Tech

Intelligent cameras are the next milestone in image and video processing A team of researchers at the Chair of Multimedia Communications and Signal Processing at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) has developed an intelligent camera that achieves not only high spatial and temporal but also spectral resolution. The camera has a wide range of applications that can improve environmental protection and resource conservation measures as well as autonomous driving or modern agriculture. The findings of the research have been publishedas an open access publication.

'Research up to now has mainly focused on increasing spatial and temporal resolution, which means the number of megapixels or images per second,' explains lecturer Dr. Jürgen Seiler. 'Spectral resolution - the wavelength and thus the perception of colours - has largely been adjusted to match human sight during the development of cameras, which merely corresponds to measuring the colours red, green, and blue. However, much more information is hidden in the light spectrum that can be used for a wide range of tasks. For example, we know that some animals use additional light spectra for hunting and searching for food.'

Three resolutions in one camera

Seiler, who is an electrical engineer, has therefore developed a high-resolution multi-spectral camera that enhances human perception with his team at the Chair of Multimedia Communications and Signal Processing (LMS) led by Prof. Dr. Kaup at FAU. It combines all three resolutions - spatial, temporal and spectral - in a cost-efficient solution. 'Up to now, there were only extremely expensive and complex methods for measuring the ultraviolet or infrared ranges of light or individual spectral bands for special industrial applications,' says Seiler. 'We looked for a cost-efficient model and we were able to develop a very cost-effective multi-spectral camera.'

The researchers connected several inexpensive standard cameras with various spectral filters to form a multi-spectral camera array. 'We then calculated an image in order to combine the various spectral information from each sensor,' explains Nils Genser, research associate at LMS. 'This new concept enables us to precisely determine the materials of each object captured using just one single image.'

At the same time, the new camera is greatly superior to existing systems in terms of its spatial, temporal and spectral resolution. As the surroundings are recorded by several 'eyes' as is the case with human sight, the system also provides a precise indication of depth. This means that the system not only precisely determines the colour and certain material properties of objects it captures, but also the distance between them and the camera.

Ideal for autonomous driving and environmental technology

Autonomous driving is a potential application for these new intelligent cameras. 'A whole range of solutions to various problems has now opened up thanks to our new technology,' says Seiler. 'In the infrared range, for example, we can differentiate between real people and signposts using the thermal signature. For night driving, we can detect animals crossing the road with sufficient warning.'

The high-resolution multi-spectral cameras could also be used for protecting the environment and conserving resources. 'Several plastics differ significantly from each other in various ranges of the spectrum, which is something the new intelligent camera can reliably detect,' Genser emphasises. 'Large amounts of plastics are simply burned instead of separated for recycling as they have a similar appearance. We can now separate them reliably.'

Using a new method, physicists at the Heidelberg Max Planck Institute for Nuclear Physics have investigated the ultrafast fragmentation of hydrogen molecules in intense laser fields in detail. They used the rotation of the molecule triggered by a laser pulse as an "internal clock" to measure the timing of the reaction that takes place in a second laser pulse in two steps. Such a "rotational clock" is a general concept applicable to sequential fragmentation processes in other molecules.

How does a molecule break apart in an intense laser field and what sequential processes take place how quickly? Physicists at the Heidelberg Max Planck Institute for Nuclear Physics have investigated this question in collaboration with a research group from Ottawa in Canada with a new method - studying the example of the hydrogen molecule H2. To do this, they use extremely short laser flashes on the order of femtoseconds (fs, a millionth of a billionth of a second). Such laser pulses also play a key role in controlling molecular reactions, as they directly influence the dynamics of the electrons responsible for chemical bonding.

If a hydrogen molecule (H2) is exposed to a strong infrared laser flash (800 nm wavelength) of a few 1014 W/cm2 intensity, the electric field of the laser first rips off one of the two electrons. More than 10 photons are absorbed at the same time in this ionization process. The remaining molecular ion H2+ with only one electron is no longer in equilibrium and becomes stretched due to the repulsion of the two protons. By absorbing further photons, it can break up into a proton (H+) and a neutral hydrogen atom (H). This reaction is called "above threshold dissociation" (ATD). If the molecular ion is stretched further to a nuclear distance of a few atomic radii, the remaining electron can absorb energy resonantly by the laser field, as in a small antenna, and is eventually also released. This mechanism is called "enhanced ionization" (EI). It leads to the "Coulomb explosion" of the two repelling protons.

