, mated across emerging species boundaries. "Speciation under gene flow is rare. Usually, species are assumed to be reproductively isolated because geographical or genetic barriers inhibits genetic exchange. Apparently however, this does not apply to whales", explains Fritjof Lammers, co-lead-author of the study, Senckenberg Biodiversity and Climate Research Centre.

Teaming up with cetacean specialist Professor Ulfur Arnason at University of Lund, Sweden, Lammers and his colleagues are the first to have sequenced the complete genome of the blue whale and other rorquals, including the humpback and the gray whale. For these migratory whales, geographical barriers do not exist in the vastness of the ocean, instead some rorquals differentiated by inhabiting different ecological niches. Cross-genome analyses now indicate that there are apparently no genetic barriers between species and that there has been gene flow among different rorqual species in the past.

This is confirmed by spotting hybrids between fin and blue whales still to date, which have been witnessed and genetically studied by Professor Arnason. However, the researchers could not detect traces of recent liaisons between the two species in their genomes. This is probably because whale genomes are currently known only from one or two individuals.

To track down the rorquals' evolution, the scientists have applied so-called evolutionary network analyses. "In these analyses, speciation is not considered as a bifurcating phylogenetic tree as Darwin has envisioned it, but as an interwoven network. This allows us to discover hidden genetic signals, that otherwise would have stayed undetected", says Janke.

Overall, the research also shows that the relationships among the rorqual species are more complicated than hitherto thought. So far, the humpback whale has been seen as an outsider among the rorquals because of its enormous fins. The genome reveals that this classification does match the evolutionary signals. The same is true for the gray whale, which was believed to be evolutionarily distinct from rorquals due to its appearance. Genomic analyses show however that gray whales are nested within rorquals. Gray whales just happened to occupy a new ecological niche by feeding on crustaceans in coastal oceanic waters.

"Our research highlights the enormous potential of genome sequencing to better understand biological processes and the fundamentals of biodiversity. It even reveals how population sizes of whales have changed during the last million years", summarizes Janke. Janke is one of the leading researchers at the Hessian LOEWE Research Centre for Translational Biodiversity Genomics (LOEWE-TBG). Launched in January 2018, LOEWE-TBG is set to systematically analyze complete genomes or all active genes. The research center is envisaged to do basic research with a strong emphasis on transferring knowledge to benefit the study of natural products and protect biodiversity.

Researchers at the Centre for Environmental and Climate Research at Lund University have studied how pollination varies in different agricultural landscapes, by placing pots with either wild strawberry or field bean in field borders. Plants that were placed in a small-scale agricultural landscape, with pastures and other unploughed environments, were better pollinated than plants in landscapes dominated by arable land.

The researchers also investigated how sown flower strips, i.e. flower plantings which farmers often create to benefit pollinators, affected pollination in the different landscape types. In landscapes dominated by arable fields, pollination increased adjacent to the flower strip. A few hundred metres further away, however, the sown flower strips had no effect on the pollination of wild strawberry and field bean. In more small-scale agricultural landscape, the sown flower strips instead reduced pollination of adjacent plants, likely because the increased amount of flowers resulted in competition among flowers for pollinating insects.

"In our study, pollination was highest in small-scale agricultural landscape, with pastures, meadows and other unploughed habitats. Wild bees are important pollinators and manage better in a landscape with a lot of field borders and other unexploited environments. In intensively farmed landscapes, where such environments have disappeared, we can increase pollination, at least in the immediate vicinity, by sowing flowering plants to attract pollinating insects", says Lina Herbertsson, one of the researchers behind the study.

Farmers can receive financial support to implement measures that promote biodiversity, some of which may also benefit pollinating insects. An evaluation is currently underway of the EU's common agricultural policy, CAP, which among other things regulates the support for greening measures, aimed at reducing the climate impact of European agriculture and promoting biodiversity in the agricultural landscape.

