Culture

North America's beloved Monarch butterflies are known for their annual, multi-generation migrations in which individual insects can fly for thousands of miles. But Monarchs have also settled in some locations where their favorite food plants grow year round, so they no longer need to migrate.

Micah Freedman, a graduate student at the Center for Population Biology at UC Davis, took a deep dive into museum collections to see how migration has shaped the species. Monarchs are native to North America, but have also established non-migrating populations in the Caribbean, Central and South America, and islands in the Pacific and Atlantic oceans. These island-hopping butterflies may have been blown by storms before being lucky enough to reach dry land.

Monarchs that established new, non-migrating populations also had those larger wings. But over time, the wings of these colonists got smaller.

Selection at work in opposing directions

The shift between longer and shorter wings shows two opposite selection forces at work, Freedman and colleagues wrote in a paper published this week in Proceedings of the National Academy of Sciences. Migration selects for longer, larger forewings while non-migration seems to relax this and lead to smaller wings.

Alternatively, wing size could be influenced by other environmental factors depending on where butterflies are hatched and grow up. To test this, Freedman raised Monarch butterflies from non-migrating populations in Hawaii, Guam, Australia and Puerto Rico outdoors in Davis, California alongside native migrating Monarchs. The non-migrating butterflies retained their smaller wings, showing that the effect is due to genetics and not the rearing environment.

"Our findings provide a compelling example of how migration-associated traits may be favored during the early stages of range expansion, and also the rate of reductions in those same traits upon loss of migration," the authors wrote.

Today, the imminent climate change crisis demands a shift from conventionally used fossil fuels to efficient sources of green energy. This has led to researchers looking into the concept of "personalized energy," which would make on-site energy generation possible. For example, solar cells could possibly be integrated into windows, vehicles, cellphone screens, and other everyday products. But for this, it is important for the solar panels to be handy and transparent. To this end, scientists have recently developed "transparent photovoltaic" (TPV) devices--transparent versions of the traditional solar cell. Unlike the conventionally dark, opaque solar cells (which absorb visible light), TPVs make use of the "invisible" light that falls in the ultraviolet (UV) range.

Conventional solar cells can be either "wet type" (solution based) or "dry type" (made up of metal-oxide semiconductors). Of these, dry-type solar cells have a slight edge over the wet-type ones: they are more reliable, eco-friendly, and cost-effective. Moreover, metal-oxides are well-suited to make use of the UV light. Despite all this, however, the potential of metal-oxide TPVs has not been fully explored until now.

To this end, researchers from Incheon National University, Republic of Korea, came up with an innovative design for a metal-oxide-based TPV device. They inserted an ultra-thin layer of silicon (Si) between two transparent metal-oxide semiconductors with the goal of developing an efficient TPV device. These findings were published in a study in Nano Energy, which was made available online on August 10, 2020 (ahead of the scheduled final publication in the December 2020 issue). Prof Joondong Kim, who led the study, explains, "Our aim was to devise a high-power-producing transparent solar cell, by embedding an ultra-thin film of amorphous Si between zinc oxide and nickel oxide."

This novel design consisting of the Si film had three major advantages. First, it allowed for the utilization of longer-wavelength light (as opposed to bare TPVs). Second, it resulted in efficient photon collection. Third, it allowed for the faster transport of charged particles to the electrodes. Moreover, the design can potentially generate electricity even under low-light situations (for instance, on cloudy or rainy days). The scientists further confirmed the power-generating ability of the device by using it to operate the DC motor of a fan.

Based on these findings, the research team is optimistic that the real-life applicability of this new TPV design will soon be possible. As for potential applications, there are plenty, as Prof Kim explains, "We hope to extend the use of our TPV design to all kinds of material, right from glass buildings to mobile devices like electric cars, smartphones, and sensors." Not just this, the team is excited to take their design to the next level, by using innovative materials such as 2D semiconductors, nanocrystals of metal-oxides, and sulfide semiconductors. As Prof Kim concludes, "Our research is essential for a sustainable green future--especially to connect the clean energy system with no or minimal carbon footprint."

PITTSBURGH, Nov. 2, 2020 - University of Pittsburgh School of Medicine scientists have discovered the fastest way to identify potent, neutralizing human monoclonal antibodies against SARS-CoV-2, the virus that causes COVID-19.

The method--as well as a trio of successful animal studies on an antibody called "Ab1"--are described today in the Proceedings of the National Academy of Sciences. Ab1 is on track for human clinical trials by early next year.

At any given time, the human body contains up to 10 billion different antibodies. With samples from a few hundred people, senior author Dimiter Dimitrov, Ph.D., director of Pitt's Center for Antibody Therapeutics (CAT), and his team over the last several years built multiple libraries containing a total of 1 trillion human antibodies. With such a large number, odds are that these libraries contain an effective antibody against any pathogen--the challenge is in identifying the right antibodies in the libraries, something the Pitt team has mastered.

