Culture

A new study published in the Journal of Alzheimer's Disease provides insight into the association of blood markers of diabetes with brain beta-amyloid accumulation among older people at risk of dementia. The results suggest a link between Alzheimer's pathology, lower levels of insulin and lower insulin resistance.

The deposition of beta-amyloid plaques in the brain is known to be one of the key elements of Alzheimer's disease and can begin years or even decades before the disease progresses to the dementia stage. Amyloid accumulation in the brain can be detected by PET scans.

Type 2 diabetes is a known risk factor for cognitive impairment and Alzheimer's disease, but the underlying mechanisms are still unknown. Autopsy studies have found that diabetes is associated with small vessel pathology typical of vascular dementia, but not specifically of Alzheimer's disease. Insulin resistance, an indicator of a pre-diabetic state, has been associated with amyloid accumulation in cognitively normal middle-aged and late middle-aged individuals, but not in the older age groups.

In the present study, researchers from the University of Eastern Finland investigated the association of blood markers of diabetes with beta-amyloid accumulation detected in PET scans in older people at risk of dementia. The study population included 41 participants from the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER). FINGER has investigated the cognitive benefits of a multidomain lifestyle intervention for people over 60, who are at risk of cognitive decline.

Results from the study indicate slightly better insulin homeostasis in amyloid positive older individuals at risk of dementia. The findings contrast with earlier findings, possibly due to the fact that this study population was at high risk of cognitive decline.

"The results could also suggest that in people with diabetes and vascular pathology, less amyloid accumulation in the brain may be needed to trigger the onset of Alzheimer's dementia," Associate Professor Alina Solomon from the University of Eastern Finland says.

"Interestingly, no association was found for amyloid deposition with fasting glucose levels or HbA1c, which measures the average level of blood sugar."

This new study adds to the growing amount of data on the associations of insulin resistance and diabetes with Alzheimer's disease pathology.

Due to its promising results, the FINGER study has expanded around the globe as part of the World Wide FINGERS research network, which has been setup to help execute lifestyle interventions for, and research into, cognitive impairment and dementia prevention. In the future, this will enable the replication of the results obtained in this study with larger populations and help gain further insight into the connections between diabetes and Alzheimer's disease.

At the start of a COVID-19 infection, the coronavirus SARS-CoV-2 docks onto human cells using the spike-like proteins on its surface. The spike protein is at the centre of vaccine development because it triggers an immune response in humans. A group of German scientists, including members of the European Molecular Biology Laboratory (EMBL) in Heidelberg, the Max Planck Institute of Biophysics, the Paul-Ehrlich-Institut, and Goethe University Frankfurt have focused on the surface structure of the virus to gain insights they can use for the development of vaccines and of effective therapeutics to treat infected patients.

The team combined cryo-electron tomography, subtomogram averaging, and molecular dynamics simulations to analyse the molecular structure of the spike protein in its natural environment, on intact virions, and with near-atomic resolution. Using EMBL's state-of-the-art cryo-electron microscopy imaging facility, 266 cryotomograms of about 1000 different viruses were generated, each carrying an average of 40 spikes on its surface. Subtomogram averaging and image processing, combined with molecular dynamics simulations, finally provided the important and novel structural information on these spikes.

The results were surprising: the data showed that the globular portion of the spike protein, which contains the receptor-binding region and the machinery required for fusion with the target cell, is connected to a flexible stalk. "The upper spherical part of the spike has a structure that is well reproduced by recombinant proteins used for vaccine development," explains Martin Beck, EMBL group leader and a director of the Max Planck Institute (MPI) of Biophysics. "However, our findings about the stalk, which fixes the globular part of the spike protein to the virus surface, were new."

"The stalk was expected to be quite rigid," adds Gerhard Hummer, from the MPI of Biophysics and the Institute of Biophysics at Goethe University Frankfurt. "But in our computer models and in the actual images, we discovered that the stalks are extremely flexible." By combining molecular dynamics simulations and cryo-electron tomography, the team identified the three joints - hip, knee and ankle - that give the stalk its flexibility.

"Like a balloon on a string, the spikes appear to move on the surface of the virus and thus are able to search for the receptor for docking to the target cell," explains Jacomine Krijnse Locker, group leader at the Paul-Ehrlich-Institut. To prevent infection, these spikes are targeted by antibodies. However, the images and models also showed that the entire spike protein, including the stalk, is covered with chains of glycans - sugar-like molecules. These chains provide a kind of protective coat that hides the spikes from neutralising antibodies: another important finding on the way to effective vaccines and medicines.

DALLAS - Aug. 18, 2020 - The amount of calcified plaque in the heart's arteries is a better predictor of future heart attacks than of strokes, with similar findings across sex and racial groups, according to new research from UT Southwestern.

The study, published today in Circulation: Cardiovascular Imaging, is the first to examine the predictive value of recently recommended coronary artery calcium (CAC) score categories for heart attacks and strokes. Using two population-based, multiethnic cohorts, the researchers evaluated how well the amount of calcium detected by a CT scan of the heart predicted whether white, Black, and Hispanic men and women would have a stroke or a heart attack in the next 10 years.

Calcium is part of the fatty plaque that builds up in arteries supplying blood to the heart and brain and can lead to blockages, causing heart attacks or strokes. As plaque becomes more calcified and hardens, it becomes more visible on a heart CT scan.