Processes distinguished via their kinetic energy

The researchers investigate these processes at the laser laboratory of the Max Planck Institute for Nuclear Physics using a reaction microscope, which allows for the detection of all charged fragments (protons, electrons) after the break-up of the molecule. The femtosecond laser pulses are focused onto a thin supersonic beam of hydrogen molecules in order to achieve the desired intensity. Protons from the ATD and EI processes can be distinguished via their kinetic energy.

Obviously, EI takes a little more time than ATD - but how much and can this be measured? Here, a problem arises since the laser pulse has to last long enough (approx. 25 fs) to start these processes, but has to be short enough to extract precise time information (a few fs). Since this cannot be realized in one single laser pulse, the researchers used the following trick: In principle, every molecule possesses a kind of "internal clock" since it can be stimulated to rotate.

A first (slightly weaker) pump pulse excites the molecular rotation, followed with a variable time delay by a second (slightly stronger) probe pulse triggering the fragmentation (ATD or EI). Both processes are sensitive to the orientation of the molecular axis relative to the plane in which the electric field oscillates - they are most likely for parallel orientation. The two laser pulses are linearly polarized perpendicular to each other in order to sort out fragmentation events from the first pulse.

A general approach to the control of molecular dynamics

The experimental yield of ATD and EI events shows an almost regular up and down, corresponding to the rotation of the molecule. In a closer analysis, however, a slight delay of approx. 5.5 fs is observed for EI compared to ATD. This is the typical time that the molecular ion needs to stretch until the electron couples resonantly to the laser field. Using theoretical model calculations, further details can be extracted and the experimental results are very well reproduced. The experiment was also carried out with the heavier isotope deuterium (D2). Here, the delay is found to be approx. 6.5 fs. This is slightly less than the value expected based on the mass ratio (factor ?2). The reason is the slower motion of D2+, which reaches the EI region after approx. 20 fs - for this, there is hardly enough time during a 25 fs laser pulse.

The method of a "rotation clock" can - in principle - be applied to similar multi-step reactions in other molecules and thus possibly even forms the basis for a general approach to the control of molecular dynamics.

For millions of years, viruses have participated in a far-flung, import-export business, exchanging fragments of themselves with both viral and non-viral agents and acquiring new features. What these tiny entities lack in outward complexity, they make up for with their astonishing abilities to swap out modular genomic components and ceaselessly reinvent themselves.

In new research appearing in the journal mBio, Arvind Varsani and his colleagues investigate a recently discovered class of viruses that have taken the characteristic versatility of the viral world to new heights.

Referred to as cruciviruses, these minute forms reveal a fusion of components from both RNA and DNA viruses, proving that these previously distinct genomic domains can, under proper conditions, intermingle, producing a hybrid or chimeric viral variant.

Varsani, a virologist at the Arizona State Univeristy Biodesign Center for Fundamental and Applied Microbiomics, is deeply intrigued with these new viruses, which are starting to crop up in greater abundance and diversity in a wide range of environments.

"It is great to see the research groups that first identified cruciviruses around the same time teaming up for the sharing and mining of metagenomic data with an aim to identify a larger diversity of cruciviruses," says Varsani, an associate professor with ASU School of Life Sciences.

New virus in town

Crucivirus sequences were identified by Varsani's colleague and co-author Kenneth M. Stedman and his group at Portland State University. The team detected the viruses flourishing in an extreme environment--Boiling Springs Lake (BSL) in Lassen Volcanic National Park, Northern California. Around the same time, Varsani and Mya Breitbart's research group identified a crucivirus in a dragonfly sample from Florida.

Since their discovery in 2012, cruciviruses have been found in diverse environments around the world, from lakes in upstate New York and Florida, to the Antarctic and deep-sea sediments. Some 80 distinct cruciviruses had been identified, prior to the current study, which expands the number to 461.

The first cruciviruses were identified using a technique known as viral metagenomics, in which viral genetic material obtained directly from the environment is sequenced rather than being cultivated or cultured from a host species or natural reservoir.

The results of these early investigations revealed peculiar genetic sequences, radically distinct from anything that had been seen before. This sequences clearly displayed the signature of a DNA virus, yet also contained a gene that appeared to be derived from an RNA virus.

