Brain

By coupling magnetic behavior to a superconducting circuit, Argonne scientists pave the way for quantum information systems.

Quantum computing promises to revolutionize the ways in which scientists can process and manipulate information. The physical and material underpinnings for quantum technologies are still being explored, and researchers continue to look for new ways in which information can be manipulated and exchanged at the quantum level.

In a recent study, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have created a miniaturized chip-based superconducting circuit that couples quantum waves of magnetic spins called magnons to photons of equivalent energy. Through the development of this “on chip” approach that marries magnetism and superconductivity for manipulation of quantum information, this fundamental discovery could help to lay the foundation for future advancements in quantum computing.

“By pairing the right length of resonator with the right energy of our magnons and photons, we are in essence creating a kind of echo chamber for energy and quantum information,” — Valentine Novosad, Argonne materials scientist.

Magnons emerge in magnetically ordered systems as excitations within a magnetic material that cause an oscillation of the magnetization directions at each atom in the material — a phenomenon called a spin wave. “You can think of it like having an array of compass needles that are all magnetically linked together,” said Argonne materials scientist Valentine Novosad, an author of the study. “If you kick one in a particular direction, it will cause a wave that propagates through the rest.”

Just as photons of light can be thought of as both waves and particles, so too can magnons. “The electromagnetic wave represented by a photon is equivalent to the spin wave represented by a magnon — the two are analogues of each other,” said Argonne postdoctoral researcher Yi Li, another author of the study.

Because photons and magnons share such a close relationship to each other, and both contain a magnetic field component, the Argonne scientists sought a way to couple the two together. The magnons and photons “talk” to each other through a superconducting microwave cavity, which carries microwave photons with an energy identical to the energy of magnons in the magnetic systems that could be paired to it.

Using a superconducting resonator with a coplanar geometry proved effective because it allowed the researchers to transmit a microwave current with low loss. Additionally, it also allowed them to conveniently define the frequency of photons for coupling to the magnons.

“By pairing the right length of resonator with the right energy of our magnons and photons, we are in essence creating a kind of echo chamber for energy and quantum information,” Novosad said. “The excitations stay in the resonator for a much longer length of time, and when it comes to doing quantum computing, those are the precious moments during which we can perform operations.”

Because the dimensions of the resonator determine the frequency of the microwave photon, magnetic fields are required to tune the magnon to match it.

“You can think of it like tuning a guitar or a violin,” Novosad said. “The length of your string — in this case, our resonator of photons — is fixed. Independently, for the magnons, we can tune the instrument by adjusting the applied magnetic field, which is similar to modifying the amount of tension on the string.”

Ultimately, Li said, the combination of a superconducting and a magnetic system allows for precise coupling and decoupling of the magnon and photon, presenting opportunities for manipulating quantum information.

Researchers have engineered gold-based molecules that target cancer cells and leave healthy cells unharmed, in a critical step towards precision cancer drugs with fewer toxic side effects.

Pre-clinical studies have shown the molecules were up to 24 times more effective at killing cancer cells than the widely used anti-cancer drug cisplatin and were also better at inhibiting tumour growth.

The molecules were also more targeted and selective, making them promising candidates for development into a new class of gold-based drugs that can wipe out the cancer without destroying healthy cells.

Significantly, the synthetic molecules are built with resistance-fighting features to keep them effective over time, unlike current chemotherapies.

The study by researchers at RMIT University, detailing four new bio-active molecules and their effectiveness against five types of cancer cells, is published in Chemistry - A European Journal.

Dr Neda Mirzadeh, co-leader of the Molecular Engineering Group at RMIT, said the limitations of commonly used metal-based chemotherapies drove a need to find better alternatives.

"We've made huge inroads in cancer treatment over recent decades, but the disease still kills over 9.6 million people globally each year and remains the world's second leading cause of death," Mirzadeh said.

"While metal-based drugs have successfully pushed survival rates up, their effectiveness is limited because of toxic side effects, drug resistance and poor stability.

"The gold-based molecules we've designed are far more selective and stable.

"Our results show there's incredible potential here for the development of new cancer-fighting therapeutics that can deliver lasting power and precision."

The molecules were evaluated in pre-clinical tests and found to be highly cytotoxic against prostate, breast, cervical, melanoma and colon cancer cells. Animal trials showed treatment with the molecules significantly inhibited tumour growth (up to 46.9%, compared with 29% for cisplatin).

