Culture

"They're out there," goes a saying about extraterrestrials. It would seem more likely to be true in light of a new study on planetary axis tilts.

Astrophysicists at the Georgia Institute of Technology modeled a theoretical twin of Earth into other star systems called binary systems because they have two stars. They concluded that 87% of exo-Earths one might find in binary systems should have axis tilts similarly steady to Earth's, an important ingredient for climate stability that favors the evolution of complex life.

"Multiple-star systems are common, and about 50% of stars have binary companion stars. So, this study can be applied to a large number of solar systems," said Gongjie Li, the study's co-investigator an assistant professor at Georgia Tech's School of Physics.

Single-star solar systems like our own with multiple planets appear to be rarer.

Alpha Centauri B? Wretched

The researchers started out contrasting how the Earth's axis tilt, also called obliquity, varies over time with the variation of Mars' axis tilt. Whereas our planet's mild obliquity variations have been great for a livable climate and for evolution, the wild variations of Mars' axis tilt may have helped wreck its atmosphere, as explained in the section below.

Then the researchers modeled Earth into habitable, or Goldilocks, zones in Alpha Centauri AB - our solar system's nearest neighbor, a binary system with one star called "A" and the other "B." After that, they expanded the model to a more universal scope.

"We simulated what it would be like around other binaries with multiple variations of the stars' masses, orbital qualities, and so on," said Billy Quarles, the study's principal investigator and a research scientist in Li's lab. "The overall message was positive but not for our nearest neighbor."

Alpha Centauri A actually didn't look bad, but the outlook for mild axis dynamics on an exo-Earth modeled around star B was wretched. This may douse some hopes because Alpha Centauri AB is four lightyears away, and a mission named Starshot with big-name backers plans to launch a space probe to look for signs of advanced life there.

The researchers are publishing their study, which was co-led by Jack Lissauer from NASA Ames Research Center, in Astrophysical Journal on November 19, 2019, under the title: "Obliquity Evolution of Circumstellar Planets in Sun-like Stellar Binaries." The research was funded by the NASA Exobiology Program.

No exoplanets have been confirmed around A or B; an exoplanet has been confirmed around the nearby red dwarf star Proxima Centauri, but it is very likely to be uninhabitable.

Earth? Just right

Even with its ice ages and hot phases, Earth's climatological framework has been calm for hundreds of millions of years - in part because of its mild orbital and axis-tilt dynamics - allowing evolution to take big strides. Wildly varying dynamics, and thus climate, like on Mars would stand to regularly kill off advanced life, stunting evolution.

Earth's orbit around the sun is on a slight incline that seesaws gently and very slowly through a slight precession, a kind of oscillation. As Earth revolves, it shifts position relative to the sun, circling it a little like a spirograph drawing. The orbit also precesses in shape between slightly more and slightly less oblong over 100,000-year periods.

Earth's axis tilt precesses between 22.1 and 24.5 degrees over the course of 41,000 years. Our large moon stabilizes our tilt through its gravitational relationship with Earth, otherwise, bouncy gravitational interconnections with Mercury, Venus, Mars, and Jupiter would jolt our tilt with resonances.

"If we didn't have the moon, Earth's tilt could vary by about 60 degrees," Quarles said. "We'd look maybe like Mars, and the precession of its axis appears to have helped deplete its atmosphere."

Mars' axis precesses between 10 degrees and 60 degrees every 2 million years. At the 10-degree tilt, the atmosphere condenses at the poles, creating caps that lock up a lot of the atmosphere in ice. At 60 degrees, Mars could grow an ice belt around its equator.

Universe? Hopeful

In Alpha Centauri AB, star B, about the size of our sun, and the larger star, A, orbit one another at about the distance between Uranus and our sun, which is a very close for two stars in a binary system. The study modeled variations of an exo-Earth orbiting either star but concentrated on a modeled Earth orbit in the habitable zone centered around B, with A being the orbiting star.

A's orbit is very elliptical, passing close by and then moving very far away from B and slinging powerful gravity, which, in the model, overpowered exo-Earth's own dynamics. Its tilt and orbit varied widely; adding our moon to the model didn't help.

"Around Alpha Centauri B, if you don't have a moon, you have a more stable axis than if you do have a moon. If you have a moon, it's pretty much bad news," Quarles said.

Even without a moon and with mild axis variability, complex, Earthlike evolution would seem to have a hard time on the modeled exo-Earth around B.

"The biggest effect you would see is differences in the climate cycles related to how elongated the orbit is. Instead of having ice ages every 100,000 years like on Earth, they may come every 1 million years, be worse, and last much longer," Quarles said.

But a sliver of hope for Earthlike conditions turned up in the model: "Planetary orbit and spin need to precess just right relative to the binary orbit. There is this tiny sweet spot," Quarles said.

When the researchers expanded the model to binary systems in the universe, the probability of gentle obliquity variations ballooned.

"In general, the separation between the stars is larger in binary systems, and then the second star has less of an effect on the model of Earth. The planet's own motion dynamics dominate other influences, and obliquity usually has a smaller variation," Li said. "So, this is quite optimistic."

HOUSTON -- Newly diagnosed prostate cancer patients have multiple standard-of-care treatment options available, but many are not fully informed of their choices. A study led by researchers at The University of Texas MD Anderson Cancer Center found men who seek treatment at a multidisciplinary (MultiD) prostate cancer clinic are more likely to be advised about treatment choices and to receive care that complies with evidence-based treatment guidelines. African American men who visited the MultiD clinic also were more likely to receive definitive, or curative, therapy, compared with national trends.

