Wednesday, October 21, 2020

Cannabis Reduces OCD Symptoms by Half in the Short-Term

People with obsessive-compulsive disorder, or OCD, report that the severity of their symptoms was reduced by about half within four hours of smoking cannabis, according to a Washington State University study.

Buds of marijuana (cannabis indica inflorescence) in a small green ceramic cup.
 

Credit: Efiks / Wikimedia Commons

The researchers analyzed data inputted into the Strainprint app by people who self-identified as having OCD, a condition characterized by intrusive, persistent thoughts and repetitive behaviors such as compulsively checking if a door is locked. After smoking cannabis, users with OCD reported it reduced their compulsions by 60%, intrusions, or unwanted thoughts, by 49% and anxiety by 52%.

The study, recently published in the Journal of Affective Disorders, also found that higher doses and cannabis with higher concentrations of CBD, or cannabidiol, were associated with larger reductions in compulsions.

"The results overall indicate that cannabis may have some beneficial short-term but not really long-term effects on obsessive-compulsive disorder," said Carrie Cuttler, the study's corresponding author and WSU assistant professor of psychology. "To me, the CBD findings are really promising because it is not intoxicating. This is an area of research that would really benefit from clinical trials looking at changes in compulsions, intrusions and anxiety with pure CBD."

The WSU study drew from data of more than 1,800 cannabis sessions that 87 individuals logged into the Strainprint app over 31 months. The long time period allowed the researchers to assess whether users developed tolerance to cannabis, but those effects were mixed. As people continued to use cannabis, the associated reductions in intrusions became slightly smaller suggesting they were building tolerance, but the relationship between cannabis and reductions in compulsions and anxiety remained fairly constant.

Traditional treatments for obsessive-compulsive disorder include exposure and response prevention therapy where people's irrational thoughts around their behaviors are directly challenged, and prescribing antidepressants called serotonin reuptake inhibitors to reduce symptoms. While these treatments have positive effects for many patients, they do not cure the disorder nor do they work well for every person with OCD.

"We're trying to build knowledge about the relationship of cannabis use and OCD because it's an area that is really understudied," said Dakota Mauzay, a doctoral student in Cuttler's lab and first author on the paper.

Aside from their own research, the researchers found only one other human study on the topic: a small clinical trial with 12 participants that revealed that there were reductions in OCD symptoms after cannabis use, but these were not much larger than the reductions associated with the placebo.

The WSU researchers noted that one of the limitations of their study was the inability to use a placebo control and an "expectancy effect" may play a role in the results, meaning when people expect to feel better from something they generally do. The data was also from a self-selected sample of cannabis users, and there was variability in the results which means that not everyone experienced the same reductions in symptoms after using cannabis.

However, Cuttler said this analysis of user-provided information via the Strainprint app was especially valuable because it provides a large data set and the participants were using market cannabis in their home environment, as opposed to federally grown cannabis in a lab which may affect their responses. Strainprint's app is intended to help users determine which types of cannabis work the best for them, but the company provided the WSU researchers free access to users' anonymized data for research purposes.

Cuttler said this study points out that further research, particularly clinical trials on the cannabis constituent CBD, may reveal a therapeutic potential for people with OCD.

This is the fourth study Cuttler and her colleagues have conducted examining the effects of cannabis on various mental health conditions using the data provided by the app created by the Canadian company Strainprint. Others include studies on how cannabis impacts PTSD symptoms, reduces headache pain, and affects emotional well-being.


Contacts and sources:
Sara Zaske / Carrie Cuttler
Washington State University

Publication: Acute Effects of Cannabis on Symptoms of Obsessive-Compulsive Disorder.  A Dakota Mauzay, Emily M. LaFrance, Carrie Cuttler.  Journal of Affective Disorders https://www.sciencedirect.com/science/article/abs/pii/S0165032720328202?via%3Dihub http://dx.doi.org/10.1016/j.jad.2020.09.124




When a Greenhouse Disaster Wiped Out Almost All Life on Earth

Illustration depicting the onset of the Permian-Triassic mass extinction based on findings of Jurikova et al. (2020). Ocean acidification and vanishing marine life in the surface ocean caused by a large release of volcanic CO2 from Siberian Traps. Illustrated by: Dawid Adam Iurino
Credit: (PaleoFactory, Sapienza University of Rome) for Jurikova et al. (2020).

Earth's history knows catastrophes which are unimaginable for humans. For example, around 66 million years ago an asteroid impact marked the end of the dinosaur era. Long before however, 252 million years ago at the boundary between the Permian and Triassic epochs, Earth witnessed a far more extreme mass extinction event that extinguished about three-quarters of all species on land and some 95 percent of all species in the ocean. Volcanic activity on an enormous scale in today's Siberia has long been debated as a likely trigger of the Permian-Triassic mass extinction, but the exact sequence of events that led to the extinction remained highly controversial. Now, a team of researchers from GEOMAR Helmholtz Centre for Ocean Research Kiel, in collaboration with the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences and Italian and Canadian universities, provides for the first time a conclusive reconstruction of the key events that led to the mega-catastrophe. Their research also draws bleak lessons for the future. They report about their discoveries in the journal Nature Geoscience.

The international team led by Hana Jurikova studied isotopes of the element boron in the calcareous shells of fossil brachiopods - clam-like organisms - and with it determined the rate of ocean acidification over the Permian-Triassic boundary. Because the ocean pH and atmospheric carbon dioxide (CO2) are closely coupled, the team was able to reconstruct changes in atmospheric CO2 at the onset of the extinction from boron and carbon isotopes. They then used an innovative geochemical model to study the impact of the CO2 injection on the environment. Their findings showed that volcanic eruptions, from the then active flood basalt province "Siberian Traps", released immense amounts of CO2 into the atmosphere. This large CO2 release lasted several millennia and led to a strong greenhouse effect on the late Permian world, causing extreme warming and acidification of the ocean. Dramatic changes in chemical weathering on land altered productivity and nutrient cycling in the ocean, and ultimately led to vast de-oxygenation of the ocean. The resulting multiple environmental stressors combined to wipe out a wide variety of animal and plant groups. Dr. Jurikova says: "We are dealing with a cascading catastrophe in which the rise of CO2 in the atmosphere set off a chain of events that successively extinguished almost all life in the seas.".

Secondary ion mass spectrometry (SIMS) facility at GFZ German Research Centre for Geosciences in Potsdam.
Photo: Frédéric Coffignal 

Hana Jurikova adds: "Ancient volcanic eruptions of this kind are not directly comparable to anthropogenic carbon emissions, and in fact all modern fossil fuel reserves are far too insufficient to release as much CO2 over hundreds of years, let alone thousands of years as was released 252 million years ago. But it is astonishing that humanity's CO2 emission rate is currently fourteen times higher than the annual emission rate at the time that marked the greatest biological catastrophe in Earth's history".

A large part of the work was done by the researcher at GEOMAR in Kiel, but she later joined the GFZ (Section 4.3) in Potsdam, and the "icing on the cake" for her were the results from a collaboration with the SIMS laboratory led by Michael Wiedenbeck at the GFZ (Section 3.1). Using the state-of-the-art large-geometry secondary ion mass spectrometer (SIMS), the isotopic composition of the shells could be measured directly on the specimens at the micrometer-scale. This made it possible to determine the boron isotopic composition even in the smallest fragments of brachiopod shells. Depending on the degree of acidification of the seas, the calcareous shells of the organisms living in them differ ever so slightly in their chemical composition. In this way, the pH value of long vanished oceans could be determined in the remains of the shells preserved as fossils in the rock record.
 
This work is part of the 'BASE-LiNE Earth' Innovative Training Network (ITN) funded by the European Union's Horizon 2020 research and innovation programme (No 643084).
 

Contacts and sources:
Josef Zens
Helmholtz Center Potsdam - The GFZ German Research Center for Geosciences

Publication:Permian-Triassic mass extinction pulses driven by major marine carbon cycle perturbations. Jurikova H., Gutjahr M., Wallmann K., Flögel S., Liebetrau V., Posenato R., Angiolini L., Garbelli C., Brand U., Wiedenbeck M., Eisenhauer A. (2020):  Nature Geoscience, https://www.nature.com/articles/s41561-020-00646-4.

High Levels of Microplastics Released from Infant Feeding Bottles during Formula Prep

AMBER and Trinity researchers discover infants up to 12 months old injest on average 1,000,000 microplastics every day from baby bottle, based on World Health Organisation guidelines for sterilisation and infant formula preparation.
Credit: AMBER, and Trinity College Dublin.

New research shows that high levels of microplastics (MPs) are released from infant-feeding bottles (IFBs) during formula preparation. The research also indicates a strong relationship between heat and MP release, such that warmer liquids (formula or water used to sterilise bottles) result in far greater release of MPs.

In response, the researchers involved - from AMBER, the SFI Research Centre for Advanced Materials and Bioengineering Research, TrinityHaus and the Schools of Engineering and Chemistry at Trinity College Dublin - have developed a set of recommendations for infant formula preparation when using plastic IFBs that minimise MP release.

