Stanford engineers have developed a genetic microlab that can detect COVID-19 in minutes

Using "lab on a chip" technology, Stanford engineers have created a microlab half the size of a credit card that can detect COVID-19 in just 30 minutes.

STANFORD SCHOOL OF ENGINEERING

Research News

 

Throughout the pandemic, infectious disease experts and frontline medical workers have asked for a faster, cheaper and more reliable COVID-19 test. Now, leveraging the so-called "lab on a chip" technology and the cutting-edge genetic editing technique known as CRISPR, researchers at Stanford have created a highly automated device that can identify the presence of the novel coronavirus in just a half-hour.

"The microlab is a microfluidic chip just half the size of a credit card containing a complex network of channels smaller than the width of a human hair," said the study's senior author, Juan G. Santiago, the Charles Lee Powell Foundation Professor of mechanical engineering at Stanford and an expert in microfluidics, a field devoted to controlling fluids and molecules at the microscale using chips.

The new COVID-19 test is detailed in a study published on Nov. 4 in the journal Proceedings of the National Academy of Sciences. "Our test can identify an active infection relatively quickly and cheaply. It's also not reliant on antibodies like many tests, which only indicates if someone has had the disease, and not whether they are currently infected and therefore contagious," explained Ashwin Ramachandran, a Stanford graduate student and the study's first author.

The microlab test takes advantage of the fact that coronaviruses like SARS-COV-2, the virus that causes COVID-19, leaves behind tiny genetic fingerprints wherever they go in the form of strands of RNA, the genetic precursor of DNA. If the coronavirus's RNA is present in a swab sample, the person from whom the sample was taken is infected.

To initiate a test, liquid from a nasal swab sample is dropped into the microlab, which uses electric fields to extract and purify any nucleic acids like RNA that it might contain. The purified RNA is then converted into DNA and then replicated many times over using a technique known as isothermal amplification.

Next, the team used an enzyme called CRISPR-Cas12 - a sibling of the CRISPR-Cas9 enzyme associated with this year's Nobel Prize in Chemistry - to determine if any of the amplified DNA came from the coronavirus.

If so, the activated enzyme triggers fluorescent probes that cause the sample to glow. Here also, electric fields play a crucial role by helping concentrate all of the important ingredients - the target DNA, the CRISPR enzyme and the fluorescent probes - together into a tiny space smaller than the width of a human hair, dramatically increasing the chances they will interact.

"Our chip is unique in that it uses electric fields to both purify nucleic acids from the sample and to speed up chemical reactions that let us know they are present," Santiago said.

The team created its device on a shoestring budget of about $5,000. For now, the DNA amplification step must be performed outside of the chip, but Santiago expects that within months his lab will integrate all the steps into a single chip.

Several human-scale diagnostic tests use similar gene amplification and enzyme techniques, but they are slower and more expensive than the new test, which provides results in just 30 minutes. Other tests can require more manual steps and can take several hours.

The researchers say their approach is not specific to COVID-19 and could be adapted to detect the presence of other harmful microbes, such as E. coli in food or water samples, or tuberculosis and other diseases in the blood.

"If we want to look for a different disease, we simply design the appropriate nucleic acid sequence on a computer and send it over email to a commercial maker of synthetic RNA. They mail back a vial with the molecule that completely reconfigures our assay for a new disease," Ramachandran said.

The researchers are working with the Ford Motor Company to further integrate the steps and develop their prototype into a marketable product.

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Climate change will give rise to more cancers

UCSF study focuses on global impact for major cancers and steps needed to lessen risks

UNIVERSITY OF CALIFORNIA - SAN FRANCISCO

Research News

 

Climate change will bring an acute toll worldwide, with rising temperatures, wildfires and poor air quality, accompanied by higher rates of cancer, especially lung, skin and gastrointestinal cancers, according to a new report from UC San Francisco.

In an analysis of nearly five dozen published scientific papers, the researchers provided a synopsis of future effects from global warming on major cancers, from environmental toxins to ultraviolet radiation, air pollution, infectious agents and disruptions in the food and water supply.

Ultimately, the most profound challenge to the global cancer picture could come from the disruption of the complex health care systems required for cancer diagnosis, treatment, and care, the authors wrote. The review appears in The Lancet Oncology.

"In the worldwide battle to mitigate climate change, the international community is not on track to slow emissions of greenhouses gases," said lead author Robert A. Hiatt, MD, PhD, UCSF professor of epidemiology and biostatistics, and associate director for population science at the UCSF Helen Diller Family Comprehensive Cancer Center. "2015-2019 were the five warmest years on record, and 2020 has seen tremendous climate impacts, from wildfires to hurricanes."

The impacts of climate change on health are large and are expected to continue growing without rapid action. High temperatures, poor air quality and wildfires cause higher rates of respiratory and cardiovascular diseases. Warmer temperatures and changing rainfall patterns raise the risk and spread of vector-borne disease, such as malaria and dengue. "Extreme weather events cause death, injury, displacement, and disrupt health-care delivery," the authors wrote.

Cancer is widely predicted to be the leading cause of death in the 21st century. Worldwide, there were 24.5 million new cases of cancer and 9.6 million deaths in 2017, a striking increase from 2008 with 12.7 million cases and 7.6 million deaths.