The gold-based compounds also inhibit the action of an enzyme found in cancer cells, thioredoxin reductase, that is linked with cancer progression and the development of drug resistance.

In addition, the molecules have strong anti-inflammatory properties, giving them a dual therapeutic effect and potential application in the treatment of chronic inflammatory conditions like arthritis.

Molecular design pioneers

Part of RMIT's Centre for Advanced Materials and Industrial Chemistry (CAMIC), the Molecular Engineering Group brings together synthetic chemists with pharmacologists and has over two decades of expertise in designing gold molecules for practical applications.

The pioneering group, one of just a few in the world focusing on the medical potential of gold-based molecules, has had two patents awarded for their work to date.

Team leader and CAMIC Director, Distinguished Professor Suresh Bhargava, said gold had an ancient history of medical use, particularly in India and China.

"We know that gold is readily accepted by the human body and we know it has been used for thousands of years in treating various conditions," Bhargava said.

"Essentially, gold has been market tested, but not scientifically validated.

"Our work is helping both provide the evidence base that's missing, as well as delivering new families of molecules that are tailor-made to amplify the natural healing properties of gold."

The research team has completed successful in vitro and in vivo pre-clinical studies and is seeking funding to support the next stage of the research - clinical studies and regulatory approval.

The team includes Dr Srinivasareddy Telukutla, a graduate from RMIT's joint PhD program with the Indian Institute of Chemical Technology (IICT), Ganga Reddy Velma, a PhD candidate at IICT and Visiting Research Fellow at RMIT, and synthetic chemist Dr Steven Priver.

The paper, Potent and selective cytotoxic and anti-inflammatory gold(III) compounds containing cyclometallated phosphine sulfide ligands, with co-authors from the IICT and University of Melbourne, will feature on the cover of a forthcoming edition of Chemistry - A European Journal (DOI: 10.1002/chem.201903388).

Humans can visually perceive the motion of a small object better than that of a large one. By contrast, according to a study reported in the journal Current Biology on September 5, babies under 6 months of age are better at seeing the movement of large objects than small objects.

In adults, the motion of a bigger object is more difficult to see. This counterintuitive phenomenon is thought to reflect surround suppression, an inhibitory mechanism observed in visual cortical neurons that suppresses irrelevant visual information in the areas surrounding an object we are focusing on.

"We found that infants under 6 months showed the opposite pattern to adults, that is, better perception of large than small objects' motion," says Yusuke Nakashima, JSPS research fellow at Chuo University in Tokyo. "Infants over 6 months, on the other hand, lose this ability and become good at seeing small objects' motion. These results suggest that surround suppression is not present until the second half of the first year."

It is known that surround suppression is also weak in older adults, the result of which is that they can see the motion of large objects better than younger adults.

"Younger infants' results, we found, are similar to the characteristics of older people's motion perception," says So Kanazawa, professor at Japan Women's University. "Both younger babies and older adults can see large objects' motion well due to weak surround suppression."

Why do we lose the "superior" ability to perceive large objects' motion during development? Surround suppression is thought to contribute to the visual function that separates moving objects from background motion. "Younger babies may fail to see an object's motion when surrounded by irrelevant motion," says Nakashima. "We may acquire a truly superior ability to see an object's motion by losing sensitivity for large-size motion."

Hannibal. Voldemort. Skeletor and Gargamel. It's hard to imagine any nefarious villain having redeeming qualities. But what if someone were to tell you that the Joker is a monster only because he learned the behavior from people around him and it's possible that, one day, he might change for the better?

A new study out of Columbia University suggests that the way we perceive others' bad behavior -- as either biological and innate or potentially changeable -- impacts our willingness to cut them some slack.

The study, published in the Journal of Experimental Psychology: General, found that adults are less willing to be charitable toward "bad" individuals whose moral characteristics are attributed to an innate biological source. Conversely, adults are more apt to be generous toward individuals when led to focus on other explanations for moral "badness" that suggest potential for change. Unlike adults, children did not appear to distinguish between characters whose moral characteristics were described in different ways.

The findings may have implications for how we perceive individuals in society, such as those imprisoned for crimes.

"If people want to take something away from this study and apply it to their own lives, it is to be mindful of how they talk about others and their transgressions," said Larisa Heiphetz, an assistant professor of psychology and the study's principal investigator. "People often encounter moral transgressions, whether in others' behaviors or their own. This study reveals that the way we treat those individuals can be strongly influenced by the way others describe their transgressions."