AMBER and Trinity researchers identify global prevalence of microplastics produced by plastic infant feeding bottle and suggest behavioural and technological solutions.
Credit: AMBER, and Trinity College Dublin.

Led by Dr Jing Jing Wang, Professor John Boland and Professor Liwen Xiao at Trinity, the team analysed the potential for release of MPs from polypropylene infant-feeding bottles (PP-IFBs) during formula preparation by following international guidelines. They also estimated the exposure of 12-month-old infants to MPs in 48 countries and regions and have just published their findings in the high-profile journal Nature Food.

Key findings

  • PP-IFBs can release up to 16 million MPs and trillions of smaller nanoplastics per litre. Sterilisation and exposure to high temperature water significantly increase microplastic release from 0.6 million to 55 million particles/l when temperature increases from 25 to 95 °C
  • Other polypropylene plastic-ware products (kettles, lunchboxes) release similar levels of MPs
  • The team undertook a global survey and estimated the exposure of 12-month-old infants to microplastics in 48 regions. Following current guidelines1 for infant-feeding bottle sterilisation and feeding formula preparation the average daily exposure level for infants is in excess of 1 million MPs. Oceania, North America and Europe have the highest levels of potential exposure, at 2,100,000, 2,280,000, and 2,610,000 particles/day, respectively
  • The level of microplastics released from PP-IFBs can be significantly reduced by following modified sterilisation and formula preparation procedure

Recommended sterilisation and formula preparation procedures
  • Sterilising infant feeding bottles
  • Sterilise the bottle following WHO recommended guidelines and allow to cool
  • Prepare sterilised water by boiling in a non-plastic kettle/cooker (e.g. glass or stainless steel)
  • Rinse the sterilised bottle using room temperature sterilised water at least 3 times

Preparing infant formula
  • Prepare hot water using a non-plastic kettle/cooker
  • Prepare infant formula in a non-plastic container using at least 70oC water. Cool to room temperature and transfer prepared formula into a high-quality plastic infant feeding bottle

Standard Precautions
  • Do not reheat prepared formula in plastic containers and avoid microwave ovens
  • Do not vigorously shake the formula in the bottle at any time
  • Do not use sonication to clean plastic infant feeding bottles
Studying microplastics through a project of scale

There is growing evidence to suggest that micro2 and nano plastics are released into our food and water sources through the chemical and physical degradation of larger plastic items. Some studies have demonstrated the potential transfer of micro and nano plastics from oceans to humans via the food chain3 but little is known about the direct release of microplastics (MPs) from plastic products through everyday use.

Polypropylene (PP) is one of the most commonly produced plastics in the world for food preparation and storage. It is used to make everyday items such as lunch boxes, kettles and infant-feeding bottles (IFBs). Despite its widespread use the capacity of PP to release microplastics was not appreciated until now.

Measuring Polypropylene microplastic release (PP-MPs) from infant feeding bottles (IFB)

Drawing on international guidelines for infant formula preparation (cleaning, sterilising, and mixing techniques), the team developed a protocol4 to quantify the PP-MPs released from 10 representative infant-feeding bottles that account for 68.8% of the global infant-feeding bottle market.

When the role of temperature on the release of PP-MPs was analysed a clear trend emerged; the higher the temperature of liquid inside the bottle, the more microplastics released.

Under a standardised protocol, after sterilisation and exposure to water at 70?C, the PP-IFBs released up to 16.2 million PP-MP per litre. When the water temperature was increased to 95?C, as much as 55 million PP-MP per litre were released, while when the PP-IFB's were exposed to water at 25?C - well under international guidelines for sterilisation or formula preparation - 600,000 PP-MP per litre were generated.

Estimating the exposure of 12-month-old infants to MPs from PP-IFBs

Given the widespread use of PP-IFBs and the quantity of MPs released through normal daily use, the team realised the potential exposure of infants to MPs is a worldwide issue. The team estimated the exposure of 12-month-old infants to MPs in 48 countries and regions by using MP release rates from PP-IFBs, the market share of each PP-IFB, the infant daily milk-intake volume, and breastfeeding rates.

The team found that the overall average daily consumption of PP-MPs by infants per capita was 1,580,000 particles.

Oceania, North America and Europe were found to have the highest levels of potential exposure corresponding to 2,100,000, 2,280,000, and 2,610,000 particles/day, respectively.

Mitigating exposure

Given the global preference for PP-IBFs it is important to mitigate against unintended generation of micro and nanoplastics in infant formula. Based on their findings the team devised and tested a series of recommendations for the preparation of baby formula that will help minimise the production of MPs.

They note though, that given the prevalence of plastic products in daily food storage and food preparation, and the fact that every PP product tested in the study (infant bottles, kettles, lunch boxes and noodle cups) released similar levels of MPs, there is an urgent need for technological solutions.

As Professor John Boland, AMBER, CRANN, and Trinity's School of Chemistry explains: "When we saw these results in the lab we recognised immediately the potential impact they might have. The last thing we want is to unduly alarm parents, particularly when we don't have sufficient information on the potential consequences of microplastics on infant health.

"We are calling on policy makers, however, to reassess the current guidelines for formula preparation when using plastic infant feeding bottles. Crucially, we have found that it is possible to mitigate the risk of ingesting microplastics by changing practices around sterilisation and formula preparation."

Professor Liwen Xiao at TrinityHaus and Trinity's School of Engineering said: "Previous research has predominantly focused on human exposure to micro and nanoplastics via transfer from ocean and soils into the food chain driven by the degradation of plastics in the environment.

"Our study indicates that daily use of plastic products is an important source of microplastic release, meaning that the routes of exposure are much closer to us than previously thought. We need to urgently assess the potential risks of microplastics to human health. Understanding their fate and transport through the body following ingestion is an important focus of future research. Determining the potential consequences of microplastics on our health is critical for the management of microplastic pollution."

Lead authors, Dr Dunzhu Li and Dr Yunhong Shi, researchers at CRANN and Trinity's School of Engineering, said:"We have to accept that plastics are pervasive in modern life, and that they release micro and nano plastics through everyday use. We don't yet know the risks to human health of these tiny plastic particles, but we can develop behavioural and technological solutions and strategies to mitigate against their exposure."

Dr Jing Jing Wang, Microplastics Group at AMBER and CRANN, said: "While this research points to the role of plastic products as a direct source of microplastic the removal of microplastics from the environment and our water supplies remains a key future challenge.

"Our team will investigate specific mechanisms of micro and nano plastic release during food preparation in a host of different contexts. We want to develop appropriate technologies that will prevent plastics degrading and effective filtration technologies that will remove micro and nanoplastics from our environment for large scale water treatment and local distribution and use."

This work has been undertaken by the Microplastics Group led by Dr Jing Jing Wang at AMBER and CRANN, with internal collaboration from TrinityHaus and Trinity's School of Engineering and School of Chemistry. This research was supported by Enterprise Ireland, Science Foundation Ireland, a School of Engineering Scholarship at Trinity, and the China Scholarship Council.


Contacts and sources:
Rachel Kavanagh
Trinity College Dublin


Publication: Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation. Dunzhu Li, Yunhong Shi, Luming Yang, Liwen Xiao, Daniel K. Kehoe, Yurii K. Gun’ko, John J. Boland & Jing Jing Wang   Nature Food (2020)
http://dx.doi.org/10.1038/s43016-020-00171-y



Mouthwashes, Oral Rinses May Inactivate Human Coronaviruses

Certain oral antiseptics and mouthwashes may have the ability to inactivate human coronaviruses, according to a Penn State College of Medicine research study. The results indicate that some of these products might be useful for reducing the viral load, or amount of virus, in the mouth after infection and may help to reduce the spread of SARS-CoV-2, the coronavirus that causes COVID-19.

Craig Meyers, distinguished professor of microbiology and immunology and obstetrics and gynecology, led a group of physicians and scientists who tested several oral and nasopharyngeal rinses in a laboratory setting for their ability to inactivate human coronaviruses, which are similar in structure to SARS-CoV-2. The products evaluated include a 1% solution of baby shampoo, a neti pot, peroxide sore-mouth cleansers, and mouthwashes.

 Mouthwash
Credit: Claude TRUONG-NGOC / Wikimedia Commons

The researchers found that several of the nasal and oral rinses had a strong ability to neutralize human coronavirus, which suggests that these products may have the potential to reduce the amount of virus spread by people who are COVID-19-positive.

“While we wait for a vaccine to be developed, methods to reduce transmission are needed,” Meyers said. “The products we tested are readily available and often already part of people’s daily routines.”