"Making a diverse antibody library is an art," said co-author John Mellors, M.D., chief of the Division of Infectious Diseases at Pitt and UPMC. "Not everyone can do it. Dr. Dimitrov and his team not only identified potential therapies in record time, before most Americans were even aware that a pandemic was looming, but by publishing their method, they've also better prepared the world for future emerging diseases."

In contrast, the major method used this year to identify antibodies that neutralize SARS-CoV-2 was to find patients who have recovered from COVID-19, isolate their cells that produce antibodies against the virus and extract the antibodies from those cells. Large numbers of antibodies then must be screened to find those that bind most tightly to the virus, which adds more time to the discovery process. So while the Pitt team had identified Ab1 back in February, major companies didn't have their monoclonal antibodies until the end of March or early April.

When Chinese scientists published the genetic sequence for SARS-CoV-2 in January of this year, Dimitrov's team rapidly generated the virus's receptor binding domain--part of the spike protein that attaches to human cells--and used it as "bait" to pan their multiple libraries of monoclonal antibodies. Dimitrov decided to focus only on the receptor binding domain as a bait because his team was the first to identify it during the original SARS outbreak in 2003 and show that it is the most important part of the spike protein to attract potent neutralizing antibodies.

Like prospectors trying to find gold in rivers of silt during the California Gold Rush, Dimitrov's team panned their libraries against the spike protein receptor binding domain in February, quickly washing away useless antibodies and homing in on the most promising candidates, which block the virus from binding to the ACE2 receptor. The team struck "gold" in just six days.

Ab1 is a fully human monoclonal antibody that neutralizes SARS-CoV-2 by tightly binding to the virus, preventing it from infecting human cells. In tests on hamsters, regular mice and mice genetically engineered to express the human ACE2 receptor--the entry point of SARS-CoV-2 into cells--Ab1 was highly effective at preventing and treating COVID-19 or its animal analogue. Ab1 currently is in production and could be added to Operation Warp Speed or other human clinical trials as early as January 2021.

"The main differences between our rapid 'panning' method and the 'screening' process used by most companies this year to discover antibodies against SARS-CoV-2 is that panning is much quicker than screening, and we don't have to wait for infected patients to recover and make antibodies," Dimitrov said. "We found our monoclonal antibody in under a week in February, which validated how well our panning methods work. This will save precious time in getting antibody therapy into people the next time a deadly virus emerges."

Last month, Mellors and Dimitrov announced the discovery of Ab8, a smaller-sized but very potent antibody isolated from their antibody libraries by Wei Li, Ph.D., assistant director of the Center for Antibody Therapeutics, who also discovered Ab1. Ab8 isn't as far along in development as Ab1, but being a smaller molecule, it could potentially be administered subcutaneously or even through inhalation, which might make it more practical for widespread use.

Global warming of 2°C would lead to about 230 billion tonnes of carbon being released from the world's soil, new research suggests.

Global soils contain two to three times more carbon than the atmosphere, and higher temperatures speed up decomposition - reducing the amount of time carbon spends in the soil (known as "soil carbon turnover").

The new international research study, led by the University of Exeter, reveals the sensitivity of soil carbon turnover to global warming and subsequently halves uncertainty about this in future climate change projections.

The estimated 230 billion tonnes of carbon released at 2°C warming (above pre-industrial levels) is more than four times the total emissions from China, and more than double the emissions from the USA, over the last 100 years.

"Our study rules out the most extreme projections - but nonetheless suggests substantial soil carbon losses due to climate change at only 2°C warming, and this doesn't even include losses of deeper permafrost carbon," said co-author Dr Sarah Chadburn, of the University of Exeter.

This effect is a so-called "positive feedback" - when climate change causes knock-on effects that contribute to further climate change.

The response of soil carbon to climate change is the greatest area of uncertainty in understanding the carbon cycle in climate change projections.

To address this, the researchers used a new combination of observational data and Earth System Models - which simulate the climate and carbon cycle and subsequently make climate change predictions.

"We investigated how soil carbon is related to temperature in different locations on Earth to work out its sensitivity to global warming," said lead author Rebecca Varney, of the University of Exeter.

State-of-the-art models suggest an uncertainty of about 120 billion tonnes of carbon at 2°C global mean warming.

The study reduces this uncertainty to about 50 billion tonnes of carbon.

Co-author Professor Peter Cox, of Exeter's Global Systems Institute, said: "We have reduced the uncertainty in this climate change response, which is vital to calculating an accurate global carbon budget and successfully meeting Paris Agreement targets."

Why do most viral epidemics spread cyclically in autumn and winter in the globe's temperate regions? According to an interdisciplinary team of researchers of the Italian National Institute for Astrophysics, the University of Milan, the Lombardy regional agency for the environment and the Don Gnocchi Foundation, the answer is intimately related to our Sun: their theoretical model shows that both the prevalence and evolution of epidemics are strongly correlated with the amount of daily solar irradiation that hits a given location on the Earth at a given time of the year. The work of the Italian team was recently published in the iScience journal.

