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Researchers Discover Nucleotide Sequence Responsible For Effectively Fighting Pathologies (Biology)

HSE researchers uncover the fundamental mechanisms behind the maturation of microRNA molecules

Researchers from HSE University have discovered nucleotide sequences characteristic of microRNA isoforms (microRNAs with errors). The discovery will help predict errors in microRNA behaviour and create drugs that can detect targets (such as viruses) more effectively. The results of the study have been published in the RNA Biology journal.

MicroRNAs (miRNAs) are very small molecules that regulate all the processes in a cell, including the transformation of inherited information in RNA or proteins (gene expression). Each microRNA has its own unique set of targets–genes whose activity it can suppress. Recent studies show that even slight changes in microRNA nucleotide sequences (so-called microRNA isoforms or isomiRs) can completely rebuild numerous targets. This can drastically alter the biological function of the molecule. However, until recently, researchers did not know why some microRNAs have isoforms, while others do not.

HSE Faculty of Biology and Biotechnology researchers Anton Zhiyanov, Stepan Nersisyan, and Alexander Tonevitsky applied bioinformatics methods to find the answer to this question. The team managed to create an algorithm that characterizes the fundamental differences between microRNAs that have isoforms and those that do not.

Stepan Nersisyan, Junior Research Fellow at the HSE International Laboratory of Microphysiological Systems © Stepan Nersisyan

Their study also has important applications for the creation of artificial molecules similar to microRNAs. Dozens of research teams across the globe are currently working to solve this problem. Researchers artificially synthetize molecules that are similar to microRNAs (so-called short hairpin RNAs or shRNAs) in order to ‘knock down’ the gene they are interested in. In addition to having academic applications, this technology is also used in therapy to suppress ‘bad’ genes that cause diseases.

The authors of the study demonstrated that such artificially synthetized molecules can also have isoforms.

‘Some combinations of nucleotides (AGCU, AGUU) are most often found in microRNAs where no errors occur. Combinations such as CCAG and some of its variations can predict changes and target failure with up to 70% precision. Sequencing short hairpin RNAs from our own experiments revealed that they also have isoforms. This means that it is possible to have a situation where we invent a molecule with a specific list of targets, but in practice, isoforms appear with unintended targets of their own. Our algorithm helps predict such events at the computer analysis stage without having to carry out costly experiments,’ said Stepan Nersisyan, Junior Research Fellow at the HSE International Laboratory of Microphysiological Systems.

Featured image: The pattern discovered by the researchers. Letters that grow upwards represent error-free microRNA processing, while those growing downwards represent a processing pattern with errors. The bigger the letter, the stronger the correlation. © Nersisyan S. et al.

Reference: Anton Zhiyanov, Stepan Nersisyan & Alexander Tonevitsky (2021) Hairpin sequence and structure is associated with features of isomiR biogenesis, RNA Biology, DOI: 10.1080/15476286.2021.1952759

Provided by HSE

The LHCb Results Strengthen Hints Of A Violation of Lepton Flavour Universality (Particle Physics)

Today the LHCb experiment at CERN announced new results which, if confirmed, would suggest hints of a violation of the Standard Model of particle physics. The results focus on the potential violation of lepton flavour universality and were announced at the Moriond conference on electroweak interactions and unified theories, as well as at a seminar held online at CERN, the European Organization for Nuclear Research.

The measurement made by the LHCb (Large Hadron Collider beauty) collaboration, compares two types of decays of beauty quarks. The first decay involves the electron and the second the muon, another elementary particle similar to the electron but approximately 200 times heavier. The electron and the muon, together with a third particle called the tau, are types of leptons and the difference between them is referred to as “flavours”. The Standard Model of particle physics predicts that decays involving different flavours of leptons, such as the one in the LHCb study, should occur with the same probability, a feature known as lepton flavour universality that is usually measured by the ratio between the decay probabilities. In the Standard Model of particle physics, the ratio should be very close to one.

