Earth

Cormorant predation may reduce perch catches, especially close to breeding areas

image: Research was carried out in the Quark (Merenkurkku) in Finland.

Image: 
Picture: Luke/Lari Veneranta

The joint study of the Natural Resources Institute Finland (Luke) and University of Jyväskylä estimated the impact of cormorants breeding and living in Quark on perch populations and catches in the area. A large number of breeding cormorants in the important perch fishing and reproduction areas may reduce perch populations and catches especially in areas affected by breeding. On a larger spatial scale, the impact of cormorant predation is lower. The study was published in the ICES Journal of Marine Science in August 2020.

Since 2016, a large number of cormorants had breeding colonies in Quark. Their impact on perch populations was studied using Passive iIntegrated Transponder (PIT) tags in 2018, when 3,140 cormorant nests were calculated in the area. A total of 1,977 perch individuals were marked using small and invisible PIT tags placed under the skin.

"The PIT tags showed that a large number of breeding cormorants in a key perch fishing and reproduction area may reduce perch populations and catches locally. On a wider spatial scale, the impact of predation decreases. Overall, the large cormorant population in Quark may reduce the profitability of perch fishing, especially in the area affected by breeding colonies", says Lari Veneranta, research scientist at the Natural Resources Institute Finland (Luke).

Some nine per cent of the total number of the tags placed were found from colonies. These results help to determine that, during the whole breeding and migration period, cormorants caught at most 20 to 33 per cent of the tagged perch individuals, if the fish consumption of young individuals is included and if it is assumed that cormorants remained in the same area after breeding.

"Based on literature, we estimated that roughly half of all perch individuals consumed by cormorants and all the tags placed ended up in colonies during the breeding period. The tags were recovered well, and according to our tests, some 90 per cent of the tags found from breeding colonies were discovered using detection equipment", Veneranta says.

Cormorants were estimated to increase natural mortality in the tagged perch populations by seven to 26 percentage points. The growth rate of perch individuals affects how large a proportion of perch populations is caught by cormorants. The typical length of a perch individual eaten by a cormorant is 15 cm. On the basis of the determined age and growth of perch individuals, roughly half of perch individuals in the studied area remain small-sized, while the other half reach the fishing threshold size of 22 to 25 cm in three to four years. Small-sized individuals can be at risk of being caught by cormorants throughout their lives, while they are rarely at risk of being caught by fishermen.

In the 2,800 square-kilometre fisheries statistical rectangle surrounding the breeding colonies, the proportion of the biomass and production of perch individuals of more than two years consumed by cormorants was estimated to be roughly eight per cent, while other natural mortality accounted for 63 and fishing for 29 per cent. The impact of fish caught by cormorants migrating through the area was not included in the calculations.

The impact of cormorants on perch populations in Quark has been assessed in the long term

If perch populations decrease, cormorants will increasingly use other fish species. Other natural mortality will also decrease and the growth and reproduction rate of perch individuals may increase.

"These factors compensate for the decreasing impact of cormorants on perch populations, at least in part. The size of perch populations is mostly affected by environmental factors, such as the temperature during the first summer of young perch individuals", says Outi Heikinheimo, visiting specialist at Luke.

The long-term impact of cormorants on perch catches in the Quark has been assessed on the basis of the results of the PIT tag study and other available data. The aim is to take into account any uncertainties associated with the background data and their impact on results.

If the number of cormorants and the density of two-year-old perch individuals remained at the 2018 level in the long term, perch catches would decrease by at most 32 to 67 per cent in the predation area of breeding cormorants, assuming that perch populations do not migrate, young cormorants catch their food in the same area in which they nest and cormorants remain in the same area until they migrate. When generalised over a broader area, statistical rectangle, perch catches would decrease by at most ten to 33 per cent.

"Estimates of fish catches, expanded from test results, have broad probability distributions, as initial data about perch population dynamics, regional distribution and movements comprises rough estimates at best. Nevertheless, these probability distributions offer the best available data from 2018 regarding the maximum impact of cormorant populations on perch populations and catches in Quark", says Timo J. Marjomäki, lecturer in the Department of Biological and Environmental Science at the University of Jyväskylä.

Credit: 
University of Jyväskylä - Jyväskylän yliopisto

New research reveals effect of global warming on Greenland ice melt

image: Iceberg off Ammassalik Island, southeast Greenland.

Image: 
Professor Edward Hanna

New analysis of almost 30 years' worth of scientific data on the melting of the Greenland Ice Sheet predicts global sea level rise of at least 10 centimetres by the end of the 21st Century if global warming trends continue.

The estimates, which scientists warn are "conservative" given the powerful effects of changes in weather systems and possible ways of accelerating ice loss, are broadly consistent with recent predictions reported by the Intergovernmental Panel on Climate Change.

Professor Edward Hanna of the University of Lincoln, UK, led an international team involving Belgian, Danish, Swiss and American glaciologists and climatologists in the new study that quantifies the response of the Greenland Ice Sheet to climate change. Their findings are published in the International Journal of Climatology.

The Greenland Ice Sheet is a giant reservoir of ice that contains enough water to ultimately raise global sea-level by seven metres.

The researchers provide an updated analysis of Greenland surface air temperature data for the last three decades through to 2019, focusing mainly on coastal weather stations but also analysing records from relatively long-running sites on the interior plateau of the ice sheet. They found that Greenland coastal regions warmed significantly by about 4.4 degrees Celsius (degC) in winter and 1.7 degC in summer from 1991 to 2019. Their work, combining Greenland temperature data with computer model output of ice-sheet mass balance for 1972 to 2018, shows that each 1degC of summer warming corresponds to some 91 billion tonnes per year of surface mass loss and 116 billion tonnes per year of total mass loss from the ice sheet.

The research team then used some of the latest available global and regional climate modelling tools to estimate that, under sustained strong global warming (a "business as usual" scenario), Greenland is likely to warm 4.0 to 6.6 degC by the year 2100. These recent and projected future Greenland warmings are considerably greater than global temperature changes for equivalent time periods, reflecting a high sensitivity of the polar regions to climate change.

The scientists then used the relation they derived between recent changes in Greenland summer temperature and surface mass balance to calculate a 10 to 12.5 centimetres increase in global sea-level rise by 2100 arising from increased Greenland ice melt and surface mass loss.