Meyers and colleagues used a test to replicate the interaction of the virus in the nasal and oral cavities with the rinses and mouthwashes. Nasal and oral cavities are major points of entry and transmission for human coronaviruses. They treated solutions containing a strain of human coronavirus, which served as a readily available and genetically similar alternative for SARS-CoV-2, with the baby shampoo solutions, various peroxide antiseptic rinses and various brands of mouthwash. They allowed the solutions to interact with the virus for 30 seconds, one minute and two minutes, before diluting the solutions to prevent further virus inactivation. According to Meyers, the outer envelopes of the human coronavirus tested and SARS-CoV-2 are genetically similar so the research team hypothesizes that a similar amount of SARS-CoV-2 may be inactivated upon exposure to the solution.

To measure how much virus was inactivated, the researchers placed the diluted solutions in contact with cultured human cells. They counted how many cells remained alive after a few days of exposure to the viral solution and used that number to calculate the amount of human coronavirus that was inactivated as a result of exposure to the mouthwash or oral rinse that was tested. The results were published in the Journal of Medical Virology.

The 1% baby shampoo solution, which is often used by head and neck doctors to rinse the sinuses, inactivated greater than 99.9% of human coronavirus after a two-minute contact time. Several of the mouthwash and gargle products also were effective at inactivating the infectious virus. Many inactivated greater than 99.9% of virus after only 30 seconds of contact time and some inactivated 99.99% of the virus after 30 seconds.

According to Meyers, the results with mouthwashes are promising and add to the findings of a study showing that certain types of oral rinses could inactivate SARS-CoV-2 in similar experimental conditions. In addition to evaluating the solutions at longer contact times, they studied over-the-counter products and nasal rinses that were not evaluated in the other study. Meyers said the next step to expand upon these results is to design and conduct clinical trials that evaluate whether products like mouthwashes can effectively reduce viral load in COVID-19-positive patients.

“People who test positive for COVID-19 and return home to quarantine may possibly transmit the virus to those they live with,” said Meyers, a researcher at Penn State Cancer Institute. “Certain professions including dentists and other health care workers are at a constant risk of exposure. Clinical trials are needed to determine if these products can reduce the amount of virus COVID-positive patients or those with high-risk occupations may spread while talking, coughing or sneezing. Even if the use of these solutions could reduce transmission by 50%, it would have a major impact.”

Future studies may include a continued investigation of products that inactive human coronaviruses and what specific ingredients in the solutions tested inactivate the virus.

Janice Milici, Samina Alam, David Quillen, David Goldenberg and Rena Kass of Penn State College of Medicine and Richard Robison of Brigham Young University also contributed to this research.

The research was supported by funds from Penn State Huck Institutes for the Life Sciences. The researchers declare no conflict of interest.


Contacts and sources:
Barbara Schindo
Penn State


Publication: Lowering the transmission and spread of human coronavirus Craig Meyers PhD Richard Robison PhD Janice Milici BS Samina Alam PhD David Quillen MD David Goldenberg MD, FACS Rena Kass MD https://onlinelibrary.wiley.com/doi/10.1002/jmv.26514 http://dx.doi.org/10.1002/jmv.26514




Monday, October 19, 2020

Ground-Breaking Discovery Finally Proves Rain Really Can Move Mountains

A pioneering technique which captures precisely how mountains bend to the will of raindrops has helped to solve a long-standing scientific enigma.


The dramatic effect rainfall has on the evolution of mountainous landscapes is widely debated among geologists, but new research led by the University of Bristol and published today in Science Advances, clearly calculates its impact, furthering our understanding of how peaks and valleys have developed over millions of years.

Its findings, which focused on the mightiest of mountain ranges – the Himalaya – also pave the way for forecasting the possible impact of climate change on landscapes and, in turn, human life.

Lead author Dr Byron Adams, Royal Society Dorothy Hodgkin Fellow at the university’s Cabot Institute for the Environment, said: “It may seem intuitive that more rain can shape mountains by making rivers cut down into rocks faster. But scientists have also believed rain can erode a landscape quickly enough to essentially ‘suck’ the rocks out of the Earth, effectively pulling mountains up very quickly.

“Both these theories have been debated for decades because the measurements required to prove them are so painstakingly complicated. That’s what makes this discovery such an exciting breakthrough, as it strongly supports the notion that atmospheric and solid earth processes are intimately connected.”

While there is no shortage of scientific models aiming to explain how the Earth works, the greater challenge can be making enough good observations to test which are most accurate.

The study was based in the central and eastern Himalaya of Bhutan and Nepal, because this region of the world has become one of the most sampled landscapes for erosion rate studies. Dr Adams, together with collaborators from Arizona State University (ASU) and Louisiana State University, used cosmic clocks within sand grains to measure the speed at which rivers erode the rocks beneath them.

“When a cosmic particle from outer space reaches Earth, it is likely to hit sand grains on hillslopes as they are transported toward rivers. When this happens, some atoms within each grain of sand can transform into a rare element. By counting how many atoms of this element are present in a bag of sand, we can calculate how long the sand has been there, and therefore how quickly the landscape has been eroding,” Dr Adams said.

“Once we have erosion rates from all over the mountain range, we can compare them with variations in river steepness and rainfall. However, such a comparison is hugely problematic because each data point is very difficult to produce and the statistical interpretation of all the data together is complicated.”

First and corresponding author Dr Byron Adams in the steep terrain of the Greater Himalaya, central Bhutan.

Credit: Second author Professor Kelin Whipple

Dr Adams overcame this challenge by combining regression techniques with numerical models of how rivers erode.

“We tested a wide variety of numerical models to reproduce the observed erosion rate pattern across Bhutan and Nepal. Ultimately only one model was able to accurately predict the measured erosion rates,” Dr Adams said. “This model allows us for the first time to quantify how rainfall affects erosion rates in rugged terrain.”

Research collaborator Professor Kelin Whipple, Professor of Geology at ASU, said: “Our findings show how critical it is to account for rainfall when assessing patterns of tectonic activity using topography, and also provide an essential step forward in addressing how much the slip rate on tectonic faults may be controlled by climate-driven erosion at the surface.”

The study findings also carry important implications for land use management, infrastructure maintenance, and hazards in the Himalaya.


Looking upstream within a tributary of the Wang Chu, southwestern Bhutan.
Credit: Dr Byron Adams



In the Himalaya, there is the ever-present risk that high erosion rates can drastically increase sedimentation behind dams, jeopardising critical hydropower projects. The findings also suggest greater rainfall can undermine hillslopes, increasing the risk of debris flows or landslides, some of which may be large enough to dam the river creating a new hazard – lake outburst floods.

Dr Adams added: “Our data and analysis provides an effective tool for estimating patterns of erosion in mountainous landscapes such as the Himalaya, and thus, can provide invaluable insight into the hazards that influence the hundreds of millions of people who live within and at the foot of these mountains.”

The Ta Dzong overlooking the Paro Valley, western Bhutan.
Credit: Dr Byron Adams

The research was funded by the Royal Society, the UK Natural Environmental Research Council (NERC), and the National Science Foundation (NSF) of the US.

Building on this research, Dr Adams is currently exploring how landscapes respond after large volcanic eruptions.

“This new frontier of landscape evolution modelling is also shedding new light on volcanic processes. With our cutting-edge techniques to measure erosion rates and rock properties, we will be able to better understand how rivers and volcanoes have influenced each other in the past,” Dr Adams said. “This will help us to more accurately anticipate what is likely to happen after future volcanic eruptions and how to manage the consequences for communities living nearby.”

Paper:‘Climate controls on erosion in tectonically active landscapes’ by Byron Adams et al in Science Advances.


Contacts and sources:
The Cabot Institute for the Environment
University of Bristol







Sunday, October 18, 2020

World's Greatest Mass Extinction Triggered Switch to Warm-Bloodedness

Mammals and birds today are warm-blooded, and this is often taken as the reason for their great success.

University of Bristol palaeontologist Professor Mike Benton identifies in the journal Gondwana Research that the ancestors of both mammals and birds became warm-blooded at the same time, some 250 million years ago, in the time when life was recovering from the greatest mass extinction of all time.

The origin of endothermy in synapsids, including the ancestors of mammals. The diagram shows the evolution of main groups through the Triassic, and the scale from blue to red is a measure of the degree of warm-bloodedness reconstructed based on different indicators of bone structure and anatomy.
Credit: Mike Benton, University of Bristol. Animal images are by Nobu Tamura, Wikimedia

The Permian-Triassic mass extinction killed as much as 95 per cent of life, and the very few survivors faced a turbulent world, repeatedly hit by global warming and ocean acidification crises. Two main groups of tetrapods survived, the synapsids and archosaurs, including ancestors of mammals and birds respectively.

Palaeontologists had identified indications of warm-bloodedness, or technically endothermy, in these Triassic survivors, including evidence for a diaphragm and possible whiskers in the synapsids.

More recently, similar evidence for early origin of feathers in dinosaur and bird ancestors has come to light. In both synapsids and archosaurs of the Triassic, the bone structure shows characteristics of warm-bloodedness.


Posture shift at the end of the Permian, 252 million years ago. Before the crisis, most reptiles had sprawling posture; afterwards they walked upright. This may have been the first sign of a new pace of life in the Triassic.


