Mastodon Scientific Frontline

Sunday, October 3, 2021

Mysterious Metal-Rich Near-Earth Asteroids


An artist impression of a close flyby of the metal-rich near-Earth asteroid 1986 DA.
Astronomers using the NASA Infrared Telescope
Facility have confirmed that the asteroid is made of 85% metal.
Addy Graham/University of Arizona
Metal-rich near-Earth asteroids, or NEAs, are rare, but their presence provides the intriguing possibility that iron, nickel and cobalt could someday be mined for use on Earth or in Space.

New research, published in the Planetary Science Journal, investigated two metal-rich asteroids in our own cosmic backyard to learn more about their origins, compositions and relationships with meteorites found on Earth.

These metal-rich NEAs were thought to be created when the cores of developing planets were catastrophically destroyed early in the solar system's history, but little more is known about them. A team of students co-led by University of Arizona planetary science associate professor Vishnu Reddy studied asteroids 1986 DA and 2016 ED85 and discovered that their spectral signatures are quite similar to asteroid 16 Psyche, the largest metal-rich body in the solar system. Psyche, located in the main asteroid belt between the orbits of Mars and Jupiter rather than near Earth, is the target of NASA's Psyche mission.

"Our analysis shows that both NEAs have surfaces with 85% metal such as iron and nickel and 15% silicate material, which is basically rock," said lead author Juan Sanchez, who is based at the Planetary Science Institute. "These asteroids are similar to some stony-iron meteorites such as mesosiderites found on Earth."

Astronomers have been speculating as to what the surface of Psyche is made of for decades. By studying metal-rich NEAs that come close to the Earth, they hope to identify specific meteorites that resemble Psyche’s surface.

"We started a compositional survey of the NEA population in 2005, when I was a graduate student, with the goal of identifying and characterizing rare NEAs such as these metal-rich asteroids," said Reddy, principal investigator of the NASA grant that funded the work. "It is rewarding that we have discovered these 'mini Psyches' so close to the Earth."

"For perspective, a 50-meter (164-foot) metallic object similar to the two asteroids we studied created the Meteor Crater in Arizona," said Adam Battle, who is a co-author of the paper along with fellow Lunar and Planetary Laboratory graduate students Benjamin Sharkey and Theodore Kareta, and David Cantillo, an undergraduate student in the Department of Geosciences.

The paper also explored the mining potential of 1986 DA and found that the amount of iron, nickel and cobalt that could be present on the asteroid would exceed the global reserves of these metals.

Additionally, when an asteroid is catastrophically destroyed, it produces what is called an asteroid family – a bunch of small asteroids that share similar compositions and orbital paths.

The team used the compositions and orbits of asteroids 1986 DA and 2016 ED85 to identify four possible asteroid families in the outer region of the main asteroid belt, which is home to the largest reservoir of small bodies in the inner part of the solar system. This also happens to be the region where most of the largest known metallic asteroids including 16 Psyche reside.

"We believe that these two 'mini Psyches' are probably fragments from a large metallic asteroid in the main belt, but not 16 Psyche itself," Cantillo said. "It's possible that some of the iron and stony-iron meteorites found on Earth could have also come from that region in the solar system too."

The paper's findings are based on observations from the NASA Infrared Telescope Facility on the island of Hawaii. The work was funded by the NASA Near-Earth Object Observations Program, which also funds the NASA Infrared Telescope Facility.

Source/Credit: University of Arizona


Scientists Cite Destructive Dangers of Climate Change


Imja Lake, Nepal, is considered one of the most hazardous lakes in Nepal. The moraine dam at lower left was engineered in 2016 to reduce the lake level slightly and to stabilize the outlet river so as to slightly reduce the glacial lake outburst flood (GLOF) hazard. A hazard early warning system is arranged downstream.  Credit: Jeffrey S. Kargel, 2016.

In a new paper in the Georgetown Journal of International Affairs, seven researchers hailing from five countries have called for greater attention to the destructive potential and recent history of disasters seen in the world’s mountain ranges, including places like the Himalaya and Andes.