Prof. Hanna's team also explored the relation between Greenland air temperature changes and a phenomenon called atmospheric high pressure blocking which involves a greater than normal mass of air sometimes positioned over Greenland. This relation is generally present but has strengthened in spring and summer in recent decades. The authors show Greenland blocking played a crucial role in the near-record Greenland melt in the summer of 2019 (narrowly surpassed by the all-time record in 2012), and point out that possible future changes in blocking need to be better considered in computer-model projections of climate change.

Prof. Hanna, Professor of Climate Science and Meteorology in Lincoln's School of Geography and Lincoln Centre for Water and Planetary Health, said "The Greenland Ice Sheet is one of the most sensitive and reliable measures of global climate change. Here we have used relatively simple statistical analysis of data and model output from the last 30 years as a sense-check on prediction of future ice-sheet surface mass change. Our work, which represents in part a major updated analysis of Greenland climate records, is highly interdisciplinary since it cross-cuts between climate science and glaciology, and so will help improve interpretation of recent ice-sheet changes."

Credit: 
University of Lincoln

Filling the void in ammonia synthesis: The role of nitrogen vacancies in catalysts

image: Nickel particles dissociate H2 to provide H atoms to either N atoms from the CeN crystal lattice itself or protruding N atoms from N2 molecules filling a nitrogen vacancy. In this study, it was found that CeN without Ni can also dissociate H2 molecules.

Image: 
2020 American Chemical Society

Scientists at Tokyo Institute of Technology (Tokyo Tech) explore how nitrogen vacancies in catalysts participate in the synthesis of ammonia, a pivotal chemical in the fertilizer industry. They devised a general rule for the smart design of nitride-based catalysts based on their nitrogen vacancy formation energy and created a high performing catalyst for ammonia synthesis using cerium, an abundant transition metal.

Ammonia (NH3) is a naturally occurring chemical in the environment, but its widespread use as an important ingredient in various manufacturing processes has made it one of the most produced chemicals. It is pivotal in the production of fertilizers and helps to increase the yield of various crops. Owing to its high demand, well over 150 million tons of NH3 are produced yearly. Not surprisingly, chemists have been actively looking for eco-friendly and energy-efficient ways of synthesizing NH3.

The conventional way to produce NH3 is by directly using nitrogen (N2) and hydrogen (H2) gases. But, breaking the strong bond between N atoms is challenging. This is where catalysts (materials that facilitate the necessary reactions) come into play. Unfortunately, today's best performing catalyst for NH3 synthesis requires ruthenium, a rare and expensive metal. In an effort to find alternatives, scientists from Tokyo Tech, including Dr. Tian-Nan Ye, Prof Masaaki Kitano, and Prof Hideo Hosono, have recently tried to find out exactly what makes a good catalyst for breaking N2 and producing NH3.

In a previous paper published in Nature , Hosono and colleagues had presented a novel strategy to produce NH3 that involved the use of lanthanum nitride (LaN) coupled with nickel (Ni) nanoparticles. The key contribution of this study was the realization that nitrogen vacancies play an important role in the catalytic process, which allowed them to design a La-based catalyst with a performance comparable to that of ruthenium-based ones. In a recent study, published in the Journal of the American Chemical Society , the research team took their findings even further and explored if the energy required to produce these nitrogen vacancies is what ultimately defines the performance of catalysts during NH3 production.

The nitrogen vacancies in the catalyst's surface can easily capture N2 and weaken its N-N bond, after which atoms dissociated from H2 at the Ni nanoparticles jump onto the protruding N atom to produce NH3. In addition, dissociated H atoms can also form NH3 directly using N atoms from the catalyst crystalline lattice itself, thus creating new nitrogen vacancies in the process. Following the success of their previous Ni/LaN catalyst, in this study, they created and compared similar catalysts with different nitrogen vacancy formation energies (ENV).

Among the catalysts tested, Ni-loaded cerium nitride (CeN) exhibited the best catalytic performance due to its relatively low ENV. The performance of the other materials tested was also directly related to their respective ENV. Excited about the results, Prof Hosono remarks, "We can now propose a general rule for the design of nitride-based catalysts for NH3 synthesis, in which their ENV dominates their catalytic performance." Most notably, the catalytic activity of Ni/CeN was comparable to that of ruthenium-based catalysts, representing a potential eco-friendly alternative made up of materials that are more abundant.

What's more, the team also noted that Ni loading on CeN was not even necessary; nitrogen vacancies in CeN can also trigger the dissociation of H2 molecules. "CeN by itself and with Ni loading were demonstrated to produce the most efficient and stable catalysts for ammonia synthesis among the different nitride catalysts we investigated," explains Ye. The team is hopeful that the insight gained from this study could be useful in applications other than ammonia synthesis too. Kitano concludes, "Understanding the role of nitrides may shed light on the design and development of efficient transition metal-based catalysts for other chemical processes."

Credit: 
Tokyo Institute of Technology

Long-term exposure to traffic noise may impact weight gain in the UK population

Transport noise is a major problem in Europe, with over 100 million people living in areas where road traffic noise exceeds levels greater than 55dB, the health-based threshold set by the EU. A new study by the University of Oxford and the University of Leicester has found a connection between traffic noise and obesity. Long-term exposure to road traffic noise, such as living near a motorway or on a busy road, was associated with an increase in body mass index and waist circumference, which are key markers of obesity. The study was published today in the journal Environmental Research.

'While modest, the data revealed an association between those living in high traffic-noise areas and obesity, at around a 2% increase in obesity prevalence for every 10dB of added noise,' says lead author Dr Samuel Yutong Cai, a senior epidemiologist at the University of Oxford. 'The association persisted even when we accounted for a wide range of lifestyle factors, such as smoking, alcohol use, physical activity and diet, as well as when taking into account socio-economic status of both individuals and the overall area. Air pollution was also accounted for, especially those related to traffic.'

This is the largest study to date on noise and obesity, looking at data on over 500,000 people from three European biobanks in the UK, Norway and the Netherlands. Links between noise and weight were found in the UK and Norway, but not the Netherlands cohort. While the study is unable to confirm a causal relationship, the results echo those from a number of previous studies conducted in other European countries.