"In our study, there was a twofold greater risk of heart attack than stroke at CAC levels at or above 100," a score indicating moderate to high levels of calcified plaque, says Parag Joshi, M.D., a cardiologist and assistant professor of internal medicine at UT Southwestern and senior author of the study. "That held true for Black, white, and Hispanic men and women."

Women and Black individuals generally have higher stroke risk, Joshi says.

"In fact, while the calcium score may not be a strong predictor of stroke risk for most, for some reason it did well in predicting strokes in Black participants," says Anurag Mehta, M.D., the first author of the study, formerly at UT Southwestern and now at Emory University School of Medicine.

The findings could help guide health care providers as they decide how aggressively to treat patients with risk factors such as high cholesterol and blood pressure but who have never had a major cardiovascular event.

In 2018, the American Heart Association and the American College of Cardiology issued joint cholesterol management guidelines that recommend using the CAC score as an aid when deciding whether to prescribe a cholesterol lowering statin drug in situations where the decision - based on the routine risk assessment using systolic blood pressure, cholesterol level, etc. - is uncertain.

Joshi's study evaluated data from more than 7,000 participants in two large studies - the Multi-Ethnic Study of Atherosclerosis (MESA) funded by the National Institutes of Health, and the Dallas Heart Study at UT Southwestern.

The authors divided study participants by the AHA/ACC calcium risk categories - 0, 1-99, and 100 or above - to evaluate how useful the calcium scores would have been in predicting heart attacks and strokes. It also subdivided the participants by sex and race (Black, white, and Hispanic) to calculate the risk levels for the different groups.

For participants with a calcium score of zero, there was a similarly low risk of either a stroke or a heart attack in the coming 10 years - less than 2 percent for either event among all study participant categories, according to the study.

The risk level for both heart attacks and strokes rose a bit for those with scores of 1-99, yet still remained below 6 percent - increasing about equally for both and across most demographic groups. At this level, women did have a greater increase in the risk for stroke than for heart attack, whereas men had higher heart attack risk than stroke.

Greater differences were found when the CAC scores rose to 100 or above, with heart attack risk twice as high as stroke risk for the entire study population. While 10-year heart attack risk jumped above 12 percent for men and over 14 percent for Hispanic individuals, heart attack risk for women was approximately 8 percent, according to the study.

Meanwhile, stroke risk remained below 8 percent across all groups, although women, Black, and Hispanic people had higher risk than men and white participants.

For doctors and patients, the findings could help tilt the scales either toward or away from using statin drugs to lower cholesterol in cases where the decision is not clear-cut from factors such as age, sex, cholesterol, systolic blood pressure, and smoking history.

Patients are sometimes reluctant to begin what is likely to become a lifelong drug therapy, Joshi says. "If you think your patient should be on a statin and your patient doesn't want to take it, this can be a good arbitrator of that," he says. "Our findings also highlight some of the nuance between heart attack risk and stroke risk and how our patients might consider those two risks in their decision making."

In 2020 China plans to launch the largest battery complex in the world with a capacity of 800 MW*h (approximately this amount of energy per year is consumed by a household with 200 apartments). This complex is based not on the usual lithium-ion or lead-acid batteries, but on the redox flow battery where the electricity is stored in the form of chemical energy of solutions - electrolytes. Battery consists of two tanks in which electrolytes are stored and membrane-electrode assembly (MEA) - solutions are supplied to MEA by pumps where they undergo electrochemical reactions which provide charging and discharging of the battery.

Due to this setup, redox flow batteries, unlike many other energy storage devices, enable independent scaling of power and capacity of the battery, which are determined by the size of MEA and electrolyte volume, respectively. In addition, redox flow batteries exhibit minimal self-discharge over extended periods and their electrolytes do not degrade even after tens of thousands of operating cycles, making them promising candidates for storing large amounts of energy in the smart power grids. For example, they can store excess electricity generated by photovoltaic solar cells during daylight and generate back-up electricity at night or in cloudy weather.

"Flow batteries are being actively integrated into the power grids of China, Germany and other countries, on one hand, and on the other hand, are continued to be developed and refined in laboratories", comments one of the authors of the work, researcher at the NTI Competence Center at IPCP RAS, Dmitry Konev. "We have proposed a completely new design of MEA, which will facilitate the research process and greatly reduce entrance threshold for new research groups into this area. In the future, this will help to achieve significant progress and will bring distributed energy resources from niche positioning to very high level of commercialization, including in Russia".

Sandwich with laser filling

The MEA is the heart of the flow battery. It looks like a sandwich of different sheets materials, divided into two symmetrical parts supplied with its own electrolyte. When the battery is connected to a power supply, the one electrolyte is oxidized, while another is reducing and so the battery is charging. After that, the power source can be disconnected and replaced with energy consumer - the electrolytes will undergo reverse processes and the battery will begin to discharge.

An important part of the MEA is the flow field plates, sandwich layers through which the electrolyte is pumped to the electrodes where the electrolytes are oxidized or reduced. The performance of the battery, i.e. power and efficiency, depend strongly on how well the flow fields are organized. Therefore, researchers often select different types of fields to optimize battery performance, but now this is a very labor-intensive task: flow fields are milled in dense graphite plates, which is time-consuming procedure. Russian researchers have proposed a different approach.

"We form flow fields by using several thin layers of flexible graphite materials: the necessary patterns in them are cutted by a laser and then these layers are superimposed on each other to get the required field", says the first author of the work, researcher at Mendeleev Univeristy, Roman Pichugov. "The procedure to create flow fields takes only a few minutes, which is much less than traditional milling of graphite. Plus, cheaper materials are used, and as a result, there is more scope for variation and selection of flow fields."