"Our study underlines the importance of carefully designing measures intended to increase biodiversity, in order to achieve the desired effect. The same measure could have different impact in different places. If we want to increase pollination in varied agricultural landscapes, it seems to be a better strategy to restore and maintain pastures and meadows, and to manage field borders in a way that favours the local flora, rather than adding sown strips of flowering plants", concludes Lina Herbertsson.

EAST LANSING, Mich. -- Diabetic retinopathy is considered one of the most disabling complications of diabetes and the leading cause of new cases of vision loss among adults.

A new Michigan State University study is the first to find that a particular type of lipid, or fat, thought to only exist in the skin, now lives in your eye and might play a major role in deterring the eye disease.

"Our study presents an unexpected finding that the connections between cells in the retinal blood vessels contain unusual, long-chain lipids that may keep vessels from leaking, possibly preventing diabetic retinopathy from occurring," said Julia Busik, lead author of the study and a physiology professor.

The research is published in the journal Diabetes.

Blood vessels in the retina are closely connected by structures called tight junctions, which are part of the blood-retinal barrier, a virtually impenetrable wall.

Busik, along with graduate student Nermin Kady, showed that these connecting structures contain omega-linked acyl-very long chain ceramides - elongated lipids that appear to strengthen this barrier.

Diabetes can expose blood vessels to high levels of glucose and unhealthy amounts of lipids, which throws off the balance of nutrients that are transported throughout the body.

"When this becomes unbalanced, the vessels leak and become fragile, leading to the development of diabetic retinopathy," Busik said. "It appears though that these long-chain lipids and the enzymes that produce them can protect the retina and its blood vessels."

In cases of diabetes, the enzyme ELOVL4 is suppressed by the disease, which decreases its ability to produce these helpful lipids and prevent further damage.

Next steps for Busik will be to understand what these lipids can really do and how exactly they're situated in the tight junctions of the retina so new treatments may be possible.

"Incorporating more of the long-chain lipids into the eye could potentially be a new treatment down the road and involve injections or even eye drops," she said.

Lipids often get a bad rap due to their association with health issues such as high cholesterol and heart disease, but Busik is encouraged by what she's found.

"There are bad lipids and then there are good lipids," she said. "We've found good lipids in the eye that have the potential of changing the development of diabetic retinopathy."

A KAIST team presented a highly customizable neural stimulation method. The research team developed a technology that can print the heat pattern on a micron scale to enable the control of biological activities remotely.

The researchers integrated a precision inkjet printing technology with bio-functional thermo-plasmonic nanoparticles to achieve a 'selective nano-photothermal neural stimulation method.'

The research team of Professor Yoonkey Nam at the Department of Bio and Brain Engineering expects this will serve as an enabling technology for personalized precision neuromodulation therapy for patients with neurological disorders.

The nano-photothermal neural stimulation method uses the thermo-plasmonic effect of metal nanoparticles to modulate the activities of neuronal networks. With the thermo-plasmonic effect, metal nanoparticles can absorb specific wavelength of illuminated light to efficiently generate localized heat. The research team discovered the inhibitory behavior of spontaneous activities of neurons upon photothermal stimulation four years ago. Since then, they have developed this technology to control hyperactive behaviors of neurons and neural circuits, which is often found in neurological disorders such as epilepsy.

In order to overcome the limitation on the spatial selectivity and resolution of the previously developed nano-photothermal method, the team adopted an inkjet printing technology to micro pattern the plasmonic nanoparticles (a few tens of microns), and successfully demonstrated that the nano-photothermal stimulation can be selectively applied according to the printed patterns.

The researchers applied a polyelectrolyte layer-by-layer coating method to printing substrates in a way to improve the pattern fidelity and achieve the uniform assembly of nanoparticles. The electrostatic attraction between the printed nanoparticles and the coated printing substrate also helped the stability of the attached nanoparticles. Because the polyelectrolyte coating is biocompatible, biological experiments including cell culture are possible with the technology developed in this work.

Using printed gold nanorod particles in a few tens of microns resolution over a several centimeters area, the researchers showed that highly complex heat patterns can be precisely formed upon light illumination according to the printing image.