"Our model offers a simple answer to an important, yet still unsolved, scientific question", says Fabrizio Nicastro, INAF researcher and PI of the work. "Why do many viral respiratory epidemics, such as influenza, develop cyclically during autumn and winter only in the temperate regions of the globe's northern and southern hemispheres, while they seem to be present at all times - albeit with lower prevalence compared to the seasonal cycles in the temperate regions - in the equatorial belt? And what triggers and determines such seasonality? In our work, we propose that what causes the seasonality of airborne-transmitted epidemics is exactly the same mechanism that causes seasons on our Planet: the amount of daily solar irradiation on the Earth".

It is well known that ultraviolet (UV) light is able to deactivate viruses and bacteria of many different kinds. The solar UV light that reaches the Earth must therefore have some disinfecting power on the exposed parts of the Planet. The efficiency of the UV deactivation of a particular virus or bacterium depends on the virus or bacterium itself, but, for a given location on Earth, it is undoubtedly greater when the solar irradiation is stronger (summer) and lower when the solar irradiation is weaker (winter). Such cyclicality of the solar disinfecting action, with annual frequency, is able to constructively resonate with another frequency typical of epidemics: the loss of immunity of the virus's host due to its antigenic shift/drift. The combination of these two mechanisms triggers the seasonality of epidemics, on timescales that range from a few years to tens of years, depending on the antigenic frequency.

The model proposed by the Italian researchers reproduces the seasonality observed in different locations of the Earth accurately for epidemics with an intrinsic reproductive number (R0) lower than about 2 - an influenza typically has R0~1 - and is also able to model epidemics with a much larger intrinsic reproductive number, such as the current SARS-CoV-2 pandemic with R0?3-4. These models predict high-intensity intermittent initial cycles, which eventually stabilize (on timescales that depend on the antigenic-shift frequency) onto seasonally-synchronized, moderate-intensity annual cycles.

"From an epidemiologic point of view, these models clarify an important and long-standing mystery: why do influenza epidemics disappear every year when the number of susceptible individuals is still very far from that needed to trigger the herd immunity mechanism?", adds Mario Clerici, Immunologist at the University of Milan and the Don Gnocchi Foundation.

"The Italian data of the SARS-CoV-2 pandemics can also be described accurately by our model - concludes Nicastro - but the predictive power of the model depends critically (other than on the implementation of new restriction measures) on the exact UV-B/A lethal doses for the Covid-19 virus, which our collaboration is about to measure".

Everything you ever really needed to know you learned back in kindergarten - that old saying gets some scientific support in a new study by researchers at Canada's Université de Montréal and Université Sainte-Anne.

"We've known for years that getting off to a good start in kindergarten leads to better achievement over the long-term," said lead author Caroline Fitzpatrick, an assistant professor of psychology at USA, in Nova Scotia.

"But now with our study we can really lock in the idea that early childhood skills help you achieve success and adopt a healthier lifestyle in emerging adulthood. And that's promising for society as a whole."

The study was published today in Pediatrics.

"Many children begin kindergarten inadequately prepared to benefit from classroom instruction," said senior author Linda Pagani, a professor at UdeM's School of Psycho-Education.

"Those who go in unprepared risk struggling throughout their academic journey. They arrive without the necessary tools in terms of cognitive skills, social skills and motor skills from physical activity", added Pagani, who is also Senior researcher at CHU Sainte-Justine pediatric hospital in Montreal.

Math skills important

Fitzpatrick and Pagani examined associations between kindergarten readiness and academic, psychological and health risks that mainfested themselves when a child reached the end of high school.

"Kindergarten math skills contributed to better end-of high-school achievement and a lower dropout risk, and that was supported by observations from teachers, who also noted a reduced risk of substance abuse later on, said Fitzpatrick.

"Kindergarten classroom engagement also predicted involvement in physical activity and a 65-per-cent drop in the risk of a child being overweight by age 17," added Pagani, who worked on the study with UdeM postdoctoral researcher Elroy Boers.

The authors came to their conclusions after examining Institut de la statistique du Québec data from a cohort of 2,000 children born in 1997 or 1998 who were part of the Quebec Longitudinal Study of Child Development .

At age 5, trained examiners assessed each child's knowledge of numbers and their receptive vocabulary. Each spring, teachers reported kindergarten classroom engagement, such as how a child did tasks, followed directions and worked with others. At age 17, participants reported on their academic grades, their feelings of connectedness, whether they abused drugs or alcohol, their involvement in physical activity, and their height and weight. The drop-out risk was also estimated for each participant based on their grades retention and engagement at school.

Confounding factors discarded

The researchers then analyzed the data to identify any significant link between kindergarten readiness and academic, psychological and health risks by the end of high school. They attempted to discard possible confounding factors by adjusting their analyses for key indicators in the children (their sex, weight per gestational age, non-verbal IQ and internalizing and externalizing behaviors) and in their families (parental involvement, maternal depression, immigration status, family configuration and socioeconomic status).