The scientists, headed by lead author and Planetary Science Institute Senior Scientist Jeffrey S. Kargel, in “Climate Change, Land Use Change, and Mountain Disasters,” a two-part article, review how climate change and burgeoning development of the world’s mountain regions are driving a variety of natural hazards that can inflict harm on people and damage to critical infrastructure. Read Part One here and Part Two here.

Climate change is driving an increased tempo of the global hydrological cycle as well as thawing of the icy cryosphere. These consequences of global warming may be contributing to an increase of some types of hazards and disasters. “Climate change and other human-caused alterations of the Earth system during this modern era are forcing shifts of the processes and geographic distribution of mountain hazards,” Kargel said. “This is happening even as the exposed human populations and infrastructure of many mountain regions are increasing. Some of these natural processes, such as landslides and glacier lake outburst floods, end up producing disasters.”

Saturday, October 2, 2021

Scientists reverse pancreatic cancer progression in ‘time machine’ made of human cells


Bumsoo Han, professor of mechanical engineering, has built a realistic model of a pancreatic structure that acts as a “time machine” to understand cancer and reverse its spread.
(Purdue University photo/John Underwood)

What makes pancreatic cancer so deadly is its covert and quick spread. Now, a “time machine” built by Purdue University engineers has shown a way to reverse the course of cancer before it spreads throughout the pancreas.

“These findings open up the possibility of designing a new gene therapy or drug because now we can convert cancerous cells back into their normal state,” said Bumsoo Han, a Purdue professor of mechanical engineering and program leader of the Purdue Center for Cancer Research. Han has a courtesy appointment in biomedical engineering.

The time machine that Han’s lab built is a lifelike reproduction of a pancreatic structure called the acinus, which produces and secretes digestive enzymes into the small intestine. Pancreatic cancer tends to develop from chronic inflammation that happens when a mutation has caused these digestive enzymes to digest the pancreas itself.

Increased infectiousness of coronavirus variants explained


Artist's impression of a mutating coronavirus
Researchers from the Universities of Oxford and Dundee have made a discovery that helps explain why variations in the virus causes COVID-19 to spread so rapidly.

Coronaviruses are so named because of the spikes on their surface that make it look like a crown, the Latin word for which is corona. The virus uses these spikes to attach to and enter cells, where they then replicate. All common SARS-CoV-2 variants have mutations in the part of their spike proteins that binds to cells.

The Oxford-Dundee team found that most, but not all, of the common mutations in spike individually strengthened binding to ACE2, a protein found on the surface of our cells.

Furthermore, ACE2 variants found naturally in humans were shown to strengthen binding between it and the virus, suggesting that individuals with common ACE2 variants could be more susceptible to COVID-19 infection.

Professor Anton van der Merwe, from the Sir William Dunn School of Pathology at the University of Oxford, said: 'The purpose of our study was to measure the precise effect of mutations in spike and ACE2 on the strength of their interaction.

'This is important because it helps us understand why some SARS-CoV-2 variants spread more rapidly and should also help us predict whether individuals with mutations in ACE2 would be more susceptible to COVID-19.

'Knowing the precise effect of spike mutations on binding to ACE2 helps us understand why SARS-CoV-2 variants spread more rapidly. This may inform our response to these new variants and help us identify potentially dangerous new variants before they spread widely.'

Even as the world recovers from the pandemic, more infectious variants of the coronavirus have emerged. The Alpha variant rapidly replaced all other variants in the UK and in other countries, while the Delta variant, which largely superseded it, continues to spread around the world. The Beta and Gamma variants also emerged in populations that had previously been infected with the original SARS-CoV-2 virus.

This has led scientists around the world to study these new variants to try and understand the properties which make them more infectious. This latest research has also shown that while common ACE2 mutations led to increased binding, this is not the case for all SARS-CoV-2 variants.

Professor Geoff Barton from Dundee’s School of Life Sciences, said: 'These results are a great example of how collaboration between experts in Computational Biology working with leading experimentalists can result in exciting new findings.