The authors said the biggest cancer threats are likely to be from air pollution, exposure to ultraviolent radiation and industrial toxins, and disruptions in food and water supply. Lung cancer, already the primary cause of cancer deaths worldwide, is expected to increase as a result of escalating exposure to particulate matter in air pollution, estimated to be responsible for as much as 15 percent of new cases.

While the overall effects of climate change on nutrition-related cancers are difficult to determine, the authors said, one comprehensive modeling study predicted more than half a million climate-related deaths worldwide, including cancer deaths, as a result of changes in food supply by 2050, such as reduced consumption of fruits and vegetables.

Climate change is already exacerbating social and economic inequities, leading to higher rates of migration and poverty. The authors note that poor people and communities of color are disproportionately affected by cancer and have a higher cancer mortality. World Bank estimates that climate change will push 100 million people globally back into poverty by 2030.

Major disruptions are also expected to take place in the infrastructure of health care systems for cancer control, which could affect all cancers. The COVID-19 pandemic has provided a clear example of this disruption, shifting medical resources away from cancer and causing thousands of patients to delay cancer screenings out of fear of contracting the virus.

"Extreme weather events such as storms and flooding can destroy or damage health-care infrastructure, reducing health care quality and availability," said the authors. These events also interrupt service delivery by causing power shortages, disrupting supply chains, transportation, and communication, and resulting in staff shortages. Ironically, COVID-19 also revealed a ray of hope in reversing the damage.

"The early pandemic response resulted in a striking reduction in air pollution," Hiatt said, "showing the potential of extreme measures to result in rapid environmental change."

It could take decades to fully understand the impact of climate change on cancer, given a sometimes lengthy delay from exposure to clinical diagnosis. But the authors said that shouldn't prevent acting now, as the harmful impacts from air pollution and other climate risks will continue to grow during that time.

"There is a lot we can be doing to mitigate climate change and to mitigate the impact on cancer," said co-author Naomi Beyeler, MPH, co-director of the Evidence to Policy Initiative and Lead for Climate and Health at the UCSF Institute for Global Health Sciences. "We should be doing both, and we should be doing both with urgency."

By reducing pollution, deaths from lung cancer could decline, the authors said, and there are numerous clinical, behavioral, and policy solutions to slow climate change, and prevent cancer cases and deaths.

"The COVID-19 pandemic has shown us the importance of science and public health," said Beyeler, "and we have seen over the past months that as a global health community, we are able to mobilize the investments, research, and collective action needed to solve health problems on a global scale. Now is the time to apply this ambition to tackling the climate crisis."

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About UCSF:

The University of California, San Francisco (UCSF) is exclusively focused on the health sciences and is dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. UCSF Health, which serves as UCSF's primary academic medical center, includes top-ranked specialty hospitals and other clinical programs, and has affiliations throughout the Bay Area. Learn more at ucsf.edu, or see our Fact Sheet.

 

Rare ancient child burial reveals 8,000-year-old secrets of the dead

AUSTRALIAN NATIONAL UNIVERSITY

Research News

IMAGE: ENTRANCE TO MAKPAN CAVE, ALOR ISLAND, WHERE THE BURIAL WAS DISCOVERED view more 

CREDIT: IMAGE: DR SHIMONA KEALY, ANU

Archaeologists from The Australian National University (ANU) have discovered a rare child burial dating back 8,000 years on Alor Island, Indonesia.

The one-of-its-kind burial for the region is from the early mid-Holocene and gives important insights into burial practices of the time.

Lead researcher Dr Sofia Samper Carro said the child, aged between four and eight, was laid to rest with some kind of ceremony.

"Ochre pigment was applied to the cheeks and forehead and an ochre-coloured cobble stone was placed under the child's head when they were buried," she said.

"Child burials are very rare and this complete burial is the only one from this time period," Dr Samper Carro said.

"From 3,000 years ago to modern times, we start seeing more child burials and these are very well studied. But, with nothing from the early Holocene period, we just don't know how people of this era treated their dead children. This find will change that."

Notably, the child's arm and leg bones were removed before interment and disposed of elsewhere.

"The lack of long bones is a practice that has been documented in several other burials from a similar time period in Java, Borneo and Flores, but this is the first time we have seen it in a child's burial," Dr Samper Carro said.

"We don't know why long bone removal was practised, but it's likely some aspect of the belief system of the people who lived at this time."

The estimated age of the child based on teeth correspond to a six- to eight-year-old child, but the skeleton is that of a four- to five-year-old child.

"We want to do some further paleo-health research to find out if this smaller skeleton is related to diet or the environment or possibly to being genetically isolated on an island," Dr Samper Carro said.

"My earlier work from Alor showed adult skulls were also small. These hunter-gatherers had a mainly marine diet and there is evidence to suggest protein saturation from a single food source can cause symptoms of mal-nourishment, which affects growth. However, they could have been eating other terrestrial resources such as tubers.

"By comparing other adult burials we have found from the same time period with this child burial in a future project, we hope to build a chronology and general view of burial practices in this region from between 12,000 to 7,000 years ago which at the moment is still scant."