Lastly, the team confirmed that the printed heat patterns can selectively and instantaneously inhibit the activities of cultured hippocampal neurons upon near-infrared light illumination. Because the printing process is applicable to thin and flexible substrates, the technology can be easily applied to implantable neurological disorder treatment devices and wearable devices. By selectively applying the heat patterns to only the desired cellular areas, customized and personalized photothermal neuromodulation therapy can be applied to patients.

"The fact that any desired heat patterns can be simply 'printed' anywhere broadens the applicability of this technology in many engineering fields. In bioengineering, it can be applied to neural interfaces using light and heat to modulate physiological functions. As another engineering application, for example, printed heat patterns can be used as a new concept of anti-counterfeit applications," said the principal investigator, Yoonkey Nam at KAIST.

The receptors that sense the Earth's magnetic field are probably located in the birds' eyes. Now, researchers at Lund University have studied different proteins in the eyes of zebra finches and discovered that one of them differs from the others: only the Cry4 protein maintains a constant level throughout the day and in different lighting conditions.

Cry4 belongs to a group of proteins called cryptochromes. Normally they regulate the biological clock, but have also been considered significant for the magnetic sense. With this study, we now know which of the birds' cryptochromes do what.

"Cry4 is an ideal magnetoreceptor as the level of the protein in the eyes is constant. This is something we expect from a receptor that is used regardless of the time of day", explains Atticus Pinzón-Rodríguez, one of the researchers behind the study.

The conclusion is thus that this specific protein helps the magnetic sense to function, while other cryptochromes, whose levels in the body vary at different times of the day, take care of the biological clock instead.

Last year, Atticus Pinzón-Rodríguez and his colleagues noted that not only migratory birds navigate using a magnetic compass. Even resident birds that do not migrate in the spring and autumn have a magnetic sense and navigate using their internal magnetic compass. He now takes this one step further:

"This and last year's results indicate that other animals, perhaps all of them, have magnetic receptors and can pick up on magnetic fields."

A lot of research remains in order to map in detail how animals discover and use the Earth's magnetic field. What is clear is that it involves chemical reactions that interact with magnetic fields. According to Atticus Pinzón-Rodríguez, this knowledge may be of use when developing new navigation systems.

Chickens that grow up in an environment that they perceive as more diverse and manageable, retain an optimistic view of life and cope with stress better than individuals that grow up in more sterile surroundings, according to a new study published in Scientific Reports. A team of researchers lead by researchers from Linköping University, Sweden, measured how optimism in chickens is affected by stress.

With people, you can measure optimism by asking a person whether they see a glass as half-empty or half-full. Most people answer that the glass is half-full, unless they are suffering from depression. But how can you measure optimism in chickens? The method that the researchers used to determine whether an animal had a more or less optimistic attitude corresponds to asking whether the glass is half-full or half-empty. Young chicks were taught to distinguish between black and white, where one of the colours contained a reward, through a process known as associative learning. The chickens were then given a new challenge, and presented with grey symbols intermediate between the rewarded and the unrewarded colours. The researchers measured the response of the birds toward the grey colour where chickens that reacted to grey in the same manner as they had reacted to the rewarded colour were considered to be optimistic. Chickens that reacted to grey similarly to their response to the unrewarded colour were considered to be less optimistic.

The researchers also measured levels of dopamine, an important signal substance, in the brain of these chickens. In humans, dopamine is linked to well-being and optimism. The results showed that chickens assessed to be optimistic had higher levels of dopamine.

"In this study we wanted to investigate how stress influences optimism, and whether a more complex environment during development can buffer and counteract negative effects of stress," says Hanne Løvlie, associate professor in the Department of Physics, Chemistry and Biology at Linköping University, who has led the study.

In the study, the researchers compared chickens that grew up in rather sterile surroundings, to those that had grown up in a more complex and stimulating environment.

"One interesting result was that chickens in both types of environments were equally optimistic before being exposed to stress," says Hanne Løvlie.