The new result indicates hints of a deviation from one: the statistical significance of the result is 3.1 standard deviations, which implies a probability of around 0.1% that the data is compatible with the Standard Model predictions. “If a violation of lepton flavour universality were to be confirmed, it would require a new physical process, such as the existence of new fundamental particles or interactions,” says LHCb spokesperson Professor Chris Parkes from the University of Manchester and CERN. “More studies on related processes are under way using the existing LHCb data. We will be excited to see if they strengthen the intriguing hints in the current results.”

The deviation presented today is consistent with a pattern of anomalies measured in similar processes by LHCb and other experiments worldwide over the past decade. The new results determine the ratio between the decay probabilities with greater precision than previous measurements and use all the data collected by the LHCb detector so far for the first time.

The LHCb experiment is one of the four large experiments at the Large Hadron Collider at CERN, situated underground on the Franco-Swiss border near Geneva. The experiment is designed to study decays of particles containing a beauty quark, a fundamental particle that has roughly four times the mass of the proton. The results presented today focus on lepton flavour universality, but the LHCb experiment also studies matter-antimatter differences. 

Looking towards the future, the LHCb experiment is well placed to clarify the potential existence of new physics effects hinted at in the decays presented today. The LHCb experiment is expected to start collecting new data next year following an upgrade to the detector.

Additional material:

Photo of the LHCb experiment http://cds.cern.ch/record/2302374?ln=fr#24

Caption: “The LHCb experiment is one of the four large experiments at the Large Hadron Collider at CERN, situated underground on the Franco-Swiss border near Geneva.”

VNR : https://videos.cern.ch/record/2758757

LHCb paper : LHCb collaboration: R. Aaij et al., “Test of lepton universality in beauty-quark decays”, ArXiv, 2021. https://arxiv.org/abs/2103.11769

Featured image: Very rare decay of a beauty meson involving an electron and positron observed at LHCb (Image: CERN)

Provided by CERN

Large Transporter Protein Linked to Schizophrenia (Psychiatry)

Investigations of a cellular protein have uncovered a possible link with schizophrenia.

Scientists have suspected mutations in a cellular cholesterol transport protein are associated with psychiatric disorders, but have found it difficult to prove this and to pinpoint how it happens. Now, Kazumitsu Ueda of Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS) and colleagues in Japan have provided evidence that mice with disrupted ABCA13 protein demonstrate a hallmark behaviour of schizophrenia. The team investigated ABCA13’s functions and published their findings in the Journal of Biological Chemistry.

Abnormalities in the cholesterol transport protein ABCA13 have been shown to lead to schizophrenia in a mouse model. © Mindy Takamiya/Kyoto University iCeMS

ABCA13 belongs to a family of cellular transporter proteins called ATP-binding cassette (ABC) proteins, which are involved in moving cholesterol and other molecules into and out of cells. Ueda and his team have been studying ABC proteins for 35 years, giving them extra leverage for uncovering the elusive roles of what is suspected to be the largest of these proteins, ABCA13.

The scientists studied ABCA13 in different types of human cells. They also turned off the gene that codes for the protein in mice. Finally, they investigated the effects of mutated ABCA13 proteins in human cells. The team found that ABCA13 was a large protein localized in cellular vesicles, and helps transport cholesterol from the cell’s membrane into the vesicles.

“We found that ABCA13 accelerates the internalization of cholesterol in cells and that its loss of function is associated with the pathophysiology of some psychiatric disorders,” says Ueda.

Mice lacking ABCA13 looked normal and had a normal lifespan. But a series of behavioural investigations showed abnormal results for the ‘startle response and prepulse inhibition test’. Normally, a weak ‘prepulse’ stimulus, like a sound, can reduce the feeling of being startled by a subsequent stronger stimulus. However, people with some psychiatric disorders, still feel startled by a main stimulus despite being preceded by a prepulse. The scientists found that both normal mice and the mice lacking ABCA13 had a normal startle response. But only the engineered mice were startled when the startling stimulus was preceded by a prepulse.

The scientists further wanted to know how ABCA1 deletion affected nerve cells in the brain. They found that vesicles in brain nerve endings in the mice that lacked ABCA1 did not accumulate cholesterol. Synaptic nerve vesicles are vital for the transmission of information from one nerve to another, so this malfunction could contribute to the pathophysiology of psychiatric disorders, the researchers say.