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Dr Samper Carro's paper, Burial practices in the early mid-Holocene of the Wallacean Islands: A sub-adult burial from Gua Makpan, Alor Island, Indonesia, is published in Quaternary International.

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Articulated left foot (bottom left) and right foot (centre) excavated in the ANU laboratory. Image: Ms Tahlia Stewart, ANU

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Fragmented mandible and cranial vault. The temporo-mandibular joint appears articulated

Social media can guide public pandemic policy: QUT research

Social media analytics now a valuable tool in understanding the thoughts and actions of the public during a pandemic

QUEENSLAND UNIVERSITY OF TECHNOLOGY

: LED BY ASSOCIATE PROFESSOR TAN YIGITCANLAR FROM QUT'S SCHOOL OF BUILT ENVIRONMENT, AND IN COLLABORATION WITH RESEACHERS IN AFGHANISTAN, IRAN AND ITALY, THE RESEARCHERS COLLECTED 96,666 GEOTAGGED TWEETS ORIGINATING FROM... view more


With 2020 hijacked by COVID-19, a team of QUT researchers in Brisbane, Australia, say social media analytics can capture the attitudes and perceptions of the public during a pandemic. They also suggest social media is now the best way to encourage people to follow measures and restrictions.

Led by Associate Professor Tan Yigitcanlar from QUT's School of Built Environment, and in collaboration with researchers in Afghanistan, Iran and Italy, the researchers collected 96,666 geotagged tweets originating from Australia between 1 January and 4 May 2020, and analysed 35,969 of them after data cleaning to remove automated messages, irrelevant messages and web links.

The resultant paper - How can social media analytics assist authorities in pandemic-related policy decisions? Insights from Australian states and territories - has been published by Springer journal Health Information Science and Systems.

"From the Plague of Athens in 430 B.C., to the Black Death of the 1300s, through to the Spanish Flu of 1918-1920 and the Swine Flu outbreak in 2009, pandemics are not new. However, increased globalisation since the 1980s has accelerated their spread, as we have seen this year with COVID-19," said Professor Yigitcanlar.

"What started late last year in Wuhan, China was declared a pandemic by the World Health Organization in March. Global cases are heading towards 50 million and there have been more than 1.2 million deaths so far.

"The pandemic has led to many countries introducing lockdowns and limited citizen movements. These restrictions in turn have triggered an increased use of digital technologies and platforms by the public.

"Our aim was to generate insights into how social media analytics can assist authorities in pandemic-related policy decisions.

"We chose Australia as our case study because it has been highly successful in flattening the curve and social media analytics are increasingly used by the health sector here.

"Australia is also an advanced nation with a diverse culture that adapts the technological trends of the world, with the largest being social media. In 2018, 79 per cent of Australians used social media."

Professor Yigitcanlar said the study concluded social media analytics are a valuable tool in understanding the thoughts and actions of the public during a pandemic. Co-author and QUT PhD student Nayomi Kankanamge added that crowdsourced social media data could guide interventions and decisions of authorities during a pandemic.

"We also found that effective use of government social media channels, such as Twitter or Facebook, can help enhance public health education and awareness concerning social distancing restrictions and other measures or restrictions such as the latest lockdown in the UK and much of Europe. This is the best way to reach people in the 21st century", she said.

"In this digital age, local community perceptions and suggestions about social distancing policies, self-isolation, quarantines, movement control, travel restrictions, lockdowns and other changes are well reflected through social media messages.

"A thorough analysis of such social media data helps us understand the community demands, issues, and reflections."

Associate Professor Yigitcanlar said the researchers chose Twitter because it has become the fastest growing social media platform source in the world. It also offers an Application Programming Interface (API) to researchers and practitioners to conduct analysis.

"Social media analytics can help assist policy- and decision-makers to review community perceptions about COVID-19, and to identify the key requirements of the community to cope with the pandemic situation", he said.

"Our analysis has shown that the Australian public was not happy at the early stage of the pandemic curve as they seemed to believe that the Australian government was not responding appropriately.

"As such, people were in a panic mode, and tried to prepare to face the pandemic at their capacity. The words, 'toilet/paper' were very common in Twitter in all states/territories during this stage. This was because consumer panic buying patterns took place in Australia, where people tried to stock toilet paper, hand sanitisers, food, and other commodities. This indicated how Australian people act when the government does not provide confidence.

"From February 2020 onwards, the Australian government started to add travel restrictions to combat COVID-19 which built trust. Popular words like 'testing' and 'shutdown' among positively classified tweets showed people were generally happy about the actions taken by the government to combat the virus dispersion in Australia.

"For instance, the tweets circulated in Queensland emphasised the significance of expanding the number of testing per day at the early stage to stop spreading the virus rapidly. Most of the tweets discussed the importance of wearing masks."

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Seabirds' response to abrupt climate change transformed sub-Antarctic island ecosystems

New study finds seabirds' response to abrupt climate change 5,000 years ago transformed sub-Antarctic island ecosystems

THE UNIVERSITY OF HONG KONG

Research News

 

IMAGE: A ROOKERY OF BLACK-BROWED ALBATROSS (THALASSARCHE MELANOPHRIS) NEST AT A WINDY, EXPOSED TUSSAC GRASSLAND ON WEST POINT ISLAND, FALKLAND ISLANDS. view more 

CREDIT: DULCINEA GROFF

The Falkland Islands are a South Atlantic refuge for some of the world's most important seabird species, including five species of penguins, Great Shearwaters, and White-chinned Petrels. In recent years, their breeding grounds in the coastal tussac (Poa flabellata) grasslands have come under increasing pressure from sheep grazing and erosion. And unlike other regions of the globe, there has been no long-term monitoring of the responses of these burrowing and ground nesting seabirds to climate change.