In order to expose the chickens to stress, the researchers created an unpredictable environment for them by moving things around in the animals' pens, and expose them to irregular light and noise intervals. The animals were exposed to such stressors for a limited period. It was only when the chickens were exposed to stress that differences appeared: individuals that had lived in a simpler environment lost their optimistic attitude after being exposed to stress, while chickens in a more complex environment retained their optimistic attitude and thus seemed to be better able to cope with stress.

"If a chicken can hide under something or fly up and perch somewhere, it can manage a stressful situation better. We believe that the possibility of controlling the situation better resulted in these individuals being able to maintain optimism, even after a period with increased stress," says Josefina Zidar, who holds a doctorate in ethology from Linköping University.

Since the difference between the groups arose only after the animals had been exposed to additional stress, it suggests that repeated stress can reduce optimism.

"It has previously been shown that additive stress can have unfortunate consequences, and this should be considered in animal husbandry to provide better welfare," says Josefina Zidar.

A multinational South American team from Peru, Brasil and Bolivia led by the Universidad de San Martin de Porres at Lima, Peru, published the first genetic study on the modern descendants of the imperial Inka lineages in the journal Molecular Genetics and Genomics. This work supported by funds from the Genographic Project (Geno 2.0), shows new insights about the Inkas origins and lineages.

The Inka people arrived to Cusco valley and in a few centuries they built the Tawantinsuyu, the largest empire in the Americas. The Tawantinsuyu was the cultural climax of 6,000 years of Central Andes civilizations overlapping modern countries of Peru, Bolivia, Ecuador, the South of Colombia and the North of Argentina and Chile. In contrast with the richness of archeological and cultural evidence, pre Columbian history vanishes in time as it intermingles with myths due to the lack of writing systems before the arrival of the European chroniclers. Very little is known about the Inka origins and some genetic information could help reconstruct part of their history. Unfortunately the mummies and bodily remains of the Inka emperors, worshiped as gods, were burnt and buried in unknown locations due to religious and political persecution by the Christian Conquistadors and Inquisitors, so no direct material remain to study their DNA. "Thus for now, only the genetic analysis of modern families of Inka descent could provide some clues about their ancestors" remarks geneticist Jose Sandoval, first author, working at Universidad de San Martin de Porres at Lima, Peru.

There were two foundational myths for the origin of the Inkas before they established in Cusco valley to build their capital city. One is that Manco Capac and Mama Ocllo, considered children of the Sun God and founder parents of the civilization, came from Lake Titicaca about 500 km southwards from the border of North Bolivia and South Peru, more or less the same region where Tiwanaku empire existed a few centuries before. The second myth narrates that four Ayar brothers, with divine powers, came out from the caves inside of a hill in the area of Paccarictambo, 50 km south of Cusco and only one of them, Manco, arrived to the Cusco valley. Concerning the succession of the rulers (between 12 to 14), most chroniclers mention only one patrilineal heritage, however other authors think that it was a complex selection of military and administrative skills not necessarily electing the son of a previous Inka. "A unique patrilineal cluster would be expected in the first case. In the second case, two or more patrilineal pattern will be evident" says geneticist Ricardo Fujita, senior author, also at Universidad de San Martin de Porres". The research team included historian Ronald Elward, who studied documentation of twelve Inka noble families and followed up from the conquista times to their contemporary descendants. "Most of them still living in the towns of San Sebastian and San Jeronimo, Cusco, Peru, at present, are probably the most homogeneous group of Inka lineage" says Elward.