Heiphetz's research also revealed that a person's "goodness" was seen by both age groups as more of a biological, innate trait than "badness." Both children and adults were more likely to say that goodness, rather than badness, was something with which people are born and a fundamental, unchanging part of who they are.

The study, funded by Columbia University, the Indiana University Lilly School of Philanthropy and the John Templeton Foundation, is one in a growing area of research focused on psychological essentialism -- how we think about people's characteristics in essentialist terms (e.g., innate, immutable and due to biological factors) or non-essentialist terms (socially learned, changeable). Prior work has shown that people readily attribute many human characteristics to innate, unchanging factors.

To learn how people perceive moral goodness and moral badness, Heiphetz and a group of Columbia students asked children and adults what they thought about a variety of morally good and morally bad characteristics. They found that both groups perceived "goodness" as a more central, unchanging feature of who someone is than badness, which was more likely to be perceived as something that can improve over time. That led Heiphetz to wonder if there were any consequences associated with this perception, so she gave children and adults material resources, including stickers and entries to a lottery, and told them about pairs of fictional people that had the same "bad" moral characteristics, but for different reasons: One was described in an essentialist way - born bad -- and the other in a non-essentialist way -- bad as a result of behavior they learned from other people in their lives.

When study participants were asked to share their possessions with the characters, the children shared equally but adults shared more resources with the character described as bad due to learned behavior, with the potential to change. When study participants were then told that neither of the fictional characters - whether born bad or having learned the behavior -- would ever change for the better, adults still shared more resources with the character who had been described in the non-essentialist way, as having learned the behavior.

Words, as this study shows, have impact.

Wildfires are widespread across the globe. They occur in places wherever plants are abundant -- such as the raging fires currently burning in the Brazilian Amazon. Such biomass burning (BB) can be an environmental calamity.

The smoke from BB events produces large amounts of aerosol particles and gases. These emissions can cause major problems for visibility and health, as well as for local and global climate.

BB emissions are expected to increase in the future as a result of climate change. Tarballs, which are microscopic organic BB particles, are estimated to contribute up to 30% of BB aerosol mass. Because tarballs are a dominant, light-absorbing type of aerosol particle in BB smoke, understanding their influence on climate is crucial. But details of how they form and influence climate change have been unclear.

Senior researcher Kouji Adachi, currently working at the Meteorological Research Institute in Tsukuba, Japan, was a postdoctoral research associate from 2005 until 2011 with Professor Peter Buseck of Arizona State University's School of Molecular Sciences and School of Earth and Space Exploration.

Their work attracted the attention of colleagues from the Department of Energy's Brookhaven National Lab in Upton, New York. Principal Investigators, Arthur Sedlacek III and Lawrence Kleinman, with support from the Atmospheric Sciences Program, were planning the Biomass Burning Operational Period (BBOP) field campaign, in which an instrumented airplane would measure rapid chemical changes in wildfire smoke.

Sedlacek and Kleinman approached Buseck about participating in BBOP, as the sampling strategy provided an ideal laboratory in the sky to study tarball formation.

The results, published online September 5, are in a Proceedings of the National Academy of Sciences paper titled "Spherical tarball particles form through rapid chemical and physical changes of organic matter in biomass-burning smoke."

The team's observations show that tarballs form through a combination of chemical and physical changes of organic aerosols formed within the first hours following smoke production.

"I'm so pleased that tarballs, the subject of this paper, were first reported in 2003 papers in which an ASU chemistry graduate student, Li Jia, and postdoctoral research associate, Mihaly Posfai, were major contributors; thus the School of Molecular Sciences and the School of Earth and Space Exploration had an important role," said Buseck.

Buseck, an ASU Regents Professor, also is being awarded the 2019 Roebling Medal this month, the highest award of the Mineralogical Society of America for outstanding original research in mineralogy.

"This study of tarball particles and the possible effects on climate change further shows the breadth and diversity of Buseck's research," said School of Earth and Space Exploration Director Meenakshi Wadhwa. "From solid-state geochemistry and mineralogy, to atmospheric geochemistry, to cosmochemistry, he continually proves to be a pioneer in his field."

"Peter Buseck and his group have developed the use of transmission electron microscopy to study minerals, meteorites and aerosol particles in a uniquely interesting way," said Professor Neal Woodbury, director of the School of Molecular Sciences. "His team's current findings on tarball formation are a good example and will significantly improve assessments of biomass burning impacts on regional and global climate."

