Culture

Gender gap in academic medicine has negative impact, but there are simple solutions

image: This is Dr. Sharon Straus, director of the Knowledge Translation Program at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, co-led this study.

Image: 
St. Michael's Hospital

TORONTO, April 9, 2018 - Existing gender gaps in academic medicine may have a negative impact on workplace culture and organizational effectiveness, but there are simple, systems-based solutions, suggests a new study.

Published today in BMC Medicine, the study led by Dr. Reena Pattani and Dr. Sharon Straus analyzed interviews conducted with female and male faculty members at the University of Toronto and its six fully-affiliated hospitals. Interviews with frontline staff uncovered that the gender gap in academic medicine has a negative impact.

"We identified three key themes that the gender gap fuels: social exclusion of female colleagues, reinforced stereotypes, and unprofessional behaviour," said Dr. Straus, director of the Knowledge Translation Program at the Li Ka Shing Knowledge Institute of St. Michael's Hospital. "Interestingly, instead of just focusing on the issues, the study's participants also offered system-based solutions to close the gap."

Several opportunities to mitigate the gap emerged from this research, said Dr. Straus, who is also interim physician-in-chief at St. Michael's. The participants suggested more streamlined recruitment, hiring, and promotions processes and simple amendments to the work environment, such as unconscious bias training for leaders and holding meetings during work hours so that all faculty members can attend. Formalized mentorship and consistent monitoring of the gender gap were also offered as solutions.

"These are solutions at the level of the institution, rather than at the level of the individual," said Dr. Pattani, a physician at St. Michael's. "The advice historically given to women has been about how they can change their own personal behaviours. That overlooks some of the systemic factors holding women back. We need to ensure that institutions can create a more inclusive environment for all."

This work builds on previous research conducted by Dr. Straus, which found that a significant gender gap existed across the research institute at St. Michael's Hospital. Since then, steps have been taken to reduce the gender imbalance. Across the University of Toronto's Department of Medicine, search guidelines, transparent promotions processes, and a formal mentorship program have also been implemented, and a biennial faculty survey helps university and hospital leadership monitor trends of the gender gap over time. At St Michael's Hospital, the Department of Medicine has also been hosting networking opportunities for female trainees.

"These are inspiring measures to promote equity. We can work together to institute more system-based approaches like these ones, which are low cost and easy to implement," Dr. Pattani said.

The researchers acknowledge that there are also other factors beyond gender that impact workplace culture, which were not studied in this paper. Further research is needed to understand how sexual orientation, race and ethnicity play a role in the representation gap, Dr. Straus said.

Credit: 
St. Michael's Hospital

Wheat research discovery yields genetic secrets that could shape future crops

image: This is floral architecture in wheat. The spikelets highlighted in purple are the additional spikelets which form part of the paired spikelets.

Image: 
CSIRO

A new study has isolated a gene controlling shape and size of spikelets in wheat in a breakthrough which could help breeders deliver yield increases in one of the world's most important crops.

The team from the John Innes Centre say the underlying genetic mechanism they have found is also relevant to inflorescence (floral) architecture in a number of other major cereals including corn, barley and rice.

The genetic identification of an agronomically-relevant trait represents a significant milestone in research on wheat; a crop with a notoriously complex genome.

The findings, published today in the journal The Plant Cell, give breeders a new tool to accelerate the global quest to improve wheat. The study also highlights a range of next generation techniques available for fundamental research into wheat, the world's most abundantly produced crop.

The Wheat Initiative, which co-ordinates global research for wheat, has identified floral architecture as one of the key traits which must be improved if a 1.6% yield increase needed to feed a growing world population is to be reached.

Dr Scott Boden from the John Innes Centre, whose crop genetics laboratory led the study alongside colleagues from Australia and Cambridge, said it represented a breakthrough both in lab and field.

"This paper is an example of what we are capable of doing in wheat now with a lot of the resources that are coming on board. We have gone from the field to the lab and back again. This is a developmental gene that contributes to a lot of agronomically important traits. This knowledge and the resources that come from this study can be used to see if it really does benefit yield."

"We have approached this in an academic sense but we have moved it towards giving breeders tools they can work with to optimise floral development."