"Early childhood readiness forecasts a later protective edge in emerging adulthood and suggests that youngsters who begin school with the right preparedness gain a lifestyle advantage," said Fitzpatrick. "Our findings show a way to eliminate the established link between underachievement and disease by providing children with the conditions that will promote kindergarten readiness."

Added Pagani: "Promoting kindergarten readiness seems, over the long-term, to help reduce the lifestyle risks generated by dropping out of high school. Therefore, policies to promote and preserve children's early skills, such as providing stimulating childcare and diminishing family adversity, may thus represent a valuable policy strategy for governments to invest in."

Scientists from an international group led by the RIKEN Center for Integrative Medical Sciences and Yokohama City University have discovered that a pair of proteins play a key role in allowing an important type of functional non-coding RNA, known as SINEUPs, to act to promote their target messenger RNA.SINEUPs are a recently discovered type of RNA that work specifically to amplify the production of proteins by messenger RNAs, and hence could be important for developing therapeutics for diseases where a certain protein is insufficiently synthesized.

While it was once believed that DNA was simply transcribed into RNA which was then translated into proteins, it is now known that RNA plays a more complex role. While nearly all DNA is transcribed into RNA, it turns out that only 30% of RNA is translated into proteins. The remaining 70% play roles such as enhancing gene expression, epigenetic regulation and--in the case of SINEUPs--up-regulating the production of proteins by target RNA.

The current research, published in Nucleic Acids Research, looks at a certain type of non-coding RNA, known as SINEUPs. These are essentially "genetic parasites" that have incorporated themselves as repeating elements within the genome. Though it is understood that they function to amplify the activity of the messenger RNAs that they are associated with, the mechanism behind this activity remained a mystery.

According to Hazuki Takahashi of the RIKEN Center for Integrative Medical Sciences, one of the corresponding authors of the paper, "We wanted to figure out the mechanism for the action of SINEUPs. Understanding how these RNAs work would be a tremendous breakthrough, because there are a number of diseases caused by a failure of genes to create sufficient quantities of a certain protein, and knowing how SINEUPs function could provide us with a way to remedy this."

The group did have clues from their previous research. They had noted that the SINEUPs only affected the action of their target messenger RNA when they had been transported, together with the messenger RNA, out of the cell nucleus and into the cytosol where the protein production takes place.

Through a series of experiments involving both natural SINEUPs and artificial SINEUPs fitted with a fluorescent protein to allow the team to examine their movements, they discovered that a pair of RNA binding proteins, called PTBP1 and HNRNPK, interact with the SINEUPs both to allow their transport and to make it possible for them to act upon the messenger RNA. These two proteins are quite interesting as they have been found to work together in a variety of biological functions such as maintaining the pluripotency of cells. They are also biologically very important, as it has been shown that knocking out the HNRNPK gene in mice is lethal embryonically.

According to Piero Carninci of the RIKEN Center for Integrative Medical Sciences, the leader of the research group, "We are very pleased to have discovered the role of these binding proteins in the activities of SINEUPs. Because of the ability of SINEUPs specifically to modulate the translation of targeted mRNAs as needed, they are ideal for future therapies in humans where increasing the level of a specific protein could have a therapeutic effect. There are hundreds of diseases that would benefit from SINEUPs treatments, caused by deficiency of one functional copy of a gene: these diseases are known with the general terms of haploinsufficiencies. In addition, SINEUPs have potential to enhance currently limited antibody drug production. Understanding the mechanism of SINEUPs and other functional long non-coding RNAs mechanism is a very important first step for future applications of these RNAs for improving human health."

A study published today in the journal Science Advances has revealed that the United States ranks as high as third among countries contributing to coastal plastic pollution when taking into account its scrap plastic exports as well as the latest figures on illegal dumping and littering in the country. The new research challenges the once-held assumption that the United States is adequately "managing" - that is, collecting and properly landfilling, recycling or otherwise containing - its plastic waste. A previous study using 2010 data that did not account for plastic scrap exports had ranked the United States 20th, globally, in its contribution to ocean plastic pollution from mismanaged waste.

Using plastic waste generation data from 2016 - the latest available global numbers - scientists from Sea Education Association, DSM Environmental Services, University of Georgia, and Ocean Conservancy calculated that more than half of all plastics collected for recycling (1.99 million metric tons of 3.91 million metric tons collected) in the United States were shipped abroad. Of this, 88% of exports went to countries struggling to effectively manage, recycle, or dispose of plastics; and between 15-25% was low-value or contaminated, meaning it was effectively unrecyclable. Taking these factors into account, the researchers estimated that up to 1 million metric tons of U.S.-generated plastic waste ended up polluting the environment beyond its own borders.

"For years, so much of the plastic we have put into the blue bin has been exported for recycling to countries that struggle to manage their own waste, let alone the vast amounts delivered from the United States," said lead author Dr. Kara Lavender Law, research professor of oceanography at Sea Education Association. "And when you consider how much of our plastic waste isn't actually recyclable because it is low-value, contaminated or difficult to process, it's not surprising that a lot of it ends up polluting the environment."