Using a shotgun approach to trawl through a potentially vast sequence space, viral metagenomics enables researchers to identify all of the genomic patterns present in an environmental sample, then separate out distinct viral sequences, like a fisherman retrieving a variety of sea creatures from his net.

The technique has revolutionized the discipline of virology. In addition to identifying a galaxy of previously unknown viruses, metagenomics has offered up exciting clues about genetic diversity and is helping to unlock some of the secrets of viral evolution, all without the need to initially isolate viral species or cultivate viruses in the lab.

Form and function

Cruciviruses belong to a broader class of viruses known as CRESS, (for circular Rep-encoding single-stranded) DNA viruses which have recently been classified into the phylum Cressdnaviricota. The defining characteristic of such viruses is their mode of replication, which relies on a specific component, known as the Rep protein. The Rep protein is important for guiding the replication method of these viruses, known as rolling circle DNA replication. Presence of the Rep protein and rolling circle replication pinpoints a virus as belonging to cressdnaviruses and helps researchers untangle the devilishly complex relationships and lineages found in the viral world.

In addition to the Rep found in cressdnaviruses, cruciviruses contain another centrally important feature--a capsid protein that is similar to that previously found only in RNA viruses. Capsids are vitally important, forming the outer shell or envelope that encloses the virus's identity--its genetic sequence. The capsid shelters the vital nucleic acids sequestered within from digestion by host cell enzymes, enables virus particles to attach themselves to host cells and allows viruses to evade host cell defenses. Finally, capsids contain specialized features that give the virus its ability to puncture the host cell membrane and inject viral nucleic acid into the cell's cytoplasm.

Analysis indicates that the capsid protein of cruciviruses is closely related to the capsid protein of another virus from the family Tombusviridae --a single-stranded RNA virus known to infect plants. This hybrid viral character, containing both DNA- and RNA virus derived coding components, is what makes cruciviruses so unique.

Uncertain origins

But how did a run-of-the-mill cressdnavirus come to acquire its RNA virus capsid protein coding sequence? This remains an issue of considerable debate, though presumably some form of lateral gene transfer occurred.

Viruses can acquire genes from their immediate progenitors, the way genetic traits are passed from human parents to their offspring. Viruses, however, are far more genetically promiscuous, collecting new genes from the cells they infect, from other unrelated viruses and even from bacterial symbionts. (The phenomenon is also common among bacteria, which can use horizontal gene transfer to acquire antibiotic resistance.)

Through some such mechanism, a cressdnavirus acquired an RNA virus capsid-like gene, creating the first crucivirus. It also appears that various cruciviruses have actively exchanged functional elements among themselves, further scrambling their evolutionary history.

While the HOW of crucivirus DNA-RNA recombination remains mysterious, the WHY may be more straightforward. Clearly, the ability to borrow genetic traits from such distantly related viral sources could provide single-stranded DNA viruses with a considerable adaptive edge.

Collector's edition

In the current study, researchers explored a vast dataset including 461 cruciviruses and 10 capsid-encoding circular genetic elements identified from varied environments and organisms, making this the most expansive investigation of crucivirus sequences yet undertaken.

The samples were found in environments ranging from temperate lakes to permafrost and lurking within organisms including red algae and invertebrates. The study points to the stramenopiles/alveolates/Rhizaria or SAR supergroup, (a diverse assemblage of eukaryotes, including many photosynthetic organisms) as the plausible candidate hosts for these unusual viruses, though this has yet to be verified.

After examining the windfall of sequences, the researchers assembled similarity networks of cruciviral proteins with related viruses to try to better understand the twisting evolutionary paths that may have given rise to them, finding a rich cross-pollination of viral traits between many large families of viruses including Geminiviridae, Circoviridae, Nanoviridae, Alphasatellitidae, Genomoviridae, Bacilladnaviridae, Smacoviridae, and Redondoviridae.

Intriguing questions remain

The findings may provide new insights into the early transition from RNA as the primary hereditary molecule of life to the adoption of more complex DNA genomes that has come to dominate life in the cellular world. The existence and behavior of cruciviruses suggest that viruses may have played a crucial role in this all-important transition, acting as a kind of genomic bridge between the RNA and DNA worlds, during the earliest emergence of life, though much more work is needed to explore these possibilities.