The findings, published in Cancer, are based on the largest and longest analysis of a MultiD clinic database. The study evaluated treatment choice at MD Anderson's Multidisciplinary Prostate Cancer Clinic in comparison to U.S. national trends assessed by reviewing the Surveillance, Epidemiology, and End Results (SEER) database.

According to the American Cancer Society, 174,650 new cases of prostate cancer will be diagnosed this year, making it the most common non-skin cancer in men. Previous studies have shown mortality rates are similar for those who opt for active surveillance versus treatment, yet many men continue to experience preventable treatment side effects.

"Men who visit a MultiD prostate clinic have the opportunity to see a radiation oncologist and a urologist in the same visit, giving them the chance to discuss treatments options and potential side effects in order to make an informed treatment decision," said Chad Tang, M.D., assistant professor of Radiation Oncology and study author. "Patients and their families appreciate the opportunity to hear all treatment options and receive assistance with decision-making."

The study analyzed 4,451 men with prostate cancer treated at the MultiD clinic from 2004-2016. To compare nationwide trends, 392,710 men with prostate cancer diagnosed from 2004-2015 were selected from the SEER database.

Men with low-risk disease were more likely to choose active surveillance in the MultiD clinic than the SEER group. In 2015, the rate of active surveillance among men with low-risk disease in the MultiD clinic was 74% compared with 54% in the SEER group. The tendency toward active surveillance for patients with low-risk prostate cancer is supported by the current National Comprehensive Cancer Network (NCCN) guidelines and national trends.

At the high risk end of the spectrum, significantly more men were offered aggressive treatment in the MultiD clinic group as compared to SEER patients. Nearly 20% of men with high-risk disease chose non-definitive treatment in the SEER group whereas all men with high-risk disease received definitive treatment in the MultiD clinic group. NCCN guidelines recommend men with high-risk prostate cancer receive definitive treatment.

In the MultiD clinic, African American men over 70 with low-risk disease were more likely to choose active surveillance than older white men. In all other age and risk groups, African Americans were more likely to receive definitive treatment. In the SEER cohort, the opposite was found where African Americans in all risk groups were more likely to receive definitive treatment across age groups.

Previous studies have shown increased use of definitive therapy among white patients compared with African American patients. Among MultiD clinic patients an opposite trend was found for high-risk, intermediate-risk and young low-risk patients, with African American patients having higher rates of definitive therapy.

"These results suggest that when offered treatment options by a multidisciplinary team, African American men may choose a more definitive treatment choice," Tang said. "The outcomes of this study offer an important motivation to provide multidisciplinary clinical care on the national level."

MD Anderson has implemented multidisciplinary prostate cancer clinics across the MD Anderson Cancer Network®. MD Anderson Cancer Network collaborates with community hospitals and health care systems to provide higher quality and advanced care to patients in the communities in which they live.

The authors note several limitations to the study. Those included the current SEER database contains data through 2015, where the MultiD clinic database has information through 2016. The SEER database also lacks significant details regarding complete therapy and does not have data on whether patients were treated with active surveillance, watchful waiting, hormones alone or "benign neglect." Finally, there is inherent patient referral preference to this single center MultiD clinic.

Follow-up studies will look at other aspects of treatment choice. A current study evaluates financial effects of patients who choose external beam radiotherapy, brachytherapy and prostatectomy and the availability of choice across the country using the SEER database.

Husbands are least stressed when their wives earn up to 40% of household income but they become increasingly uncomfortable as their spouse's wages rise beyond that point and are most stressed when they are entirely economically dependent on their partner, new research from the University of Bath shows.

The study of over 6,000 American heterosexual couples over 15 years showed husbands are anxious when they are the sole breadwinner, shouldering all the burden of responsibility for the household's finances. Stress levels decline as their wives' earnings approach 40% of household income. But as women's earnings go through that point, the study showed husbands' stress levels gradually increasing.

"These findings suggest that social norms about male breadwinning - and traditional conventions about men earning more than their wives - can be dangerous for men's health. They also show how strong and persistent are gender identity norms," said Dr Joanna Syrda, an economist at the University of Bath's School of Management.

"This is a large study but of a specific group - other conventions apply in other groups and societies and the results may change as times move on. However, the results are strong enough to point to the persistence of gender identity norms, and to their part in male mental health issues. Persistent distress can lead to many adverse health problems, including physical illness, and mental, emotional and social problems," she said.

Dr Syrda noted the study also showed that husbands did not suffer psychological distress about their wives' income if their wife was the higher earner before marriage and the existing and potential income gap was clear to them.

Figures from the Pew Research Centre in the US show only 13% of married women earned more than their husbands in 1980. But by 2017 the figure was close to one third and the trend was likely to continue. Dr Syrda said she and other researchers were increasingly interested in how this would affect social norms, wellbeing, and our understanding of masculinity.

"The consequences of traditional gender role reversals in marriages associated with wives' higher earnings span multiple dimensions, including physical and mental health, life satisfaction, marital fidelity, divorce, and marital bargaining power," Dr Syrda said.

"With masculinity closely associated with the conventional view of the male breadwinner, traditional social gender norms mean men may be more likely to experience psychological distress if they become the secondary earner in the household or become financially dependent on their wives, a finding that has implications for managing male mental health and society's understanding of masculinity itself," she said.

Dr Syrda said her study also shed light on the 'bargaining power' between husband and wife.