'It is well-known that unwanted noise can affect quality of life and disturb sleep,' says co-author Professor Anna Hansell, Director of the University of Leicester's Centre for Environmental Health and Sustainability. 'Recent studies have raised concerns that it also may influence general health, with some studies suggesting links to heart attacks and diabetes. Road traffic noise may increase stress levels, which can result in putting on weight, especially around the waist.'

'On the individual level, sticking to a healthy lifestyle remains a top strategy to prevent obesity,' says Dr Cai. 'However, at the population level, these results could have some policy implications. Environmental policies that target reducing traffic noise exposure may help tackle many health problems, including obesity.'

Led by Professor Hansell, work is ongoing to investigate other sources of noise in the UK, such as aircraft noise, and its effect on health outcomes. In the future, long-term follow-up studies would be valuable in providing more information on how the relationship between noise and weight functions.

'As we emerge and recover from COVID-19, we would encourage the government to look at policies that could manage traffic better and make our public spaces safer, cleaner and quieter,' says Dr Cai. 'Air pollution is already a well-known health risk, but we now have increasing evidence that traffic noise is an equally important public health problem. The UK should take this opportunity to think about how we can, as a society, re-organise cities and communities to support our health and reap better health outcomes across the whole population.'

Credit: 
University of Oxford

New research will improve early warning of devastating megastorms

image: Intense dust storms, such as this haboob in Mali in August 2006, proceed torrential rain

Image: 
Françoise GUICHARD / Laurent KERGOAT / CNRS Photo Library

Ground-breaking scientific research will make it easier to predict the path of some of the world's most powerful storms, enabling communities to better protect themselves from severe flooding.

Mesoscale convective systems (MCSs) are 'megastorms' that affect large parts of the world, including Africa, Australia, Asia and the Americas, causing human and livestock deaths plus major damage to infrastructure. They can potentially:

last from several hours up to two days

release energy equivalent to the UK consumption for an entire year

be bigger than the size of England and travel 1,000kms in distance

unleash over 100mm of rainfall in just an hour

In Sahelian Africa, these extreme storms have tripled in frequency since the 1980s due to global warming.

Until now, it was thought that the path of these complex weather systems was largely unpredictable.

However, a new study by the UK Centre for Ecology & Hydrology (UKCEH) has found that land surface conditions frequently affect the direction and intensity of megastorms after they have formed.

The research is now helping scientists to develop online tools to better forecast the path and strength of an approaching storm, which will inform alert systems for communities across Africa, providing them with up to six hours' warning. This includes Senegal, where UKCEH is working with the national meteorological service, ANACIM, to see how useful very short-term forecasts are for local emergency responses.

The new study, published in the journal PNAS, was funded by the Department for International Development (DFID) and Natural Environment Research Council (NERC) as part of the UK aid Future Climate for Africa research programme.

The researchers looked at satellite data on the activity of thousands of storms, plus land temperatures, in the Sahel for the period 2006 to 2010.

Lead author Dr Cornelia Klein of UKCEH explains: "It is well known that heat provides thunderstorms with great energy, but it was commonly thought that once they are moving, they were not affected by the state of the ground over which they travelled.

"However, we found that drier soils increased the intensity of an MCS mid-storm, affecting the amount of rainfall they release and also where they travel. Conversely, we found storms were often weakened over moister soils."

"Our finding means that, for the first time, we can predict, from satellite-observed surface conditions, how these extremely large West African storms may behave when, for example, they approach a city. A more effective alert system will enable local people to take action to protect themselves as well as their homes, livestock and possessions, plus plan emergency responses."

Flash flooding frequently occurs during the storm season in the Sahel, peaking between June and September, and can have a serious impact, with water entering homes and people losing property and a safe, dry space to live. Flooding can also cause sewage overflow from inadequate drainage systems, posing a health risk to humans and animals.

The study's authors say the results have important implications for 'nowcasting' (forecasting for several hours ahead) of severe weather not just in the Sahel, but potentially other MCS hotspot regions of the world.

Professor Chris Taylor of UKCEH, co-author of the new paper, adds: "The pattern of these megastorms is supposed to be difficult to forecast but we found a surprising level of predictability. Very dry soils influenced around half of storms in late afternoon or early evening, when they are at their peak.

"Further research and advances in satellite technology will increase our certainties about their movement. In decades to come, scientists will look back at this latest study as a gamechanger in the reliable forecasting of these devastating storms."

The research is part of the UKCEH-led AMMA-2050 project, which is carrying out multidisciplinary climate research to support improved forecasting, in order to enable better decision making by town planners, farmers and communities. Comprising partners from Europe and West Africa, it is funded by DFID and NERC.

A DFID spokesperson said:

"Highly destructive megastorms are becoming much more common because of climate change. They can devastate entire communities and it is the world's poorest people who are most at risk.

"UK aid is supporting ground-breaking research, led by British experts, to better anticipate storms so vulnerable African communities can better prepare for their impact, protecting themselves and their families, and making their economies more resilient to climate shocks."

NOTES TO EDITORS

Paper information

Cornelia Klein and Christopher M Taylor. 2020. Dry soils can intensify mesoscale convective systems. Proceedings of the National Academy of Sciences (PNAS). DOI: 10.1073/pnas.2007998117

Recent flooding events in West Africa

Due to heavy flooding in the countries of Niger and Mali since June 2020, 19 people are reported to have died and 35 injured, with 2,244 houses destroyed. An estimated 112,452 people are at risk of being affected by floods in Mali this year, compared to 95,000 people last year. During the rainy season in Niger in 2017, estimated 200,000 people were affected by flooding in the country, with 56 deaths. About 12,000 houses were damaged and 16,000 heads of cattle died and 9,800 hectares of cultivated land lost.

In late July 2020, it was reported at least seven people died in flooding in the Niger state in central Nigeria, while 15,000 people were displaced in northern Nigeria in the first week of August after flooding damaged homes.

Ouagadougou, capital of Burkina Faso, has been regularly hit by flash flooding in recent years. In July 2020, crocodiles were seen in the streets after torrential rain forced them from their habitat at a nearby city park.

Thousands of people were displaced in northern Burkina Faso in mid-June 2020 after shelters were damaged there. Ouagadougou, the country's capital, has been regularly hit by flash flooding in recent years. In 2009, a downpour of 263mm over several hours forced 150,000 residents to leave their homes and eight people were killed. Within a few weeks in mid-2016, heavy rain and strong winds caused flash floods, leaving 15 dead and severely affecting healthcare facilities.