Recombining in endless forms, viruses have become the planet's most ubiquitous biological entities, affecting every living organism and occupying every ecological niche. Increasingly, viruses are revealing themselves not only as agents of disease but as drivers of species evolution and vital actors in the molding of ecosystems.

The expanded abilities of cruciviruses to borrow genomic elements from the most far-flung regions of viral sequence space suggest that entirely new virus groups may arise though prolific recombination events between distantly related forms.

The main parasite that causes malaria can alter its gene expression to survive undetected in the human blood stream, new research has shown.

A team of international researchers, including Dr Mario Recker from the University of Exeter, has studied how the parasite, Plasmodium falciparum, can lie seemingly dormant during unfavourable conditions.

The study explains how the parasite can remain in a person without showing observable symptoms, before allowing malaria to re-emerge when mosquito populations resurge during the rainy season.

The study is published in leading journal Nature Medicine.
Malaria is a still a major cause of death in Africa, killing hundreds of thousand people each year, most of whom are children under the age of 5 years.

Although the majority of cases occur during the rainy season, due to the abundance of mosquitoes that spread P. falciparum, the ability of the parasite to persist in the human host for long periods of time allows it to bridge the dry period when mosquitoes become rare and the opportunity for transmission very low.

However, how the parasite is able to remain in the human host under continuous attack by the immune system is poorly understood.

In the new study the team led by Silvia Portugal from the University of Heidelberg, Germany, followed individuals in Mali over consecutive dry and rainy seasons and found that by the end of the dry season the parasites had a distinct pattern of gene transcription.

This pattern was associated with reduced adherence of infected red blood cells to blood vessels, which enabled the infected blood cells to be cleared to low levels by the spleen.

Dr Recker, from the University of Exeter and who led the mathematical modelling part of this study said: "We knew that the parasite can prolong infections by continuously altering its appearance to the immune system.

"What this study shows is that the parasite also adopts another strategy that effectively allows it to hide in plain view by using the spleen to keep its numbers below the immune radar."

The authors conclude that these characteristics contribute to the maintenance of a low reservoir of P. falciparum in the body that evades detection and elimination by the immune system and can fuel the malaria transmission cycle in the subsequent rainy season.

Further research is needed to elucidate how environmental changes affect the transcriptional profiles of P. falciparum, which allow it to survive under specific conditions.

Regular training enhances your strength, but recovery is equally important. Elastic bandages and compression garments are widely used in sports to facilitate recovery and prevent injuries. Now, a research team from Tohoku University has determined that compression garments also reduce strength loss after strenuous exercise.

Their research findings were published in the European Journal of Applied Physiology.

The team - led by assistant professor János Négyesi and professor Ryoichi Nagatomi from the Graduate School of Biomedical Engineering - used a computerized dynamometer to train healthy subjects until they became fatigued. The same equipment was used to detect changes in the maximal strength and knee joint position sense straight after, 24 hours after and one week after the training.

Their results revealed that using a below-knee compression garment during training compensates for fatigue effects on maximal strength immediately following the exercise and once 24 hours has elapsed. In other words, one can begin the next maximal intensity strength training earlier if one has used a below-knee compression garment in the previous workout.

Although compression garments reduce strength loss, their findings reaffirmed that they afford no protection against knee joint position sense errors.

"Our previous studies focused only on the effects of compression garments on joint position sense," said Dr. Négyesi. "The present study found such garments to have the potential to reduce strength loss after a fatiguing exercise, which may help us better understand how applying a compression garment during exercise can decrease the risk of musculoskeletal injuries during sports activities."

The researchers believe wearing a below-knee compression garment during regular workouts is beneficial because of the mechanical support and tissue compression it provides.

Looking ahead, the team aims to detect whether maximal intensity programs that last for weeks produce different outcomes than the current findings to determine the longitudinal effects of compression garments.

People who have been exposed to chemical warfare agents (CWAs) feel uncertain, decades after the exposure, about their survival and ability to build a family, a University of Gothenburg study shows. Women are more severely affected than men.

The study, published in BMJ Open, is based on qualitative, in-depth interviews with 16 survivors of the massive 1988 poison-gas attack on Halabja, a city in the Kurdistan Region of Iraq, when 5,000 people died and twice as many were injured. The interviewees, ten women and six men aged 34 to 67, were all diagnosed with chronic lung complications.