Tarballs used in this study were collected from large wildfires sampled during the BBOP campaign in the summer of 2013 in the northwestern United States. Using a Gulfstream-1 research airplane, the team collected wildfire aerosol particles on repeated flights through smoke plumes. Shapes and compositions of more than 10,000 particles were measured using transmission electron microscopy, with detailed chemical analysis of tarballs performed using scanning transmission X-ray spectroscopy.

The analysis reveals that the fraction of aerosol particles that are tarballs increases with particle age. In addition, the tarball ratios of nitrogen and oxygen relative to potassium, and the particle roundness, also increase with particle age.

In summary, BB emissions including tarballs are expected to increase in coming decades as a result of climate change. This study reveals their formation process through chemical and microphysical analyses. The findings can be used to improve interpretation of BB smoke from satellite data and ground-based observations by considering tarball shape, viscosity and compositional changes during aging and to provide better estimates of their effects in climate models.

A study by an assistant professor at The University of Texas at Arlington published in the Journal of Marketing shows that marketers of relatively high-priced products should consider keeping prices high, as many consumers associate high price with high quality.

Narayanan Janakiraman, UTA assistant professor of marketing in the College of Business, said these same consumers equate lower prices with lower quality.

"Why are we willing to pay much more for a six pack of craft beer, a locally produced bottle of wine or a regional brand item, often choosing them over national brands?" Janakiraman said. "It's because when people prefer to buy local, they more frequently base their decisions on price as a perception of quality."

The study suggests that marketers can use this understanding of local identity versus global identity to shape consumers' price perceptions and behavior. UTA and three other universities contributed to the study.

"Consumers tend to use price to judge a product's quality when their local identity is most important to them," Janakiraman said. "When promoting high-priced or branded products, marketers can situationally activate consumers' local identity. To accomplish this objective, businesses can encourage consumers to think locally or employ local cultural symbols in advertising and other promotional material."

Findings also suggest that discount stores, such as dollar stores, should discourage consumers from using the price of a product to infer its quality.

"Discount stores, therefore, would be better served by temporarily making consumers' global identity more prominent," Janakiraman said. "Cues in advertisements that focus on a product's global appeal would help achieve that goal."

Many companies find it difficult to set and increase prices in the digital marketplace because of the pricing transparency of the internet, consumers' deal-seeking attitudes and global product availability.

For their study, Janakiraman and his colleagues conducted in-depth interviews, two field studies and seven experiments, and reviewed secondary data. In their interviews with 15 senior-level managers from Fortune 500 companies, they found that while the executives considered local or global communities in their pricing decisions, none knew when such strategies were effective or why.

Through the field studies, experiments and secondary data, the researchers found that when consumers perceive greater variance among brands, it increases their reliance on price as a cue to judge quality.

Past research has found that consumers from more globalized countries and communities, such as the United States and its larger cities, often have a stronger global mindset because they interact with many types of people and cultures and hear news from abroad. In contrast, those living in smaller population areas or from isolated or insular nations often have a stronger local identity because they have less access to other cultures.

This paper provides useful guidelines for firms to adapt strategies for different regions and address whether companies should be more locally or globally oriented.

"For products to be marketed to the places where people tend to have a more local identity, such as rural areas, local flavors and ingredients can be used in the products," Janakiraman and his co-authors wrote. "As these consumers are more likely to make price-quality associations, marketers may not need to allocate much ad budget to convince them about price-quality associations."

The opposite is true as well, according to the authors, indicating that in more metropolitan areas, consumers most often don't have an established connection between price and quality. For marketers, this means that putting additional effort into differentiating their brand will help consumers associate a higher price with higher quality.

Elten Briggs, chair of the Department of Marketing, said Janakiraman's research is an outstanding asset for companies to embrace.

"The Journal of Marketing is the top research outlet in our field," Briggs said. "The study will contribute greatly to managers' understanding of consumer price perceptions."

When Kīlauea Volcano erupted in 2018, it injected millions of cubic feet of molten lava into the nutrient-poor waters off the Big Island of Hawai'i. The lava-impacted seawater contained high concentrations of nutrients that stimulated phytoplankton growth, resulting in an extensive plume of microbes that was detectable by satellite.