From cell to stack

Flow batteries can operate with different types of electrolytes. The most common (including those that are installed in China and are being introduced in other countries) utilize vanadium electrolytes, namely solutions of vanadium salts. Exactly on this electrolyte Russian scientists tested their cell design. They sorted out various types of flow fields, varied the electrolyte flow rate and obtained results that on a qualitative level coincide with the best world studies and on a quantitative level even slightly surpass them: the power of tested MEA slightly exceeded the power of similar cells on graphite.

Thus, the new design of MEA is greatly simplifying laboratory test and in the future can be used in real energy storage systems for distributed power grids. Now Russian scientists in collaboration with InEnergy LLC are developing and testing a vanadium flow battery composed of 10 such cells with a total power of 20 watts. The construction of the cell itself and the stack of 10 cells are protected by patents, the last of which belongs to ADARM company, created by the employees of MUCTR. In addition, scientists develop other types of flow batteries utilizing different electrolytes on the basis of the proposed design of MEA.

Scientists have revealed how nanomaterials inspired by insect wings are able to destroy bacteria on contact.

The wings of cicadas and dragonflies are natural bacteria killers, a phenomenon that has spurred researchers searching for ways to defeat drug-resistant superbugs.

New anti-bacterial surfaces are being developed, featuring different nanopatterns that mimic the deadly action of insect wings, but scientists are only beginning to unravel the mysteries of how they work.

In a review published in Nature Reviews Microbiology, researchers have detailed exactly how these patterns destroy bacteria - stretching, slicing or tearing them apart.

Watch and embed the video

Lead author, RMIT University's Distinguished Professor Elena Ivanova, said finding non-chemical ways of killing bacteria was critical, with more than 700,000 people dying each year due to drug-resistant bacterial infection.

"Bacterial resistance to antibiotics is one of the greatest threats to global health and routine treatment of infection is becoming increasingly difficult," Ivanova said.

"When we look to nature for ideas, we find insects have evolved highly effective anti-bacterial systems.

"If we can understand exactly how insect-inspired nanopatterns kill bacteria, we can be more precise in engineering these shapes to improve their effectiveness against infections.

"Our ultimate goal is to develop low-cost and scaleable anti-bacterial surfaces for use in implants and in hospitals, to deliver powerful new weapons in the fight against deadly superbugs."

Bacteria-killing surfaces

The wings of cicadas and dragonflies are covered in tiny nanopillars, which were the first nanopatterns developed by scientists aiming to imitate their bactericidal effects.

Since then, they've also precisely engineered other nanoshapes like sheets and wires, all designed to physically damage bacteria cells.

Bacteria that land on these nanostructures find themselves pulled, stretched or sliced apart, rupturing the bacterial cell membrane and eventually killing them.

The new review for the first time categorises the different ways these surface nanopatterns deliver the necessary mechanical forces to burst the cell membrane.

"Our synthetic biomimetic nanostructures vary substantially in their anti-bacterial performance and it's not always clear why," Ivanova said.

"We have also struggled to work out the optimal shape and dimensions of a particular nanopattern, to maximise its lethal power.

"While the synthetic surfaces we've been developing take nature to the next level, even looking at dragonflies, for example, we see that different species have wings that are better at killing some bacteria than others.

"When we examine the wings at the nanoscale, we see differences in the density, height and diameter of the nanopillars that cover the surfaces of these wings, so we know that getting the nanostructures right is key."

Ivanova said producing nanostructured surfaces in large volumes cost-effectively, so they could be used in medical or industrial applications, remained a challenge.

But recent advancements in nanofabrication technologies have shown promise for opening a new era of biomedical antimicrobial nanotechnology, she said.

BLOOMINGTON, Ind. -- About $7 billion reportedly will be spent this fall on television and digital commercials from political campaigns and political action committees, filling the airwaves with political ads many viewers dislike. Companies running ads immediately afterward have been concerned about the potential of a negative spillover effect on how they and their products and services are perceived.

But new research from the Indiana University Kelley School of Business finds that the opposite is true. Contrary to mainstream thought, political ads instead yield positive spillover effects for nonpolitical advertisers.

And this happens regardless of whether the political ad is an attack ad or not, who the ad supports, and whether it's sponsored by a candidate, political party or PAC. Political advertising accounts for nearly 10 percent of all U.S. television ad revenue.

The findings are in the article, "Impact of Political Television Advertisements on Viewers' Response to Subsequent Advertisements ," -- accepted for publication in Marketing Science -- by Beth Fossen, assistant professor of marketing; Girish Mallapragada, associate professor of marketing and Weimer Faculty Fellow; and doctoral candidate Anwesha De, all from the Kelley School of Business.

"Our investigations provide insights into the previously unexplored ad-to-ad spillover effects and, more broadly, provides insights into how political messages influence consumers," Fossen said. "Nonpolitical ads that follow political ads benefit through a reduction in audience decline and an increase in positive post-ad chatter."

Using data for 849 national prime-time ads during the 2016 U.S. general election, the researchers found that ads airing after a political commercial saw an 89 percent reduction in audience decline and a 3 percent increase in post-ad chatter online.

Their findings remained consistent when examining the effect by TV network and political party affiliation.