Credit: animal drawings by Jim Robins, University of Bristol


The evidence that mammal ancestors had hair from the beginning of the Triassic has been suspected for a long time, but the suggestion that archosaurs had feathers from 250 million years ago is new.

But a strong hint for this sudden origin of warm-bloodedness in both synapsids and archosaurs at exactly the time of the Permian-Triassic mass extinction was found in 2009. Tai Kubo, then a student studying the Masters in Palaeobiology degree at Bristol and Professor Benton identified that all medium-sized and large tetrapods switched from sprawling to erect posture right at the Permian-Triassic boundary.

Their study was based on fossilised footprints. They looked at a sample of hundreds of fossil trackways, and Kubo and Benton were surprised to see the posture shift happened instantly, not strung out over tens of millions of years, as had been suggested. It also happened in all groups, not just the mammal ancestors or bird ancestors.

Professor Benton said: “Modern amphibians and reptiles are sprawlers, holding their limbs partly sideways.

“Birds and mammals have erect postures, with the limbs immediately below their bodies. This allows them to run faster, and especially further. There are great advantages in erect posture and warm-bloodedness, but the cost is that endotherms have to eat much more than cold-blooded animals just to fuel their inner temperature control.”

The evidence from posture change and from early origin of hair and feathers, all happening at the same time, suggested this was the beginning of a kind of ‘arms race’. In ecology, arms races occur when predators and prey have to compete with each other, and where there may be an escalation of adaptations. The lion evolves to run faster, but the wildebeest also evolves to run faster or twist and turn to escape.

Something like this happened in the Triassic, from 250 to 200 million years ago. Today, warm-blooded animals can live all over the Earth, even in cold areas, and they remain active at night. They also show intensive parental care, feeding their babies and teaching them complex and smart behaviour. These adaptations gave birds and mammals the edge over amphibians and reptiles and in the present cool world allowed them to dominate in more parts of the world.

Professor Benton added: “The Triassic was a remarkable time in the history of life on Earth. You see birds and mammals everywhere on land today, whereas amphibians and reptiles are often quite hidden.

“This revolution in ecosystems was triggered by the independent origins of endothermy in birds and mammals, but until recently we didn’t realise that these two events might have been coordinated.

“That happened because only a tiny number of species survived the Permian-Triassic mass extinction – who survived depended on intense competition in a tough world. Because a few of the survivors were already endothermic in a primitive way, all the others had to become endothermic to survive in the new fast-paced world.”

Paper: ‘The origin of endothermy in synapsids and archosaurs and arms races in the Triassic’ by M. J. Benton in Gondwana Research.



Contacts and sources:
Mike Benton
University of Bristol

 




New Evidence for Possible Link Between Blood Type and COVID-19 Susceptibility and Severity



Individuals with blood type O may have lowest risk of infection; individuals with A and AB may have increased risk of severe clinical outcomes.

Two studies published today in Blood Advances suggest people with blood type O may have a lower risk of COVID-19 infection and reduced likelihood of severe outcomes, including organ complications, if they do get sick.

This illustration, created at the Centers for Disease Control and Prevention (CDC), reveals ultrastructural morphology exhibited by the 2019 Novel Coronavirus (2019-nCoV). Note the spikes that adorn the outer surface of the virus, which impart the look of a corona surrounding the virion, when viewed electron microscopically. This virus was identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China.
Credit: CDC

As the pandemic continues, the global biomedical research community is working urgently to identify coronavirus risk factors and potential therapeutic targets. The potential role of blood type in predicting risk and complications of COVID-19 infection has emerged as an important scientific question. These new studies add evidence that there may be an association between blood type and vulnerability to COVID-19; however, additional research is needed to better understand why and what it means for patients.

INDIVIDUALS WITH BLOOD TYPE O MAY BE LESS VULNERABLE TO COVID-19 INFECTION

Blood type O may offer some protection against COVID-19 infection, according to a retrospective study. Researchers compared Danish health registry data from more than 473,000 individuals tested for COVID-19 to data from a control group of more than 2.2 million people from the general population. Among the COVID-19 positive, they found fewer people with blood type O and more people with A, B, and AB types.

The study results suggest that people with blood types A, B, or AB may be more likely to be infected with COVID-19 than people with type O. The researchers did not find any significant difference in rate of infection between A, B, and AB types. Since blood group distributions vary among ethnic subgroups, the researchers also controlled for ethnicity and maintained that fewer people with blood type O tested positive for the virus.

“It is very important to consider the proper control group because blood type prevalence may vary considerably in different ethnic groups and different countries,” said study author Torben Barington, MD, of Odense University Hospital and the University of Southern Denmark. “We have the advantage of a strong control group – Denmark is a small, ethnically homogenous country with a public health system and a central registry for lab data – so our control is population-based, giving our findings a strong foundation.”
BLOOD GROUPS A AND AB ASSOCIATED WITH INCREASED RISK OF SEVERE CLINICAL OUTCOMES OF COVID-19 INFECTION

People with blood groups A or AB appear to exhibit greater COVID-19 disease severity than people with blood groups O or B, according to a separate retrospective study. Researchers examined data from 95 critically ill COVID-19 patients hospitalized in Vancouver, Canada. They found that patients with blood groups A or AB were more likely to require mechanical ventilation, suggesting that they had greater rates of lung injury from COVID-19. They also found more patients with blood group A and AB required dialysis for kidney failure.

Together, these findings suggest that patients in these two blood groups may have an increased risk of organ dysfunction or failure due to COVID-19 than people with blood types O or B. Furthermore, while people with blood types A and AB did not have longer overall hospital stays than those with types O or B, they did remain in the intensive care unit (ICU) for a longer average time, which may also signal a greater COVID-19 severity level.

“The unique part of our study is our focus on the severity effect of blood type on COVID-19. We observed this lung and kidney damage, and in future studies, we will want to tease out the effect of blood group and COVID-19 on other vital organs,” said study author Mypinder S. Sekhon, MD, of the University of British Columbia. “Of particular importance as we continue to traverse the pandemic, we now have a wide range of survivors who are exiting the acute part of COVID-19, but we need to explore mechanisms by which to risk stratify those with longer-term effects.”





Contacts and sources:
Leah Enser
American Society of Hematology

Publication: Reduced prevalence of SARS-CoV-2 infection in ABO blood group O.
Mike Bogetofte Barnkob, Anton Pottegård, Henrik Støvring, Thure Mors Haunstrup, Keld Homburg, Rune Larsen, Morten Bagge Hansen, Kjell Titlestad, Bitten Aagaard, Bjarne Kuno Møller, Torben Barington. Blood Advances, 2020; 4 (20): 4990 DOI: 10.1182/bloodadvances.2020002657


The association of ABO blood group with indices of disease severity and multiorgan dysfunction in COVID-19. Ryan L. Hoiland, Nicholas A. Fergusson, Anish R. Mitra, Donald E. G. Griesdale, Dana V. Devine, Sophie Stukas, Jennifer Cooper, Sonny Thiara, Denise Foster, Luke Y. C. Chen, Agnes Y. Y. Lee, Edward M. Conway, Cheryl L. Wellington, Mypinder S. Sekhon.Blood Advances,



'Silent" Mutations Gave COVID-19 Evolutionary Edge

RNA folding may help explain how the coronavirus became so hard to stop after it spilled over from wildlife to humans.


SARS-CoV-2, the coronavirus that causes COVID-19, appears to have evolved silent changes to its RNA code that gave it a biological edge over previous strains.

Credit: Felipe Esquivel Reed

We know that the coronavirus behind the COVID-19 crisis lived harmlessly in bats and other wildlife before it jumped the species barrier and spilled over to humans.

Now, researchers at Duke University have identified a number of “silent” mutations in the roughly 30,000 letters of the virus’s genetic code that helped it thrive once it made the leap -- and possibly helped set the stage for the global pandemic. The subtle changes involved how the virus folded its RNA molecules within human cells.

For the study, published Oct. 16 in the journal PeerJ, the researchers used statistical methods they developed to identify adaptive changes that arose in the SARS-CoV-2 genome in humans, but not in closely related coronaviruses found in bats and pangolins.

“We’re trying to figure out what made this virus so unique,” said lead author Alejandro Berrio, a postdoctoral associate in biologist Greg Wray’s lab at Duke.

Previous research detected fingerprints of positive selection within a gene that encodes the “spike” proteins studding the coronavirus’s surface, which play a key role in its ability to infect new cells.

The new study likewise flagged mutations that altered the spike proteins, suggesting that viral strains carrying these mutations were more likely to thrive. But with their approach, study authors Berrio, Wray and Duke Ph.D. student Valerie Gartner also identified additional culprits that previous studies failed to detect.

The researchers report that so-called silent mutations in two other regions of the SARS-CoV-2 genome, dubbed Nsp4 and Nsp16, appear to have given the virus a biological edge over previous strains without altering the proteins they encode.