In 2012, there was over 140mm of rainfall within a single hour in Dakar area of Senegal, producing floods which affected more than 250,000 people, with 26 deaths. Similar flooding in the Dakar region in 2009 affected an estimated 30,000 houses, with losses of US $82m.

Credit: 
UK Centre for Ecology & Hydrology

Targeted therapy combination effective for patients with advanced cholangiocarcinoma and BRAF mutations

image: Vivek Subbiah, M.D.

Image: 
The University of Texas MD Anderson Cancer Center

HOUSTON -- In a Phase II trial led by researchers at The University of Texas MD Anderson Cancer Center, the combination of dabrafenib, a BRAF inhibitor, and trametinib, a MEK inhibitor, achieved a 51% overall response rate (ORR) in patients with cholangiocarcinoma marked by the BRAF V600E mutation.

This trial represents the first prospective study for patients with BRAF-mutated cholangiocarcinoma, or bile duct cancer, and suggests this targeted therapy combination could serve as a much-needed treatment option for patients with treatment-resistant advanced disease. The trial results were published today in Lancet Oncology.

"In this study, we saw that the dabrafenib and trametinib combination demonstrates clinical benefit and should be considered as a therapeutic option for these patients ," said lead author Vivek Subbiah, M.D., associate professor of Investigational Cancer Therapeutics. "These findings also reinforce the need for routine testing of BRAF mutations in patients with biliary tract cancers. As we move forward with precision oncology, we're seeing that alterations present in these rare cancers are actionable and the patients do benefit from targeted therapies."

This study is part of an ongoing Phase II, open-label, multicenter trial testing the efficacy and safety of the combination therapy in patients with a variety of BRAF V600E-mutated rare cancers. The bile duct cohort enrolled 43 patients, all of whom had received at least one prior line of therapy.

Trial participants were 91% Caucasian, 5% Asian (Japanese heritage), 2% Asian (East Asian heritage) and 2% white (Arabic/North African). The median age was 57, with women accounting for 56% and men 44% of participants.

Bile duct cancer is a rare disease diagnosed in about 8,000 people each year in the U.S. Most cases are diagnosed at advanced stages, and thus clinical outcomes are generally poor, with a five-year survival rate below 20%. Standard of care includes surgery, when possible, and chemotherapy.

In patients with advanced disease, median overall survival with chemotherapy treatment is less than one year, so there is a significant unmet need for effective new treatment approaches, explained Subbiah.

Mutations in the BRAF gene are found in 5-7% of those diagnosed with bile duct cancer, and patients with the BRAF V600E mutation are more likely to have poor outcomes. Trials with single-agent therapies targeting BRAF have been effective for treating these patients, but have shown significant toxicities, including secondary malignancies.

However, combining these agents with MEK inhibitors, which act downstream in the same signaling pathway, have proven effective and are FDA-approved for use in other cancer types, including melanoma, lung cancer and anaplastic thyroid cancer. These agents are not currently approved by the FDA to treat cholangiocarcinoma.

In the current trial, the combination therapy achieved an ORR of 51% (22 patients) according to investigator assessments. The median duration of response was 8.7 months, with seven patients seeing an ongoing response beyond 12 months.

Median progression-free survival was 9.1 months and median overall survival was 13.5 months, with 56.4% and 35.8% of patients still alive at 12 months and 24 months, respectively.

All patients experienced at least one adverse event, with the most common being fever, nausea, vomiting, diarrhea and fatigue. Twenty-four patients (56%) experienced a Grade 3 or 4 adverse event, the most common of which was an increase in gamma-glutamyltransferase, an enzyme found in the liver and bile ducts. According to the authors, these side effects were consistent with those seen previously from this combination in other cancer types.

"The trajectory of cholangiocarcinoma is changing rapidly," said co-author Milind Javle, M.D., professor of Gastrointestinal Medical Oncology. "Targeted therapy has made meaningful inroads, and this study is an excellent example of that. This is an important development for patients with cholangiocarcinoma and BRAF V600E mutations, who often have limited treatment options."

This research was supported by GlaxoSmithKline and Novartis. Co-authors from MD Anderson include Milind Javle, M.D., of Gastrointestinal Medical Oncology. A full list of co-authors and disclosures can be found with the full paper here.

Credit: 
University of Texas M. D. Anderson Cancer Center

Wearable sensors printed on natural materials analyze substances present in sweat

image: Applied to skin as a piece of sticking plaster, the device developed by Brazilian researchers can be used to monitor human metabolism and administer drugs.

Image: 
Robson Rosa da Silva

A wearable sensor printed on microbial nanocellulose, a natural polymer, has been created in Brazil by researchers at the University of São Paulo (USP) in São Carlos in collaboration with colleagues at São Paulo State University (UNESP) in Araraquara, the University of Araraquara (UNIARA), the University of Campinas (UNICAMP), and the Brazilian National Nanotechnology Laboratory (LNNano).

The skin-adherent sensor is an improved substitute for conventional sensors printed on plastic surfaces. It can be used for noninvasive detection and monitoring of body fluids present in sweat.

The study was led by Osvaldo Novais de Oliveira Junior and supported by FAPESP via the projects “Printed and implantable biosensors made from biopolymers for long-term monitoring”, “Design and fabrication of nanostructured flexible devices for biomarker detection” and “Development of analytical tools based on electronic tongues for simultaneous detection of bacterial threats”, as well as a Multiuser Equipment grant.

The article titled “Microbial nanocellulose adherent to human skin used in electrochemical sensors to detect metal ions and biomarkers in sweat” is published in the journal Talanta.

“Microbial nanocellulose is a 100% natural polymer. It is produced by bacteria from sugar. Its main advantage over plastic is its far better interface with human skin. It’s been commercially available for some years for use in wound dressings, among other applications, but it had never before been studied as an electrochemical sensor substrate,” said Robson Rosa da Silva, a co-first author of the article.

One of the problems with wearable sensors on plastic substrates is that perspiration forms a barrier between the skin and sensor, hindering detection and promoting allergies. “Nanocellulose is totally breathable, enabling sweat to reach the electrode’s active layer,” Silva said.