"It seems reasonable to assume that Fox News viewers are more likely to be positively stimulated by pro-Republican ads than viewers of other channels," researchers wrote. "However, evidence from our data suggests that the positive spillover from pro-Republican ads is not higher and is nearly lower on Fox News viewership decline than when pro-Republican ads air on other channels."

They found a similar trend when it came to advertising on MSNBC, whose viewers frequently identify with the Democratic Party and progressive causes.

Mallapragada said the findings show that television networks and stations can leverage the positive spillover effects on subsequent ads by implementing differential pricing and systematic ad sequencing.

Prevailing belief in the business industry has suggested that political ads on television hurt the effectiveness of subsequent ads. To illustrate this concern, during the 2020 Super Bowl, game broadcaster Fox isolated political ads from other paying advertisers in their own ad breaks, a decision that cost the network millions in ad revenue, because it ran nonpaid show promos alongside the political ads instead of commercials from paying advertisers.

"The insights from this research enable advertisers to advocate for the inclusion of ad positioning in ad buys and, specifically, negotiate that their ads follow political ads," he said. "Our results may also encourage advertisers outside of the television context to experiment with advertising next to political content, an experimentation that may be especially beneficial for online advertisers given that they commonly blacklist political topics to avoid having their ads appear near political content."

WASHINGTON--Earth's tropics are expanding poleward and that expansion is driven by human-caused changes to the ocean, according to new research.

The tropics wrap around Earth's middle like a warm, wet belt. This part of the globe gets the most direct sunlight throughout the year and is characterized by high average temperatures and heavy rainfall. In contrast to the tropics' lush interior, however, this region's edges are hot and parched.

Scientists have noticed for the past 15 years that these arid bands are expanding toward the poles into regions like the Mediterranean, southern Australia and southern California. Interestingly, these dry areas have expanded more in the Southern Hemisphere than the Northern Hemisphere and researchers have struggled to pinpoint exactly what is driving the trend.

A new study in AGU's ,Journal of Geophysical Research: Atmospheres argues that the failure to agree on an exact mechanism has been, in part, because most researchers have been looking in the wrong place. The new study found tropical expansion is driven primarily by ocean warming caused by climate change rather than direct changes to the atmosphere. A bigger shift is happening in the Southern Hemisphere because it has more ocean surface area, according to the new study.

Tropical expansion could have profound economic and social implications: the process could shift storm paths and cause more severe wildfires and droughts in places like California and Australia that are already water-stressed.

The new findings provide the clearest evidence yet that tropical expansion is in fact primarily driven by climate change, according to the study authors. While natural long-term climate fluctuations contribute to the observed trends, these variations alone cannot explain the extent to which expansion has already occurred.

This means, the authors argue, that climate change might have already significantly contributed to tropical expansion, especially in the ocean-dominated Southern Hemisphere.

"We demonstrate that the enhanced subtropical ocean warming is independent from the natural climate oscillations," said Hu Yang, a climate scientist at the Alfred Wegner Institute in Bremerhaven, Germany and lead author of the new study. "This is a result of global warming."

A disconcerting phenomenon

A 2006 paper published in the journal Science announced a troubling finding: in some parts of the world, the tropics were expanding. Researchers have attempted to figure out the culprit ever since that paper was published. Scientists estimate from satellite observations that this widening is happening at a rate of 0.25 to 0.5 degrees latitude per decade. But without pinpointing a root cause, they cannot accurately model how quickly the expansion will occur in the future or what regions it will impact.

Some researchers have suggested greenhouse gas emissions, ozone depletion and aerosols in the atmosphere are driving the expansion. But climate models using these variables to explain the expansion consistently underestimate the speed of the shift and do not account for why expansion is happening in some regions but not others. This has led some researchers to theorize that tropical expansion can simply be explained by natural oscillations in Earth's climate. But natural variation does not quite fit the patterns scientists have already observed.

Ocean versus atmosphere

Yang and colleagues began to take notice of tropical expansion in 2015, when analyzing ocean currents that carry warm water toward the poles. This got them thinking: what if tropical expansion was driven not by changes in the atmosphere, but changes in the ocean?

Because the ocean and atmosphere are highly connected systems, it is often difficult to tell which is driving the other, Yang said. In the new study, Yang and his colleagues analyzed water temperatures in the major ocean gyres, large circular ocean currents that carry warm water toward the poles and cold water toward the equator. They used satellite observations of sea surface temperature between 1982, the year observations began, and 2018, and compared these observations to data on the expanding tropics that stretches back to 1979.

They found excess heat building up in the subtropical oceans since global warming began in the mid-1800s has driven tropical edges and ocean gyres toward the poles. When the researchers compared movement of the ocean gyres to tropical expansion, they found the two phenomena matched: tropical expansion was happening in places where the ocean gyres were moving poleward.

"I actually am really impressed with this paper," said Kristopher Karnauskas, associate professor in the Department of Atmospheric and Oceanic Sciences at the University of Colorado Boulder who was not connected to the new study. "There really aren't a lot of papers out there that really investigate the role of the ocean in the tropical expansion problem."

In infectious disease outbreaks, digital contact tracing alone could reduce the number of cases, but not as much as manual contract tracing, new University of Otago-led research published in the Cochrane Library reveals.

Senior Research Fellow in the Department of Preventive and Social Medicine, Dr Andrew Anglemyer, led this systematic review of the effectiveness of digital technologies for identifying contacts of an identified positive case of an infectious disease, in order to isolate them and reduce further transmission of the disease.