"The elevated psychological distress that comes with husbands' economic dependence on their wives can also have practical underpinnings due to bargaining in the shadow of dissolution or the fear of reduced economic status in the event of an actual divorce. These effects are larger among cohabiting couples, possibly due to the higher probability of dissolution," she said.

The study also showed a disparity in the way husbands and wives assessed their own psychological distress and that of their partner. Survey respondents were asked to measure distress in terms of feeling sad, nervous, restless, hopeless, worthless, or that everything was an effort. Men reported better mental health than their wives reported on their behalf.

"This too may be down to gender norms. If masculine social roles preclude the admission of vulnerability, and men are inclined to hide symptoms of stress and depression, it follows that wives' responses [about their spouses] will be less accurate," Dr Syrda said.

In fact, wives reported their husbands' lowest distress level was when they were contributing 50% of the household income, while husbands reported lowest distress when their wives contributed 40%.

"The fact that a wife observes to a lesser degree her husband's elevated psychological distress when he is financially dependent on her may be simply because he does not communicate it - this may be yet another manifestation of gender norms," she said.

PITTSBURGH--Trash talking has a long and colorful history of flustering game opponents, and now researchers at Carnegie Mellon University have demonstrated that discouraging words can be perturbing even when uttered by a robot.

The trash talk in the study was decidedly mild, with utterances such as "I have to say you are a terrible player," and "Over the course of the game your playing has become confused." Even so, people who played a game with the robot -- a commercially available humanoid robot known as Pepper -- performed worse when the robot discouraged them and better when the robot encouraged them.

Lead author Aaron M. Roth said some of the 40 study participants were technically sophisticated and fully understood that a machine was the source of their discomfort.

"One participant said, 'I don't like what the robot is saying, but that's the way it was programmed so I can't blame it,'" said Roth, who conducted the study while he was a master's student in the CMU Robotics Institute.

But the researchers found that, overall, human performance ebbed regardless of technical sophistication.

The study, presented last month at the IEEE International Conference on Robot & Human Interactive Communication (RO-MAN) in New Delhi, India, is a departure from typical human-robot interaction studies, which tend to focus on how humans and robots can best work together.

"This is one of the first studies of human-robot interaction in an environment where they are not cooperating," said co-author Fei Fang, an assistant professor in the Institute for Software Research. It has enormous implications for a world where the number of robots and internet of things (IoT) devices with artificial intelligence capabilities is expected to grow exponentially. "We can expect home assistants to be cooperative," she said, "but in situations such as online shopping, they may not have the same goals as we do."

The study was an outgrowth of a student project in AI Methods for Social Good, a course that Fang teaches. The students wanted to explore the uses of game theory and bounded rationality in the context of robots, so they designed a study in which humans would compete against a robot in a game called "Guards and Treasures." A so-called Stackelberg game, researchers use it to study rationality. This is a typical game used to study defender-attacker interaction in research on security games, an area in which Fang has done extensive work.

Each participant played the game 35 times with the robot, while either soaking in encouraging words from the robot or getting their ears singed with dismissive remarks. Although the human players' rationality improved as the number of games played increased, those who were criticized by the robot didn't score as well as those who were praised.

It's well established that an individual's performance is affected by what other people say, but the study shows that humans also respond to what machines say, said Afsaneh Doryab, a systems scientist at CMU's Human-Computer Interaction Institute (HCII) during the study and now an assistant professor in Engineering Systems and Environment at the University of Virginia. This machine's ability to prompt responses could have implications for automated learning, mental health treatment and even the use of robots as companions, she said.

Future work might focus on nonverbal expression between robot and humans, said Roth, now a Ph.D. student at the University of Maryland. Fang suggests that more needs to be learned about how different types of machines -- say, a humanoid robot as compared to a computer box -- might invoke different responses in humans.

Researchers from Istituto Italiano di Tecnologia (IIT) and University of Salento, both in Lecce, Italy, and Harvard Medical School in Boston have developed a new light-based method to capture and pinpoint the epicenter of neural activity in the brain.

The approach, described Oct. 7 in Nature Methods, lays the foundation for novel ways to map connections across different brain regions--an ability that can enable the design of devices to image various areas of the brain and even treat conditions that arise from malfunctions in cells inhabiting these regions, the researchers said.

The work was led by Ferruccio Pisanello at IIT, Massimo De Vittorio at IIT and University of Salento, and Bernardo Sabatini, the Alice and Rodman W. Moorhead III Professor of Neurobiology in the Blavantik Institute at Harvard Medical School, and funded by the European Research Council and by the National Institutes of Health in the United States.

One of the central challenges in modern neuroscience is recording the exchange of information between different regions of the brain, as well as between different cell types. The new method overcomes this challenge by allowing the simultaneous collection of signals from various brain regions through the use of a tapered optical probe.

The study marks the first instance of successfully using light to decode the activity of specific neuronal populations as well as manipulation of different brain regions with the use of a single probe. The approach relies on bringing fluorescent molecules into specific nerve cells in order to track their electric activity and to measure the level of neurotransmitters--molecules that act as chemical messengers across neurons.

To achieve this, the team used an optical fibre in the shape of a narrow cone with a tip so thin and so precise that it is capable of capturing light from single neurons along regions as long as 2 millimetres (0.07 inches).

The researchers inserted the light-sensing probe inside the striatum, a region of the brain involved in planning movements, and used it to track the release of dopamine, a critical neurotransmitter involved in motor control which also plays a key role in the development of disorders like Parkinson's disease, schizophrenia and depression.

The device successfully captured neural activity in specific sub-regions of the striatum involved in the release of dopamine during specific behaviours.