A 14,000-year paleoecological reconstruction of the sub-Antarctic islands done by an international research team led by The University of Maine (UMaine) including Dr Moriaki YASUHARA from the School of Biological Sciences and The Swire Institute of Marine Science, The University of Hong Kong (HKU), has found that seabird establishment occurred during a period of regional cooling 5,000 years ago. Their populations, in turn, shifted the Falkland Island ecosystem through the deposit of high concentrations of guano that helped nourish tussac, produce peat and increase the incidence of fire. The findings were recently published in the journal Science Advances.

Nutrient inputs from seabirds

"This terrestrial-marine link is critical to the islands' grasslands conservation efforts going forward," says Dulcinea GROFF, who led the research as a PhD student in UMaine. "The connection of nutrients originating in the marine ecosystem that are transferred to the terrestrial ecosystem enrich the islands' nutrient-poor soil, thereby making the Falkland Islands sensitive to changes in climate and land use.

"Our work emphasizes just how important the nutrients in seabird poop are for the ongoing efforts to restore and conserve their grassland habitats. It also raises the question about where seabirds will go as the climate continues to warm," said Groff, who conducted the research in the Falkland Islands during expeditions in 2014 and 2016 led by Jacquelyn GILL, an Associate Professor of paleoecology and plant ecology in the UMaine Climate Change Institute.

The UMaine expedition team collected a 476-centimeter peat column from Surf Bay, East Falkland. The 14,000-year record revealed in the undecomposed tussac leaves of the peat column captures the development of a terrestrial-marine linkage that supports some of the most important breeding colonies of seabirds in the Southern Ocean today.

The absence of seabirds at the East Falklands site prior to 5,000 years ago suggests that seabirds may be sensitive to warmer mediated sea surface temperatures, which can impact their food supply, according to the research team. With a warming South Atlantic today, the question is whether the Falkland Islands, about 300 miles east of South America, will continue to be a seabird breeding "hot spot". The research team suggests that as the Southern Ocean continues to warm in the coming decades, the Falkland Islands seabird communities may undergo abrupt turnover or collapse, which could happen on the order of decades.

The 14,000-year record from East Falkland revealed that for 9,000 years before the arrival of seabirds, the region was dominated by low levels of grasses, a heathland of ferns and dwarf Ericaceous shrubs. About 5,000 years ago, the researchers says, an "abrupt transition" appears to occur. Concentrations in bio-elements such as phosphorus and zinc increase. Grass pollen accumulation rates skyrocket, indicating the establishment of tussac grasslands within 200 years of the establishment of seabird colonies on the island. Also found in the core: increased accumulation rates of peat and charcoal. "This timing is consistent with that of the Southern Ocean cooling that known paleoclimatic records consistently indicate.", said Yasuhara, a paleoecologist and paleoclimatologist in HKU, who is familiar with polar paleoclimatology and paleoceanography.

It is clear that the addition of seabird populations bringing nutrients from the marine environment to the island drove changes in the terrestrial plant community structure, composition and function, as well as increased fire activity and nutrient cycling. What remains unclear is what drove the abrupt ecosystem shift, including the impacts of climate change and extinction, and the geographical distribution of living things through space and time.

"Our study is also a powerful reminder of why we need to understand how different ecosystems are connected as the world warms," says Gill. "Such understanding is especially important in polar regions and ecosystems that are known to be sensitive to climate change," continues Yasuhara. Gill concluded, "We know that many seabirds in the South Atlantic rely on these unique coastal grasslands, but it turns out that the grasses also depend on the nutrients seabirds provide. Because they rely on ecosystems in the ocean and on land for their survival, seabirds are really excellent sentinels of global change. We just don't have good long-term monitoring data for most of these species, so we don't know enough about how sensitive they are to climate change. The fossil record can help us fill in the gaps."

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Link of the journal paper: https://advances.sciencemag.org/content/6/43/eabb2788

Images download and captions: https://www.scifac.hku.hk/press

 

When new males take over, these female primates hurry up and mature

CELL PRESS

Research News

 

IMAGE: THIS PHOTO SHOWS A YOUNG FEMALE GELADA GROOMING THE DOMINANT BREEDING MALE OF HER GROUP. view more 

CREDIT: RACHEL PERLMAN)

Most mammals--including humans and other primates--reach sexual maturity early or late depending on lots of different factors, such as how much food there is to eat. Now, researchers studying close primate relatives of baboons known as geladas have shown for the first time that females of this species suddenly hurry up and mature when a new male enters the picture. Their findings are reported in the journal Current Biology on November 5th.

"We found that prepubertal females are more likely to mature right after a new breeding male arrives in the group - even if it means maturing earlier than expected," said senior author Jacinta Beehner (@jcbeehner), a Professor of Psychology and Anthropology at the University of Michigan. "We also noticed that some of these maturing females were maturing much later than expected."