Finally, the scientists studied human cells containing mutated versions of ABCA13 thought to be associated with some psychiatric disorders. They found the mutations impaired ABCA13’s functions and ability to locate within cellular vesicles.

The team suggests further studies on ABCA13 functions could lead to the development of novel therapeutic strategies for psychiatric disorders like schizophrenia, bipolar disorder and major depression.

Reference: Nakato M, Shiranaga N, Tomioka M, Watanabe H, Kurisu J, Kengaku M, Komura N, Ando H, Kimura Y, Kioka N, Ueda K. ABCA13 dysfunction associated with psychiatric disorders causes impaired cholesterol trafficking. J Biol Chem. 2020 Dec 8:jbc.RA120.015997. doi: 10.1074/jbc.RA120.015997. Epub ahead of print. PMID: 33293368. https://pubmed.ncbi.nlm.nih.gov/33293368/

Provided by Kyoto University

Early Signs of Alzheimer’s Disease in People With Down’s Syndrome (Medicine)

Researchers at Karolinska Institutet in Sweden have studied the incidence and regional distribution of Alzheimer’s disease biomarkers in the brains of people with Down’s syndrome. The results can bring new possibilities for earlier diagnosis and preventive treatment of dementia. The study is published in Molecular Neurodegeneration.

While medical advances and improvements of life quality have increased the life expectancy of people with Down’s syndrome to an average of 60 years, up to 90 percent develop Alzheimer’s disease if they live long enough.

In Alzheimer’s disease, clumps of amyloid form plaques around the neurons of the brain, while another protein, tau, accumulates inside the nerve cells in what are referred to as tangles. Plaque and tangles appear first in one region of the brain and then spread, causing gradually deteriorating functional impairment.

People with Down’s syndrome have an extra copy of chromosome 21. One reason for the high incidence of Alzheimer’s disease in people with Down’s syndrome is that the gene coding for the production of amyloid is located on chromosome 21, which can cause an accumulation of amyloid in the brain already in childhood.

“Previous studies of Down’s syndrome by our group and others have been able to demonstrate that pathological forms of amyloid and tau can appear years before someone shows signs of dementia,” says Lotta Granholm, professor at Karolinska Institutet and the University of Denver, and one of the paper’s principal authors.

In the current study, the researchers studied the extent and distribution of tau and amyloid in the brain tissue of people with Down’s syndrome with or without an Alzheimer’s diagnosis, and of people who had died with Alzheimer’s disease but without any other functional disability.

Their analyses showed that the incidence of tau in the brain tissue of people with Down’s syndrome and Alzheimer’s disease was higher than in people with Alzheimer’s but without Down’s syndrome, suggesting that tau is an early change in Down’s syndrome.

“Apart from a high level of tau, we also measured a different regional distribution of tau in the brains of people with Down’s syndrome and Alzheimer’s disease compared to the control group,” says the paper’s first author Laetitia Lemoine, assistant professor at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet.

Traces of tau were also detected in the brain tissue of fetuses with Down’s syndrome. Early prophylactic measures against tau accumulation could prevent the development of Alzheimer pathology in childhood for this patient group, the researchers believe.

“Our studies support the need for continued research on the progress and incidence of amyloid plaque and tau in the brain by imaging the brains of live individuals with Down’s syndrome,” says Agneta Nordberg, professor at the Department of Neurobiology, Care Sciences and Society, and the paper’s second principal author. “Our aim is a better understanding of how we can take early steps to discover pathological changes that produce cognitive symptoms and begin medication that helps to improve life quality.”

The study was financed by grants from the National Institute on Aging, the Bright Focus Foundation, the Swedish Foundation for Strategic Research, the Swedish Research Council, Region Stockholm, Karolinska Institutet, the Swedish Brain Fund, the Swedish Alzheimer’s Foundation, the foundation for old servants, the Gun and Bertil Stohne Foundation, the Gunvor and Josef Anér Foundation, the Loo and Hans Osterman Foundation for Medical Research, the Dementia Research Fund and the Croatian Science Foundation. There are no reported conflicts of interest.