Using 2016 data, the paper also estimated that 2-3% of all plastic waste generated in the U.S. - between 0.91 and 1.25 million metric tons - was either littered or illegally dumped into the environment domestically. Combined with waste exports, this means the United States contributed up to 2.25 million metric tons of plastics into the environment. Of this, up to 1.5 million metric tons of plastics ended up in coastal environments (within 50 km of a coastline), where proximity to the shore increases the likelihood of plastics entering the ocean by wind or through waterways. This ranks the United States as high as third globally in contributing to coastal plastic pollution.

"The United States generates the most plastic waste of any other country in the world, but rather than looking the problem in the eye, we have outsourced it to developing countries and become a top contributor to the ocean plastics crisis," said Nick Mallos, senior director of Ocean Conservancy's Trash Free Seas® program and a co-author of the study. "The solution has to start at home. We need to create less, by cutting out unnecessary single-use plastics; we need to create better, by developing innovative new ways to package and deliver goods; and where plastics are inevitable, we need to drastically improve our recycling rates."

The study noted that although the United States accounted for just 4% of the global population in 2016, it generated 17% of all plastic waste. On average, Americans generated nearly twice as much plastic waste per capita as residents of the EU.

"Previous research has provided global values for plastic input into the environment and coastal areas, but detailed analyses like this one are important for individual countries to further assess their contributions," said Dr. Jenna Jambeck, Distinguished Professor at the University of Georgia's College of Engineering and a co-author of the study. "In the case of the United States, it is critically important that we examine our own backyard and take responsibility for our global plastic footprint."

"For some time, it has been cheaper for the United States to ship its recyclables abroad rather than handle them here at home, but that has come at great cost to our environment," said Natalie Starr, principal at DSM Environmental Services and a co-author of the study. "We need to change the math by investing in recycling technologies and collection programs, as well as accelerating research and development to improve the performance and drive down the costs of more sustainable plastics and packaging alternatives to address the current challenge."

What The Study Did: This observational study examined how well sociodemographic features, laboratory value and comorbidities of patients hospitalized with COVID-19 in Eastern Massachusetts might predict a course of severe illness.

Authors: Roy H. Perlis, M.D., M.Sc., of Massachusetts General Hospital in Boston and an associate editor at JAMA Network Open, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2020.23934)

Editor's Note: The article includes conflict of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

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Media advisory: The full study is linked to this news release.

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About JAMA Network Open: JAMA Network Open is the new online-only open access general medical journal from the JAMA Network. On weekdays, the journal publishes peer-reviewed clinical research and commentary in more than 40 medical and health subject areas. Every article is free online from the day of publication.

LUGANO, 31 October, 2020 - Researchers have developed a novel allergen-depleted and anti-inflammatory fragrance that can be used in moisturisers for people with extremely dry, xerotic skin. Beiersdorf researchers in Germany report the results of two tests proving the fragrance is anti-inflammatory at today's 29th EADV Congress, EADV Virtual.

Tests on skin cells found that the anti-inflammatory ingredients of the allergen-depleted fragrance composition reduced expression of both Prostaglandin E2 and Interleukin-8 after applying a stressor substance. The researchers also studied the fragrance formulated in a moisturiser applied to the forearm of human volunteers after they shaved their skin on three consecutive days to induce skin irritation. They found that skin redness was significantly reduced in the skin treated with the moisturiser.

Fragrances are one of the most frequent causes of allergic contact dermatitis. The novel fragrance was developed without using not only any of the 26 commonly known allergens, but also without the additional 60+ potential allergens currently under evaluation. However, it still has a pleasant scent, which can significantly improve the cosmetic acceptability of moisturisers and, consequently, enhance patients' treatment adherence.

Dr Julia Gallinger, a senior scientist at Beiersdorf AG's Research and Development department explains: "A moisturiser containing our novel fragrance could provide an improved treatment option for people with dry skin conditions. It would be both pleasant to use due to its scent, enhancing patients` treatment adherence, and actively soothe inflammation. Hence, the long-standing paradigm of fragranced moisturisers considered as allergenic risk in the treatment of xerotic dermatoses may soon become obsolete. The fragrance has been integrated into two new Eucerin UreaRepair PLUS products for dry skin to provide skin care with a pleasurable experience."

In addition, a patient preference study among 86 people with dry skin who used the fragranced moisturiser for two weeks showed that 97% agree that it doesn't just feel like they have to apply something on their skin, but now they also enjoy it. 91% confirmed that the scented lotion makes their care routine more pleasant. Furthermore, 71% confirmed that they like the scented product better than the unscented moisturiser they normally use.

New research by an international team of scientists shows how marine organisms were forced to 'reboot' to survive following the asteroid impact 66 million years ago which killed three quarters of life on earth.

Researchers from the University of Southampton and UCL, along with colleagues in Paris, California, Bristol and Edinburgh used an exceptional record of plankton fossils and eco-evolutionary modelling techniques to examine how organisms behaved before and after this extinction event - and why some survived and some didn't.