A previous study revealed that the victims experienced severe deterioration of their physical and mental health. The focus is now on their experience of marriage and family building, three decades after their exposure to CWAs.
The study shows the sense of uncertainty most of the interviewees felt about survival and forming couple relationships and families. Their anxiety characterized all decision-making in the private and social spheres, but was most clearly apparent regarding the issue of building a family. Their fear of having children with congenital defects was huge.

The results also followed a gendered pattern: women who had been exposed to CWAs were more psychosocially affected than men from the same background. The women were also more often unemployed, divorced, single, and living in socioeconomically vulnerable conditions.

The first author of the study is Faraidoun Moradi, a doctoral student of occupational and environmental medicine at Sahlgrenska Academy, University of Gothenburg, who is also a registered pharmacist and a specialist in general medicine.

"The exposure not only affects women's physical work capacity, but also has repercussions like social stigmatization, emotional neglect, and a sense of social abandonment," he states.

"The women regard themselves as contaminated, and others think the same. There's a fear of being unable to have healthy children, although there's no strong scientific evidence for that."

"This creates difficulties in starting a family, or results in divorce -- which, in turn, means that they may stay involuntarily single and, more often than the men, live in disadvantaged socioeconomic circumstances," Moradi adds.
The researchers behind the study work at the University of Gothenburg and the Johannesburg Institute for Advanced Study, South Africa. Together, they possess expertise in medicine, psychology, and social anthropology, and stress the importance of broad knowledge of how people are affected by chemical weapons, such as nerve and mustard gas.

"Hundreds of people who were exposed to CWAs have now settled in Sweden, and many of them have severe somatic and psychosocial symptoms from the chemical exposure. We need more research and knowledge in this field to improve treatment and administration of survivors in health and social care," Moradi concludes.

Commercially sold water filters do a good job of making sure any lead from residential water pipes does not make its way into water used for drinking or cooking.

Filters do not do a good job, however, of letting the user know how much lead was captured.

Until now, when a researcher, public works department or an individual wanted to know how much lead was in tap water, there wasn't a great way to find out. Usually, a scientist would look at a one-liter sample taken from a faucet.

Researchers in the McKelvey School of Engineering at Washington University in St. Louis have devised a new method that allows them to extract the lead from these "point-of-use" filters, providing a clearer picture of what's coming out of the faucet.

And they can do it in less than an hour.

Their research was published this past summer in the journal Environmental Science: Water Research & Technology.

The problem with just collecting a one-liter sample is that "We don't know how long it was in contact with that lead pipe or if it just flowed through quickly. Everyone's water use patterns are different," said Daniel Giammar, the Walter E. Browne Professor of Environmental Engineering in the Department of Energy, Environmental & Chemical Engineering.

"Collecting a single liter is not a good way of assessing how much lead a resident would be exposed to if not using a filter," he said. "To do that, you'd need to see all that the person was drinking or using for cooking."

A better method would be to collect the lead from a filter that had been in use long enough to provide an accurate picture of household water use. Most of the commercial filters for sale at any major retail store will last for about 100 gallons -- 40 times the amount of the typical water sample.

The idea to use filters in this way isn't new, but it hasn't been done very efficiently, precisely because the filters do such a good job at holding onto the lead.

Giammar said he had probably heard about this method previously, but a light went off after a conversation about indoor air quality. He had been talking to a professor at another institution who was monitoring indoor air quality using a box that sucked in air, collecting contaminants in a tube. The user can then remove the collection tube and send it to a lab to be analyzed.

"I said, 'Let's do what you're doing with air,'" pull water through a filter, collect contaminants and then analyze them. "Then we realized, they already make and sell these filters."

Liberating the lead

Point-of-use filters are typically made of a block of activated carbon that appears solid, almost like a lump of coal. The water filters through tiny pores in the carbon; the carbon binds to the lead, trapping it before the water flows out of the faucet.

"If you want to take the lead out of the water, you need something that is really good at strongly holding on to it," which carbon is, Giammar said.

"So we had to hit it with something even stronger to pull that lead off."

The solution? Acid.

Working with senior Elizabeth Johnson, graduate student Weiyi Pan tried different methods, but ultimately discovered that slowly passing an acidic solution through the filter would liberate 100% of the lead.