The team of researchers summarised the findings of six observational studies from outbreaks of different infectious diseases in Sierra Leone, Botswana and the USA and six studies that simulated the spread of diseases in an epidemic with mathematical models.

The results of the review suggest the need for caution by health authorities relying heavily on digital contact tracing systems.

"Digital technologies, combined with other public health interventions, may help to prevent the spread of infectious diseases but the technology is largely unproven in real-world, outbreak settings," Dr Anglemyer says.

"Modelling studies provide low certainty of evidence of a reduction in cases, and this only occurred when digital contact tracing solutions were used together with other public health measures such as self-isolation," he says.

"However, limited evidence shows that the technology itself may produce more reliable counts of contacts."

Overall, the team of researchers from New Zealand, the USA, the UK and Australia conclude there is a place for digital technologies in contact tracing.

"The findings of our review suggest that to prevent the spread of infectious diseases, governments should consider digital technologies as a way to improve current contact tracing methods, not to replace them," the researchers state.

"In the real world, they won't be pitted against each other, the technology would hopefully just augment the current contact tracing methods in a given country."

They recommend governments consider issues of privacy and equity when choosing digital contact tracing systems.

"If governments implement digital contact tracing technologies, they should ensure that at-risk populations are not disadvantaged and they need to take privacy concerns into account.

"The COVID-19 pandemic is disproportionately affecting ethnic minorities, the elderly and people living in high deprivation. These health inequities could be magnified with the introduction of digital solutions that do not consider these at-risk populations, who are likely to have poor access to smartphones with full connectivity."

Contact tracing teams in the studies reviewed reported that digital data entry and management systems were faster to use than paper systems for recording of new contacts and monitoring of known contacts and possibly less prone to data loss.

But the researchers conclude there is "very low certainty evidence" that contact tracing apps could make a substantial impact on the spread of COVID-19, while issues of low adoption, technological variation and health equity persist.

Accessibility or privacy and safety concerns were identified in some of the studies. Problems with system access included patchy network coverage, lack of data, technical problems with hardware or software that were unable to be resolved by local technical teams and higher staff training needs including the need for refresher training. Staff also noted concerns around accessibility and logistical issues in administering the systems, particularly in marginalised or under-developed areas of the world.

The research, published today by the Cochrane Library a collection of high-quality, independent evidence to inform healthcare decision-making, has been carried out as the COVID-19 pandemic shows no signs of waning and the World Health Organization and more than 30 countries are exploring how digital technology solutions could help stop the spread of the virus.

Senior Research Fellow Tim Chambers from the University of Otago, Wellington, and Associate Professor Matthew Parry from the Department of Statistics, were also co-authors of the paper.

In their first follow-up to a high-profile 2017 study which showed microbes in Antarctica have a unique ability to essentially live on air, researchers from UNSW Sydney have now discovered this process occurs in soils across the world's three poles.

Specifically, researchers found the target genes responsible for the atmospheric chemosynthesis phenomenon they discovered are abundant and widely distributed in the polar soils of the Antarctic, Arctic and Tibetan Plateau in the Hindu Kush-Himalayas.

The new research was published in the journal Frontiers this month and was a collaboration between UNSW, the Australian Antarctic Division and China's Institute of Tibetan Plateau Research.

The study's senior author Associate Professor Belinda Ferrari, of UNSW Science, said living on air was such a minimalistic way to survive that their findings lent further potential for microbial life to exist on other planets.

"This is what NASA's Mars 2020 Perseverance Rover is aiming to do - to search for signs of ancient microbial life in core samples of Martian rock and soil," A/Prof Ferrari said.

"A future mission will take the samples back to Earth and NASA scientists will analyse the soil in a similar way we do, to try and see whether there are any indicators of life."

A/Prof Ferrari said the researchers' findings meant that microbes which use trace gases as their energy and carbon source to grow - unlike photosynthesis which uses light - was not a process isolated to Antarctica.

"There are whole ecosystems probably relying on this novel microbial carbon fixation process where microbes use the energy obtained from breathing in atmospheric hydrogen gas to turn carbon dioxide from the atmosphere into carbon - in order to grow," she said.

"We think this process occurs simultaneously alongside photosynthesis when conditions change, such as during the polar winter when there is no light, but we aim to confirm this hypothesis in the next stage of our research.

"So, while more work is needed to confirm this activity occurs globally, the fact that we detected the target genes in the soils of the three poles means this novel process likely occurs in cold deserts around the world, but has simply been overlooked until now."

Antarctic, Artic and Tibetan Plateau soil analysed

Researchers analysed 122 soil samples from 14 terrestrial cold desert sites across Antarctica (Windmill Islands and Vestfold Hills), the high Arctic and Tibetan Plateau, which they collected between 2005 and 2019.

The study's lead author, UNSW PhD candidate Angelique Ray, said one of the big questions the team had when they finished their previous study was whether this new process of atmospheric chemosynthesis - also known as carbon fixation or carbon sink - was similarly occurring in other places around the world.

"So, this time we did a global study. We collected the top 10-centimetre layer of soil from various sites at the three poles, which is the depth where most of the organisms we study are found," she said.

"The ground at those locations is completely frozen for most of the year - and there's not a lot of soil because it's mostly rock."

The researchers extracted DNA from the soil samples and then sequenced the DNA to detect the target genes responsible for the process of carbon fixation.

Ms Ray said the scientists also conducted environmental analyses of each location to gauge the conditions under which the microbes lived.