A study led by researchers at the University of Hawai'i (UH) at Mānoa and University of Southern California (USC) and published today in the journal Science revealed that this biological response hinged on unexpectedly high concentrations of nitrate, despite the negligible amount of nitrogen in basaltic lava. The research team determined that nitrate was brought to the surface ocean when heat from the substantial input of lava into the ocean warmed nutrient-rich deep waters and caused them to rise up, supplying the sunlit layer with nutrients.

After observing the phytoplankton bloom in satellite images, the UH Mānoa Center for Microbial Oceanography: Research and Education (C-MORE) organized a rapid response oceanographic expedition on UH research vessel Ka'imikai-O-Kanaloa from July 13 to 17, 2018--in the thick of Kilauea's activity. The team conducted round-the-clock operations in the vicinity of the lava entry region to test water chemistry and the biological response to the dramatic event.

Co-lead authors Sam Wilson at C-MORE and Nick Hawco, a USC researcher who will be joining the UH Mānoa Oceanography Department in January 2020, tested the hypothesis that lava and volcanic dust would stimulate microorganisms that are limited by phosphate or iron, which are chemicals found in lava.

As it turned out, since there was so much lava in the water, the dissolved iron and phosphate combined into particles, making those nutrients unavailable for microbes. Further, deep, heated seawater became buoyant and brought up nitrate which caused other classes of phytoplankton to bloom.

It is possible that this mechanism has led to similar ocean fertilization events in the past associated with the formation of the Hawaiian Islands and other significant volcanic eruptions, the authors suggest. Depending on their location, sustained eruption on this scale could also facilitate a large flux of nitrate from the deep ocean and perturb larger scale ocean circulation, biology and chemistry.

"The expedition in July 2018 provided a unique opportunity to see first-hand how a massive input of external nutrients alters marine ecosystems that are finely attuned to low-nutrient conditions," said Wilson. "Ecosystem responses to such a substantial addition of nutrients are rarely observed or sampled in real time. UH has a strong tradition of not only volcanic research, but also looking at its impacts on the surrounding environment such as the ocean, groundwater, atmosphere. This latest piece of research improves our understanding of lava-seawater interactions within the much broader context of land-ocean connections."

"Science is a team sport," said Dave Karl, senior author and co-director of the UH Mānoa Simons Collaboration on Ocean Processes and Ecology (SCOPE).  "SCOPE emphasizes collaboration, where scientists with complementary skills came together to complete this unique, interdisciplinary project."

In the future, the team hopes to sample the newly-formed ponds at the bottom of the Halema'uma'u crater and further investigate lava-seawater interactions in the laboratory.

The dinosaur, whose nearly complete skeleton was unearthed from 72 million year old marine deposits in Mukawa Town in northern Japan, belongs to a new genus and species of a herbivorous hadrosaurid dinosaur, according to the study published in Scientific Reports. The scientists named the dinosaur Kamuysaurus japonicus.

A partial tail of the dinosaur was first discovered in the outer shelf deposits of the Upper Cretaceous Hakobuchi Formation in the Hobetsu district of Mukawa Town, Hokkaido, in 2013. Ensuing excavations found a nearly complete skeleton that is the largest dinosaur skeleton ever found in Japan. It's been known as "Mukawaryu," nicknamed after the excavation site.

In the current study, a group of researchers led by Professor Yoshitsugu Kobayashi of the Hokkaido University Museum conducted comparative and phylogenetic analyses on 350 bones and 70 taxa of hadrosaurids, which led to the discovery that the dinosaur belongs to the Edmontosaurini clade, and is closely related to Kerberosaurus unearthed in Russia and Laiyangosaurus found in China.

The research team also found that Kamuysaurus japonicus, or the deity of Japanese dinosaurs, has three unique characteristics that are not shared by other dinosaurs in the Edmontosaurini clade: the low position of the cranial bone notch, the short ascending process of the jaw bone, and the anterior inclination of the neural spines of the sixth to twelfth dorsal vertebrae.

According to the team's histological study, the dinosaur was an adult aged 9 or older, measured 8 meters long and weighed 4 tons or 5.3 tons (depending on whether it was walking on two or four legs respectively) when it was alive. The frontal bone, a part of its skull, has a big articular facet connecting to the nasal bone, suggesting the dinosaur may have had a crest. The crest, if it existed, is believed to resemble the thin, flat crest of Brachylophosaurus subadults, whose fossils have been unearthed in North America.