Instead of affecting proteins, Berrio said, the changes likely affected how the virus’s genetic material -- which is made of RNA -- folds up into 3-D shapes and functions inside human cells.

What these changes in RNA structure might have done to set the SARS-CoV-2 virus in humans apart from other coronaviruses is still unknown, Berrio said. But they may have contributed to the virus’s ability to spread before people even know they have it -- a crucial difference that made the current situation so much more difficult to control than the SARS coronavirus outbreak of 2003.

The research could lead to new molecular targets for treating or preventing COVID-19, Berrio said.

“Nsp4 and Nsp16 are among the first RNA molecules that are produced when the virus infects a new person,” Berrio said. “The spike protein doesn’t get expressed until later. So they could make a better therapeutic target because they appear earlier in the viral life cycle.”

More generally, by pinpointing the genetic changes that enabled the new coronavirus to thrive in human hosts, scientists hope to better predict future zoonotic disease outbreaks before they happen.

“Viruses are constantly mutating and evolving,” Berrio said. “So it's possible that a new strain of coronavirus capable of infecting other animals may come along that also has the potential to spread to people, like SARS-CoV-2 did. We’ll need to be able to recognize it and make efforts to contain it early.”

CITATION: "Positive Selection Within the Genomes of SARS-CoV-2 and Other Coronaviruses Independent of Impact on Protein Function," Alejandro Berrio, Valerie Gartner, Gregory A Wray. PeerJ, October 16, 2020. DOI: 10.7717/peerj.10234

Contacts and sources:
Robin A. Smith 
Duke University



Publication: Positive selection within the genomes of SARS-CoV-2 and other Coronaviruses independent of impact on protein function.
Alejandro Berrio, Valerie Gartner, Gregory A. Wray. PeerJ, 2020; 8: e10234 DOI: 10.7717/peerj.10234




What Happens in a Zeptosecond? A Trillionth of a Billionth of a Second: Shortest Time Ever Measured

In the global race to measure ever shorter time spans, physicists from Goethe University Frankfurt have now taken the lead: together with colleagues at the accelerator facility DESY in Hamburg and the Fritz-Haber-Institute in Berlin, they have measured a process that lies within the realm of zeptoseconds for the first time: the propagation of light within a molecule. A zeptosecond is a trillionth of a billionth of a second (10-21 seconds).

chematic representation of zeptosecond measurement. The photon (yellow, coming from the left) produces electron waves out of the electron cloud (grey) of the hydrogen molecule (red: nucleus), which interfere with each other (interference pattern: violet-white). The interference pattern is slightly skewed to the right, allowing the calculation of how long the photon required to get from one atom to the next. 
SPhoto: Sven Grundmann, Goethe University Frankfurt

In 1999, the Egyptian chemist Ahmed Zewail received the Nobel Prize for measuring the speed at which molecules change their shape. He founded femtochemistry using ultrashort laser flashes: the formation and breakup of chemical bonds occurs in the realm of femtoseconds. A femtosecond equals 0.000000000000001 seconds, or 10-15 seconds.

Now atomic physicists at Goethe University in Professor Reinhard Dörner’s team have for the first time studied a process that is shorter than femtoseconds by magnitudes. They measured how long it takes for a photon to cross a hydrogen molecule: about 247 zeptoseconds for the average bond length of the molecule. This is the shortest timespan that has been successfully measured to date.

The scientists carried out the time measurement on a hydrogen molecule (H2) which they irradiated with X-rays from the synchrotron lightsource PETRA III at the Hamburg accelerator centre DESY. The researchers set the energy of the X-rays so that one photon was sufficient to eject both electrons out of the hydrogen molecule.

Electrons behave like particles and waves simultaneously, and therefore the ejection of the first electron resulted in electron waves launched first in the one, and then in the second hydrogen molecule atom in quick succession, with the waves merging.

The photon behaved here much like a flat pebble that is skimmed twice across the water: when a wave trough meets a wave crest, the waves of the first and second water contact cancel each other, resulting in what is called an interference pattern.

The scientists measured the interference pattern of the first ejected electron using the COLTRIMS reaction microscope, an apparatus that Dörner helped develop and which makes ultrafast reaction processes in atoms and molecules visible. Simultaneously with the interference pattern, the COLTRIMS reactions microscope also allowed the determination of the orientation of the hydrogen molecule. The researchers here took advantage of the fact that the second electron also left the hydrogen molecule, so that the remaining hydrogen nuclei flew apart and were detected.

“Since we knew the spatial orientation of the hydrogen molecule, we used the interference of the two electron waves to precisely calculate when the photon reached the first and when it reached the second hydrogen atom,” explains Sven Grundmann whose doctoral dissertation forms the basis of the scientific article in Science. “And this is up to 247 zeptoseconds, depending on how far apart in the molecule the two atoms were from the perspective of light.”

Professor Reinhard Dörner adds: “We observed for the first time that the electron shell in a molecule does not react to light everywhere at the same time. The time delay occurs because information within the molecule only spreads at the speed of light. With this finding we have extended our COLTRIMS technology to another application.”





Contacts and sources:
Goethe University Frankfurt



Publication: Zeptosecond Birth Time Delay in Molecular Photoionization.
Sven Grundmann, Daniel Trabert, Kilian Fehre, Nico Strenger, Andreas Pier, Leon Kaiser, Max Kircher, Miriam Weller, Sebastian Eckart, Lothar Ph. H. Schmidt, Florian Trinter, Till Jahnke, Markus S. Schöffler, Reinhard Dörner.Science, 2020 DOI: 10.1126/science.abb9318




Scientists Develop ‘Mini-Brains’ to Help Robots Recognize Pain and to Self-Repair

Using a brain-inspired approach, scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed a way for robots to have the artificial intelligence (AI) to recognise pain and to self-repair when damaged.

The system has AI-enabled sensor nodes to process and respond to 'pain' arising from pressure exerted by a physical force. The system also allows the robot to detect and repair its own damage when minorly 'injured', without the need for human intervention.
Credit: NTU Singapore

Currently, robots use a network of sensors to generate information about their immediate environment. For example, a disaster rescue robot uses camera and microphone sensors to locate a survivor under debris and then pulls the person out with guidance from touch sensors on their arms. A factory robot working on an assembly line uses vision to guide its arm to the right location and touch sensors to determine if the object is slipping when picked up.


Today's sensors typically do not process information but send it to a single large, powerful, central processing unit where learning occurs. As a result, existing robots are usually heavily wired which result in delayed response times. They are also susceptible to damage that will require maintenance and repair, which can be long and costly.


The new NTU approach embeds AI into the network of sensor nodes, connected to multiple small, less-powerful, processing units, that act like 'mini-brains' distributed on the robotic skin. This means learning happens locally and the wiring requirements and response time for the robot are reduced five to ten times compared to conventional robots, say the scientists.


Combining the system with a type of self-healing ion gel material means that the robots, when damaged, can recover their mechanical functions without human intervention.


The breakthrough research by the NTU scientists was published in the peer-reviewed scientific journal Nature Communications in August.


Co-lead author of the study, Associate Professor Arindam Basu from the School of Electrical & Electronic Engineering said, "For robots to work together with humans one day, one concern is how to ensure they will interact safely with us. For that reason, scientists around the world have been finding ways to bring a sense of awareness to robots, such as being able to 'feel' pain, to react to it, and to withstand harsh operating conditions. However, the complexity of putting together the multitude of sensors required and the resultant fragility of such a system is a major barrier for widespread adoption."


Assoc Prof Basu, who is a neuromorphic computing expert added, "Our work has demonstrated the feasibility of a robotic system that is capable of processing information efficiently with minimal wiring and circuits. By reducing the number of electronic components required, our system should become affordable and scalable. This will help accelerate the adoption of a new generation of robots in the marketplace."


Robust system enables 'injured' robot to self-repair

To teach the robot how to recognise pain and learn damaging stimuli, the research team fashioned memtransistors, which are 'brain-like' electronic devices capable of memory and information processing, as artificial pain receptors and synapses.


Through lab experiments, the research team demonstrated how the robot was able to learn to respond to injury in real time. They also showed that the robot continued to respond to pressure even after damage, proving the robustness of the system.


When 'injured' with a cut from a sharp object, the robot quickly loses mechanical function. But the molecules in the self-healing ion gel begin to interact, causing the robot to 'stitch' its 'wound' together and to restore its function while maintaining high responsiveness.


First author of the study, Rohit Abraham John, who is also a Research Fellow at the School of Materials Science & Engineering at NTU, said, "The self-healing properties of these novel devices help the robotic system to repeatedly stitch itself together when 'injured' with a cut or scratch, even at room temperature. This mimics how our biological system works, much like the way human skin heals on its own after a cut.


"In our tests, our robot can 'survive' and respond to unintentional mechanical damage arising from minor injuries such as scratches and bumps, while continuing to work effectively. If such a system were used with robots in real world settings, it could contribute to savings in maintenance."