References: L Lemoine, A Ledreux, EJ Mufson, SE Perez, G Simic, E Doran, I Lott, S Carroll, K Bharani, S Thomas, A Gilmore, ED Hamlett, A Nordberg, AC Granholm, “Regional binding of tau and amyloid PET tracers in Down syndrome autopsy brain tissue.”, Molecular Neurodegeneration, 23 November 2020, doi: 10.1186/s13024-020-00414-3. https://molecularneurodegeneration.biomedcentral.com/articles/10.1186/s13024-020-00414-3

Provided by Karolinska Institute

Rapid Climate Change Around 180 Million Years Ago Spread Well-known Long-necked Dinosaurs (Paleontology)

Global warming triggered the evolution of giant dinosaurs. An international team of paleontologists, including LMU Professor Oliver Rauhut, finds evidence of rapid climate change 180 million years ago as the cause of the spread of the well-known long-necked dinosaurs.

Live reconstruction of the early sauropod Bagualia alba. Illustration: Jorge Gonzales

When we hear the word dinosaur, most of us probably immediately think of giant animals with massive bodies, long necks and tails, and tiny heads. These „quintessential dinosaurs“ actually represent one prominent subgroup of the Dinosauria, the so called Sauropoda (‚long-necked dinosaurs‘ in popular culture). Sauropods were truly amazing animals, and included the largest land-living animals known, with body lengths of up to 40 m and weights of 70 tons or more.

However, these giant animals did not appear directly at the beginning of the era of dinosaurs. For the first fifty million years of their evolutionary history, the Sauropodomorpha – the lineage that the sauropods belong to – were represented by several groups of bipedal to quadrupedal animals. Although some of them reached already large body sizes of about ten meters in length and a few tons in weight, these groups also included smaller, and lightly built animals, some of which not larger than a goat. Furthermore, all of these animals had rather slender teeth, indicating that these plant-eating animals fed on rather soft and lush vegetation. However, towards the end of the Early Jurassic period, some 180 million years ago, all these groups suddenly disappear, and only one lineage survived and thrived – the sauropods. What caused this faunal change during the Early Jurassic has remained enigmatic so far.

An international team of researchers, led by Argentinean paleontologist Diego Pol and including Munich researcher Oliver Rauhut of the Ludwig-Maximilians-University and the Bayerische Staatssammlung für Paläontologie und Geologie, now report new evidence on what might have caused these changes. In the province of Chubut, Argentinean Patagonia, they did not only discover the fossil remains of one of the oldest large sauropods known, which the team named Bagualia alba, but could also place it very precisely in its temporal and ecological context. Thus, the layers the new sauropod comes from could very precisely be dated as 179 million years ago, just after the mysterious disappearance of the other sauropodomorph groups, and finds of plant fossils in rock layers just before that time and at the time that Bagualia alba lived provide evidence for the climate and the ecology that these animals lived in.

Thus, the data indicate that there was a relative rapid change in climate about 180 million years ago, from a temperate warm and humid climate, in which a diverse, lush vegetation flourished, to a strongly seasonal, very hot and dry climate, characterized by a less diverse flora, dominated by forms showing adaptations for hot climates, such as certain conifers. These environmental changes were apparently driven by a greenhouse effect due to climate gasses such as CO2 and methane caused by increased volcanism at that time; evidence of these volcanic eruptions are found on many southern continents, such as the Drakensberge in southern Africa.

With their slender teeth, the non-sauropodan sauropodomorphs were adapted to the rather soft vegetation flourishing before this global warming event, but when this flora was replaced by the much tougher greenhouse vegetation, these animals died out. The sauropods represented the only group of sauropodomorphs with a much more robust dentition, well-adapted for such tough vegetation, and thus they flourished and became the dominant group of herbivorous dinosaurs at that time. Indeed the specialization for this kind of vegetation was probably one of the reasons why these animals reached their gigantic sizes: As large digestion chambers are needed to cope with such food, there was a general tendency for these animals to become ever larger.