The entire process took about two liters of acid and about a half hour.

In the near future, Giammar sees the filters being put to use for research, as opposed to being put in the trash.

"The customer has a filter because they want to remove lead from the water. The water utility or researcher wants to know how much lead is in the home's water over some average period of time," Giammar said. Even if the customer doesn't care, they've got this piece of data that usually they'd just throw away.

"We'd rather them send it to their utility service, or to us, and we can use it to get information."

CHAPEL HILL, N.C.--A new study by scientists at UNC Lineberger Comprehensive Cancer Center and colleagues published Oct. 30, 2020, in Science, showed that mice exposed to potentially lethal levels of total body radiation were protected from radiation damage if they had specific types of bacteria in their gut. Radiation absorbed in a clinical setting or during an accidental exposure can cause damage to tissues. In this study, the bacteria mitigated radiation exposure and enhanced the recovery of blood cell production as well as repair of the gastrointestinal (GI) tract.

The researchers noted that only an 'elite' set of mice had a high abundance of two types of bacteria, Lachnospiraceae and Enterococcaceae, in their guts that strongly countered the effects of the intense radiation. Importantly for humans, these two types of bacteria were found to be abundant in leukemia patients with mild GI symptoms who underwent radiotherapy.

The study showed that the presence of the two bacteria led to an increased production of small molecules known as propionate and tryptophan. These metabolites provided long-term protection from radiation, lessened damage to bone marrow stem cell production, mitigated the development of severe gastrointestinal problems and reduced damage to DNA. Both metabolites can be purchased in some countries as health supplements but there is currently no evidence that the supplements could aid people exposed to intense forms of radiation.

"This truly trans-UNC collaborative effort showed that these beneficial bacteria caused a profound change in gut metabolites," said corresponding author Jenny P.Y. Ting, PhD, William Rand Kenan Professor of Genetics in the UNC School of Medicine and a UNC Lineberger immunology program co-leader.

Damage to bodily organs from high levels of radiation, either from accidental exposure, cancer radiotherapy, targeted radiation attacks, among other forms of exposure, can lead to serious illness and even death. Blood cells in the body as well as tissues in the GI tract renew quickly and therefore remain particularly susceptible to radiation damage. On the protective side, however, the GI tract hosts over 10 trillion microbial microorganisms that could play an important role in limiting radiation-induced damage.

"Substantial federal efforts have been made to mitigate acute radiation symptoms -- however, it remains a long-standing and unresolved problem," said first study author Hao Guo, PhD, a postdoctoral fellow in Ting's lab. "Our work produced a comprehensive dataset of bacteria and metabolites that can serve as a powerful resource to identify actionable therapeutic targets in future microbiome studies."

Because radiotherapy that is widely used to treat cancer often leads to GI side-effects, the investigators wanted to understand how their experiments in mice could translate to people. They worked with colleagues at Duke University, Memorial Sloan Kettering and Weill Cornell Medical College, and studied fecal samples from 21 leukemia patients due to receive radiation therapy as part of an arduous stem cell transplant conditioning. The scientists found that patients with shorter periods of diarrhea had significantly higher abundances of Lachnospiraceae and Enterococcaceae than patients with longer periods of diarrhea. These findings correlated closely with the researcher's findings in mice although Ting cautions that much larger studies are needed to verify these conclusions.

Importantly for potential human use, in mice that were supplemented with Lachnospiraceae, the benefits of cancer radiotherapy were not lessened.

"Granulocyte-colony stimulating factor is the only drug that has been approved by the FDA as an effective countermeasure for high-dose radiation exposure, but it is expensive and has potential adverse side-effects," said Ting. "However, bacteria that we can cultivate, and especially metabolites that are relatively inexpensive and already elements in the food we eat, may be a good alternative."

The researchers are hoping to launch a clinical trial soon in people to test the benefits of giving these metabolites to patients receiving radiation.

ORLANDO, Oct. 30, 2020 - The increase in online education has allowed a new type of teacher to emerge ¬-- an artificial one. But just how accepting students are of an artificial instructor remains to be seen.

That's why researchers at the University of Central Florida's Nicholson School of Communication and Media are working to examine student perceptions of artificial intelligence-based teachers.