Markers for Y chromosome and mtDNA were used for the genetic analysis of these families and compared with a database for 2400 native individuals from Peru, Bolivia, Ecuador and Brazil. "The results show distinctive patrilineal origins to two founder individuals who lived between 1000 to 1500 AD, a period between the decline of former Tiwanaku (south) and Wari (north) contemporary empires, and the rise of the Inca empire a few centuries later" says geneticist Fabricio Santos from the Universidad Federal de Minas Gerais at Belo Horizonte, Brazil. The first patrilineal haplotype named AWKI-1 (awki means crown prince in quechua language) is found in the putative families descending of 2 earlier Incas Yahuar Huacac and Viracocha. The same pattern of the Inca descendants was also found in individuals living south to Cusco, mainly in Aymaras of Peru and Bolivia. The second patrilineal haplotype named AWKI-2 was found in one descendant of a more recent Inca, Huayna Capac, father of the two brothers (Huascar and Atahualpa) who were fighting a fraternal war over the empire at the arrival of the Conquistadors. "AWKI-2 is also found in dozens of individuals from different locations in the Andes and occasionally in the Amazon, suggesting a populational expansion" says Dr. Santos.

"In addition to San Sebastian and San Jeronimo, most locations of AWKI-1, AWKI-2 were southwards to Cusco including the basin of lake Titicaca and neighboring Paccarictambo, in agreement with the two foundational myths of the Incas" says Ricardo Fujita, "probably two pictures at different times of the same journey with final destination Cusco" adds Fujita. "It is also remarkable that in these contemporary Inka noblility families there is a continuity since pre Columbian times" says Ronald Elward. The analysis of their mtDNA suggested a highly varied matrilineal marker whose counterparts are found all over the Andes reflecting a high genetic flow. "This probably reflects the political alliances by arranged marriages between Cusco nobility and daughters of lords of kingdoms and chiefdoms all over the empire" states Jose Sandoval.

This work is the continuation of several studies performed by the team to reconstruct South American history by Genetics and also funded by a previous grant of the Genographic Project (Geno 1.0) led in South America by Fabricio Santos. Two published works included the unique ancient roots of the Uros, people from the Floating Islands of the Lake Titicaca and the Quechwa-Lamistas in Peruvian Amazon. Modern Uros are Aymara speaking people that some have thought to be people from the Aymara ethnia who profited tourism by living on the floating islands. However the team showed that they were genetically isolated people who had lost their original Uro language, shifting to more the widely used Aymara language. On the other hand the Kechwa-Lamista are Amazonian people who speak the Andean Quechua language and they were presumed descendants of Andeans Chancas, former enemies of the Incas, and were chased by them towards the Amazon. DNA showed that they are actually descendants of linguistically different Amazonian people who were gathered by Catholic missions and were taught the Quechua language (learn by the missionaries at the Andes) for a better evangelization.

"In some cases Genetics shows us something different than the official history. What is no written or badly written in historical records, can be revealed by what is written in our DNA. " concludes Ricardo Fujita. "This study is just the tip of the iceberg in trying to solve part of several enigmas of one of the most remarkable civilizations. The DNA of one Inka monarch bodily remain or of one direct descendant who lived at the beginning of the Spanish colonization could give more certainty about the Inca lineage, and our team is looking forward to it" declares Jose Sandoval.

WASHINGTON - Human airways already demonstrate gender-based differences in DNA methylation signatures at birth, providing an early hint of which infants may be predisposed to develop respiratory disorders like asthma later in life, a research team reports in a paper published online April 3, 2018, in Scientific Reports.

It's clear that boys and young men are more likely to develop neonatal respiratory distress syndrome, bronchopulmonary dysplasia, viral bronchiolitis, pneumonia, croup and childhood asthma. Unlike boys, girls have an additional copy of the X chromosome, which is enriched with immune-related genes, some of which play key roles in the development of respiratory conditions. Methylation prevents excessive gene activity in X-linked genes, however much remains unknown about how this process influences infants' risk of developing airway diseases.

A multi-institution research team that includes Children's National Health System attempted to characterize gender-based epigenomic signatures in the human airway early in children's lives with a special attention to defining DNA methylation patterns of the X chromosome.

"It's clear as we round in the neonatal intensive care unit that baby boys remain hospitalized longer than girls and that respiratory ailments are quite common. Our work provides new insights about gender differences in airway disease risk that are pre-determined by genetics," says Gustavo Nino, M.D., a Children's pulmonologist and the study's senior author.