The approach has effectively allowed scientists to capture how nerve signals travel in time and space and to gauge the concentration of specific neurotransmitters during specific actions. The method enriches researchers' methodological repertoire and augments their ability to study the central nervous system and probe the molecular causes of neurological disorders.

COLUMBIA, Mo. - Down syndrome, due to an extra chromosome 21, occurs in 250,000 children and adults in the United States, making it the country's most common chromosomal disorder. Inherited heart defects, thyroid cancer, celiac disease and developmental disabilities are common Down syndrome complications. Only recently has catatonia, a behavioral condition marked by new onset immobility, mutism, withdrawal and other behavioral abnormalities, been recognized in Down syndrome.

While considerable research has been done on Down syndrome, little is known about associated catatonia. Now, researchers at the University of Missouri have conducted the first longitudinal study of consecutively diagnosed individuals with catatonia in order to identify the most effective treatments and outcomes.

Judith Miles, professor emerita of child health-genetics in the MU Thompson Center for Autism and Neurodevelopmental Disorders, thoroughly assessed seven adolescents with Down syndrome and diagnosed with catatonia between 2013 and 2018.

"As this was the first well-studied group of patients with Down syndrome who developed catatonia, we collected a comprehensive data set of medical, developmental, demographic, family, social and genetic information," Miles said. "By involving the patients' families throughout the process, we were able to monitor progress over time in a patient-centered way."

Miles found catatonia in young people with Down syndrome, for the most part, resembles catatonia complicating other psychiatric and medical disorders. Lorazepam, a sedative drug that helps restore the balance of neurotransmitters in the brain, and electroconvulsive therapy, which involves a brief electrical stimulation of the brain while the patient is under anesthesia, both resulted in reduced behavioral symptoms over time. The research highlights the importance of sustained treatment to help patients with Down syndrome and catatonia maintain recovery long-term.

"This research can help families, physicians and psychiatrists who take care of kids with catatonia," Miles said. "Our main goal is to enhance medical services and treatment options in order to ultimately improve health outcomes."

Genetic analyses have revealed remarkably higher species diversity in common red seaweed than previously assumed. It was thought that there were only five related species of the Gloiopeltis genus (known as 'funori' in Japanese) worldwide. However, genetic analyses of historic and modern specimens have revealed that there are over ten in Japan alone. The reinstatement of the species Gloiopeltis compressa (new Japanese name: Ryukyu-funori) was proposed by this research. It is found in Okinawa and has previously been confused with other species of Gloiopeltis.

These discoveries were made by an international research collaboration group consisting of the following members from Kobe University; Assistant Professor Takeaki Hanyuda, Professor Hiroshi Kawai (both of the Research Center for Inland Seas) and Kensho Yamamura (2nd year Masters in Biology at the Graduate School of Science).

The results of this research were published in the following journals; 'Phycologia' (October 14, 2019) and 'Phycological Research' (October 29, 2019).

Research Findings

Gloiopeltis is a genus of seaweed that is reddish brown to dark yellow in color. Called 'funori' in Japanese, it has been utilized to make glue and binding since ancient times. It is also used as an ingredient in miso soup.

Until recently, there were five identified species worldwide, three of which were found in Japan- 'fukuro-funori' (Gloiopeltis furcata), 'ma-funori' (Gloiopeltis tenax) and 'hana-funori' (Gloiopeltis complanata). This research team revealed through genetic analyses that there are in fact over ten species of Gloiopeltis in Japan alone.

Analyses of Gloiopeltis furcata

Gloiopeltis furcata has the widest distribution range among Gloiopeltis species. It is found in the inter-tidal zones of temperate to cold water regions covering most of the northern Pacific Coasts. The research team genetically analyzed specimens of G. furcata collected from many habitats across its wide distribution. They revealed that there are 4 to 5 unnamed species that have previously been misclassified as G. furcata. These are easily confused with each other unless genetically analyzed.

Genetic analysis also suggested that some populations of G. furcata had previously been miscategorized as separate species. It was shown that Gloiopeltis minuta native to California and so called due to its small size, was in fact G. furcata. A 19th century sample from Kamchatka, Russia was classified as G. dura, however this species has not been reported since the name was introduced. Genetic analysis showed that this species was also synonymous with G. furcata.

The research group also genetically analyzed the type specimen of G. furcata taken from Sitka in Alaska in the 19thcentury. This specimen is currently housed at the V. L. Komarov Botanical Institute in St. Petersburg, Russia. Analyses revealed that this specimen was very close genetically to the specimens found in the Hokkaido and Tohoku areas of Japan. It was determined that they are conspecific- they belong to the same species. As G. furcata has been reported over a much wider range of Japan, it is thought that there are several different species south of Tohoku- more research is required to illuminate this.

Analyses of the Gloiopeltis complanata subgenus

Gloiopeltis complanata is distinguishable from G. furcata by its smaller size and greater number of branches.

To discover more about the G. complanata clade, genetic analyses were performed on historic and modern samples from the Okinawa region. This included 19th century specimens now held at Trinity College Herbarium in Ireland. These historical samples were taken by American botanist Charles Wright during the North Pacific Exploring Expedition of 1853-56.

The results confirmed that there is a separate species that was previously thought to be the same as G. complanata, which was very close genetically to a species which was described as Caulacanthus compressus in the 19th century. Therefore, this research group proposed the reinstatement of the species Gloiopeltis compressa (new Japanese name: Ryukyu-funori). It is mainly found in Okinawa (formerly the Ryukyu kingdom) and is characterized by its smaller size.