The team found that prior to the asteroid impact, species of nannoplankton - microscopic algae - were exclusively reliant on harnessing energy from sunlight (photoautotrophs), but those living afterwards were capable of capturing food and eating it in addition to using photosynthesis to feed (mixotrophs). This suggests the blocking of light from the sun played an important role in killing off some species and over time, encouraging others to evolve and adapt.

Findings are published in the journal Science Advances.

The research team's breakthrough came when they found that many of the nannoplankton skeletons (coccospheres) post mass-extinction included a large hole, indicating the position of flagella - tiny tail like structures used by the algae for movement and feeding. This indicates these microscopic organisms, which survived the asteroid strike, were capable of hunting and ingesting food.

"Those species that were lost at the mass extinction show no evidence of a mixotrophic lifestyle and were likely to be completely reliant on sunlight and photosynthesis," explains Dr Samantha Gibbs of the University of Southampton. "Fossils following the Cretaceous-Paleogene (K-Pg) extinction show that mixotrophy dominated and our model indicates this is because of the exceptional abundance of small prey cells - most likely surviving bacteria - and reduced numbers of larger 'grazers' in the post-extinction oceans."

Opposing evolutionary forces led to the emergence of more diverse feeding strategies and eventually a return to greater reliance on photosynthesis in open ocean nannoplankton. Most nannoplankton today only photosynthesise.

So, what caused this devastating mass extinction of photoautotrophs and other species?

The simple answer is a lack of light. The K/Pg event was triggered by an asteroid impact that formed the Chicxulub crater in Mexico, and is well known for the extinction of dinosaurs, plesiosaurs, ammonites and many other groups.

"This huge impact flung vast amounts of debris, aerosols and soot into the atmosphere, causing darkness, cooling and acidification over days and years," says Paul Bown, Professor of Micropalaeontology at UCL. "The significant bias found in the nannoplankton extinctions - removal of open-ocean photoautotrophs but survival of mixotrophs that could hunt and feed - can only be fully explained by the darkness caused by the asteroid impact acting as a kill mechanism."

Samantha Gibbs adds: "This 'blackout' or shutdown of primary productivity would have been felt across all of Earth's ecosystems and reveals that the K/Pg event is distinct from all other mass extinctions that have shaped the history of life, both in its rapidity, related to an instantaneous impact event, and its darkness kill mechanism, which shook the foundations of the food chains.

"The K/Pg boundary event likely represents the only truly geologically instantaneous mass extinction event."

'This is pretty mind blowing'

Patients treated by highly skilled surgeons are more likely to survive long-term

Ask your surgeon how many similar procedures they have done

Colon cancer is one of most common in U.S.

CHICAGO --- Patients of more technically skilled surgeons, as assessed by review of operative video, have better long-term survival after surgery for the treatment of colon cancer, reports a new Northwestern Medicine study.

Patients whose surgery was performed by a highly skilled surgeon had a 70 percent lower risk of dying over five years compared to patients with a lower skilled surgeon, the study found.

"This is pretty mind blowing," said lead author Dr. Karl Bilimoria, professor of surgery at Northwestern University Feinberg School of Medicine and a Northwestern Medicine surgical oncologist. "The long-term effect is huge."

The paper will be published October 30 in JAMA Oncology and presented virtually at the Commission on Cancer Annual Meeting.

Although the importance of surgical skill has long been presumed, this is the first study, to the authors' knowledge, to demonstrate a surgeon's skill is important to long-term outcomes among patients undergoing cancer treatment surgery.

"It may seem common sense in some ways, but we didn't realize the magnitude of the effect," Bilimoria said. In a prior study the team conducted, there were 25% fewer short-term complications -- such as a colon leak or bleeding -- when a highly skilled surgeon performed the colon cancer operation.

Colon cancer is one of the most common cancers, with over 100,000 new cases diagnosed annually in the United States. In many cases, surgery is the primary treatment.

Bilimoria also is director of the Surgical Outcomes and Quality Improvement Center of Northwestern and a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

One possible reason for the difference is that a skilled surgeon may be more likely to remove lymph nodes that contain colon cancer, said study first author Dr. Brian Brajcich, a Northwestern surgical resident and research fellow.

"A less skilled surgeon may not remove as many lymph nodes, potentially leaving behind cancer," Brajcich said. "Patients who would benefit from chemotherapy after surgery won't receive it if we don't know that the cancer has spread to the lymph node."

How do you find a highly skilled cancer surgeon?

How do you find a highly skilled cancer surgeon? Ask about the number of similar procedures they have done, Bilimoria said.

"Lots of experience with the procedure is a good marker of skill," Bilimoria said. "General surgeons, colorectal surgeons and surgical oncologists all do colon cancer surgery, and there can be excellent cancer surgeons in each of those fields."

In the study, a surgeon's technical skill was scored based on review of video footage of colon surgery by other surgeons, including peers and expert reviewers. The outcomes of patients treated by surgeons with higher and lower skill scores were then compared.