"By looking at the environmental parameters in the soil, that's how we knew there was low carbon, low moisture and other factors at play," she said.

"So, we correlated the target genes for the carbon fixation process against the different sites and found the locations which are drier and lower in nutrients - carbon and nitrogen - had a greater potential to support this process, which made sense."

Findings to change thinking on carbon fixation

A/Prof Ferrari said the researchers' findings would change the way scientists thought about the limitations required for life to exist, as well as how microbiology was taught.

"By investigating places outside Antarctica, we can determine how significant the contribution of this new form of chemotrophy is to the global carbon budget," she said.

"Before we discovered this new carbon sink process, the two main known chemotrophic forms were photosynthesis and geothermal chemotrophy - the latter is where bacteria harness inorganic compounds like hydrogen sulfide to fix carbon.

"But now we have found the genes involved in this process are abundant in cold deserts, although we are yet to study hot deserts, our finding probably indicates atmospheric chemosynthesis is contributing to the global carbon budget."

A/Prof Ferrari said it was likely the bacteria which survived on nothing but air had become key players in the environments in which they lived.

"A lot of these ecosystems are quite dry and nutrient poor - so, these locations are mostly dominated by bacteria," she said.

"Particularly at the original east Antarctic sites we studied, there is not much else there apart from some mosses and lichens (fungus).

"Because these bacteria have adapted to survive and have the ability to use trace gases to live, their environment has selected them to become significant contributors to their ecosystems."

A/Prof Ferrari said the researchers looked forward to making new discoveries in carbon fixation.

"As part of the next phase, we aim to isolate one of these novel bacteria in the laboratory - to obtain a pure culture," she said.

"This is difficult because the bacteria are used to growing on very little and an agar plate is different to their natural environment.

"Hopefully then, we can fully understand the conditions these bacteria need to carry out this unique process of living on air."

When talking to babies, humans slow down their speech, raise their pitch and change the "color" of their voice. This "baby talk," as people know it, increases the infant's attention and facilitates language learning. Among animals, mothers often engage in pup-directed vocalizations too, but does this also imply voice changes? A team of scientists that included Smithsonian Tropical Research Institute (STRI) researchers explored whether infant-directed communication in bats resulted in vocalization changes.

They focused on the greater sac-winged bat Saccopteryx bilineata, a common Central and South American species with a large vocal repertoire employed in the elaboration of complex songs for territorial defense and courtship. Female choice in mating is very pronounced in this species, which probably led to the complexity of courtship vocalizations in males.

During their first three months of life, as S. bilineata pups start experimenting with their "speech," female and male adult bats respond to them differently. Through sound recordings of their vocal interactions, the research team found that mother bats interact with pups as they "babble," which could be interpreted as positive feedback to pups during vocal practice.

Much like human "baby talk," the pup-directed vocalizations of adult females presented a different "color" and pitch than the calls directed towards other adult bats. Male bats also communicated with the pups, but in a way that seemed to transmit the "vocal signature" of their social group.

"Pup isolation calls are acoustically more similar to those of males from the same social group than to those of other males," said Mirjam Knörnschild, STRI research associate and co-author of the paper. "These results suggest that adult male vocalizations may serve as guidance for the development of group signatures in pup calls."

This is the first time that scientists describe a phenomenon that could resemble "baby talk" among bats, indicating that parent-offspring communication in bats is more complex than previously thought and opening new avenues for further research.

"These results show that social feedback is important during vocal development, not only in humans but also in other vocal-learning species like Saccopteryx bilineata," said Ahana Fernandez, former STRI visiting scientist who conducted this research as part of her doctoral thesis at the Free University Berlin and is now a post-doctoral researcher at the Natural History Museum in Berlin. "I believe that bats are a very promising taxon to investigate key shared features of language, such as the vocal learning ability, and that this study will inspire further studies in the biolinguistics field."

New research from a European group of smell disorder experts, including Prof Philpott at the University of East Anglia, shows how smell loss associated with Covid-19 infection differs from what you typically might experience with a bad cold or flu.

The new study published today is the first to compare how people with Covid-19 smell and taste disorders differ from those with other causes of upper respiratory tract infections.

The main differences found are that, although Covid-19 patients also lose their sense of smell, they can breathe freely, do not tend to have a runny or blocked nose, and they cannot detect bitter or sweet tastes.

These findings lend weight to the theory that Covid-19 infects the brain and central nervous system.

The research team hope that their work could help develop smell and taste tests for fast Covid-19 screening - in primary care and emergency departments.

Lead researcher Prof Carl Philpott, from UEA's Norwich Medical School, said: "The loss of smell and taste is a prominent symptom of Covid-19, however it is also a common symptom of having a bad cold. We wanted to find out exactly what differentiates Covid-19 smell loss with the kind of smell loss you might have with a cold and blocked-up nose."

The research team carried out smell and taste tests on 10 Covid-19 patients, 10 people with bad colds and a control group of 10 healthy people - all matched for age and sex.

Prof Philpott said: "We wanted to see if their smell and taste test scores could help discriminate between Covid-19 patients and those with a heavy cold.

"We know that Covid-19 behaves differently to other respiratory viruses, for example by causing the body's immune system to over-react, known as a cytokine storm, and by affecting the nervous system.

"So we suspected that patterns of smell loss would differ between the two groups.

"We found that smell loss was much more profound in the Covid-19 patents. They were less able to identify smells, and they were not able to identify bitter or sweet tastes. In fact it was this loss of true taste which seemed to be present in the Covid-19 patients compared to those with a cold.