References: D. Pol , J. Ramezani , K. Gomez , J. L. Carballido , A. Paulina Carabajal , O. W. M. Rauhut , I. H. Escapa and N. R. Cúneo, “Extinction of herbivorous dinosaurs linked to Early Jurassic global warming event”, Proceedings of Royal Society B, 2020. https://royalsocietypublishing.org/doi/10.1098/rspb.2020.2310# https://doi.org/10.1098/rspb.2020.2310

Provided by LMU Munich

Scientists Use Bacteria As Micro-3D Printers (Medicine)

Technique creates highly customised structures that could be used in regenerative Medicine.

A team at Aalto University has used bacteria to produce intricately designed three-dimensional objects made of nanocellulose. With their technique, the researchers are able to guide the growth of bacterial colonies through the use of strongly water repellent – or superhydrophobic – surfaces. The objects show tremendous potential for medical use, including supporting tissue regeneration or as scaffolds to replace damaged organs. The results have been published in the journal ACS Nano.

Unlike fibrous objects made through current 3D printing methods, the new technique allows fibres, with a diameter a thousand times thinner than a human hair, to be aligned in any orientation, even across layers, and various gradients of thickness and topography, opening up new possibilities for application in tissue regeneration. These kinds of physical characteristics are crucial for support materials in the growth and regeneration of certain types of tissues found in muscles as well as in the brain.

Unlike in conventional 3D printing, the fibres can be aligned in any direction, even across layers. Image: Luiz Greca/Aalto University

‘It’s like having billions of tiny 3D printers that fit inside a bottle,’ explains Luiz Greca, a doctoral student at Aalto University. ‘We can think of the bacteria as natural microrobots that take the building blocks provided to them and, with the right input, create complex shapes and structures.’

Once in a superhydrophobic mould with water and nutrients — sugar, proteins and air — the aerobic bacteria produce nanocellulose. The superhydrophobic surface essentially traps a thin layer of air, which invites the bacteria to create a fibrous biofilm replicating the surface and shape of the mould. With time, the biofilm grows thicker and the objects become stronger.

Using the technique, the team has created 3D objects with pre-designed features, measuring from one-tenth the diameter of a single hair all the way up to 15-20 centimetres. The nano-sized fibres do not cause adverse reactions when placed in contact to human tissues. The method could also be used to grow realistic models of organs for training surgeons or improving the accuracy of in-vitro testing.

“It’s like having billions of tiny 3D printers that fit inside a bottle.” said Luiz Greca, doctoral student.

‘It’s really exciting to expand this area of biofabrication that takes advantage of strong cellulose nanofibres and the networks they form. We’re exploring applications for age-related tissue degeneration, with this method being a step forward in this and other directions,’ says research group leader Professor Orlando Rojas. He adds that the strain of bacteria used by the team, Komagataeibacter medellinensis, was discovered in a local market in the city of Medellin, Colombia, by previous collaborators from Universidad Pontificia Bolivariana.

In both nature and engineering, superhydrophobic surfaces are designed to minimise the adhesion of dust particles as well as microorganisms. This work is expected to open new possibilities for using superhydrophobic surfaces to precisely produce naturally manufactured materials.

As the bacteria can be removed or left in the final material, the 3D objects can also evolve as a living organism over time. The findings provide an important step towards harnessing full control over bacterially fabricated materials.

‘Our research really shows the need to understand both the fine details of bacteria interaction at interfaces and their ability to make sustainable materials. We hope that these results will also inspire scientists working on both bacteria-repelling surfaces and those making materials from bacteria,’ says Dr. Blaise Tardy.

References: Greca, L. G., Rafiee, M., Karakoç, A., Lehtonen, J., Mattos, B. D., Tardy, B. L., & Rojas, O. J. (2020). Guiding Bacterial Activity for Biofabrication of Complex Materials via Controlled Wetting of Superhydrophobic Surfaces. ACS Nano. https://pubs.acs.org/doi/10.1021/acsnano.0c03999 https://doi.org/10.1021/acsnano.0c03999

Provided by Aalto University

Making A Case For Organic Rankine Cycles In Waste Heat Recovery (Engineering)

In a recent research paper published in the Energy journal, City, University of London’s Dr Martin White says cascaded organic Rankine cycle systems could improve the way in which environmentally-friendly power is generated from waste heat.

A team from City, University of London’s Department of Engineering believes that a new approach to generating energy through waste heat could yield important insights into delivering environmentally-friendly power.