The sensor is a small adhesive rectangle 1.5 cm in length by 0.5 cm in width and is as thin as a sheet of tissue paper. It can detect a range of biomarkers, such as sodium, potassium, uric acid, lactic acid and glucose, among others. “These elements or substances circulate in the bloodstream and are also detectable in sweat. Therefore, diabetes monitoring is one possible application of the nanocellulose sensor. Another is hormone control in women via detection of the hormone estradiol,” Silva said.

The device can also be used to detect the presence of atmospheric pollutants in organisms. “As proof of concept, we exposed the sensor to low levels of toxic metals such as lead and cadmium, and the result was positive,” he said.

The detection units are printed on the microbial nanocellulose substrate using a semiautomatic screen printer and a paste with a high concentration of carbon particles. Carbon is preferred owing to its significant electrical conductivity. “Chemical oxidation-reduction reactions produce an electrical signal that measures the concentration of the metabolite of interest,” explained Paulo Augusto Raymundo Pereira, the other co-first author of the article.

“The sensor is connected to a potentiostat that makes electrochemical measurements by means of variations in the electric current. The data obtained are transmitted to a computer and converted into standard curves.”

According to Pereira, wireless communication between the sensor and a data measuring and reading device can easily be engineered.

The researchers are now studying the use of the sensor to administer drugs and are working on ways of making it commercially feasible. The first phase of the project “Fabrication of screen printed electrodes on biodegradable substrates (nanocellulose and onion films Allium cepa L.) for medical, food and agroindustrial applications”, conducted by Biosmart Nanotechnology, was supported by FAPESP’s Innovative Research in Small Business (PIPE) Program.

Credit: 
Fundação de Amparo à Pesquisa do Estado de São Paulo

Equatorial winds ripple down to Antarctica

image: Lidar shooting into the Antarctic night sky, Arrival Heights Observatory.

Image: 
Danny Hampton, Ian Geraghty, Zimu Li

A CIRES-led team has uncovered a critical connection between winds at Earth's equator and atmospheric waves 6,000 miles away at the South Pole. The team has found, for the first time, evidence of a Quasi-Biennial Oscillation (QBO)--an atmospheric circulation pattern that originates at the equator--at McMurdo, Antarctica.

The discovery highlights how winds in the deep tropics affect the remote South Pole, in particular the polar vortex, which can trigger outbreaks of cold weather patterns in mid latitudes. Scientists will be able to use this information to better understand the planet's weather and climate patterns and fuel more accurate atmospheric models, the authors say.

"We have now seen how this atmospheric pattern propagates from the equator all the way to the high latitudes of Antarctica, showing how these far-away regions can be linked in ways we didn't know about before," said Zimu Li, a former CIRES research assistant who did this work at the University of Colorado Boulder, and lead author of the study out today in the Journal of Geophysical Research: Atmospheres.

"This can better our understanding of how large-scale atmospheric circulation works, and how patterns in one area of the world can ripple across the entire globe," said Xinzhao Chu, CIRES Fellow, professor in the Ann & H.J. Smead Department of Aerospace Engineering Sciences at the University of Colorado Boulder, and corresponding author on the new work.

Every two years or so, the QBO causes the stratospheric winds at Earth's equator to switch direction, alternating between easterly and westerly. Lynn Harvey, a researcher at CU's Laboratory for Atmospheric and Space Physics (LASP) and a coauthor on the study, helped the team study the polar vortices, the massive swirls of cold air that spiral over each of Earth's poles. The study reports that the Antarctic vortex expands during the QBO easterly phase and contracts during the westerly phase. The team suspects that when the QBO changes the polar vortex behavior, that, in turn, affects the behavior of atmospheric waves called gravity waves, which travel across different layers of the atmosphere. They identified specific kinds of changes in those gravity waves: The waves are stronger during the easterly period of the QBO and weaker when the QBO is westerly.

For the last nine years, members of Chu's lidar team have spent long seasons at McMurdo Station, Antarctica, braving 24-hour darkness and frigid temperatures to operate custom lasers and measure patterns in Earth's atmosphere. These long-term measurements, along with 21 years of NASA MERRA-2 atmospheric records, were critical to the new findings. Each QBO cycle takes years to complete, so long-term data streams are the only way to identify interannual connections and patterns.

"Atmospheric scientists can use this information to improve their models--before this nobody really knew how QBO impacts gravity waves in this polar region," said Xian Lu, researcher at Clemson University and a coauthor on the study. "Researchers can use this information to better model and predict climate, including the variability of atmosphere and space and long-term change."

Credit: 
University of Colorado at Boulder

COVID-19 hospitalizations analysis shows disparities across racial and ethnic groups

Adding to mounting evidence of COVID-19’s disproportionate impact on some U.S. communities, a new analysis of hospitalization rates from the University of Minnesota shows Black, Hispanic, American Indian and Alaskan Native populations in the United States are significantly more likely to be hospitalized due to COVID-19 than whites.

Published today in JAMA Internal Medicine, researchers from the U of M’s Carlson School of Management found significant disparities among racial and ethnic groups after reviewing nearly 49,000 COVID-19 hospitalizations over a two-month period in the 12 U.S. states that report such data for hospital patients.

“The unique clinical, financial and social impacts of COVID-19 on racial and ethnic populations that are often systematically marginalized in our society must be well understood in order to design and establish effective and equitable infrastructure solutions,” said Pinar Karaca-Mandic, professor and academic director of the Medical Industry Leadership Institute in the Carlson School, and study’s lead author. Soumya Sen, an associate professor in the Carlson School, is a study co-author.

The study found that, when compared to the populations of each state, people identified as being:

African American or Black were hospitalized at higher rates than those who were white in all 12 states reporting data, with Ohio (32% hospitalizations, 13% population), Minnesota (24.9% hospitalizations, 6.8% population), and Indiana (28.1% hospitalizations, 9.8% population) having the largest disparities;
Hispanic were hospitalized at higher rates than those who were white in 10 of the 11 states reporting this data, with Virginia (36.2% hospitalizations, 9.6% population), Utah (35.3% hospitalizations, 14.2% population) and Rhode Island (33% hospitalizations, 15.9% population) with the largest disparities;
American Indian and/or Alaskan Native were hospitalized at higher rates than whites in the eight states reporting data, including in Arizona where this population accounted for 15.7% of the hospitalizations, but only 4% of the state’s population.