'The work sprang from a computational analysis carried out in our group at Dundee by Dr Stuart MacGowan on the effects of human ACE2 variants on SARS-CoV-2 binding. This helped the Oxford group to focus their complementary skills in the laboratory on the most important human and coronavirus variants.'

The paper is published today in eLife.

Source/Credit: University of Oxford


Cannabis users at 'much higher' risk of developing poor mental health


Those with a recorded history of cannabis use in general practice records are at a much higher risk of developing mental ill health problems such as anxiety or depression as well as severe mental illnesses, new research shows.

The findings point to the need for a public health approach to the management of people misusing cannabis, including the need to emphasize the importance of general practitioners to continue enquiring about recreational drug use.

While the links between cannabis use and severe mental illnesses such as schizophrenia and psychosis are well researched, the associations are less clear between cannabis use as described in patient’s GP records and other, more common types of mental ill health such as depression and anxiety.

In a new study, published in Psychological Medicine, researchers in the University of Birmingham’s Institute for Mental Health and the Institute of Applied Health Research found a strong link between general practice recorded cannabis use and mental ill health in one of the largest cohorts ever explored.

Senior author Dr Clara Humpston said: “Cannabis is often considered to be one of the ‘safer’ drugs and has also shown promise in medical therapies, leading to calls for it be legalized globally. Although we are unable to establish a direct causal relationship, our findings suggest we should continue to exercise caution since the notion of cannabis being a safe drug may well be mistaken.”

Dr Joht Singh Chandan said: “The research reaffirms the need to ensure a public health approach to recreational drug use continues to be adopted across the UK. We must continue to progress measures to improve the prevention and detection of drug use as well as implement the appropriate supportive measures in an equitable manner to prevent the secondary negative health consequences.”

Using primary care data drawn from the IQVIA Medical Research Database (IMRD-UK), the researchers found following the first recorded use of cannabis, patients were three times more likely to develop common mental health problems such as depression and anxiety. In addition, they were almost 7 times more likely to develop severe mental illnesses such as psychosis or schizophrenia.

The dataset included records from 787 GP practices around the UK gathered over a 23-year period between 1995 and 2018. The researchers were able to include data from 28,218 patients who had a recorded exposure to cannabis. These were matched to 56,208 patients who had not been using cannabis and controlled for sex, age, ethnicity, smoking status and other relevant characteristics.

The cannabis users also had much higher rates of having a recorded history of using other drugs such as heroin, cocaine and amphetamines.

Future research in this area will investigate the levels of cannabis use or the potency of ingredients.

Source/Credit: University of Birmingham


Researchers identify and clear efficiency hurdle for organic solar cells


The researchers, led by the University of Cambridge, identified a loss pathway in organic solar cells which makes them less efficient than silicon-based cells at converting sunlight into electricity. In addition, they identified a way to suppress this pathway by manipulating molecules inside the solar cell to prevent the loss of electrical current through an undesirable state, known as a triplet exciton.

Their results, reported in the journal Nature, suggest that it could be possible for organic solar cells to compete more closely with silicon-based cells for efficiency.

Organic solar cells, which are flexible, semi-transparent, and cheap, can greatly expand the range of applications for solar technology. They could be wrapped around the exteriors of buildings and can be used for the efficient recycling of the energy used for indoor lighting, neither of which are possible with conventional silicon panels. They are also far more environmentally friendly to produce.

“Organic solar cells can do lots of things that inorganic solar cells can’t, but their commercial development has plateaued in recent years, in part due to their inferior efficiency,” said Dr Alexander Gillett from Cambridge’s Cavendish Laboratory, the paper’s first author. “A typical silicon-based solar cell can reach efficiencies as high as 20 to 25%, while organic solar cells can reach efficiencies of around 19% under laboratory conditions, and real-world efficiencies of about 10 to 12%.”

What's Up Oct. 2021

What's Up for October? What to look for this month at sunrise and sunset, and two brilliant stars vying for the "pole" position.