Diversity of floral architecture has been exploited by generations of crop breeders to increase yields, and genetic variation for this trait has the potential to further boost grain production.

The study focused on the genetics behind a specific mutant trait in bread wheat known as paired spikelets, where a wheat inflorescence is formed of two spikelets instead of the usual one. This trait, which bears resemblance to flower production in corn and rice, is a variation that could lead to increase in yield.

Using a range of techniques including plant transformation, gene sequencing and speed breeding, researchers investigated lines of wheat displaying paired spikelets, derived from a mapping population called a multi-parent advanced generation intercross (MAGIC); a population of spring wheat created as a tool to study and identify the genetic origins of relevant traits.

The study revealed that a gene called TEOSINTE BRANCHED1 (TB1) regulates wheat inflorescence architecture, promoting paired spikelets via a mechanism which delays flowering and reduces the expression of genes that control the development of lateral branches called spikelets.

Further analysis showed that alleles that modify the function of TB1 were present in a wide range of major modern wheat cultivars used by breeders in the UK and Europe. Also, that variant alleles for TB1 were present on two of the three wheat genomes of winter and spring wheat.

Genetic analysis also showed that TB1 is linked to another gene that has been known for a long time: the so-called Green Revolution gene, Rht-1, which controls plant height.

Further studies will determine whether some of the effects attributed to Rht-1 are actually TB1 effects.

The authors of the study say the TB1 gene is also important to the contribution of floral architecture diversity in a number of other cereals including corn, barley and rice - with interest in the paper already coming from those research communities.

Dr Boden hopes that one of the impacts of the paper will be to encourage more early-career researchers to choose wheat for developmental research projects.

The full findings are available in the paper: Teosinte Branched1 regulates inflorescence architecture and development in bread wheat.

Credit: 
John Innes Centre

Kids with regular health care less likely to have life-threatening diabetic ketoacidosis

A key factor in reducing the risk of diabetic ketoacidosis (DKA), a potentially life-threatening complication of type 1 diabetes, in children at diagnosis of type 1 diabetes, is having a regular health care provider, according to a study in CMAJ (Canadian Medical Association Journal).

Type 1 diabetes mellitus is a common chronic childhood disease. If untreated, it can result in DKA, the most common cause of death in children with type 1 diabetes. DKA occurs as the body breaks downs muscle and fats for energy in place of sugar, releasing fatty acids (ketones) into the blood.

"Having a regular primary care provider was associated with a reduced risk of DKA at diabetes onset, but this protection reached statistical significance only among those 12-17 years of age," writes Dr. Meranda Nakhla, Montreal Children's Hospital and the Research Institute of the McGill University Health Centre, Montreal, Quebec, with coauthors. "Adolescents who had a regular family physician or pediatrician were 31% less likely or 38% less likely, respectively, to present with DKA relative to those without regular primary care."

The researchers looked at data on 3704 children with newly diagnosed diabetes over the study period from 2006 to 2015. The mean age at diagnosis was 10 years and about 27% (996 children) presented with diabetic ketoacidosis at time of diagnosis. About 59% (2177 children) had a regular primary care provider before diagnosis. Children of lower socioeconomic status or living in small cities were more likely to have a diabetic ketoacidosis episode at diagnosis of diabetes than those of higher socioeconomic status or those living in urban areas.

"Our study provides further evidence for policy-makers about the need to develop and strengthen initiatives that promote primary care for children," write the authors. "Our results highlight the need to develop targeted interventions for children under 12 years of age, including increasing public and physician awareness (through educational campaigns) about the symptoms of diabetes in this age group."

In a related commentary http://www.cmaj.ca/lookup/doi/10.1503/cmaj.180220, Dr. Astrid Guttmann, The Hospital for Sick Children (SickKids) and the Institute for Clinical Evaluative Sciences (ICES), Toronto, Ontario, writes the "study serves as an example of one of the many important child health outcomes that are both sensitive to access to timely care and independently related to socioeconomic health status."

Credit: 
Canadian Medical Association Journal

There's no such thing as oversharing in conservation

image: a, This is a sociogram for an operating unit in the treatment group. b, This is a sociogram for an operating unit in the control group. IBSs are represented by white nodes, non-boundary spanners are represented by grey nodes, and projects are represented by black nodes. Nodes with orange circles are people targeted by the experiment. Black lines represent ties from people to projects in the same cluster, and grey lines represent ties from people to projects in different clusters.