Improving outcomes after surgery, especially cancer surgery, should include efforts targeting surgeons' technical skill. Comprehensive approaches to help surgeons improve their technical skill could include surgical coaching and the ability to review and discuss surgical video footage with peers and experts in the field.

Further research is needed to determine whether efforts to improve surgical skill lead to improved technical skills and patient outcomes. Additionally, the actual methods to improve surgical skill need to be advanced and studied to determine whether they are effective at improving patient outcomes.

Bilimoria acknowledged the small study size but said, "Even in this size study, we see a large impact."

People are significantly less likely to smoke - and are more likely to successfully quit - if they live in green neighbourhoods, new research has found.

The study is the first to demonstrate that access to neighbourhood greenspace is linked to lower rates of current smoking, and that this is due to higher rates of smoking cessation rather than lower uptake in these areas.

Researchers used data gathered through the Health Survey for England (HSE), conducted annually on behalf of the UK Office for National Statistics, and examined the responses of more than 8,000 adults to questions about their health, where they lived and various other lifestyle factors.

Of the HSE survey's respondents, just under one fifth (19%) described themselves as current smokers while almost half (45%) said they had regularly smoked at some point during their lives.

However, even after to taking into account other factors known to influence smoking, people living in areas with a high proportion of greenspace were 20% less likely to be current smokers than those in less green areas.

In addition, among people who had smoked at some point during their lives, those living in greener neighbourhoods were up to 12% more likely to have successfully quit smoking.

The authors suggest that improving access to greenspace may constitute an overlooked public health strategy for reducing smoking prevalence, especially given that smoking uptake and cessation are affected by stress.

Published in Social Science & Medicine, the research was led by psychologists from the University of Plymouth, the University of Exeter and the University of Vienna.

Previous studies by the same team have shown that being able to see green spaces from your home is associated with reduced cravings for alcohol, cigarettes and unhealthy foods. They have also demonstrated that individuals who visit natural spaces weekly, and feel psychologically connected to them, report better physical and mental wellbeing.

Leanne Martin, from the University of Plymouth, the lead author on all three studies, said: "This study is the first to investigate the association between neighbourhood greenspace and smoking behaviours in England. Its findings support the need to protect and invest in natural resources - in both urban and more rural communities - in order to maximise the public health benefits they may afford. If our findings are substantiated by further work, nature-based interventions could be prescribed to assist individuals attempting to give up smoking."

The research also examined whether the link between greenspace and smoking was affected by factors including socio-economic status and neighbourhood deprivation. No such impacts were found and the study's authors say this suggests that high greenspace neighbourhoods are independently associated with a lower prevalence of current smoking, irrespective of the socio-demographic characteristics of the individuals who reside in them.

Co-author Mathew White, Senior Scientist at the University of Vienna and Honorary Associate Professor at the University of Exeter, said: "Despite a decline in prevalence within the general population over the last decade, smoking remains a devastating and global public health issue. Governments across the world spend billions each year trying to tackle it, both in an attempt to improve public health and reduce the strain on health services. This study emphasises the need to preserve existing green spaces and expand the development of new ones."

Co-author Sabine Pahl, Professor of Urban and Environmental Psychology at the University of Vienna and Honorary Professor of Applied Social Psychology at the University of Plymouth, added: "While there is now considerable evidence that natural spaces are associated with stress reduction and better well-being, this is the first study to my knowledge to show that more greenspace is also linked to a reduction in unhealthy behaviours. This is intriguing and suggests that the benefits of natural green and blue spaces may reach even further than initially thought."

Ludwig-Maximilians-Universitaet (LMU) in Munich researchers have designed a light-sensitive inhibitor that can control cell division and cell death - and provides a promising approach for studies of essential cellular processes and the development of novel tumor therapies.

The ability to precisely control biological and chemical processes is an essential element of both basic research and medicine. Light represents an attractive stimulus in this context, as its effects can be accurately modulated both spatially and temporally. These desirable properties are the reason why the development of light-controllable molecules has become such an important goal for biological chemists. Such tools promise to make significant contributions to the elucidation of basic cellular functions, the detailed understanding of medical disorders and the design of new therapeutic strategies to combat them. A group of researchers led by cell biologist Esther Zanin at LMU's Biocenter, in cooperation with the chemist Henry Dube (who moved in April of this year from the LMU to the University of Erlangen-Nürnberg) has now developed a light-sensitive chemical inhibitor, that allows them to control two fundamental cellular processes, cell division and cell death, with light.

Cell division is a vital and highly complex process. It is therefore subject to tight regulation to ensure that cells divide only at the right time and error free. Defective cells are eliminated by programmed cell death (also known as 'apoptosis'). Both correct cell division and the disposal of defective cells depend on a molecular machine called the proteasome, which specifically degrades cellular proteins that are either damaged or no longer required.