"This is very exciting because it means that smell and taste tests could be used to discriminate between Covid-19 patients and people with a regular cold or flu.

"Although such tests could not replace formal diagnostic tools such as throat swabs, they could provide an alternative when conventional tests are not available or when rapid screening is needed - particularly at the level of primary care, in emergency departments or at airports.

"This research also shows that there are altogether different things going on when it comes to smell and taste loss for Covid-10 patients, compared to those with a bad cold.

"It has previously been suggested that the Covid-19 virus affects the central nervous system, based on the neurological signs developed by some patients. There are also similarities with SARS, which has also been reported to enter the brain, possibly via smell receptors in the nose.

"Our results reflect, at least to some extent, a specific involvement at the level of central nervous system in some COVID-19 patients.

"It is particularly interesting that Covid-19 seems to particularly affect sweet and bitter taste receptors, because these are known to play an important role in innate immunity.

"More research is needed to see whether genetic variation in people's bitter and sweet taste receptors might predispose them to Covid-19, or conversely, whether Covid-19 infection changes how these receptors function, either directly or through a cytokine storm - the over-reaction of the body's immune system."

DENVER--Public health screening guidelines for lung cancer followed by the United States Preventive Services Task Force (USPSTF) and the Center for Medicare and Medicaid Services (CMS) undercount African Americans, contributing to disparities in lung cancer screening and treatment, according to a study published today in the Journal of Thoracic Oncology. The JTO is the official journal of the International Association for the Study of Lung Cancer.

Current USPSTF and CMS guidelines, established by results from the National Lung Cancer Screening Trial, recommend low dose computed tomography screening for individuals that meet the following criteria: age 55-80 or 55-77 years, respectively, 30 or more pack-years cigarette smoking history, and in former smokers having quit smoking within the past 15 years.

However, African American individuals are more likely to start smoking at a later age, smoke fewer cigarettes per day, have a longer duration of smoking, are less likely to quit, and tend to be diagnosed with lung cancer at an earlier age. Previous research conducted of 48,364 ever-smokers in the Southern Community Cohort Study showed that a smaller proportion of African American individuals would have met the current USPSTF criteria compared to Whites - 17 % versus 31 %, respectively. African American ever-smokers are at increased risk for lung cancer compared to their White counterparts after adjusting for age and smoking history.

Even among those African Americans or Hispanics who are appropriately screened, access to treatment and participation in leading edge clinical trials is limited.

"Black and Hisptanic patients are under represented in cancer clinical trials and COVID-19 trials, even though they are more likely to be more affected by both diseases," said Janet Freeman-Daily at the IASLC World Conference on Lung Cancer Virtual Presidential Symposium last week. Freeman-Daily is a lung cancer patient advocate and runs the weekly lung cancer Twitter discussion #LCSM.

"In a rapid moving area like cancer care, clinical trials are treatment and represent hope," she said.

To follow up on the Southern Community Cohort Study, researchers from the University of Illinois at Chicago performed a retrospective analysis of 1,050 patients with thoracic cancer from their cancer registry. The cohort was assessed for whether each case would have been eligible by USPSTF criteria for screening based on age, pack-years (average packages of 20 cigarettes smoked per day times years smoked) and quit time. After some exclusions, the cohort of 883 ever-smokers was comprised of the following racial/ethnic makeup: 258 (29.2%) White, 497 (56.3%) African American, 69 (7.8%) Hispanic, 24 (2.7%) Asian, and 35 (4.0%) other.

The researchers analyzed this cohort using the PLCOm2012 lung cancer risk prediction screening model, based on data collected from the control arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO), a randomized controlled trial studying screening to reduce cancer mortality. The PLCOm2012 model incorporates 11 predictors, which include sociodemographic, medical history, and four smoking exposure variables.

Compared to the USPSTF criteria, the PLCOm2012 model increased the sensitivity for the African American cohort at lung cancer risk thresholds of 1.51%, 1.70%, and 2.00% per 6-years. The USPSTF criteria and the PLCOm2012 model with 1.70% risk threshold identified 62.4% and 66.0% of White cases, respectively, and 50.3% and 71.3% of African American cases, respectively. Thus, the PLCOm2012 model improved sensitivity in both Whites and African American ever-smokers and eliminated the eligibility disparity. Of the 64 African Americans ever smokers who were USPSTF-ineligible because their ages were less than 55 years, 23.4% would have qualified by the PLCOm2012 with risk threshold of 1.7%. Of 53 African American ever smokers who were USPSTF-ineligible because they had quit smoking more than 15 years ago, 49.1% would have qualified by the PLCOm2012. And of the 193 of African American ever smokers who were USPSTF-ineligible because they had pack-years less than 30, 40.4% would have qualified by the PLCOm2012.

"We found that the PLCOm2012 model was significantly more sensitive in selecting lung cancer patients as being eligible for screening for the entire cohort," said lead author Mary Pasquinelli, DNP, from the University of Illinois at Chicago. "Broader use of this model in racially diverse populations may help overcome disparities in lung cancer screening and outcomes."

When stony corals have their renowned mass spawning events, in sync with the moon’s cycle, colonies simultaneously release an underwater “cloud” of sperm and eggs for fertilization. But how do the sperm and eggs survive several hours as plankton, given threats from predators, microbes and stresses such as warming waters?