On October 10th look for the five-day-old crescent Moon to join Venus and bright, orange-colored Antares in the southwest after sunset. Then watch as Venus closes on Antares, for a close conjunction on the 15th and 16th, where the two will be only about a degree and a half apart.

Venus comes within about 1.5° of the bright orange-colored star Antares on Oct. 15 and 16, in the hour or so after sunset. Credit: NASA/JPL-Caltech
During the last week of October, Mercury pops briefly into view for early risers.

Look for it about 10 degrees above the eastern horizon, or about the width of your fist held at arm's length, about 30-45 minutes before sunrise.

In the last week of October, Mercury can be glimpsed briefly in the morning sky before sunrise for those with a fairly clear view of the eastern horizon.

Then on October 30th, in the last couple of hours before daybreak, look for the 24-day-old crescent Moon to join brilliant blue-white star Regulus.

Find the crescent Moon near brilliant star Regulus in the east before dawn on Oct. 30.

All month long, look high overhead early in the evening to find two bright stars that take turns with Polaris being the North Star. Their names are Vega and Deneb. Both of these stars are part of the Summer Triangle, and we introduced the other member of the trio, Altair, in last month's video. To find Vega and Deneb, look high overhead in the first few hours after it gets dark. They'll be two of the brightest stars you can see up there.

In October, look high overhead to find bright stars Vega and Deneb in the few hours after sunset. The pair rotate toward the west, setting in the pre-dawn hours.

Vega is a bluish-white star, and like Altair, it's a fast rotator, spinning every 12 and a half hours, compared to the Sun's 27-day rotation. NASA's Spitzer Space Telescope found Vega to have a debris disk around it that could be similar to regions in our own solar system.

Deneb is a blue-white supergiant star that is fusing hydrogen at a phenomenal rate.

With this sort of fury, the party won't last all that much longer. Deneb is likely headed for an explosive end as a supernova within a few million years. Deneb is much farther away than most bright stars in our night sky. This means it's SUPER luminous to be that bright from so far away. Because it's so bright, it's one of the most distant stars you can see with the unaided eye.

These stars rotate around the northern celestial pole, and this time of year, they dip toward the western horizon before setting in the pre-dawn hours. Both Vega and Deneb are part of a special group of stars that take turns being the pole star in the north, as Earth's axis wobbles in a circle over a period of 26,000 years. For now the distinction of "North Star" belongs to Polaris, for at least a few hundred years more.

Over 26,000 years, Polaris trades the title of North Star with a group of others, including Vega and Deneb. Of these special stars, Polaris is the bright star that coincides closest with the Celestial North Pole.

Finally, October 16th is International Observe the Moon Night, when everyone is invited to learn about the science and exploration of the Moon. Visit this link to find out how you can take part.

Source/Credit: NASA / JPL


Friday, October 1, 2021

Coral microbiome is key to surviving climate change

Siderastrea radians, Puerto Morelos, Mexico
Image Credit: Monica Medina, Penn State
The microbiomes of corals — which comprise bacteria, fungi and viruses — play an important role in the ability of corals to tolerate rising ocean temperatures, according to new research led by Penn State. The team also identified several genes within certain corals and the symbiotic photosynthetic algae that live inside their tissues that may play a role in their response to heat stress. The findings could inform current coral reef conservation efforts, for example, by highlighting the potential benefits of amending coral reefs with microbes found to bolster corals’ heat-stress responses.

“Prolonged exposure to heat can cause ‘bleaching’ in which photosymbionts (symbiotic algae) are jettisoned from the coral animal, causing the animal to die,” said Monica Medina, professor of biology, Penn State. “We found that when some corals become heat stressed, their microbiomes can protect them from bleaching. In addition, we can now pinpoint specific genes in coral animals and their photosymbionts that may be involved in this thermal stress response.”