Discovery of an unconfirmed species in Japan

This research also revealed that a species previously found in Korea - Gloiopeltis frutex - also grows around Kyushu in southern Japan. Overall, this research has identified a new species, Ryukyu-funori (Gloiopeltis compressa), and has revealed that there is great variation in the Gloiopeltis genus in Japan and worldwide. Continuing research is hoped to illuminate this further.

In the deep sea, far away from the light of the sun, organisms use chemical energy to fix carbon. At hydrothermal vents - where hot, mineral-rich water gushes out of towering chimneys called black smokers - vibrant ecosystems are fueled by chemical energy in the vent waters. Mussels thrive in this seemingly hostile environment, nourished by symbiotic bacteria inside their gills. The bacteria convert chemicals from the vents, which the animals cannot use, into tasty food for their mussel hosts. Now an international group of scientists led by Nicole Dubilier from the Max Planck Institute of Marine Microbiology in Bremen and Jillian Petersen, now at the University of Vienna, reports in ISME Journal that carbon fixation in the deep sea is more diverse than previously thought.

Meet Thiobarba, the new bacterium on the block

It has long been known that deep-sea Bathymodiolus mussels, distant relatives of the edible, shallow-water blue mussel, harbor symbionts inside their gills. In 2016, Adrien Assié carried out his PhD at the Max Planck Institute for Marine Microbiology and discovered symbiotic bacteria living between the mussel's gills, calling them Thiobarba. Adrien's further studies reveal that these bacteria not only belong to a family not yet known, but also feed in an unexpected way. "Thiobarba fixes carbon using the Calvin cycle," explains Nikolaus Leisch, shared-first author of the study. "It is the first of this bacterial group to use this pathway for carbon fixation." Usually this group uses a pathway known as the reverse TCA-cycle, which is much more energy efficient, to fix carbon. However, it does not work well in the presence of oxygen, which is abundant in the gills of these mussels. "This discovery calls into question current assumptions about which bacterial groups use which type of carbon fixation pathway," Leisch continues.

Fixing CO2 their neighbors' way

The Thiobarba family belongs to a group of bacteria called Epsilonproteobacteria, recently renamed as Campylobacterota. Members of this group were not known to live in symbiosis with mussels, or to use the Calvin cycle. But how did Thiobarba acquire the genetic toolbox for the Calvin cycle? "Our results, based on metagenomic sequencing, indicate that they obtained some of the required genes from other symbionts that also live inside the mussel's gills", says Adrien Assié, the other shared-first author of this study, who now works at the Baylor College of Medicine in Houston, Texas. "Living within its tissue, the endosymbionts have evolved a much more intimate symbiotic relationship with the mussel. Before Thiobarba was able to successfully settle on the Bathymodiolus gills, one of its ancestors must have acquired the tools of the trade from the endosymbionts, allowing its descendants to colonize mussel hosts more efficiently."

Symbiosis as a blueprint for evolutionary processes

The scientists next set off to look for similar processes in free-living Campylobacterota. And indeed, bacteria from water samples taken at hydrothermal vents contained the corresponding genes. Using the Calvin cycle might be more widespread in this group of bacteria than previously thought. "Our research on symbiotic bacteria has often revealed new insights that are also relevant for free-living bacteria. By studying symbioses, we can learn a lot about microbial life in general and its evolution," project leader Nicole Dubilier concludes.

In 2006, Japanese researchers came up with a new way of creating pluripotent stem cells through epigenetic reprogramming of connective tissue cells. Their discovery has yielded a highly valuable cell type which scientists can use to grow all cells of the human body in a Petri dish.

When culturing these so-called "induced pluripotent stem cells" (iPS cells) as three-dimensional cell aggregates, functional miniature versions of human organs, the so-called organoids, can be created by selectively adding growth factors. In the past years, this technique has been used to create cell culture models of the intestines, the lung, liver, kidneys and the brain, for example.

Previous organoids remained incomplete

Such organoid models are often surprisingly similar to real embryonic tissues. However, most remained incomplete because they lacked stromal cells and structures, the supportive framework of an organ composed of connective tissue. For instance, the tissues lacked blood vessels and immune cells. During embryonic development, all these cell types and structures are engaged in a process of constant exchange, they influence each other and thereby boost the development and maturation of the tissue and of the organ. Diseases, too, usually evolve in the tissue context with the involvement of different cell types. The selective incorporation of stromal components, and especially of functioning blood vessels, would therefore promote the maturation of already established organoid models.

Scientists from the University of Würzburg have now taken a major step towards developing such complex organoids. The anatomists, Dr. Philipp Wörsdörfer and Professor Süleyman Ergün, the head of the Institute of Anatomy and Cell Biology, were in charge of the project. In an article published in the journal "Scientific Reports" in early November 2019, the two researchers present the results of their work.

Mesodermal stem cells make miniature organs complete

"We used a trick to achieve our goal," explains Philipp Wörsdörfer. "First we created so-called mesodermal progenitor cells from pluripotent stem cells." Under the right conditions, such progenitor cells are capable of producing blood vessels, immune cells and connective tissue cells.

To demonstrate the potential of the mesodermal progenitor cells, the scientists then mixed these cells with tumour cells as well as with brain stem cells that had previously been generated from human iPS cells. This mixture grew to form complex three-dimensional tumour or brain organoids in the Petri dish featuring functional blood vessels, connective tissue, and in the case of the brain tissue, also brain-specific immune cells, the so-called microglia cells.