"We have now modified an established and versatile chemical inhibitor of the proteosome by adding a light-sensitive protective group to it," says Zanin. "This group blocks the reactive aldehyde function of the inhibitor and prevents it from binding to the proteasome." In the dark, the inhibitor is therefore inactive and the proteasome functions normally. However, exposure of the cells to blue light detaches the protective group, thus allowing the inhibitor to interact with the proteosome and inhibit its function. Since the activating blue light radiation can be accurately targeted, the action of the inhibitor can be very precisely controlled. "By this means, we are able to arrest the division of tumor cells at a specific stage of the process, and to trigger apoptosis in a targeted manner," Zanin explains.

She and her colleagues believe that the new light-sensitive proteosome inhibitor will prove to be a valuable tool for the study of a wide range of dynamic cellular processes - for example, in the context of development, during which cells and tissues undergo rapid and often radical changes during a short time and at confined locations. In addition, proteosome inhibitors have promising applications as therapeutic agents - in the treatment of cancer, for instance. "The ability to activate these compounds specifically in both time and space could make them more efficacious in the future, while reducing the incidence of side-effects," says Zanin. However, reaching this goal will require further work, as the inhibitor employed in the new study is not suitable for medical use in its present form.

One year after the publication of research on the Xiahe mandible, the first Denisovan fossil found outside of Denisova Cave, the same research team has now reported their findings of Denisovan DNA from sediments of the Baishiya Karst Cave (BKC) on the Tibetan Plateau where the Xiahe mandible was found. The study was published in Science on Oct. 29.

The research team was led by Prof. CHEN Fahu from the Institute of Tibetan Plateau Research (ITP) of the Chinese Academy of Sciences (CAS), Prof. ZHANG Dongju from Lanzhou University, Prof. FU Qiaomei from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of CAS, Prof. Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology, and Prof. LI Bo from University of Wollongong.

Using cutting-edge paleogenetic technology, the researchers successfully extracted Denisovan mtDNA from Late Pleistocene sediment samples collected during the excavation of BKC. Their results show that this Denisovan group is closely related to the late Denisovans from Denisova Cave, indicating Denisovans occupied the Tibetan Plateau for a rather long time and had probably adapted to the high-altitude environment.

Denisovans were first discovered and identified in 2010 by a research team led by Prof. Svante Pääbo. Almost a decade later, the Xiahe mandible was found on the Tibetan Plateau. As the first Denisovan fossil found outside of Denisova Cave, it confirmed that Denisovans had occupied the roof of the world in the late Middle Pleistocene and were widespread. Although the Xiahe mandible shed great new light on Denisovan studies, without DNA and secure stratigraphic and archaeological context, the information it revealed about Denisovans was still considerably restricted.

In 2010, a research team from Lanzhou University led by Prof. CHEN Fahu, current director of ITP, began to work in BKC and the Ganjia basin where it is located. Since then, thousands of pieces of stone artifacts and animal bones have been found. Subsequent analysis indicated that the stone artifacts were mainly produced using simple core-flake technology. Among animal species represented, gazelles and foxes dominated in the upper layers, but rhinoceros, wild bos and hyena dominated in the lower layers. Some of the bones had been burnt or have cut-marks, indicating that humans occupied the cave for a rather long time.

To determine when people occupied the cave, researchers used radiocarbon dating of bone fragments recovered from the upper layers and optical dating of sediments collected from all layers in the excavated profile. They measured 14 bone fragments and about 30,000 individual grains of feldspar and quartz minerals from 12 sediment samples to construct a robust chronological framework for the site. Dating results suggest that the deepest excavated deposits contain stone artifacts buried over ~190 ka (thousand years). Sediments and stone artifacts accumulated over time until at least ~45 ka or even later.

To determine who occupied the cave, researchers used sedimentary DNA technology to analyze 35 sediment samples specially collected during the excavation for DNA analysis. They captured 242 mammalian and human mtDNA samples, thus enriching the record of DNA related to ancient hominins. Interestingly, they detected ancient human fragments that matched mtDNA associated with Denisovans in four different sediment layers deposited ~100 ka and ~60 ka.

More interestingly, they found that the hominin mtDNA from 60 ka share the closest genetic relationship to Denisova 3 and 4 - i.e., specimens sampled from Denisova Cave in Altai, Russia. In contrast, mtDNA dating to ~100 ka shows a separation from the lineage leading to Denisova 3 and 4.

Using sedimentary DNA from BKC, researchers found the first genetic evidence that Denisovans lived outside of Denisova Cave. This new study supports the idea that Denisovans had a wide geographic distribution not limited to Siberia, and they may have adapted to life at high altitudes and contributed such adaptation to modern humans on the Tibetan Plateau.

However, there are still many questions left. For example, what's the latest age of Denisovans in BKC? Due to the reworked nature of the top three layers, it is difficult to directly associate the mtDNA with their depositional ages, which are as late as 20-30 ka BP. Therefore, it is uncertain whether these late Denisovans had encountered modern humans or not. In addition, just based on mtDNA, we still don't know the exact relationship between the BKC Denisovans, those from Denisova Cave in Siberia and modern Tibetans. Future nuclear DNA from this site may provide a tool to further explore these questions.