Associate Professor Nripan Mathews, who is co-lead author and from the School of Materials Science & Engineering at NTU, said, "Conventional robots carry out tasks in a structured programmable manner, but ours can perceive their environment, learning and adapting behaviour accordingly. Most researchers focus on making more and more sensitive sensors, but do not focus on the challenges of how they can make decisions effectively. Such research is necessary for the next generation of robots to interact effectively with humans.


"In this work, our team has taken an approach that is off-the-beaten path, by applying new learning materials, devices and fabrication methods for robots to mimic the human neuro-biological functions. While still at a prototype stage, our findings have laid down important frameworks for the field, pointing the way forward for researchers to tackle these challenges."

 
Contacts and sources:
Ms Junn Loh
Nanyang Technological University


Publication: Self healable neuromorphic memtransistor elements for decentralized sensory signal processing in robotics
Rohit Abraham John, Naveen Tiwari, Muhammad Iszaki Bin Patdillah, Mohit Rameshchandra Kulkarni, Nidhi Tiwari, Joydeep Basu, Sumon Kumar Bose, Ankit, Chan Jun Yu, Amoolya Nirmal, Sujaya Kumar Vishwanath, Chiara Bartolozzi, Arindam Basu, Nripan Mathews. . Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-17870-6




'Universal Law of Touch' Will Enable New Advances in Virtual Reality

Earthquakes, have been used by scientists to develop a universal scaling law for the sense of touch.

A team, led by researchers at the University of Birmingham, used Rayleigh waves to create the first scaling law for touch sensitivity. The results are published in Science Advances.

The researchers are part of a European consortium (H-Reality) that are already using the theory to develop new Virtual Reality technologies that incorporate the sense of touch.
Credit: University of Birmingham

Rayleigh waves are created by impact between objects and are commonly thought to travel only along surfaces. The team discovered that, when it comes to touch, the waves also travel through layers of skin and bone and are picked up by the body’s touch receptor cells.

Using mathematical modelling of these touch receptors the researchers showed how the receptors were located at depths that allowed them to respond to Rayleigh waves. The interaction of these receptors with the Rayleigh waves will vary across species, but the ratio of receptor depth vs wavelength remains the same, enabling the universal law to be defined.

The mathematics used by the researchers to develop the law is based on approaches first developed over a hundred years ago to model earthquakes. The law supports predictions made by the Nobel-Prize-winning physicist Georg von Békésy who first suggested the mathematics of earthquakes could be used to explore connections between Rayleigh waves and touch.

The team also found that the interaction of the waves and receptors remained even when the stiffness of the outermost layer of skin changed. The ability of the receptors to respond to Rayleigh waves remained unchanged despite the many variations in this outer layer caused by, age, gender, profession, or even hydration.

Dr Tom Montenegro-Johnson, of the University of Birmingham’s School of Mathematics, led the research. He explains: “Touch is a primordial sense, as important to our ancient ancestors as it is to modern day mammals, but it’s also one of the most complex and therefore least understood. While we have universal laws to explain sight and hearing, for example, this is the first time that we’ve been able to explain touch in this way.”

James Andrews, co-author of the study at the University of Birmingham, adds: “The principles we’ve defined enable us to better understand the different experiences of touch among a wide range of species. For example, if you indent the skin of a rhinoceros by 5mm, they would have the same sensation as a human with a similar indentation – it’s just that the forces required to produce the indentation would be different. This makes a lot of sense in evolutionary terms, since it’s connected to relative danger and potential damage.”

The work was funded by the European Union’s Horizon 2020 research and innovation programme, under collaborative project “H-Reality” (grant 801413, hreality.eu). The other institutions involved in the project are Ultraleap Ltd. (UK), Actronika (France), TU Delft (The Netherlands), and CNRS (France).



 
Contacts and sources:
Beck Lockwood,
University of Birmingham

Publication: A universal scaling law of mammalian touch.
J. W. Andrews, M. J. Adams, T. D. Montenegro-Johnson. Science Advances, 2020; 6 (41): eabb6912 DOI: 10.1126/sciadv.abb6912




Ultrafast Camera Films 3-D Movies at 100 Billion Frames Per Second

In his quest to bring ever-faster cameras to the world, Caltech's Lihong Wang has developed technology that can reach blistering speeds of 70 trillion frames per second, fast enough to see light travel. Just like the camera in your cell phone, though, it can only produce flat images.


Now, Wang's lab has gone a step further to create a camera that not only records video at incredibly fast speeds but does so in three dimensions. Wang, Bren Professor of Medical Engineering and Electrical Engineering in the Andrew and Peggy Cherng Department of Medical Engineering, describes the device in a new paper in the journal Nature Communications.

The new camera, which uses the same underlying technology as Wang's other compressed ultrafast photography (CUP) cameras, is capable of taking up to 100 billion frames per second. That is fast enough to take 10 billion pictures, more images than the entire human population of the world, in the time it takes you to blink your eye.

Wang calls the new iteration "single-shot stereo-polarimetric compressed ultrafast photography," or SP-CUP.

In CUP technology, all of the frames of a video are captured in one action without repeating the event. This makes a CUP camera extremely quick (a good cell-phone camera can take 60 frames per second). Wang added a third dimension to this ultrafast imagery by making the camera "see" more like humans do.

When a person looks at the world around them, they perceive that some objects are closer to them, and some objects are farther away. Such depth perception is possible because of our two eyes, each of which observes objects and their surroundings from a slightly different angle. The information from these two images is combined by the brain into a single 3-D image.

The SP-CUP camera works in essentially the same way, Wang says.

"The camera is stereo now," he says. "We have one lens, but it functions as two halves that provide two views with an offset. Two channels mimic our eyes."

Just as our brain does with the signals it receives from our eyes, the computer that runs the SP-CUP camera processes data from these two channels into one three-dimensional movie.

A movie showing a pulse of laser light traveling through a laser-scattering material and reflecting off surfaces 

Credit: Caltech

SP-CUP also features another innovation that no human possesses: the ability to see the polarization of light waves.

The polarization of light refers to the direction in which light waves vibrate as they travel. Consider a guitar string. If the string is pulled upwards (say, by a finger) and then released, the string will vibrate vertically. If the finger plucks it sideways, the string will vibrate horizontally. Ordinary light has waves that vibrate in all directions. Polarized light, however, has been altered so that its waves all vibrate in the same direction. This can occur through natural means, such as when light reflects off a surface, or as a result of artificial manipulation, as happens with polarizing filters.

Though our eyes cannot detect the polarization of light directly, the phenomenon has been exploited in a range of applications: from LCD screens to polarized sunglasses and camera lenses in optics to devices that detect hidden stress in materials and the three-dimensional configurations of molecules.

Wang says that the SP-CUP's combination of high-speed three-dimensional imagery and the use of polarization information makes it a powerful tool that may be applicable to a wide variety of scientific problems. In particular, he hopes that it will help researchers better understand the physics of sonoluminescence, a phenomenon in which sound waves create tiny bubbles in water or other liquids. As the bubbles rapidly collapse after their formation, they emit a burst of light.

"Some people consider this one of that greatest mysteries in physics," he says. "When a bubble collapses, its interior reaches such a high temperature that it generates light. The process that makes this happen is very mysterious because it all happens so fast, and we're wondering if our camera can help us figure it out."

The paper describing the work, titled, "Single-shot stereo-polarimetric compressed ultrafast photography for light-speed observation of high-dimensional optical transients with picosecond resolution," appears in the October 16 issue of Nature Communications. Co-authors are Jinyang Liang, formerly of Caltech now at the Institut national de la recherche scientifique in Quebec; Peng Wang, postdoctoral scholar in medical engineering; and Liren Zhu, a former graduate student of the Wang lab.

Funding for the research was provided by the National Institutes of Health.

 



Contacts and sources:
Emily Velasco
California Institute of Technology



Publication: Single-shot stereo-polarimetric compressed ultrafast photography for light-speed observation of high-dimensional optical transients with picosecond resolution.
Jinyang Liang, Peng Wang, Liren Zhu, Lihong V. Wang. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-19065-5




New Research Explores How Super Flares Affect Planets’ Habitability

Ultraviolet light from giant stellar flares can destroy a planet’s habitability. New research from the University of North Carolina at Chapel Hill will help astrobiologists understand how much radiation planets experience during super flares and whether life could exist on worlds beyond our solar system.

Super flares are bursts of energy that are 10 to 1,000 times larger than the biggest flares from the Earth’s sun. These flares can bathe a planet in an amount of ultraviolet light huge enough to doom the chances of life surviving there.

Credit: NASA / Wikimedia Commons

Researchers from UNC-Chapel Hill have for the first time measured the temperature of a large sample of super flares from stars, and the flares’ likely ultraviolet emissions. Their findings, published Oct. 5 ahead of print in Astrophysical Journal, will allow researchers to put limits on the habitability of planets that are targets of upcoming planet-finding missions.