Many of those late bloomers were the daughters of the primary breeding male prior to the new male's arrival, the researchers report. Their observations suggest that females can both speed up and slow down their maturity to avoid inbreeding with their fathers.

"Once their father is ousted by the new male, they appear to lift this suppression and immediately mature," Beehner said. "Taken together, we see that a new male causes a really obvious increase in the number of maturations in a group - whether early, on-time, or late."

The findings have been a long time coming, the research team says. About a decade ago, they started to notice that--right after a new male arrived--a few females would suddenly mature, all at the same time. That was striking because the researchers typically see only half a dozen or so females mature in any given year. But getting enough data to prove that the timing of maturation was tied to the arrival of a new male took some time.

In the Current Biology study, Beehner along with first author Amy Lu (@sbululab) of Stony Brook University and their colleagues kept track of the age at maturity for 80 females over 14 years of research in the highlands of Ethiopia, the only place geladas are found in nature. It's easy to tell when a gelada matures because they have very conspicuous "sexual swellings" surrounding a patch of skin on their chest and neck.

To understand better how this was happening, the researchers looked at the females' estrogen levels, which they can measure in their feces. They knew that estrogen levels rise just before the females visibly mature. Surprisingly, however, their data showed that estrogen levels surged in immature females of all ages just after a new male took over. In fact, that estrogen boost occurred even in females far too young to mature.

"Females usually mature around 4.5 years old, but we saw that even females as young as one year old exhibited a temporary surge in estrogen," Beehner said. "We suspect that this boost in estrogen causes females to mature, but that some females are just too young for this boost to actually work."

The findings suggest that maturation in many primates is a lot more sensitive to social environments than scientists had thought before. The discovery may even have implications for humans, according to the researchers.

"Many New World monkeys such as the marmosets and tamarins have long been known to be highly sensitive to social variables - with a dominant female suppressing the reproduction of all of the other females in the group," she says. "But, until now, we had no evidence that Old World monkeys or apes were similarly sensitive to the presence or absence of particular individuals. If an Old World monkey, like geladas, can suppress maturation in response to the presence of their biological fathers and lift this suppression in response to the arrival of a novel male, it's possible that such a process could be present in apes, and possibly even in humans."

However, they caution against taking the results in geladas too far in terms of what they might mean for humans since there are so many additional factors at play. In future studies, they hope to identify the costs and benefits associated with maturing early, on-time, or late for their gelada population.

"Once again," Beehner says, "this means we have to be patient and wait until these females, now matured, live out their reproductive lives. So, stay tuned, and we'll get back to you on that in another 14 years."

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This work was supported by the National Science Foundation, the Leakey Foundation, the National Geographic Society, the Fulbright Scholars Program, the University of Michigan, Stony Brook University, and Arizona State University.

Current Biology, Lu et al.: "Male-Mediated Maturation in Wild Geladas" https://www.cell.com/current-biology/fulltext/S0960-9822(20)31507-4

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that fea-tures papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit: http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.

CAPTION

When there is a new dominant male in a gelada group, even females as young as 3.5 years old (pictured here) can mature.

 

From hard to soft: making sponges from mussel shells

CELL PRESS

Research News

 

IMAGE: THIS PHOTO SHOWS BLUE MUSSEL SHELLS AFTER INITIAL TREATMENT WITH ACETIC ACID. view more 

CREDIT: JENNIFER MURPHY

Scientists have discovered a spongy form of calcium carbonate (CaCO3), a material found in limestone, chalk, marble, and the shells of mussels and other shellfish. While most forms of calcium carbonate are hard minerals, this new form is soft and absorbent. The researchers, reporting November 5 in the journal Matter, made the discovery while exploring new uses for leftover mussel shells.

"The local aquaculture industry here on the east coast of Canada got in touch and told us they were going to start growing more mussels in the ocean and producing more waste, and they asked us if there could be some use for it," says senior author Francesca Kerton, a professor of chemistry at Memorial University Newfoundland. "I hadn't really thought about inorganic materials in nature, so it was really a desire to use a food waste product rather than mining or drilling for minerals."

While there are many industrial applications of calcium carbonate already, the research team discovered this spongey material by accident while exploring ways to make a less-corrosive de-icer for vehicles and roads. When they combined ground up mussel shells with acetic acid--the chemical found in vinegar--a strange, white spongey material emerged in the solution overnight.

"We thought somebody was playing a joke on us, putting bits of filter paper or something into the solution, because it didn't look like anything that we put in there," says Kerton. "So we scooped out some of the material and ran X-ray diffraction on it, and that told us it was calcite."

Calcite is one of several naturally occurring forms of calcium carbonate. The researchers concluded that the material was formed from extra calcium carbonate that didn't react completely with the acetic acid. They also tested how well the substance could absorb oils and dyes, wondering if it could have applications in marine pollution cleanup. While they found that it was highly absorbent, they have not yet found a practical way to produce enough of the material to be used for large-scale cleaning projects.

"We did think it was kind of neat that we could possibly take material from an organism that grows in the sea and treat pollution in the ocean," says Kerton. "The fact that we could absorb oil as well as other materials that have been used was pretty exciting, but the scalability and cost of making this sponge will limit that application."