Some of their findings, published recently in the International Journal of Human-Computer Interaction, indicate that for students to accept an AI teaching assistant, it needs to be effective and easy to talk to.

The hope is that by understanding how students relate to AI-teachers, engineers and computer scientists can design them to easily integrate into the education experience, says Jihyun Kim, an associate professor in the school and lead author of the study.

"To use machine teachers effectively, we need to understand students' perceptions toward machine teachers, their learning experiences with them and more," Kim says. "This line of research is needed to design effective machine teachers that can actually facilitate positive learning experiences."

AI teaching assistants can help ease a teacher's workload, such as by responding to commonly asked questions by students. These questions, which often appear each semester and become numerous in online classes with hundreds of students, can become a large task for a teacher. The quick delivery of answers also helps students.

An example of an AI teaching assistant is one named Jill Watson that was created by a researcher at the Georgia Institute of Technology. Jill was fed the thousands of questions and answers commonly asked in the researcher's online class that he'd taught over the years. With some additional learning and tweaks, Jill was eventually able to answer the students' commonly asked questions accurately without any human assistance as if she was one of the researcher's human teaching assistants.

For the UCF study, the researchers asked respondents to read a news article about an AI teaching assistant used in higher education, and then they surveyed the students' perceptions of the technology.

The finding that an AI-based teaching assistant that students were most likely to accept was one that was useful and was easy to communicate with points to the importance of having an effective AI-system, Kim says.

"I hope our research findings help us find an effective way to incorporate AI agents into education," she says. "By adopting an AI agent as an assistant for a simple and repetitive task, teachers would be able to spend more time doing things such as meeting with students and developing teaching strategies that will ultimately help student learning in meaningful ways."

HOUSTON - (Oct. 30, 2020) - Let's call it the Texas two-step, but for molecules.

Rice University scientists have developed a method to reduce alkenes, molecules used to simplify synthesis, to more useful intermediates for drugs and other compounds via a dual-catalyst technique known as cooperative hydrogen atom transfer, or cHAT.

The process enables the hydrogenation of alkenes, hydrocarbons that contain a carbon-carbon double bond, in a simpler and more environmentally friendly way.

The work by Rice chemist Julian West and postdoctoral researcher Padmanabha Kattamuri is detailed in the Journal of the American Chemical Society.

In each step, a catalyst contributes a single electron and a proton. The cHAT twist is that both reactions happen in one synergistic process, the second catalyst taking over as soon as the first is done.

"The fundamental reaction of hydrogenation is super useful for making molecules," said West, who joined Rice last year with funding from the Cancer Prevention and Research Institute of Texas (CPRIT). "There are a few elements that are really good at this, and can do a lot of different transformations, but they're very expensive and not the most sustainable."

Because cHAT employs Earth-abundant iron and sulfur as catalysts, it costs far less than industry-standard methods that rely on expensive noble metals like platinum, palladium, gold and silver, as well as hydrogen gas and oxidizing reagents that create toxic waste.

The goal is to make hydrogen atoms more available to react with other molecules of choice to form new compounds. The cHAT process employs no added oxidants, works with a variety of substrates and is highly scalable. The dual-catalyst approach also serves to produce hydrogenation diastereomers, or a different form of the same product molecule that can't be made with noble metals.

West used a baseball analogy to describe cHAT. "If you remember 'Moneyball,' you know that instead of trying to hire one superstar who can do everything but is really expensive, it's better to get a few bit players and have them work together to achieve a similar transformation," he said.

"Furthermore, through teamwork, we introduced a strategy to get us to new variations of our products as well," West said. "By combining dirt-cheap iron with an organic sulfur compound, we were able to cobble together a nice win-win. The iron catalyst tees up the process by giving it one hydrogen atom, and gets out of the way. Then the sulfur can come in and give it the second one."

He noted flammable hydrogen gas is a common reagent in industrial hydrogenation. "Our process uses this simple, bench-stable reagent, phenylsilane, as a hydrogen source," West said. "We just add it to ethanol with both catalysts and the alkene. And ethanol is a green solvent as well.

"And when you're making drugs on the ton scale you want to avoid generating tons of toxic solvent waste," he said. "That's something to avoid at all costs. So this could be a big win for pharmaceutical companies."

He said his lab is working to configure its catalysts to produce a variety of products. "That would give us a lot of chemical complexity and diversity from a single starting material," West said. "We want to know if we can exert this high level of control over the process."