A Rutgers-led team has discovered some surprising features in coral sperm and eggs (collectively called gametes), according to a study in the journal PeerJ.

While coral eggs are large and sperm cells are tiny and far more numerous, the scientists showed for the first time that eggs and sperm appear to be surprisingly similar when it comes to the gene functions they express during the planktonic stage. Proteins encoded by genes, in a process called gene expression, play many critical roles and perform most of the work in cells.

The scientists also identified two genes that may be involved in how coral sperm and eggs recognize each other in dynamic ocean waters, allowing fertilization.

“Much more attention needs to be paid to coral gametes because both egg and sperm are vulnerable to climate change and other insults,” said senior author Debashish Bhattacharya, a distinguished professor in the Department of Biochemistry and Microbiology in the School of Environmental and Biological Sciences at Rutgers University–New Brunswick. “It goes without saying that without robust sperm and egg, the coral reproductive cycle will be significantly weakened. Therefore, we need to understand in more detail how natural selection has acted on coral gametes to ensure their survival, leading to successful fertilization.”

Coral reefs protect coastlines from erosion and storms; serve as habitat, nursery and spawning grounds for fish; and provide food for about 500 million people as well as their livelihoods, according to the National Oceanic and Atmospheric Administration. But corals are threatened by global climate change that warms the ocean and leads to coral bleaching, disease, sea-level rise and ocean acidification. Other threats include unsustainable fishing, land-based pollution, tropical storms, damage from vessels, marine debris and invasive species.

By analyzing the genes of the Hawaiian stony coral Montipora capitata, the scientists revealed a blueprint for how coral eggs and sperm function. The next steps include further analyses of coral genomes to identify the substances they produce to ensure their survival and fertilization. The scientists are also interested in investigating coral species that don’t release sperm and eggs into the water before fertilization and comparing the results to the stony coral study.

“Our results pave the way for future genetic investigations, particularly in the context of climate change influences on the marine environment,” Bhattacharya said.

Philadelphia, August 18, 2020 - Fluid milk consumption among children is vital, as adequate consumption of dairy products, especially during childhood, has beneficial health outcomes later in life. These benefits include reduced risk of osteoporosis, hypertension, obesity, and cancer in adulthood. Milk consumption among children has been declining for decades, so understanding and fulfilling the needs of children is crucial to reverse the decline. In an article appearing in the Journal of Dairy Science, scientists from North Carolina State University and Cornell University studied key contributors to increasing milk consumption among children.

Factors evaluated in the study included food trends, nutritional and school meal program requirements, children's perceptions and preferences, and environmental influences. Among these influences, flavor and habit were the primary drivers for long-term milk consumption. Intrinsic factors ranged in influence over milk preference in the examination, showing that flavoring, heat treatment, and sweeteners positively correlated with higher milk consumption. Extrinsic factors, such as social influence (i.e., peers, parents or caregivers, and school staff), packaging, and health benefits, all affected children's attitudes toward milk as well.

"Making milk more appealing to children, having schools include milk in their meal plans, and increasing the types of milk available in schools are all positive options to encourage children consume fluid milk and receive those health benefits," said senior author MaryAnne Drake, PhD, Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, NC, USA. "The findings in this study, however, reveal critical insights that will aid in efforts to increase milk consumption among children."

Understanding how to create milk products that are appealing to children without compromising the health benefits and taking note of the various factors that influence a child's choice are necessary to encourage and increase lifelong milk consumption.

Low levels of HDL cholesterol, the so-called 'good' cholesterol, are the most common lipid disorder in countries in Latin America and the Caribbean, a new meta-analysis published in eLife shows.

Cholesterol levels in the blood can be important indicators of heart health or cardiovascular disease. By providing regional insights on cholesterol patterns, the study may help local public health leaders develop new strategies to reduce rates of cardiovascular disease by improving cholesterol levels in their communities.

Tracking cholesterol data in Europe, North America, Australia and New Zealand has helped guide initiatives that have delayed the onset of heart disease. Monitoring rising cholesterol levels in Asia and the Pacific is helping clinicians in those regions test strategies to curb this trend. But limited population-level data have been available to guide heart health initiatives in Latin America and the Caribbean. "We wanted to find out which kind of lipid disorder is most common in these two regions," says lead author Rodrigo M. Carrillo-Larco, a Wellcome Trust International Training Fellow at the School of Public Health, Imperial College London, UK, and Research Associate at CRONICAS Centre of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia, Peru.

Carrillo-Larco and colleagues based in Peru analysed data from 197 studies between 1964 and 2016 that collected information on blood cholesterol and lipid levels from individuals in Latin America and the Caribbean. Their results showed no substantial changes in blood cholesterol or lipid levels in these areas over time. "Since 2005, the most common lipid disorder in this region has been low HDL cholesterol, followed by high triglycerides and high LDL cholesterol," Carrillo-Larco explains.

Their analysis provides a starting point for researchers to track cholesterol and lipid levels in these populations by collecting the data during routine visits, or by conducting large studies that follow thousands of individuals over time.

"Our results also suggest that efforts to boost levels of HDL cholesterol may provide the greatest heart health benefits to people living in these regions," concludes senior author Antonio Bernabe-Ortiz, Research Associate at the CRONICAS Center of Excellence in Chronic Disease, Universidad Peruana Cayetano Heredia, Peru. "Such efforts could include public health campaigns to increase physical activity by improving walking infrastructure, or to reduce rates of diabetes or obesity by promoting access to healthy foods."