“We found planets orbiting young stars may experience life-prohibiting levels of UV radiation, although some micro-organisms might survive,” said lead study author Ward S. Howard, a doctoral student in the Department of Physics and Astronomy at UNC-Chapel Hill.

Howard and colleagues at UNC-Chapel Hill used the UNC-Chapel Hill Evryscope telescope array and NASA’s Transiting Exoplanet Survey Satellite (TESS) to simultaneously observe the largest sample of super flares.

The team’s research expands upon previous work that has largely focused on flare temperatures and radiation from only a handful of super flares from a few stars. In expanding the research, the team discovered a statistical relationship between the size of a super flare and its temperature. The temperature predicts the amount of radiation that potentially precludes on-surface life.

A modern solar flare recorded Dec. 5, 2006, by the X-ray Imager onboard NOAA's GOES-13 satellite. The flare was so intense, it actually damaged the instrument that took the picture. Researchers believe Carrington's flare was much more energetic than this one.

Credit: NASA

Super flares typically emit most of their UV radiation during a rapid peak lasting only five to 15 minutes. The simultaneous Evryscope and TESS observations were obtained at two-minute intervals, ensuring multiple measurements were taken during the peak of each super flare.

This is the first time the temperatures of such a large sample of super flares has ever been studied. The frequency of observations allowed the team to discover the amount of time super flares can cook orbiting planets with intense UV radiation.

The flares observed have already informed the TESS Extended Mission to discover thousands of exoplanets in orbit around the brightest dwarf stars in the sky. TESS is now targeting high priority flare stars from the UNC-Chapel Hill sample for more frequent observations.

“Longer term these results may inform the choice of planetary systems to be observed by NASA’s James Webb Space Telescope based on the system’s flaring activity,” said study co-author Nicholas M. Law, associate professor of physics and astronomy at UNC-Chapel Hill and principal investigator of the Evryscope telescope.


Contacts and sources:
University of North Carolina at Chapel Hill



Publication: EvryFlare III: Temperature Evolution and Habitability Impacts of Dozens of Superflares Observed Simultaneously by Evryscope and TESS. A
Ward S. Howard, Hank Corbett, Nicholas M. Law, Jeffrey K. Ratzloff, Nathan Galliher, Amy L. Glazier, Ramses Gonzalez, Alan Vasquez Soto, Octavi Fors, Daniel del Ser, Joshua Haislip. strophysical Journal, 2020 https://arxiv.org/abs/2010.00604



Friday, October 16, 2020

Sudden Permanent Hearing Loss Linked to COVID=19



Condition not common, but awareness is important as prompt treatment can reverse it.

Although uncommon, sudden permanent hearing loss seems to be linked to COVID-19 infection in some people, warn doctors, reporting the first UK case in the journal BMJ Case Reports.




Credit: Alissa Eckert and Dan Higgins / CDC

Awareness of this possible side effect is important, because a prompt course of steroid treatment can reverse this disabling condition, they emphasise.

Sudden hearing loss is frequently seen by ear, nose and throat specialists, with around 5–160 cases per 100,000 people reported every year. It’s not clear what the causes are, but the condition can follow a viral infection, such as flu, herpes, or cytomegalovirus.

Despite plenty of published research on sudden onset hearing loss, only a handful of other cases associated with COVID-19 have been reported, and none in the UK--until now.

The doctors describe a case of a 45 year old man with asthma who was referred to the ear nose and throat department at their hospital after suddenly experiencing hearing loss in one ear while being treated for COVID-19 infection as an inpatient.

He had been admitted to hospital with COVID-19 symptoms which had been going on for 10 days. He was transferred to intensive care as he was struggling to breathe.

He was put on a ventilator for 30 days and developed other complications as a result. He was treated with remdesivir, intravenous steroids and a blood transfusion after which he started to get better.

But a week after the breathing tube was removed and he left intensive care, he noticed ringing (tinnitus) in his left ear followed by sudden hearing loss in that ear.

He had not lost his hearing or had ear problems before. And apart from asthma, he was otherwise fit and well.

Examination of his ear canals revealed that he had no blockages or inflammation. But a hearing test showed that he had substantially lost his hearing in the left ear. He was treated with steroid tablets and injections after which his hearing partially recovered.

He tested negative for other potential causes, including rheumatoid arthritis, flu and HIV, prompting his doctors to conclude that his hearing loss was associated with COVID-19 infection.

“Despite the considerable literature on COVID-19 and the various symptoms associated with the virus, there is a lack of discussion on the relationship between COVID-19 and hearing,” say the report authors.

“Hearing loss and tinnitus are symptoms that have been seen in patients with both COVID-19 and influenza virus, but have not been highlighted.” The first case of hearing loss mentioning COVID-19 alone was reported in April this year.

SARS-CoV-2, the virus responsible for COVID-19, is thought to lock on to a particular type of cell lining the lungs. And the virus has also recently been found in similar cells lining the middle ear, explain the report authors.

SARS-CoV-2 also generates an inflammatory response and an increase in the chemicals that have been linked to hearing loss.

“This is the first reported case of sensorineural hearing loss following COVID-19 infection in the UK,” write the report authors. “Given the widespread presence of the virus in the population and the significant morbidity of hearing loss, it is important to investigate this further.”

They add: “This is especially true given the need to promptly identify and treat the hearing loss and the current difficulty in accessing medical services,” they say. Doctors should ask patients in intensive care about hearing loss and refer them for urgent treatment, they advise.

Contacts and sources:
BMJ



Publication: Sudden irreversible hearing loss post COVID-19.
Foteini Stefania Koumpa, Cillian T Forde, Joseph G Manjaly.BMJ Case Reports, 2020; 13 (11): e238419 DOI: 10.1136/bcr-2020-238419




All-Terrain Microrobot Flips Through a Live Colon

Live ultrasound footage shows a microrobot tumbling through a colon in vivo. 
Credit: Purdue University video/Elizabeth Niedert and Chenghao Bi 

A rectangular robot as tiny as a few human hairs can travel throughout a colon by doing back flips, Purdue University engineers have demonstrated in live animal models.

Why the back flips? Because the goal is to use these robots to transport drugs in humans, whose colons and other organs have rough terrain. Side flips work, too.

Why a back-flipping robot to transport drugs? Getting a drug directly to its target site could remove side effects, such as hair loss or stomach bleeding, that the drug may otherwise cause by interacting with other organs along the way.

The study, published in the journal Micromachines, is the first demonstration of a microrobot tumbling through a biological system in vivo. Since it is too small to carry a battery, the microrobot is powered and wirelessly controlled from the outside by a magnetic field.


“When we apply a rotating external magnetic field to these robots, they rotate just like a car tire would to go over rough terrain,” said David Cappelleri, a Purdue associate professor of mechanical engineering. “The magnetic field also safely penetrates different types of mediums, which is important for using these robots in the human body.”

The researchers chose the colon for in vivo experiments because it has an easy point of entry – and it’s very messy.

“Moving a robot around the colon is like using the people-walker at an airport to get to a terminal faster. Not only is the floor moving, but also the people around you,” said Luis Solorio, an assistant professor in Purdue’s Weldon School of Biomedical Engineering.

“In the colon, you have all these fluids and materials that are following along the path, but the robot is moving in the opposite direction. It’s just not an easy voyage.”

But this magnetic microrobot can successfully tumble throughout the colon despite these rough conditions, the researchers’ experiments showed. A video explaining the work is available on YouTube.

The team conducted the in vivo experiments in the colons of live mice under anesthesia, inserting the microrobot in a saline solution through the rectum. They used ultrasound equipment to observe in real time how well the microrobot moved around.

The microrobots could also tumble in colons excised from pigs, the researchers found, which have similar guts to humans.


The microrobot can be seen just to the right of the “U” in United States on this U.S. penny
. Purdue University image/Georges Adam



“Moving up to large animals or humans may require dozens of robots, but that also means you can target multiple sites with multiple drug payloads,” said Craig Goergen, Purdue’s Leslie A. Geddes Associate Professor of Biomedical Engineering, whose research group led work on imaging the microrobot through various kinds of tissue.

Solorio’s lab tested the microrobot’s ability to carry and release a drug payload in a vial of saline. The researchers coated the microrobot with a fluorescent mock drug, which the microrobot successfully carried throughout the solution in a tumbling motion before the payload slowly diffused from its body an hour later.

“We were able to get a nice, controlled release of the drug payload. This means that we could potentially steer the microrobot to a location in the body, leave it there, and then allow the drug to slowly come out. And because the microrobot has a polymer coating, the drug wouldn’t fall off before reaching a target location,” Solorio said.

The magnetic microrobots, cheaply made of polymer and metal, are nontoxic and biocompatible, the study showed. Cappelleri’s research group designed and built each of these robots using facilities at the Birck Nanotechnology Center in Purdue’s Discovery Park.

Commonly-used roll-to-roll manufacturing machinery could potentially produce hundreds of these microrobots at once, Cappelleri said.