Researchers note the disparities found in other population groups are largely reversed among Asian communities. In six of the 10 states that reported data for this group, the proportion of hospitalizations was lower relative to their population representation. In Massachusetts, for example, individuals who identify as Asian comprise 7% of the population but only 4% of the COVID-19 hospitalizations.

“Our findings highlight the need for increased data reporting and consistency within and across all states,” said Archelle Georgiou, M.D., chief health officer at Starkey Hearing Technologies and study co-author. “The fact that only 12 of 50 states report this type of information clearly shows there is more to learn about why non-whites are being hospitalized at such higher rates than whites.”

While consistent with previous analyses from the Centers for Disease Control and Prevention and others, this study does not adjust for age, sex, comorbidities and socioeconomic factors within each race and ethnic group that are likely related to COVID-19 hospitalizations.

The data used was extracted from the University of Minnesota COVID-19 Hospitalization Tracking Project, for a period between April 30 and June 24, 2020. Researchers calculated the percentage of cumulative hospitalizations by race and ethnic categories averaged over the study period and calculated the difference from the corresponding percentage of the state’s population accounted by each race and ethnic subgroup as reported in the U.S. Census. The 12 states included in the analysis were: Arizona, Indiana, Kansas, Massachusetts, Minnesota, New Hampshire, Ohio, Oregon, Rhode Island, Utah, Virginia, and Washington.

Credit: 
University of Minnesota

Photo and collage by Elle Starkman/PPPL Office of Communications

image: Physicists Ahmed Diallo, left, and Julien Dominski shown with collage of DIII-D tokamak.

Image: 
Photo and collage by Elle Starkman/PPPL Office of Communications.

Picture strong wind blowing against a tree until it’s knocked down. Such action would mimic the process that causes damaging heat bursts called edge localized modes (ELMs) to flare up in fusion facilities called tokamaks, which scientists use to develop on Earth the fusion energy that powers the sun and stars. Such heat bursts normally occur when the pressure at the edge of the hot plasma gas that fuels fusion reactions reaches a peak, causing heat to erupt against the walls of the tokamak, much like a tree finally toppling in a growing wind.

However, researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) recently found that the heat bursts sometimes can occur during the recovery from eruptions — providing fresh insight into what triggers the bursts. The findings, based on data collected from past experiments on the DIII-D National Fusion Facility that General Atomics operates for the DOE in San Diego, California, could help tame the potentially damaging processes.

Network of waves

“Piecing the dots together, we found that a network of interacting waves suddenly plays a role in the ELMs process during recovery,” said Julien Dominski, a PPPL physicist and lead author of a paper describing the results in Plasma Physics and Controlled Fusion. “These waves come together and abruptly exchange energy,” Dominski said, “causing the ‘pedestal’ at the edge of the plasma to crash and release bursts of heat.”

This network, which consists of triads of waves, is key to the triggering, Dominski said. “Sometimes the network can be excited without causing the abrupt crash,” he said. “This enabled us to look into the physics governing this new picture.”

The findings grow from efforts to reproduce fusion reactions that combine light elements in the form of plasma — the state of matter composed of free electrons and atomic nuclei that makes up 99 percent of the visible universe — to generate massive amounts of energy in the sun and stars. Tokamaks are the most popular devices that scientists around the world use in experiments to capture and control fusion energy, hoping to create a virtually inexhaustible supply of safe and clean power to generate electricity.

Emerging picture

“The new findings are an emerging picture for the triggering mechanism of ELMs,” said Ahmed Diallo, a PPPL physicist and co-author of the paper. “Discovering this network opens a new chapter in the study of ELMs.”

Coinciding with these networks, the physicists found, are perturbations at the edge of the plasma caused by a device called a neutral beam injector (NBI) that is used to heat and fuel the plasma. The millisecond intervals between NBI perturbations correspond with the intervals between network occurrences, the scientists noticed. “Making this connection was exciting and gave us an insight into a new way to trigger ELMs,” the authors said.

The researchers next aim to conduct experiments to study how triggers for ELMs may vary and test the use of NBI beams to control the bursts. Support for this research comes from the DOE Office of Science.

Credit: 
DOE/Princeton Plasma Physics Laboratory

Targeting iron uptake to create a new class of antibiotics against UTIs

WASHINGTON, Aug. 17, 2020 -- At 11 million cases annually, urinary tract infections (UTIs) are the most common outpatient infections in the U.S., according to the U.S. Department of Health and Human Services. At least half of all women will have a UTI during their lifetimes, and many of the infections -- which have increasingly become resistant to a wide array of antibiotics -- recur. Now, researchers report early progress toward developing a new class of antibiotics that would fight these infections by starving the causative bacteria of iron.

The researchers will present their results today at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo. ACS is holding the meeting through Thursday. It features more than 6,000 presentations on a wide range of science topics.

"You can't stop bacteria from evolving and developing resistance to antibiotics," says Mary Rose Ronquillo, an undergraduate student who works in the lab of Scott C. Eagon, Ph.D. "The aim of our research is to develop a drug that acts in a different way from current drugs -- by depriving the bacteria of iron, a key nutrient essential to their survival."

Currently, most drugs that treat UTIs caused by uropathogenic E. coli (UPEC) either disrupt synthesis of the bacterial cell wall or interfere with bacterial DNA replication. Since the urinary tract is an iron-deficient environment, UPEC have evolved several ways to obtain iron, such as by producing molecules called siderophores that sop up iron bound to host proteins.

The researchers, who are at California Polytechnic State University, have collaborated on this project with other scientists at the University of Michigan School of Medicine. The collaborators previously showed that the iron acquisition process can be a target for small molecules for possible UTI treatment. In that study, they screened nearly 150,000 compounds and identified 16 that stop these bacteria from growing under iron-limiting conditions. Of these 16, two compounds were linked to disruption of the bacterial TonB system, which consists of three transmembrane proteins that help UPEC take up iron. Eagon's group is focusing on these two compounds for further study.

"We selected one of these compounds as a scaffold to modify into potential small molecule inhibitors of the TonB system," M. Cole Detels, an undergraduate student in Eagon's lab, explains. The molecule is called 2-{[(3-chloro-4-methoxyphenyl)amino]methyl}quinolin-8-ol, or more simply, the "hydroxyquinoline scaffold."