"Characterizing early airway methylation signatures holds the promise of clarifying the nature of gender-based disparities in respiratory disorders and could usher in more personalized diagnostic and therapeutic approaches."

The research team enrolled 12 newborns and infants in the study and obtained their nasal wash samples. Six of the infants were born preterm, and six were born full term. The researchers developed a robust gender classification algorithm to generate DNA methylation signals. The machine learning algorithm identified X-linked genes with significant differences in methylation patterns in boys, compared with girls.

As a comparison group, they retrieved pediatric nasal airway epithelial cultures from a study that looked at genomic DNA methylation patterns and gene expression in 36 children with persistent atopic asthma compared with 36 heathy children.

The team went on to classify X-linked genes that had significant gender-based X methylation and those genes whose X methylation was variable.

"These results confirm that the X chromosome contains crucial information about gender-related genetic differences in different airway tissues," Dr. Nino says. "More detailed knowledge of the genetic basis for gender differences in the respiratory system may help to predict, prevent and treat respiratory disorders that can affect patients over their entire lifetimes."

Novel technology developed at UT Health San Antonio gives rise to mouse pancreatic tumors that have the same traits as human pancreatic cancer. A U.S. patent is pending on the invention.

The technology could revolutionize studies of pancreatic cancer initiation and progression and spur new drug development. An article published in the journal Carcinogenesis (Oxford University Press) describes this unique approach. Results of the research were made available online in November 2017 ahead of peer-review and print publication in February 2018.

Scientists study pancreatic cancer by genetically engineering mice to develop the disease or by transplanting tumors into rodents to test drug activity. In both cases, the resulting tumors provide an artificial, rather than true, picture of the human disease, said the technology's inventor, Bruno Doiron, Ph.D., of UT Health San Antonio.

"For a decade, we have failed in treating pancreatic cancer because we didn't have a good way to test new drugs," Dr. Doiron, an assistant professor in the Joe R. & Teresa Lozano Long School of Medicine, said.

Pancreatic cancer kills 95 percent of patients within five years of diagnosis. Advances in therapy have been negligible, with chemotherapies only able to extend survival by a few months. Need for a new study tool is therefore urgent.

Delivery method

Dr. Doiron and his lab team are injecting a modified virus into the adult mouse pancreas. The virus is a delivery vehicle for two pro-cancer molecules (called KrasG12D mutation and shRNA p53) that are present in human pancreatic tumors. Upon injection, the virus permeates the pancreas with these pro-cancer factors. The effect is contained; only the pancreas is altered by this molecular cocktail. When the mice reach 28 to 30 weeks of age, tumors develop that resemble human pancreatic cancer.

"I take the two major genetic mutations involved in human pancreatic cancer and inject them directly to the pancreas, and tumors develop in the adult mice," Dr. Doiron said. "This bypasses the artificial manipulation introduced by other methods, and spontaneous cancers develop that mimic those found in people."

The procedure is performed in mice that are not of any special breeding or stock. They are from many different parents. This ensures that the development of pancreatic cancer is in a random nature, the way it occurs in humans.

A step forward

The Carcinogenesis article "is an important paper for the field of pancreatic cancer, because it demonstrates that all previous methods of study are obsolete," Dr. Doiron said.

Obesity and diabetes are major risk factors for pancreatic cancer. The risk of pancreatic cancer is increased 1.5-fold in obese subjects and two- to threefold in people with diabetes. The new technology can be used to delve into this link.

"The prevalence of obesity and Type 2 diabetes has reached epidemic proportions during the last two decades in the U.S. and worldwide, and this may explain, in part, why the death rate from pancreatic cancer has not declined in the same way as it has for some other cancers," Dr. Doiron said.

Ruben A. Mesa, M.D., FACP, director of the Mays Cancer Center, the newly named center home to UT Health San Antonio MD Anderson Cancer Center, commented: "This important work by Dr. Doiron and colleagues will allow us to better predict which treatments for the devastating disease of pancreatic cancer will be effective. These discoveries are a much-needed advance on efforts to cure pancreatic cancer."