Viridiana Avila-Magaña, former student at Penn State and currently a postdoctoral fellow at Colorado University Boulder, noted, “Previous studies on the molecular mechanisms underlying corals’ heat-stress tolerance have tended to focus on just the animal or the photosymbiont, but we now know that the entire holobiont — the coral animal, photosymbiont and microbiome — is involved in the stress response.”

AI can predict cancer risk through mammograms


Two normal mammograms showing the difference between a dense breast (left)
 and a fatty breast (right).
Photo credit: National Cancer Institute
As a hereditary disease, breast cancer has affected hundreds of families throughout the state. Annually, an average of 1,190 women are diagnosed with breast cancer in Hawaiʻi. As October approaches in recognition of National Breast Cancer Awareness Month, new public impact research from the University of Hawaiʻi Cancer Center is using artificial intelligence (AI) to improve risk assessment for breast cancer to aid in prevention and early detection, improving breast cancer outcomes for women all over the world.

To reduce unnecessary imaging for breast cancer and costs associated with it, UH Cancer Center Researcher John Shepherd and his colleagues found that AI is able to distinguish between the mammograms of women who are more likely to develop breast cancer later on, and those who are not. The study was published in Radiology.

“Conventional methods of breast cancer risk assessment using clinical risk factors haven’t been that effective,” said Shepherd, study lead author and a professor in the Population Sciences in the Pacific Program (epidemiology). “We thought that there was more in the image than just breast density that would be useful for assessing risk.”

Deep learning model

Compared to commonly used clinical risk factors, a sophisticated type of AI called deep learning has been found to be better at using mammograms to differentiate between women who will and will not be diagnosed with breast cancer in the future. Typically, mammograms provide a measure of breast cancer risk through measurements of breast density. While denser breasts on mammography are associated with a higher risk of cancer, there are other factors hidden in mammograms that are likely to contribute risk.

The study used a data set of more than 25,000 digital screening mammograms from 6,369 women who participated in screening mammography from 2006 to 2014. The researchers trained the deep learning model to find details and signals in the mammogram that might be linked to increased cancer risk. When they tested the deep learning-based model, it underperformed in assessing the risk factors for interval cancer risk (cancers diagnosed between routine screenings), but outperformed clinical risk factors in determining screening-detected cancer risk.

“The results showed that the extra signal we’re getting with AI provides a better risk estimate for screening-detected cancer than other forms of assessment,” said Shepherd. “It helped us accomplish our goal of classifying women into low risk or high risk of screening-detected breast cancer.”

He added, “By ranking mammograms in terms of the probability of seeing cancer in the image, AI is going to be a powerful second reading tool to help categorize mammograms.”

Researchers are planning to replicate the study in Native Hawaiian and Pacific Islander women, two groups that have been underrepresented in breast cancer research. They also want to extend the work beyond cancer risk to look at the risk of different grades of breast cancer, from least to most aggressive.

Learn more about breast cancer causes, prevention, treatment and screening here.

Source/Credit: University of Hawaiʻi/John Shepherd


Clinical trial produces effective oral antiviral to combat COVID-19


Scientists at the University of North Carolina at Chapel Hill say a twice-daily pill – molnupiravir — could change the way COVID-19 is treated. Today’s announcement by Merck Co. to seek emergency authorization by the Food and Drug Administration reflects research and testing conducted at UNC-Chapel Hill.

Strong clinical trial results showed the experimental COVID-19 pill reduced hospitalizations and deaths by half in people recently infected with coronavirus. Carolina began working on molnupiravir in 2016 and showed the drug could be a weapon against coronaviruses and future pandemics.

“This is a real game changer for a pandemic like COVID-19 because it allows us to treat people quicker with a method that’s convenient and accessible,” said William A. Fischer II, an associate professor of pulmonology and critical care at the UNC School of Medicine and director of emerging pathogens at the UNC Institute for Global Health and Infectious Diseases.

Featured Article

A warmer Arctic Ocean leads to more snowfall further south

An increasingly warm and ice-free Arctic Ocean has, in recent decades, led to more moisture in higher latitudes. This moisture is transporte...

Top Viewed Articles