After they made the scaffold molecule, Detels and Ronquillo prepared five variations, and another three are now in the purification stage. "While the synthesis of the potential drugs is relatively straightforward, purifying them from the soup of other chemicals used in their preparation has been challenging," Detels says.

The team says that the goal is to prepare a library of inhibitors in which the hydroxyquinoline scaffold is modified with various functional groups. "With this library in hand, we will work with our collaborators to screen them against UPEC and human cell lines to look for broad toxicity," Eagon says. "After that, the compounds will be tested in animal models to see if they kill the bacteria in vivo." Once Eagon's team finishes preparing the complete hydroxyquinoline library, they plan to make variations of the second scaffold molecule.

Because they target iron uptake, this new class of drugs is expected to have no effect on beneficial E. coli strains in other regions of the body. Iron is plentiful in the body in non-urinary tract locations, so hindering iron uptake shouldn't cause a problem for these bacteria. Most current antibiotics, however, wipe out all strains, including beneficial gut flora. And because there is no TonB homolog found in humans, the possibility of toxic side effects would also be reduced compared to other antibiotics.

Credit: 
American Chemical Society

Half of parents report butting heads with child's grandparent over parenting

image: Clashes over parenting choices and enforcing parents' rules can cause major strife between a child's parents and grandparents, a national poll suggests.

Image: 
C.S. Mott Children's Hospital National Poll on Children's Health at Michigan Medicine.

ANN ARBOR, Mich. -- Cookies for breakfast, staying up late and maybe a little more TV than usual.

For some families, what happens at grandma's house stays at grandma's house.

But for others, clashes over parenting choices and enforcing parents' rules can cause major strife between a child's parents and grandparents, a national poll suggests.

Nearly half of parents describe disagreements with one or more grandparent about their parenting, with one in seven going so far as to limit the amount of time their child sees certain grandparents, finds the C.S. Mott Children's Hospital National Poll on Children's Health at Michigan Medicine.

Disputes most commonly involve discipline (57 %), meals (44 %), and TV/screen time (36 %.) Other thorny subjects: manners, safety and health, bedtime, treating some grandchildren differently than others and sharing photos or information on social media.

"Grandparents play a special role in children's lives and can be an important resource for parents through support, advice and babysitting. But they may have different ideas about the best way to raise the child and that can cause tension," says Mott Poll co-director Sarah Clark.

"If grandparents contradict or interfere with parenting choices, it can have a serious strain on the relationship."

The nationally representative survey is based on 2,016 responses from parents of children ages 18 and under.

Discipline was the biggest source of contention. Among parents who report major or minor disagreements, 40% say grandparents are too soft on the child, and 14% say grandparents are too tough.

Nearly half of parents say disagreements arise from grandparents being both too lenient and overly harsh.

"Parents may feel that their parental authority is undermined when grandparents are too lenient in allowing children to do things that are against family rules, or when grandparents are too strict in forbidding children to do things that parents have okayed," Clark says.

Some disagreements may stem from intergenerational differences, Clark says. For example, grandparents may insist that "the way we used to do things" is the correct way to parent. New research and recommendations on child health and safety may also lead to disagreements if grandparents refuse to put babies to sleep on their back or do not use a booster seat when driving grandchildren to preschool.

In many cases, parents have tried to get grandparents to be more respectful of their parenting choices and household rules. These requests have mixed results: while about half of grandparents made a noticeable change in their behavior to be more consistent with how parents do things, 17 % outright objected.

"Whether grandparents cooperated with a request or not was strongly linked to parents' description of disagreements as major or minor," Clark says. "The bigger the conflict, the less likely grandparents were to budge."

Parents who said that grandparents refused such a request were also more likely to put limits on the amount of time their child spent with them.

"Parents who reported major disagreements with grandparents were also likely to feel that the conflicts had a negative impact on the relationship between the child and the grandparent," Clark says.

"These findings indicate that grandparents should strive to understand and comply with parent requests to be more consistent with parenting choices - not only to support parents in the difficult job of raising children, but to avoid escalating the conflict to the point that they risk losing special time with grandchildren."

Credit: 
Michigan Medicine - University of Michigan

Anschutz researchers overturn hypothesis underlying the sensitivity of the mammalian auditory system

AURORA, Colo. (August 14, 2020) - A new study from the University of Colorado Anschutz Medical Campus challenges a decades-old hypothesis on adaptation, a key feature in how sensory cells of the inner ear (hair cells) detect sound.

The paper, out today in Science Advances, examines how hair cells transform mechanical forces arising from sound waves into a neural electrical signal, a process called mechano-electric transduction (MET). Hair cells possess an intrinsic ability to fine-tune the sensitivity of the MET process (termed adaptation), which underlies our capacity to detect a wide range of sound intensities and frequencies with extremely high precision. Up until now, 30+ years of research had convinced auditory scientists that the molecules and proteins responsible for adaptation have been figured out. First published in 1987, the prevailing model for how adaptation works asserted that the sound-sensitive "antenna" of the hair cell (called the hair bundle) undergoes a mechanical change during adaptation, such that a decrease in stiffness of the hair bundle caused a decrease in MET sensitivity.

Ancillary experiments conducted over the ensuing decades have suggested that a motor protein, myosin 1c, is required for MET adaptation. Through multiple experiments and a variety of controls, Anschutz researchers determined that this existing hypothesis needs to be reexamined; that although adaptation does require myosin motors, it does not involve a mechanical change in the hair bundle.

Anschutz researchers performed a series of sophisticated experiments to examine the relationship between the mechanical properties of the hair bundle and the electrical response of the hair cell. Using a custom-built high-speed imaging technique, Giusy Caprara, PhD, post-doctoral fellow at the University of Colorado School of Medicine and lead author of the study, performed simultaneous electrical recording and imaging of hair cells in a variety of mammalian species at 10,000 frames per second to examine the mechanical changes to the hair bundle during adaptation, an extreme departure from the experiments of 1987 which used photodiodes. "The reason this wasn't uncovered earlier is because there are very few experiments that tested the mechanical properties of the hair bundle," says Anthony Peng, PhD, supervising author and assistant professor of physiology and biophysics at the University of Colorado School of Medicine. "Technology drove and made this discovery possible."

Understanding the mechanism of adaptation is important for determining how the sensory cells of the inner ear work. While the research is not directly translational, it is an important first step in fixing and replacing cochlear function, potentially leading to technological improvements for better sound processing and treatment of hearing dysfunction down the line.