"In the future, the miniature organ models generated with this new technique can help scientists shed light on the processes involved in the genesis of diseases and analyse the effect of therapeutic substances in more detail before using them on animals and human patients," says Süleyman Ergün. This would allow the number of animal experiments to be reduced. Moreover, the organ models could contribute to gaining a better understanding of embryonic development processes and grow tissue that can be transplanted efficiently since they already have a functional vascular system.

Infectious diseases are caused by pathogenic microorganisms capable of entering, colonising and growing within a host organism, thus producing an infection. Bacterial infections have been on the rise worldwide in recent years, but many mechanisms underlying bacterial pathogenesis are still poorly understood. This is highly relevant given the fact that the development of new antimicrobial therapies is largely based on current knowledge of the mechanisms behind these infections. The proteins coded by the bacterial genes are responsible for the thousands of biochemical processes essential for the efficient propagation of the pathogen. Many studies demonstrate, however, that in order to identify these genes, in vivo information is needed on what happens with the bacteria in a real case of an infected host. The in vitro studies, i.e., those recreated in laboratories with cell and bacterial cultures, later do not always correlate with data from in vivo studies. This is due to the fact that pathogenic bacterial genes essential for producing the infections depend on the environment of the colonised organism.

A team of researchers from the Department of Biochemistry and Molecular Biology of the Universitat Autònoma de Barcelona and from the Centre of Genomic Regulation (CRG) has created the BacFITBase database. Based on the results of the in vivo experiments, researchers systematically characterised the bacterial genes relevant for host cell invasion and infection. All the experiments performed were based on a technique named transposon mutagenesis, where the DNA fragments called transposons are transferred to the organism's pathogenic genes, thereby inactivating them.

By doing so, their role in the infection can be observed directly and researchers can determine which are essential for a specific host organism to become infected. Therefore, this database will make it easier to identify target proteins that can help in fighting infectious diseases and accelerate the development of new antimicrobial agents.

The database contains over 90,000 entries with information on specific pathogenic bacterial genes and their contribution to in vivo infectious conditions in five different host species. It includes information on a total of 15 bacteria (two variants of Salmonella enterica, Haemophilus influenzae, Streptococcus pyogenes, Porphyromonas gingivalis, Mycobacterium avium, three variants of Escherichia coli, Vibrio cholerae, Campylobacter jejuni, Klebsiella pneumoniae, Acinetobacter baumannii, Serratia marcescens and Vibrio parahaemolyticus) and 5 model vertebrates (cow, pig, hen, mouse and rabbit), with information across 10 different tissues.

The leftovers from a spectacular supernova that revolutionised our understanding of how stars end their lives have finally been spotted by astronomers at Cardiff University.

The scientists claim to have found evidence of the location of a neutron star that was left behind when a massive star ended its life in a gigantic explosion, leading to a famous supernova dubbed Supernova 1987A.

For more than 30 years astronomers have been unable to locate the neutron star - the collapsed leftover core of the giant star - as it has been concealed by a thick cloud of cosmic dust.

Using extremely sharp and sensitive images taken with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in the Atacama Desert of northern Chile, the team have found a particular patch of the dust cloud that is brighter than its surroundings, and which matches the suspected location of the neutron star.

The findings have been published in The Astrophysical Journal.

Lead author of the study Dr Phil Cigan, from Cardiff University's School of Physics and Astronomy, said: "For the very first time we can tell that there is a neutron star inside this cloud within the supernova remnant. Its light has been veiled by a very thick cloud of dust, blocking the direct light from the neutron star at many wavelengths like fog masking a spotlight."

Dr Mikako Matsuura, another leading member of the study, added: "Although the light from the neutron star is absorbed by the dust cloud that surrounds it, this in turn makes the cloud shine in sub-millimetre light, which we can now see with the extremely sensitive ALMA telescope."

Supernova 1987A was first spotted by astronomers on Feb 23, 1987, when it blazed in the night sky with the power of 100 million suns, and continuing to shine brightly for several months.

The supernova was discovered in a neighbouring galaxy, the Large Magellanic Cloud, only 160,000 light years away.

It was the nearest supernova explosion observed in over 400 years and, since its discovery, has continued to fascinate astronomers who have been presented with the perfect opportunity to study the phases before, during, and after the death of a star.

The supernova explosion that took place at the end of this star's life resulted in huge amounts of gas with a temperature of over a million degrees, but as the gas began to cool down quickly below zero degrees centigrade, some of the gas transformed into a solid, i.e. dust.

The presence of this thick cloud of dust has long been the main explanation as to why the missing neutron star has not been observed, but many astronomers were sceptical about this and began to question whether their understanding of a star's life was correct.

"Our new findings will now enable astronomers to better understand how massive stars end their lives, leaving behind these extremely dense neutron stars," continued Dr Matsuura.

"We are confident that this neutron star exists behind the cloud and that we know its precise location. Perhaps when the dust cloud begins to clear up in the future, astronomers will be able to directly see the neutron star for the very first time."

The so-called natural killer (NK) cells are cells of the innate immune system that recognize and eliminate infected cells or cancer cells. During a virus infection, NK cells also keep the body's own immune cells such as the T cells at bay in order to avoid excessive killing of intact body cells. In addition, NK cells release messenger molecules that support the immune defense. NK cells are therefore particularly important for immunity - if they are defective, recurrent infections with several viruses and cancer can develop.