So, while the researchers do not see this substance cleaning the ocean in the immediate future, that doesn't mean it's useless. The team now hopes to explore biomedical applications that would use much smaller amounts of the material.

"We've got lots of ideas for the future in terms of where it could be used. We're interested in whether it can take up drugs or active pharmaceutical ingredients or help control acid in the body," says Kerton. "Biological medicine might be the area where this is going to make the most impact."

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The authors were supported by the Natural Sciences and Engineering Research Council of Canada, Memorial University, the Canada Foundation for Innovation, and the provincial government of Newfoundland and Labrador.

Matter, Kerton et al.: "Hard to Soft: Biogenic Absorbent Sponge-Like Material from Waste Mussel Shells"
https://www.cell.com/matter/fulltext/S2590-2385(20)30520-8

Matter (@Matter_CP), published by Cell Press, is a new journal for multi-disciplinary, transformative materials sciences research. Papers explore scientific advancements across the spectrum of materials development--from fundamentals to application, from nano to macro.
Visit: https://www.cell.com/matter.
To receive Cell Press media alerts, please contact press@cell.com.

CAPTION

This photo shows the soft calcite material floating in water.

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This photo compares dried and ground mussel shells (left) with the soft calcite material (right).

 

Light pollution at night severely disrupts the reproductive cycle of corals

With a global transition towards LED lighting and rapid population growth in coastal regions, researchers say the harmful effects of artificial light must be considered in order to preserve coral reefs already endangered by a variety of additional threats

BAR-ILAN UNIVERSITY

Research News

 

The daily light-dark cycle arising from the earth's rotation is centrally important to biology. Marine organisms, particularly coral reefs, rely on natural light cycles of sunlight and moonlight to regulate various physiological, biological and behavioral processes.

Artificial light produced by powerful street lamps, billboards, sports and industrial facilities, hotels, and office buildings effectively extends the day for work and leisure activities. But while artificial light at night (ALAN) is one of the most important human technological advances, the alteration of natural light cycles has many undesirable effects on the earth's ecosystems. These include skyglow, light trespass, glare, and over-illumination, collectively referred to as light pollution.

Due to the high rate of urban development in marine coastal areas around the world, light pollution could further threaten coral communities' populations, which are already under severe degradation. A new study led by researchers from Bar-Ilan University in Israel demonstrates how light pollution is negatively impacting the reproductive cycle of two coral species.

The coral reproductive cycle (the development of sperm and eggs) is controlled by a biological rhythm a few months during the year in harmony with natural environmental conditions. At the conclusion gametes (sperm and eggs) are released into the water for external fertilization. The mechanism that leads to synchronized spawning is thought to be controlled by both an exogenous (i.e., environmental) and endogenous apparatus (i.e., biological clock). Successful gamete production and fertilization, development of viable offspring, and survival of new coral recruits are possibly the most important processes for replenishing degraded reefs. Moreover, sexual reproduction maintains coral populations and supports evolutionary processes which may enhance fitness.

For this study, just published in the journal Current Biology, researchers collected and tracked two coral species, Acropora millepora and Acropora digitifera, from the Indo-Pacific Ocean. Ninety colonies were transferred to the Bolinao Marine Laboratory, located in an area in the Philippines with no light pollution. The colonies were placed in outdoor tanks, exposed to natural sunlight, moonlight, and seawater. Solar exposure was adjusted to equivalent levels experienced by corals at their collection depth of five meters. Coral colonies were divided into three groups: two experimental and one control. Each group was composed of 15 colonies from each Acropora species divided randomly into three tanks. The experimental groups were treated with LED lamps possessing both cold (yellowish with less blue light) and warm (white with more blue light) spectra.

For three months the LED lamps were activated every day from sundown until sunrise. The control groups were exposed to the same conditions as the experimental colonies (natural solar light, moonlight phases) but without supplemental light at night. Chlorophyll fluorescence yield was assessed on a monthly basis as an indicator of colony health.

The results clearly showed that light pollution caused delayed gametogenesis and unsynchronized gamete release, emphasizing the importance of natural periodic illumination, both solar and lunar, as a critical factor in cueing spawning synchronicity and the gametogenic process. "Both key coral species were affected by ecological light pollution. They exhibited asynchrony in the reproductive state which was reflected in the number of oocytes per polyp, gametogenesis, and gamete maturation," says the study's lead author Prof. Oren Levy, of the Mina and Everard Goodman Faculty of Life Sciences at Bar-Ilan University. "This was further reflected at the population level where only corals exposed to natural light cycles succeeded in spawning synchronization. Light treatment with both cold and warm LED's had a similar impact on the gametogenesis cycle," added Levy. Levy led the Bar-Ilan study with the participation of the Interuniversity Institute for Marine Sciences in Eilat and Tel Aviv University team members Inbal Ayalon and Dr. Yaeli Rosenberg, and in collaboration with team leader Patrick Cabaitan, from The Marine Science Institute at the University of the Philippines, and light pollution specialists Dr. Christopher Kyba and Dr. Helga Kuechly from the German Research Centre for Geosciences GFZ.