"The discovery that the original model of adaptation was incorrect is important in a couple of ways," says Peng. "In basic science, this has opened avenues for more research, including proposing a new model of how adaptation works. More importantly, hearing sensitivity and the range of hearing we are able to achieve relies on this process, so understanding this will help us better understand different types of hearing loss people experience."

Credit: 
University of Colorado Anschutz Medical Campus

How people and ecosystems fit together on the Great Barrier Reef

image: Issuing permits for human activities at larger scales than the particular individual marine features of interest, such as reefs or islands, is part of effective management.

Image: 
Graeme Cumming

A world-first study examining the scales of management of the Great Barrier Reef has the potential to help sustain other ecosystems across the world.

Massive marine ecosystems like the Great Barrier Reef aren't just a vibrant home to fish, corals and other creatures, they are also an important source of people's food, livelihoods and recreation.

The new study suggests the way people are managed when undertaking various activities within the marine park--like fishing, boating, and scientific research--could serve as an exemplary model for sustainably managing other ecosystems that humans use.

"There is plenty of evidence to suggest that the Great Barrier Reef is managed at appropriate scales within its boundaries," said lead author Professor Graeme Cumming, incoming Director of the ARC Centre of Excellence for Coral Reef Studies.

The reef served as a case study for mapping and measuring different scale matches between people and ecosystems. Prof Cumming explains the concept of scale matches using a backyard garden as an example of an ecosystem.

"For a house with a garden, you already have permission to manage that garden--to mow the lawn and trim the trees inside your fences. To look after all the parts of it. That's a scale match," Prof Cumming said.

He says being able to manage only a flower bed within the garden is a small-scale match. "If you only have permission to manage the flower bed in your garden, you can manage the flowers, but your lawn and trees become unkempt. The weeds and pests affecting the flowers may come from an adjacent part of the garden, which you'd then have no control over," he said.

The Great Barrier Reef Marine Park Authority (GBRMPA) manages the entire marine park. Some permits, such as permission to access areas by boat as part of a commercial operation, may cover most of the park.

GBRMPA also manages smaller scale permits within the marine park boundaries--small-scale matches that work best for activities like commercial tourism, lobster fisheries or the installation of certain structures like jetties or moorings.

The study found the permits issued for human activities generally occurred at larger scales than the particular individual marine features of interest, such as reefs or islands.

"The finding that people are managed at a broader scale than ecological variation suggests a general principle for permitting and management," Prof Cumming said. "In essence, people like to have choices about where they go and how they respond to change. This means that they prefer to operate at a broader spatial scale than the ecological features they are interested in, rather than the same scale."

The findings suggest this approach to managing people at broader rather than finer scales may be more effective. For small protected areas, increasing the size of the permissible area may even be critical.

However, GBRMPA can't manage the ecosystem's biggest impact, which lies outside park boundaries: climate change.

"Broad scale problems, like climate change, can only be managed with broad scale solutions, like global action," Prof Cumming said. "This is a scale mismatch because these impacts come from well outside the marine park boundaries."

GBRMPA also don't have control over what happens on the land directly adjacent to the reef. Not being able to stop pollutants and pesticides in storm water reaching the reef is another scale mismatch.

Prof Cumming says comparing the results of this study to similar data from other marine parks, including those that are recognised as dysfunctional, will help determine if the management of the Great Barrier Reef Marine Park is unusual or typical.

"This study does not offer a direct solution for management," Prof Cumming said. "But it provides a new approach that extends our toolbox for diagnosing social-ecological scale mismatches and responding to them."

Credit: 
ARC Centre of Excellence for Coral Reef Studies

Achieving highly efficient ammonia synthesis by altering the rate-determining step

image: Schematic illustration of altering the rate-determining step of nitrogen reduction reaction by introducing cobalt single-cluster in the catalyst. The cyan, red, purple, and gray spheres represent C, N, Co, and H atoms, respectively.

Image: 
©Science China Press

Ammonia is a generic precursor for the manufacture of essential fertilizer and most nitrogen-containing organic chemicals. To date, industrial ammonia production is predominantly conducted by the Haber-Bosch process, in which nitrogen is fixed using the chemical reductant hydrogen. However, despite the development for more than one hundred years, this process still requires harsh conditions including high temperatures (673-873 K) and pressures (20-40 MPa), accounting for 1.5% of worldwide energy consumption. In this context, it is urgently demanded to seek a sustainable and less energy-intensive technology to produce ammonia.

The electrocatalytic N2 reduction reaction (NRR), using proton from water as the hydrogen source and powered by renewable electricity sources, is an alternative method to achieve N2 fixation under ambient conditions. However, in practice, it is still difficult to achieve desirable NRR performance, which causes great energy loss of the process, and the key challenge lies in the activation of the inert nitrogen-nitrogen triple bond, which is generally considered as the rate-determining step. In this context, highly active catalysts that could alter the rate-determining step of electrochemical ammonia synthesis is expected to be an ideal candidate for ammonia synthesis.

In a new research article published in the Beijing-based National Science Review, scientists at the Soochow University in Suzhou, China present the latest advances in overcoming the bottleneck of ambient ammonia synthesis. Co-authors Sisi Liu, Mengfan Wang, Haoqing Ji, Xiaowei Shen, Chenglin Yan, and Tao Qian successfully alter the rate-determining step of ambient ammonia synthesis by deliberate introduction of cobalt single clusters as electron-donating promoter in nitrogen-doped carbon, and achieve outstanding ammonia yield rate of 76.2 μg h-1 mg-1 and superior Faradaic efficiency of 52.9%. With such strategy, the superior performance would greatly reduce the energy loss of the system and cut down the fundamental cost, thus contributing to future practical applications.

These scientists likewise outline the potential development directions of future electrocatalysts for sustainable NRR systems. "When chemically adsorbed on Co cluster, N2 is spontaneously activated and experiences a significant weakening of the nitrogen-nitrogen triple bond due to the strong electron backdonation from the metal to the N2 antibonding orbitals, and the N2 dissociation becomes an exothermic process over the cobalt single cluster." Prof. Tao Qian said, "Thus, the rate-determining step has been successfully shifted from the usual N2 activation to the subsequent hydrogenation with only a small energy barrier of 0.85 eV."

Credit: 
Science China Press