Image: 
Michigan State University

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

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

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

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

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

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

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

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

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

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

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

Credit: 
Michigan State University

Organic Consumers Association sends Vedic plant believer John Fagan into farm country

Organic Consumers Association (OCA) is an industry trade group created by Ronnie Cummins, a disciple of anti-science activist Jeremy Rifkin, which funds numerous vassal groups to promote the work of their corporate clients. Two of them are a "lab" called HRI and Regeneration International. Now OCA is putting them together so Fagan, from the Maharishi University of Management in Iowa, can teach real farmers about his alternative vedic plant approach.

HIV Cell dysfunction discovery sheds light on how virus works

image: HIV infection impacts the normal function of follicular T cell.

Image: 
Carla Shaffer / AAAS

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

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

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

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

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

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

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

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

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

Credit: 
University of Texas at Austin

Nova-like explosion of spinning live bacteria explained

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

Image: 
Igor Aronson, Penn State

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

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

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

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

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

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

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

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

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

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

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

Credit: 
Penn State

Hunting for dark matter in the smallest galaxies in the Universe

image: On the left-hand side, we see the results of a computer simulation in which Eridanus II resides within a dense dark matter 'halo', as expected in the standard cosmological model. The star cluster (in green) rapidly dissolves in this model. We can, therefore, rule out this model since we see an old surviving star cluster in Eridanus II today. On the right-hand side, we see a similar computer simulation in which Eridanus II resides in a much lower density dark matter 'halo'. In this model, the star cluster not only survives but it grows to a size that matches the observed star cluster in Eridanus II, marked by the green circle in the middle.

Image: 
Observational image taken from Crnojevi et al. 2016; composite image produced by Dr Maxime Delorme (University of Surrey).

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

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

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

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

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

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

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

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

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

Credit: 
University of Surrey

How pathogenic bacteria prepare a sticky adhesion protein

image: Pathogenic gram-positive bacteria, such as S. gordonii, export a serine-rich adhesin to facilitate their attachment to host cells. Adhesin uses a dedicated secretion pathway, with several steps occurring in the cytosol before its translocation across the membrane. The adhesin GspB (shown in red) is first modified by N-acetylglucosamine (orange hexagon) and glucose (wheat hexagon) in a strictly sequential order. It is then targeted to the membrane by a complex of three accessory secretion proteins (Asp 1-3; shown in green, blue, and pink), two of which resemble carbohydrate-binding proteins (crystals structures are shown ribbon diagrams imbedded in space-filling presentation). Finally, GspB adhesin is moved through the membrane by a dedicated ATPase (SecA2) and membrane channel (SecY2) (both shown in cyan).

Image: 
Yu Chen, Harvard Medical School

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

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

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

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

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

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

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

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

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

Credit: 
American Society for Biochemistry and Molecular Biology

The blue whale genome reveals the animals' extraordinary evolutionary history

image: This is a humpback whale.

Image: 
Florian Schulz

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

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

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

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

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

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

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

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

Credit: 
Goethe University Frankfurt

Sowing strips of flowering plants has limited effect on pollination

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

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

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

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

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

Credit: 
Lund University

Unexpected finding may deter disabling diabetic eye disease

image: Julia Busik, a Michigan State University physiology professor, is the first to find that a particular type of lipid, or fat, thought to only exist in the skin, now lives in your eye and might play a major role in deterring diabetic retinopathy.

Image: 
Michigan State University

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

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

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

The research is published in the journal Diabetes.

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

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

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

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

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

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

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

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

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

Credit: 
Michigan State University

Printed thermo-plasmonic heat patterns for neurological disorder treatment

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

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

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

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

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

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

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

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

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

Credit: 
The Korea Advanced Institute of Science and Technology (KAIST)

How birds can detect the Earth's magnetic field

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

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

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

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

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

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

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

Credit: 
Lund University

Optimism remains in chickens in enriched environments despite exposure to stress

image: This is Hanne Løvlie, Associate professor, Linköping University.

Image: 
Anna Nilsen/LiU

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

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

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

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

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

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

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

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

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

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

Credit: 
Linköping University