To shed light on how relevant their findings are on a worldwide scale, the researchers created a first-of-its-kind global map that highlights areas most threatened by ALAN including the Caribbean Sea and the Pacific and Indian Oceans. One striking example is the Gulf of Aqaba/Eilat in the northern Red Sea, where considerable urban lighting is present close to shore. Here, the least affected area is 47% brighter than a natural night sky, and this rises to a maximum of 60 times brighter.

With the global transition towards LED lighting, which tends to have higher emissions in the blue spectrum, more near shore coral reefs could be affected by artificial light, as blue light penetrates deeper into the water. This spectral shift is expected to be amplified by the current rapid population growth in coastal regions. Levy and team's results demonstrate that artificial light must be considered in conservation plans for coral reefs near areas of human activity and their light pollution impact assessment can help incorporate an important variable in coral reef conservation planning.

In follow-up research Levy hopes to determine whether there are corals more adapted to light pollution and, if so, what mechanism underlies their resilience.

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Population dynamics and the rise of empires in Inner Asia

Genome-wide analysis spanning 6,000 years in the eastern Eurasian Steppe gives insights to the formation of Mongolia's empires

MAX PLANCK INSTITUTE FOR THE SCIENCE OF HUMAN HISTORY

Research News

 

IMAGE: A LEANING DEER STONE PLACED IN FRONT OF DOZENS OF SMALL STONE MOUNDS CONTAINING RITUALLY-SACRIFICED HORSE BURIALS AT THE BRONZE AGE MONUMENT SITE OF IKH TSAGAANII AM, BAYANKHONGOR PROVINCE, CENTRAL... view more 

CREDIT: WILLIAM TAYLOR

From the late Bronze Age until the Middle Ages, the eastern Eurasian Steppe was home to a series of organized and highly influential nomadic empires. The Xiongnu (209 BCE - 98 CE) and Mongol (916-1125 CE) empires that bookend this period had especially large impacts on the demographics and geopolitics of Eurasia, but due to a lack of large-scale genetic studies, the origins, interactions, and relationships of the people who formed these states remains largely unknown.

To understand the population dynamics that gave rise to the Steppe's historic empires, researchers from the Max Planck Institute for the Science of Human History (MPI-SHH), the National University of Mongolia, and partner institutions in Mongolia, Russia, Korea and the United States generated and analyzed genome-wide data for 214 individuals from 85 Mongolian and 3 Russian sites. Spanning the period of 4600 BCE to 1400 CE, it is among the largest studies of ancient Eastern and Inner Asian genomes to date.

During the mid-Holocene, the eastern Eurasian Steppe was populated by hunter-gatherers of Ancient Northeast Asian (ANA) and Ancient Northern Eurasian (ANE) ancestry, but around 3000 BCE, dairy pastoralism was introduced through the expansion of the Afanasievo culture of the Altai mountains, whose origins can be traced to the Yamnaya steppe herders of the Black Sea region more than 3,000 km to the west. Although these migrants left little genetic impact, they had an outsized cultural effect and by the Mid- to Late Bronze Age, dairy pastoralism was practiced by populations throughout the Eastern Steppe.

In the Late Bronze Age and Early Iron Age, populations in west, north and south-central Mongolia formed three distinct, geographically structured gene pools. These populations remained discrete for more than a millennium, until increased mobility, likely facilitated by the rise of horseback riding, began to break down this structure. The formation of the Xiongnu in north-central Mongolia, the first nomadic empire in Asia, is contemporaneous with this population mixture and with the influx of new gene pools originating from across Eurasia, from the Black Sea to China.

"Rather than a simple genetic turnover or replacement, the rise of the Xiongnu is linked to the sudden mixture of distinct populations that had been genetically separated for millennia. As a result, the Xiongnu of Mongolia show a spectacular level of genetic diversity that reflects much of Eurasia," says Dr. Choongwon Jeong, lead author of the study and a professor of Biological Sciences at Seoul National University.

A thousand years later, individuals from the Mongol Empire, one of largest contiguous empires in history, showed a marked increase in Eastern Eurasian ancestry compared to individuals from the earlier Xiongnu, Turkic and Uyghur periods, accompanied by a near complete loss of the ancient ANE ancestry that had been present since before the Xiongnu Empire. By the end of the Mongol Empire, the genetic makeup of the Eastern Steppe had changed dramatically, ultimately stabilizing into the genetic profile observed among present-day Mongolians.

"Our study of ancient Mongolia reveals not only early genetic contributions from populations on the Western Steppe, but also a marked genetic shift towards eastern Eurasian ancestry during the Mongol Empire. The region has a remarkably dynamic genetic history, and ancient DNA is beginning to reveal the complexity of population events that have shaped the Eurasian Steppe," says Ke Wang, co-first author of the study and a PhD student at the MPI-SHH.

In addition to the impacts of genetic events on political structures, the researchers also investigated the relationship between genetics and subsistence strategies. Despite more than 5,000 years of dairy pastoralism in the region and the continued importance of dairy in the average Mongolian diet today, researchers found no evidence for the selection of lactase persistence, a genetic trait that allows lactose digestion.

"The absence of lactase persistence in Mongolian populations both today and in the past challenges current medical models of lactose intolerance, and suggests a much more complicated prehistory of dairying. We are now turning to the gut microbiome to understand how populations adapt to dairy-based diets," says Dr. Christina Warinner, senior author of the study, a professor of Anthropology at Harvard University and a research group leader at the MPI-SHH.