Diagram illustrating cascaded organic Rankine cycle system. ©Dr Martin White, City, University of London

In this recent paper, Making the case for cascaded organic Rankine cycles for waste-heat recovery, published in the Energy journal, Dr Martin White has identified optimal single-stage and cascaded organic Rankine cycle systems (ORC) to maximise performance, and has designed accompanying heat exchangers.

The ORC is based on the principle of heating a liquid which causes it to evaporate, and the resulting gas can then expand in a turbine, which is connected to a generator, thus creating power. Waste heat to power organic Rankine cycle systems can utilise waste heat from a range of industrial processes in addition to existing power generation systems.

A cascaded ORC system is essentially two ORC systems coupled together, with the heat that is rejected from the first ORC being used as the input heat for the second.

However, in developing his model of a cascaded ORC system, Dr White hastens to add that there is a trade-off between performance and cost – in the case of the heat exchangers deployed, the general rule is that the better the performance, the larger and more costly the heat exchangers.

He says the trade-off can be explored through optimisation and the generation of what is called a ‘Pareto front’ – a collection of optimal solutions that considers the trade-off between two things.

If quite large heat exchangers (in this specific case, greater than around 200m2), were affordable, then for that amount of area, it is possible to generate more power with a cascaded system than a single-stage system.

However, if the size of the heat exchangers was restricted, one would probably be better off with a single-stage system.

Dr White’s results suggest that in applications where maximising performance is not the primary objective, single-stage ORC systems remain the best option. However, in applications where maximised performance is the goal, cascaded systems can produce more power for the same size heat exchangers.

His paper emerged out of his work on the NextORC project, funded by the Engineering and Physical Sciences Research Council (EPSRC).

References: Martin T. White, Matthew G. Read, Abdulnaser I. Sayma, “Making the case for cascaded organic Rankine cycles for waste-heat recovery”, Energy, Volume 211, 2020, 118912, ISSN 0360-5442,
https://doi.org/10.1016/j.energy.2020.118912. (http://www.sciencedirect.com/science/article/pii/S0360544220320193)

Provided by City University London

Ancient Crocodiles’ Family Tree Reveals Unexpected Twists And Turns (Paleontology)

Scientists probing a prehistoric crocodile group’s shadowy past have discovered a timeless truth – pore over anyone’s family tree long enough, and something surprising will emerge.

Scientists probing a prehistoric crocodile group’s shadowy past have discovered a timeless truth – pore over anyone’s family tree long enough, and something surprising will emerge.

Artist’s impression of Macrospondylus- an extinct fossil group of teleosauriods. ©Nikolay Zverkov

Despite 300 years of research, and a recent renaissance in the study of their biological make-up, the mysterious, marauding teleosauroids have remained enduringly elusive.

Scientific understanding of this distant cousin of present day long snouted gharials has been hampered by a poor grasp of their evolutionary journey – until now.

Researchers from the University of Edinburgh have identified one previously unknown species of teleosauroid and seven of its close relatives – part of a group that dominated Jurassic coastlines 190 to 120 million years ago.

Their analysis offers tantalising glimpses of how teleosauroids adapted to the momentous changes that occurred during the Jurassic period, as the earth’s seas experienced many changes in temperature.

“Our study just scratches the surface of teleosauroid evolution,” says study lead Dr Michela M. Johnson, of the University’s School of GeoSciences. “But the findings are remarkable, raising interesting questions about their behaviour and adaptability.

“These creatures represented some of the most successful prehistoric crocodylomorphs during the Jurassic period and there is so much more to learn about them.”

The study reveals that not all teleosauroids were engaged in cut and thrust lifestyles, snapping at other reptiles and fish from the seas and swamps near the coast.

Instead, they were a complex, diverse group that were able to exploit different habitats and seek out a variety of food sources. Their physical make-up is also more diverse than was previously understood, the scientists say.

Previous research had provided insights into the origins and evolution of this fossilised croc’s whale-like relatives metriorhynchids, but less was known about teleosauroids.

To address this, the expert team of palaeontologists examined more than 500 fossils from more than 25 institutions around the world.