NK cells eliminate their target cells in two ways. They either kill them by releasing cell toxins or activate these targets to start a "self-destruction program". NK cells have special proteins on their surface - so-called death ligands - which dock to corresponding receptors on the target cells and thus activate their self-destruction. The protein TRAIL is one of these death ligands that NK cells use to kill their target cells. TRAIL stands for "Tumor necrosis factor-related apoptosis-inducing ligand". Compared to healthy cells, tumor cells are more sensitive to TRAIL stimulation. It is therefore believed that the binding of TRAIL to the TRAIL receptor triggers the death of tumor cells without affecting healthy cells.

Accordingly, this pathway is considered a promising approach to trigger the self-destruction of cancer cells. However, TRAIL appears to play a detrimental role in certain types of infections and a better understanding of the underlying mechanism is needed. A group led by Philippe Krebs from the Institute of Pathology at the University of Bern has now discovered new functions of TRAIL in viral infections that could also be important in the fight against cancer. The findings were published in the journal EMBO (European Molecular Biology Organization) Reports.

Killer cells without TRAIL become "tame"

Ludmila Cardoso-Alves at the Institute of Pathology studied the role of TRAIL in the response against a virus that is a natural pathogen in rodents and often serves as a model of viral infection in immunology. Cardoso-Alves investigated the infection in mice whose NK cells did not have TRAIL and found that these mice were able to fight the virus better than the control animals. Mice without TRAIL had more protective T cells and were therefore better able to remove virus-infected cells.

The lack of TRAIL made the NK cells "tamer": they had reduced killer function and instead produced more messenger molecules that activate other immune cells. This is due to the fact that NK cells without TRAIL sense various signals from their environment differently: on the one hand, they are less susceptible to a trigger that leads them to release cell toxins. At the same time, they react more strongly to another signal that causes them to release more messenger molecules. "TRAIL therefore plays a greater role in NK cells than previously thought - if it is missing, the killer cells are reprogrammed, so to speak," says Cardoso-Alves. This is not limited to mice, but also affects human NK cells.

Possible relevance for cancer immunotherapy

The results of this work may be important in the fight against cancer, since the discovered signaling pathway regulates the function of NK cells, which in turn are important for the control of tumor cells. There are several new cancer therapies that aim to reactivate the immune system in order to remove tumor cells, including studies aiming at reactivating NK cells in tumor patients. "Our results show an alternative way of influencing NK cells," said Cardoso-Alves. This could be used, for example, to combined the discovered TRAIL signaling pathway with other methods against tumors.

For the little brown bat - a small mouse-eared bat with glossy brown fur - a warm, dry place to roost is essential to the species' survival. Reproductive females huddle their small furry bodies together to save thermal energy during maternity season (summer), forming "maternity colonies." In the face of severe population losses across North America, summer access to an attic or other permanent sheltered structure, as opposed to just trees or rock crevices, is a huge benefit to these bats.

In a new study published in the Ecological Society of America's journal Ecosphere, researchers with Ohio University, University of Kentucky, and the US National Park Service investigate and describe the conservation importance of buildings relative to natural, alternative roosts for little brown bats (Myotis lucifugus) in Yellowstone National Park.

Yellowstone's iconic high-elevation landscape provides abundant natural roosting places but not many buildings. The study involved four visitor areas with several buildings that are known to host bold little brown bats, which are among the few bat species that will make their homes in structures that are actively used by people, allowing humans to get up close and personal. Sometimes, the investigation even involved researchers capturing them by hand.

"We occasionally entered attics to look to see if they were occupied by bats," says lead study author Joseph Johnson, an assistant professor of vertebrate biology at Ohio University. "On these occasions we sometimes took the opportunity presented by inactive bats... We would gently pluck them from the walls and glue a transmitter on them in order to study their thermoregulation, but also to let them lead us to additional roosts."

Over the summers of 2012-2015, researchers tracked individual bats in the park. Using temperature-sensitive radio-transmitters, the researchers measured roost preferences and body temperature regulation in adult male and female bats roosting in buildings, trees, and rocks.

Their results show that reproductive females roost in attics in the study area on 84% of all days for which they collected data, while males roost exclusively in rock crevices or trees. It appears then that outside of maternity colonies, adult males and non-reproductive females will roost by themselves or in small aggregations.

The idea and study of bats using buildings is not new; people have probably seen bats in buildings ever since humans first started building them. What is new is comparing the benefits buildings provide bats with the benefits of alternative natural roosts. "That was what we did in our research," Johnson says, "using the challenging environment of Yellowstone National Park as a lens through which to view these benefits. As populations of bats continue to decline in North America, we believe that highlighting the importance of buildings to bats is important for conservation."

Outside Yellowstone and national parks, people frequently evict bats from their buildings. The removal of bats, especially maternity colonies that allow females to conserve warmth and energy, is a conservation concern as white-nose syndrome (WNS) continues to devastate populations in cave-hibernating bat populations across the continent.

WNS is named for a distinct white fungal growth around the muzzle and on wings of hibernating bats - it is the first known pathogen that kills a mammal host during hibernation. The fungus erodes skin and membranes and causes infected bats to burn through energy and fat reserves twice as fast as healthy individuals, and it essentially results in starvation. WNS fungus only thrives in the cold, damp environments typically associated with underground hibernation sites such as caves and mines, and it only grows on bats when they hibernate during winter. Bats that do survive WNS are particularly weak come spring and summer.

"To date, there have been no signs of WNS in these buildings or in Yellowstone, although the fungus has now been documented both east and west of the Park," says Johnson. If WNS is present in the study area, the researchers expect to see a sharp reduction in the number of bats present during the summer. "Thankfully," he says, "we have not seen any such decline as of yet."