The study also shed light on the origin of the Edmontosaurini clade and how it might have migrated. Its latest common ancestors spread widely across Asia and North America, which were connected by what is now Alaska, allowing them to travel between the two continents. Among them, the clade of Kamuysaurus, Kerberosaurus and Laiyangosaurus inhabited the Far East during the Campanian, the fifth of six ages of the Late Cretaceous epoch, before evolving independently.

The research team's analyses pointed to the possibility that ancestors of hadrosaurids and its subfamilies, Hadrosaurinae and Lambeosaurinae, preferred to inhabit areas near the ocean, suggesting the coastline environment was an important factor in the diversification of the hadrosaurids in its early evolution, especially in North America.

Researchers at Karolinska Institutet in Sweden have, together with colleagues from Aalto University in Finland, developed a new method for creating images of molecules in cells or tissue samples. The method is based on the use of DNA snippets and is called DNA microscopy. The approach is currently described in the scientific journal PNAS.

The new method involves researchers in the first stage mixing up a cell or tissue sample with short sequences of single-stranded DNA, selected to attach to the specific molecules that are going to be studied. If it for example involves a specific protein that is going to be investigated, small DNA snippets are used that bind to this particular protein. In the next stage, enzymes are fed to the short DNA sequences to connect and form DNA molecules.

By analysing these newly formed DNA molecules with so-called DNA sequencing, it is possible to see exactly which DNA snippets have ended up next to each other. Based on this information, you can add a puzzle that shows how all of the DNA sequences must be connected.

Since DNA sequences are attached to the molecules that are being represented, it is possible to understand how abundant they occur and where they are in the cells. What researchers are now publishing is a mathematical model that makes it possible to calculate this as well as create images from such information.

"You can liken it to the table placement game at a wedding where each guest gets a note that matches the person next to them at the table. If you have all of these notes you can recreate the table placement. In our experiments, the notes represent the DNA-snippets and the guests are the molecules that the snippets are attached to," says Björn Högberg, professor at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet.

The advantage of this method, which scientists call DNA microscopy, is that it makes it possible to search for specific molecules within a larger material, such as a whole cell collection or a tissue sample. With traditional microscopy, where you have to look at one area at a time, it is very time-consuming. But with DNA microscopy it is possible to, for example, screen for certain molecules and examine how frequent they are.

The method also makes it possible to see what role the immediate environment plays in the life of a cell, i.e. how micro-environment might affect possible disease development - to mention only two of several possible useful areas when it comes to DNA microscopy.

"This is a tool that can be used to gain a better understanding of how biology works and how cells work together. This knowledge can provide us with a better picture of how different diseases develop. In the long run, this tool can also provide opportunities for safer diagnostics," says Ian Hoffecker, researcher in Björn Högberg's Research Group at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet and the coordinator of the study.

In the steamy, often filthy world of the humble house fly, (the Musca domestica) clear division exists among the males of the species. Though not a civil war, there are differences, to be sure, between males in the north and those that hail from the south. Finding out why those differences appear in the genetic sequences of the northerners and southerners is key to understanding nothing less than sex determination, but there is an essential paradox: The genetic difference is trivial.

"We are seeing a physical difference and that tells us we will see a genetic difference that gives rise to the physical difference, but we find very little genome differences," reports Richard Meisel, UH assistant professor of biology and biochemistry, in the September cover article of Genetics journal. The physical alteration suggests temperature is a meaningful difference between the two types of males.

"We want to know how these things that are so physically different in an evolutionarily meaningful way can have such similar genetics," said Meisel.

The heart of Meisel's work is sex determination. Scientists understand it relatively well in humans - a gene on the Y chromosome initiates the male developmental process, and the process is the same in almost all mammals. But outside the class of mammals, sex determination operates differently. The house fly has substantial variation in how the male/female decision is made. There are two common ways that male development can be initiated, and they differ in their geographical distributions. One male-determining variant predominates at northern latitudes, and the other is more common in the south.

Y is why

Though minute, the difference between the two types of flies is the position of the Y chromosome in the sequence of the genes.

"If Y is the reason then there has to be something genetically about that chromosome that allows it to be that reason," said Meisel. "It's hard for us to wrap our heads around how that trivial amount of difference in the genome sequence causes this variation," said Meisel, adding that evidence indicates natural selection maintains sex determination in the house ?y.

Along with graduate student Jae Hak Son, Meisel examined Y chromosomes by performing mRNA-sequencing experiments to measure gene expression in male house ?ies carrying different Y chromosomes. The exploration allows him to identify candidate phenotype differences between males upon which natural selection can act to maintain the variation in sex determination.