"Reconstructing a 6,000-year genetic history of Mongolia has had a transformative effect on our understanding of the archaeology of the region. While answering some long-standing questions, it has also generated new questions and revealed several surprises. We hope that this research will energize future work on the rich and complex relationships between ancestry, culture, technology, and politics in the rise of Asia's nomadic empires," adds Dr. Erdene Myagmar, co-senior author of the study and professor of Anthropology and Archaeology at the National University of Mongolia.

CAPTION

Present-day home in the Mongolian countryside, known as a ger (Mongolian) or yurt (Russian)

CAPTION

A horse-hair banner adorns a hillside monument in central Bayankhongor province, Mongolia.

NYCHA secondhand smoke policy needs more time and effort to show how well it works

NYU LANGONE HEALTH / NYU SCHOOL OF MEDICINE

Research News

 

One year into a smoking ban in buildings run by the nation's largest public housing authority, tenant exposure to secondhand smoke in hallways, stairwells, and apartments has not declined, a new study shows.

Among the explanations for this, investigators say, are delays in promotion and enforcement, including putting up signage and training building managers, and reluctance among nonsmokers to report violations. They also cite lack of smoking cessation services as a possible factor.

The findings proceed from the move in July 2018 by the New York City Housing Authority (NYCHA) to implement a ban on smoking in public housing authorities issued by the U.S. Department of Housing and Urban Development (HUD). NYCHA's goal was to quell secondhand smoke exposure in its more than 165,000 low-income apartments. Similar policies had successfully reduced smoking in public places like bars and restaurants, and policymakers were hoping they would work in large apartment buildings.

Led by researchers at NYU Grossman School of Medicine, the new study found that so far, little change has occurred. Investigators tracked indoor air quality samples before and after the policy was enacted. They compared the results in 10 high-rise NYCHA buildings (in the homes of about 150 families) with those in 11 so-called Section 8 housing (about 110 families). The latter is a group of privately run apartment buildings that were not subject to the policy but whose resident makeup was similar in terms of how many received subsidized housing, how many smoked, and racial mix.

"Our findings show that more intensive efforts to support and enforce NYCHA's smoke-free housing policy are needed to really change resident smoking behaviors," says study lead author Lorna Thorpe, PhD, MPH. "Managers need to be given sufficient tools to ensure that both tenants and staff understand what the rules are, where they can report violations, and why buildings free of secondhand smoke will improve the health of all the families that are living under the same roof."

Publishing online Nov. 5 in the journal JAMA Network Open, the new study showed that in the 12 months since the policy was enacted, nicotine concentration in stairwells or inside households for either building type dipped by just an average of 0.04 micrograms per cubic meter in apartments and just 0.03 micrograms per cubic meter in stairwells. A microgram is one millionth of a gram. By comparison, a smaller study in 2017 in Philadelphia found more than a 0.20 microgram per cubic meter reduction in nicotine levels in stairwells nine months after the introduction of a smoke-free policy.

In pursuit of the policy's success, NYCHA has already taken steps recommended in the study, the researchers say. These include developing a streamlined system for tracking complaints, assigning responsibility for enforcement, and communicating the consequences of policy violations. In addition, it has added new signage in most buildings and launched the Smoke-Free NYCHA Housing Liaison program to help residents get the help they need to quit smoking.

At the same time, tenants must be empowered to speak to their neighbors and given places for people to smoke without impacting others, adds Thorpe, a professor in the Department of Population Health at NYU Langone Health. She also serves as the department's vice chair of strategy and planning and director of its Division of Epidemiology.

Involuntary exposure to secondhand smoke kills about 41,000 American adults annually, according to the U.S. Centers for Disease Control, and increases risk of cancer, heart disease, and asthma, among other ailments. Today, owing to state and federal bans on smoking in public venues, most people are exposed to cigarette smoke in the home, particularly in multi-unit housing, the study authors say.

For the investigation, the researchers used air filters to measure nicotine levels in the homes of non-smoking residents and in common areas like stairwells and hallways. They also surveyed the tenants to identify any changes in the number of people seen smoking in public spaces.

"Although the initial reductions in secondhand smoke exposure were disappointing, it does not mean that the policy has failed," says study senior author Donna Shelley, MD, MPH, a professor at the NYU School of Global Public Health. "Instead, our findings tell us that NYCHA, HUD, and other institutions need to work together to do more for real change to occur."

"Getting residents to fully comply with the policy is a serious challenge; it is going to take time," says Shelley, also affiliated with the Department of Population Health at NYU Langone. "We will reevaluate the policy impact in another year," she continues.

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Funding for the study was provided by National Cancer Institute grant R01 CA220591.

In addition to Thorpe and Shelley, other NYU Langone researchers include Elle Anastasiou, MPH; Albert Tovar; Emily Gil, MPH; Brian Elbel, PhD; Sue Kaplan, JD; Nan Jian, PhD; and Terry Gordon, PhD. Other research support was provided by Katarzyna Wyka, PhD, at the City University of New York in New York City and Ana Rule, PhD, at Johns Hopkins University in Baltimore, Md.