Another complication for little brown bats is a state of body temperature regulation called "torpor." It can be thought of as a form of hibernation, but on a daily scale. In spring through fall, the little brown bat enters a state of decreased physiological activity. Torpor saves energy for the bat when the ambient temperature gets too cool (yes, even in summer). Instead of expending energy and fat reserves to maintain a constant body temperature, torpor allows the body to cool close to their roost temperature and physiological activity to slow. While in torpor, a bat's heart rate drops from up to 210 beats per minute to as few as 8 beats per minute.

For a pregnant bat, however, their ability to regulate body temperature decreases. Torpor also slows gestation and delays the birth of offspring, potentially forcing juvenile bats to mature quickly before winter arrives, and therefore decreasing survival rates of new generations.

The study confirms that male bats roosting in rocks and trees largely allow their body temperature to dip close to the ambient temperature. Female bats in buildings, on the other hand, sustain higher body temperatures than males throughout the day, thanks to buildings being more insulated from low ambient temperatures during the middle of the maternity season.

Ultimately, the importance of buildings to bats may be especially great at high elevations and latitudes. The researchers believe that buildings allow for larger populations of little brown bats than would be possible without buildings in these landscapes, and that conservation managers need to evaluate the conservation value of buildings for bat populations as WNS continues to grow and spread.

"This warmth is important for bats during the summer months to help with their reproductive efforts," emphasizes Johnson. "Bats surviving WNS and trying to recover might benefit from a warm roost tremendously." 

Aurora, Colo. (Nov. 19, 2019) - Severe obesity affects 4.5 million children and adolescents in the United States, according to the American Academy of Pediatrics (AAP). Bariatric surgery can be life-changing for teens with severe obesity who have been unable to lose a significant amount of weight with traditional weight-loss measures. More and more research points to the benefits that teens with severe obesity can reap from bariatric surgery, including two recently published studies led by Thomas H. Inge, director of pediatric surgery and the bariatric center at Children's Hospital Colorado (Children's Colorado), and researchers at Children's Colorado. The different focuses of the two studies also highlight the multidisciplinary approach of the hospital's Bariatric Surgery Center.

Musculoskeletal Pain, Physical Function and Quality of Life After Bariatric Surgery

In a study published online today by Pediatrics, Children's Colorado researchers and their colleagues found that musculoskeletal pain, physical function and quality of life in adolescents significantly improves and is maintained three years after bariatric surgery.

"Obesity in adolescents is associated with lower extremity joint pain, poor physical function and cartilage abnormalities that place them at high risk for developing degenerative joint disease," said Thomas H. Inge, MD, PhD, Teen-LABS principal investigator. "Bariatric surgery can lead to large and sustained reductions in joint pain, and improvements in physical function in these adolescents. These improvements allow teens to move, be more functional, and participate in physical activity, all of which help improve their joint health and maintain their weight loss."

Specifically, researchers looked at three-year surgical outcomes of 242 patients, all of whom were participants in the multi-center Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS). They found that:

Musculoskeletal and lower extremity pain were reduced by 40% within 12 months of surgery, a reduction that persisted over three years.

The prevalence of poor physical function declined from 40% to less than 20%.

Physical comfort improved at six months post-surgery and beyond.

Iron and Vitamin B12 are Primary Nutritional Risks Years After Bariatric Surgery in Adolescence

Knowing that bariatric surgery does come with the risk of long-term nutritional deficiencies, particularly involving iron and vitamin B12, Children's Colorado researchers and their colleagues also conducted a five-year study of nutritional outcomes among Teen-LABS participants. The results of this study were recently published online in the journal Clinical Gastroenterology and Hepatology.

In this study, researchers focused on the nutritional impacts of the two most common forms of bariatric surgery: Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG). Their findings showed that at five years:

In both procedures, patients benefitted from weight loss of approximately 23%.

After RYGB, levels of vitamin B12 declined significantly, but B12 levels did not drop after VSG.

After RYGB, 71% of patients had low iron stores compared to 2.5% of patients prior to surgery.

Over twice as many RYGB participants than VSG recipients had multiple nutritional deficiencies (59% vs. 27%).

No significant changes were found after either procedure for folate or vitamins A, B1 or D.

"This study highlights the importance of annual nutritional screening following bariatric surgery," said Megan Kelsey, MD, pediatric endocrinologist and medical director of the Bariatric Surgery Center at Children's Colorado. "This study also found that the risk of nutritional deficiency is lowest in patients with the highest intake of recommended vitamin and mineral supplements, emphasizing the importance of providing a robust program with pediatric expertise to ensure that patients have appropriate follow-up."

"Both iron and B12 deficiency can cause anemia, and B12 deficiency can also cause significant neurological dysfunction," said Jaime Moore, MD, a nutrition expert on the bariatric team at Children's Colorado. "If caught early, treatment with additional vitamin and mineral supplements can minimize these risks, which is why lifelong annual micronutrient testing is so important. Eating a varied diet may also reduce the risk of deficiencies but can be challenging after bariatric surgery because of changes in intake. Involvement of a registered dietitian in the pre- and post-operative care of these patients is key to help address such challenges."

Because the risks of nutritional deficiency can be minimized with appropriate dietary supplementation, both studies point to a positive message overall for bariatric surgery in adolescents. In light of the increasing positive evidence in support of this path, the AAP recently called for improved access to bariatric surgery for severely obese teens.

This release has been removed at the request of the submitter. For further information, please contact Jim Sabin, Media Relations Manager, sabin@ohio.edu.