"Our results suggest that, if natural selection maintains polygenic sex determination in house ?y via gene expression differences, the phenotypes under selection likely depend on a small number of genetic targets," he said.

AURORA, Colo. (Sept. 4, 2019) - A new study led by scientists from the University of Colorado School of Medicine offers insight into the mechanism of a key cellular process.

The study focuses on the pre-mRNA (precursor-messenger RNA) splicing process where regions in the pre-mRNA that do not encode proteins (referred to as introns) are removed by the spliceosome, a huge protein-RNA complex. Remaining sections of the RNA transcript, called exons, are then stuck back together. Pre-mRNA splicing is one of several essential steps that convert pre-mRNAs into mature mRNA (messenger RNA) for protein production.

Gaining insight into the highly complex process of how RNA splicing occurs is necessary for developing a better understanding of potential causes of disease.

"Aberrant splicing contributes to at least 30 percent of human genetic disorders and causes many other diseases, such as cancer," said Rui Zhao, PhD, professor of biochemistry and molecular genetics and the lead author of the study.

In the study, published in the Advanced Online Publication of Nature on September 4, Zhao and her colleagues report cryoEM structures that provide "the first view of the earliest event in the splicing cycle that commits pre-mRNAs to splicing."

Cryo-EM, or cryogenic electron microscopy, has undergone a technical revolution in the last five years that allows for studying biomolecular structures at near-atomic resolution. In their study, Zhao and her colleagues looked at cryo-EM structures of the yeast spliceosomal E complex assembled on introns.

How the pre-mRNA splicing process works is still subject to intense investigation by scientists. Specifically, the mechanisms of how introns and exons are defined in a sea of pre-mRNAs and how circular RNAs are generated by a particular back-splicing process are fundamental unanswered questions in pre-mRNA splicing. Through their experiments, Zhao and her colleagues proposed a unified model explaining all three phenomena (intron definition, exon definition, and back-splicing) without the need of a different spliceosome for each process, that are supported by their extensive biochemical experiments.

"Splicing of pre-mRNA is essential for gene expression in all eukaryotes," Zhao said. "In higher eukaryotes such as mammals, an average of 95 percent of the nucleotides in the primary transcript of a protein-encoding gene are introns. These introns need to be precisely removed by splicing before the mRNA can be transported out of the nucleus and translated. Even a single nucleotide error can cause catastrophic consequences. It has also become increasingly clear that alternative splicing is a fundamental approach for eukaryotic gene expression regulation."

The researchers say their work, which was focused on yeast E complex but is applicable to all eukaryotes, should lead to experiments in many other systems to understand the mechanism and regulation of the splicing process.

Scientists at the University of Oxford have developed new artificial intelligence software to recognise and track the faces of individual chimpanzees in the wild. The new software will allow researchers and wildlife conservationists to significantly cut back on time and resources spent analysing video footage, according to the new paper published today in Science Advances.

'For species like chimpanzees, which have complex social lives and live for many years, getting snapshots of their behaviour from short-term field research can only tell us so much,' says Dan Schofield, researcher and DPhil student at Oxford University's Primate Models Lab, School of Anthropology. 'By harnessing the power of machine learning to unlock large video archives, it makes it feasible to measure behaviour over the long term, for example observing how the social interactions of a group change over several generations.'

The computer model was trained using over 10 million images from Kyoto University's Primate Research Institute (PRI) video archive of wild chimpanzees in Guinea, West Africa. The new software is the first to continuously track and recognise individuals in a wide range of poses, performing with high accuracy in difficult conditions such as low lighting, poor image quality and motion blur.

'Access to this large video archive has allowed us to use cutting edge deep neural networks to train models at a scale that was previously not possible,' says Arsha Nagrani, co-author of the study and DPhil student at the Department of Engineering Science, University of Oxford. 'Additionally, our method differs from previous primate face recognition software in that it can be applied to raw video footage with limited manual intervention or pre-processing, saving hours of time and resources.'

The technology has potential for many uses, such as monitoring species for conservation. Although the current application focused on chimpanzees, the software provided could be applied to other species, and help drive the adoption of artificial intelligence systems to solve a range of problems in the wildlife sciences.

'All our software is available open-source for the research community,' says Nagrani. 'We hope that this will help researchers across other parts of the world apply the same cutting-edge techniques to their unique animal data sets. As a computer vision researcher, it is extremely satisfying to see these methods applied to solve real, challenging biodiversity problems.'