Cutting edge computer software enabled the team to glean swathes of revealing data regarding their anatomical similarities and differences, by examining the entire skeleton, teeth and bony armor, which indicated whether species were closely related or not.

This information enabled the team to create an up-to-date family tree of the teleosauroids group from which emerged two new large groups, whose anatomy, abundance, habitat, geography and feeding styles differ from one another significantly.

The first group, teleosaurids, were more flexible in terms of their habitat and feeding. The second group known as machimosaurids – which included the fearsome turtle crushers, Lemmysuchus and Machimosaurus – were more abundant and widespread.

Names given by the team to seven newly described fossils, found in both teleosaurids and machimosaurids, reflect a curious range of anatomical features – among them Proexochokefalos, meaning ‘large head with big tuberosities’ and Plagiophthalmosuchus, the ‘side-eyed crocodile’.

There are even hints of their diverse behavioural characteristics and unique locations – Charitomenosuchus, meaning ‘graceful crocodile’ and Andrianavoay, the ‘noble crocodile’ from Madagascar.

Researchers have named the newly discovered species, Indosinosuchus kalasinensis, after the Kalasin Province in Thailand, where the fossil – now housed in Maha Sarakham University – was found.

The recognition of I. kalasinensis shows that at least two species were living in similar freshwater habitats during the Late Jurassic – an impressive feat as teleosauroids, with the exception of Machimosaurus, were becoming rare during this time.

Dr Steve Brusatte, Reader in Vertebrate Palaentology, at the School of Geosciences, University of Edinburgh, said: “The same way family trees of our own ancestors and cousins tell us about our history, this huge new family tree of teleosauroids clarifies their evolution. They were some of the most diverse and important animals in the Jurassic oceans, and would have been familiar sights along the coastlines for tens of millions of years.”

References: Johnson MM, Young MT, Brusatte SL. 2020. The phylogenetics of Teleosauroidea (Crocodylomorpha, Thalattosuchia) and implications for their ecology and evolution. PeerJ 8:e9808 https://doi.org/10.7717/peerj.9808 link: https://peerj.com/articles/9808/

Provided by University of Edinburgh

Astronomers Proposed Bayesian Inference Method For Identification Of Supermassive Binary Black holes (Astronomy)

Xing-Jiang Zhu and Eric Thrane presented a Bayesian method for the detection of supermassive binary black holes in the presence of red noise.

Big galaxies are assembled from smaller galaxies merging together, so collisions of supermassive black holes are expected to be common in the cosmos. But merging supermassive black holes remain elusive: No conclusive evidence of their existence has been found so far.

One way to look for these mergers is through their emission of gravitational waves—ripples in the fabric of space and time. A distant merging pair of supermassive black holes emit gravitational waves as they spiral in around each other. Since the black holes are so large, each wave takes many years to pass by Earth. Astronomers have used a technique known as pulsar timing array to observe gravitational waves from supermassive binary black holes—so far to no avail.

In parallel, astronomers have been looking for the collision of supermassive black holes with light. A number of candidate sources have been identified by looking for regular fluctuations in the brightness of distant galaxies called quasars. Quasars are extremely bright, believed to be powered by the accumulation of gas clouds onto supermassive black holes.

If the center of a quasar contains two black holes orbiting around each other instead of a single one, the orbital motion might change the gas cloud accumulation and lead to periodic variation in its brightness. Hundreds of candidates have been identified through such searches, but astronomers are yet to find the smoking-gun signal.

So, astronomers presented a Bayesian method for the detection of quasar (quasi) periodicity in the presence of red noise. They applied this method to the binary candidate PG 1302−102 and showed that, there is very strong support (Bayes factor >106) for quasiperiodicity and the data slightly favor a quasiperiodic oscillation over a sinusoidal signal, which they interpret as modest evidence against the binary black hole hypothesis. However, they argued that the signal is likely to be more complicated than current models.

References: Xing-Jiang Zhu and Eric Thrane, “Toward the umabiguous identification of supermassive black holes through Bayesian interference”,
The Astrophysical JournalVolume 900Number 2, 2020 https://iopscience.iop.org/article/10.3847/1538-4357/abac5a