The researchers believe that the microrobots could act as diagnostic tools in addition to drug delivery vehicles.

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“From a diagnostic perspective, these microrobots might prevent the need for minimally invasive colonoscopies by helping to collect tissue. Or they could deliver payloads without having to do the prep work that’s needed for traditional colonoscopies,” Goergen said.

This research is part of the Purdue Center for Cancer Research and aligns with Purdue Engineering Initiatives in Autonomous and Connected Systems and Engineering-Medicine. The work is supported by the National Science Foundation and the National Cancer Institute at the National Institutes of Health.

About Discovery Park

Discovery Park is a place where Purdue researchers move beyond traditional boundaries, collaborating across disciplines and with policymakers and business leaders to create solutions for a better world. Grand challenges of global health, global conflict and security, and those that lie at the nexus of sustainable energy, world food supply, water and the environment are the focus of researchers in Discovery Park. The translation of discovery to impact is integrated into the fabric of Discovery Park through entrepreneurship programs and partnerships.


Contacts and sources:
Kayla Wiles
Purdue University


Publication: A Tumbling Magnetic Microrobot System for Biomedical Applications Elizabeth E. Niedert, Chenghao Bi, Georges Adam, Elly Lambert, Luis Solorio, Craig J. Goergen and David J. Cappelleri DOI: 10.3390/mi11090861 http://dx.doi.org/10.3390/mi11090861




Modern Humans Reached Westernmost Europe 5,000 Years Earlier Than Previously Known

View of the excavation of the early modern human (foreground) and Neanderthal layers (background) in Lapa do Picareiro. 
Photo by Jonathan Haws 

\Modern humans \\rived in the westernmost part of Europe 41,000 – 38,000 years ago, about 5,000 years earlier than previously known, according to Jonathan Haws, Ph.D., professor and chair of the Department of Anthropology at the University of Louisville, and an international team of researchers. The team has revealed the discovery of stone tools used by modern humans dated to the earlier time period in a report published this week in the journal Proceedings of the National Academy of Sciences.

The tools, discovered in a cave named Lapa do Picareiro, located near the Atlantic coast of central Portugal, link the site with similar finds from across Eurasia to the Russian plain. The discovery supports a rapid westward dispersal of modern humans across Eurasia within a few thousand years of their first appearance in southeastern Europe. The tools document the presence of modern humans in westernmost Europe at a time when Neanderthals previously were thought to be present in the region. The finding has important ramifications for understanding the possible interaction between the two human groups and the ultimate disappearance of the Neanderthals.

“The question whether the last surviving Neanderthals in Europe have been replaced or assimilated by incoming modern humans is a long-standing, unsolved issue in paleoanthropology,” said Lukas Friedl, an anthropologist at the University of West Bohemia in Pilsen, Czech Republic, and project co-leader. “The early dates for Aurignacian stone tools at Picareiro likely rule out the possibility that modern humans arrived into the land long devoid of Neanderthals, and that by itself is exciting.”

Until now, the oldest evidence for modern humans south of the Ebro River in Spain came from Bajondillo, a cave site on the southern coast. The discovery of stone stools characterized as Aurignacian, technology associated with early modern humans in Europe, in a secure stratigraphic context at Picareiro provide definitive evidence of early modern human arrival.

“Bajondillo offered tantalizing but controversial evidence that modern humans were in the area earlier than we thought,” Haws said. “The evidence in our report definitely supports the Bajondillo implications for an early modern human arrival, but it’s still not clear how they got here. People likely migrated along east-west flowing rivers in the interior, but a coastal route is still possible.”

“The spread of anatomically modern humans across Europe many thousands of years ago is central to our understanding of where we came from as a now-global species,” said John Yellen, program director for archaeology and archaeometry at the National Science Foundation, which supported the work. “This discovery offers significant new evidence that will help shape future research investigating when and where anatomically modern humans arrived in Europe and what interactions they may have had with Neanderthals.”

The Picareiro cave has been under excavation for 25 years and has produced a record of human occupation over the last 50,000 years. An international research team from the Interdisciplinary Center for Archaeology and Evolution of Human Behavior (ICArEHB) in Faro, Portugal, is investigating the arrival of modern humans and extinction of Neanderthals in the region.

The project is led by Haws, Michael Benedetti of the University of North Carolina Wilmington, and Friedl, in collaboration with Nuno Bicho and João Cascalheira of the University of Algarve, where ICArEHB is housed, and Telmo Pereira of the Autonomous University of Lisbon.

With support from U.S. National Science Foundation grants to Haws and Benedetti, the team has uncovered rich archaeological deposits that include stone tools in association with thousands of animal bones from hunting, butchery and cooking activities.

Sahra Talamo of the University of Bologna, Italy, and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, joined the research team to determine the age of the early modern human and Neanderthal occupations. She used state-of-the-art bone pretreatment and accelerator mass spectrometry (AMS) to date the bones that show evidence of butchery cut marks and intentional breakage by humans to extract bone marrow, a highly prized and nutritious food consumed by ancient people. The dating results place the modern human arrival to the interval between 41,000 and 38,000 years ago. The last Neanderthal occupation at the site took place between 45,000 and 42,000 years ago.

“The radiocarbon results from Lapa do Picareiro are not only very precise in terms of the dating method, but also demonstrate the meticulous work of the archeologists at the site,” Talamo said. “The importance of collaboration between the radiocarbon specialist and the archaeologists is essential in order to obtain an accurate chronology like in the case of Picareiro.”

Spatial analysis of high-resolution three-dimensional data confirmed the precise stratigraphic relationships between artifacts and radiocarbon samples and revealed discrete layers of occupation at the site.

“Analysis of high-resolution spatial data is crucial for documenting and observing lenses of human occupation and reconstructing occupational patterns, especially in cave environments where complex formation processes exist,” said Grace Ellis, a Ph.D. student at Colorado State University studying landscape archaeology and ancient settlement patterns.

This was backed up by artifact refitting that showed the stone tools were not moved through post-depositional processes.

“Refitting is a task that requires a lot of time and patience, and in this case, it really was worthwhile because the results verified the geospatial observations,” said Pereira, an archaeologist who specializes in stone technology.

While the dates suggest that modern humans arrived after Neanderthals disappeared, a nearby cave, Oliveira, has evidence for Neanderthals’ survival until 37,000 years ago. The two groups may have overlapped for several thousand years in the area.

“If the two groups overlapped for some time in the highlands of Atlantic Portugal, they may have maintained contacts between each other and exchanged not only technology and tools, but also mates. This could possibly explain why many Europeans have Neanderthal genes,” said Bicho, director of ICArEHB.

“Besides genetic and archeological evidence, high-resolution temporal context and fossil evidence across the continent is crucial for answering this question. With the preserved key layers dated to the transitional period, we are now awaiting human fossils to tell us more about the nature of the transition,” Friedl said.

Despite the overlap in dates, there does not appear to be any evidence for direct contact between Neanderthals and modern humans. Neanderthals continued to use the same stone tools they had before modern humans arrived, bringing a completely different stone technology.

“Differences between the stone tool assemblages dated before and after about 41,000 years ago are striking at Picareiro,” said Cascalheira, an ICArEHB board member and specialist on stone tool technology. “Older levels are dominated by quartzite and quartz raw materials and marked by the presence of Levallois technology, a typical element of Neanderthal occupations in Europe. Aurignacian levels, on the other hand, are dominated by flint and the production of very small blades that were likely used as inserts in arrow shafts for hunting.”

Flint also was used to make tools for butchering animals such as red deer, ibex and possibly rabbits. The team recovered a few red deer canine teeth, often used as personal adornments, but so far these do not show traces of manufacturing jewelry.

“The bones from Lapa do Picareiro make up one of the largest Paleolithic assemblages in Portugal, and the preservation of these animal bones is remarkable,” said Milena Carvalho, a Ph.D. candidate at the University of New Mexico and ICArEHB researcher studying the diets and paleoecology of Neanderthals and modern humans. “The collection will provide tremendous amounts of information on human behavior and paleoecology during the Paleolithic and we will be studying it for decades.”

The cave sediments also contain a well-preserved paleoclimatic record that helps reconstruct environmental conditions at the time of the last Neanderthals and arrival of modern humans.

“We studied changes in the size of limestone clasts and the chemistry of muddy fine sediment filling the cave to understand the paleoclimatic context for the transition,” Benedetti said. “Our analysis shows that the arrival of modern humans corresponds with, or slightly predates, a bitterly cold and extremely dry phase. Harsh environmental conditions during this period posed challenges that both modern human and Neanderthal populations had to contend with.”

The cave itself has an enormous amount of sediment remaining for future work and the excavation still hasn’t reached the bottom.

“I’ve been excavating at Picareiro for 25 years and just when you start to think it might be done giving up its secrets, a new surprise gets unearthed,” Haws said. “Every few years something remarkable turns up and we keep digging.”


Contacts and sources:
Betty Coffman 
University of Louisville