'With an increasing biodiversity crisis and many of the world's ecosystems under threat, the ability to closely monitor different species and populations using automated systems will be crucial for conservation efforts, as well as animal behaviour research' adds Schofield. 'Interdisciplinary collaborations like this have huge potential to make an impact, by finding novel solutions for old problems, and asking biological questions which were previously not feasible on a large scale.'

Bottom Line: About 400 caregivers reported pain medication use by children after common surgeries such as hernia, elbow fracture, appendectomy or adenoid removal in this study. Most reported using acetaminophen or ibuprofen or both; 88 patients (22%) were prescribed an opioid at hospital discharge and most used less than prescribed. The lack of an opioid prescription wasn't associated with poor pain control, a postdischarge opioid prescription or a pain-related visit to an emergency department for patients. Limitations of the study include that it was conducted at a single center and patients weren't randomized.

Authors: Calista M. Harbaugh, M.D., M.S., University of Michigan, Ann Arbor, and coauthors

(doi:10.1001/jamasurg.2019.2529)

Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Bottom Line: This analysis reports black, Hispanic and American Indian or Alaska Native students remain underrepresented in allopathic medical schools when compared with the U.S. population, despite new diversity accreditation guidelines. The study used self-reported data on race/ethnicity and sex for medical school applicants and enrolled students (matriculants) from 2002 to 2017. New diversity accreditation guidelines were instituted in 2009 by the Liaison Committee on Medical Education. From 2002 to 2017, the number of medical school applicants increased 53.6% to nearly 51,658 and the number of matriculants increased 29.3% to 21,326. Absolute numbers and proportions of racial/ethnic minority medical school applicants and matriculants have ticked up over time but haven't kept pace with the makeup of their comparable age group in the U.S. population resulting in underrepresentation. Limitations of the study include limits of the data used. The authors suggest more robust policies and programs are needed to create a physician workforce representative of the U.S. population and progress toward that goal must be tracked.

Authors: Ronnie Sebro, M.D., Ph.D., and Jaya Aysola, M.D., M.P.H., of the University of Pennsylvania, Philadelphia, and coauthors

(doi:10.1001/jamanetworkopen.2019.10490)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Studies have suggested that the contrast between the white of human eyes - known as the sclerae - and the colourful irises allows others to detect the direction of our gaze. The ability to detect gaze is important as many other human skills, such as social learning, seem to depend on this.

In contrast, as the sclerae of apes' eyes is often darker than human eyes, researchers have long argued that their gaze is 'cryptic', or hidden. This means that nonhuman apes would not be able to see where other members of their species are looking.

Now, researchers from the National University of Singapore (NUS), together with collaborators from the University of St Andrews and Leiden University, have discovered that ape eyes possess the same pattern of colour differences as human beings. Doctoral student Mr Juan O. Perea-García and Associate Professor Antónia Monteiro from the Department of Biological Sciences at the NUS Faculty of Science suggest that this discovery may mean apes also follow each other's gaze.

Their findings were published in Proceedings of the National Academy of Sciences of the United States of America (PNAS) on 3 September 2019.

Eye-opening results

The research team compared the darkness of the sclerae contrasted with irises of over 150 humans, bonobos and chimpanzees. The researchers found that bonobos, like humans, have paler sclerae and darker irises. Chimpanzees were found to have a different pattern - with very dark sclerae, and paler irises. Both of these colour patterns show the same type of contrast seen in human eyes, and could help other apes find out where they are looking.

"Humans are unique in many ways, as no other animal can communicate with similar intricate language or build tools of such complexity. Gaze following is an important component of many behaviours that are thought to be characteristically human, so our findings suggest that apes might also engage in these behaviours," said Mr Perea-García.

Furthering our ancestral understanding

Before humans had language, our ancestors might have used the gaze of those around them to help communicate dangers or other useful information. They might not have been able to say, "Look over there!". However, a look in the direction of the predator might be sufficient, as long as it was possible to follow the direction of their gaze.

Apart from helping us understand how our ancestors communicated, this study suggests some interesting new research directions. These include questions pertaining to why human beings and bonobos evolve in a similar way, despite bonobos being more closely related to chimpanzees.

"We know that some gorillas and orangutans have eye colouration like our own, and some members of these species have eye colouration similar to the chimpanzees, but why is there this variation within a species? We are working with several zoos to find out more," shared Mr Perea-García.