CHAPEL HILL, N.C.--Both cancer patients and their medical teams found it beneficial when patients shared their symptoms in real time using a web- or telephone-based reporting system, according to a national multi-institutional study.

Ethan Basch, MD, MSc, at the University of North Carolina Lineberger Comprehensive Cancer Center, and his colleagues reported in the journal JCO Clinical Cancer Informatics findings from the PRO-TECT trial, which is evaluating the use of electronic patient-reported outcomes (ePROs) among adults receiving outpatient treatment for advanced and metastatic cancers.

"Our prior research showed that using a web-based system for patients to self-report symptoms to their cancer care team improves patient satisfaction, quality of life, physical function, reduces emergency room visits and lengthens survival," said Basch, director of UNC Lineberger's Cancer Outcomes Research Program and the Richard M. Goldberg Distinguished Professor and chief of oncology at the UNC School of Medicine. "However, it has not been clear whether this approach could be widely used in cancer practices across the U.S. or be seen as useful or valuable by patients and providers. It is essential with any strategy for improving care to make sure that people will actually use it and find it valuable."

In the new study, the researchers conducted a cluster-randomized controlled study at 52 community-based oncology practices across the United States. Half of the practices were assigned to use ePROs as part of the standard of care.

Participants in the study's intervention arm were prompted every week for a year to report their symptoms and well-being. This involved using a website or an automated telephone program to answer a series of questions about their symptoms, such as pain, nausea and depression, as well as their physical functioning and financial health. The responses had a pre-assigned value on a five-point scale. When a patient reported worsening or severe symptoms, they were sent an email with information on symptom management and a nurse was alerted in real-time to intervene.

To measure whether the ePRO process and information gathered provided value, as well as to identify challenges, the researchers surveyed the patients and clinicians. Patients provided feedback three months after they started on the study and when they completed it. Nurses and physicians shared their assessment on clinical usefulness after they had worked with the system for six months or more.

The majority of the 496 patients surveyed found the PRO-TECT digital ePRO system was easy to understand (95%) and use (93%), and the questions were relevant to their care (91%). Most of the 57 nurses responded that the information was helpful for clinical documentation (79%) and useful for patient care (75%). Of the 39 oncologists surveyed, most found ePRO information useful (91%).

Though clinicians said the ePRO system was useful overall, some reported the information collected had limited value. Sixteen percent of the nurses surveyed said it rarely or never improved discussions with patients, and 14% said it didn't improve care quality. Nearly 30% of physicians said they rarely used patient-reported information to shape their discussions with patients. Also, some nurses felt they received too many symptom alerts, yet 93% wanted to receive future alerts for severe symptoms.

"There is clearly a lot of enthusiasm from patients to connect to their care team through electronic real-time approaches, and providers also recognize this value, but we know it isn't perfect," Basch said. "Our findings lay a path forward for determining the best ways to integrate patient-reported outcomes in oncology practice."

Basch said a number of issues need to be addressed to encourage clinics and hospitals to consider using ePRO systems. The technology must be easy for patients and providers to use. Workflows may need to be modified to give nurses more time to respond to symptom alerts. Basch said it would be helpful to develop standardized ways to teach patients how to use the system and to remind them of the importance of using it. In addition, it is important to continuously monitor and troubleshoot a program while it is being implemented.

"Patient reported outcomes are well accepted and seen as valuable for quality care by patients and providers, and they improve patient engagement and experience," Basch said. "Models for health systems to successfully implement PRO programs are needed, likely based on quality improvement approaches. For wide implementation to be effective, a financial model will also be helpful for PROs, most likely through direct reimbursement from insurance companies, or as a key component of value-based alternative payment arrangements between health systems and insurance payers."

Subarctic regions are facing rapid changes in climate and land-use intensity. An international research team recently completed an investigation to see how these changes are affecting the food webs and fish communities of lakes in northern Finland. Biomasses and omega-3 fatty acids, EPA and DHA, were determined from the algal producers at the base of food web to large carnivorous fish from 20 lakes along a pronounced climatic and productivity gradient. Increasing nutrient load and rising temperature shift food webs towards murky water adapted communities.

The team measured amount of fish and invertebrates from 20 subarctic lakes along climate and productivity gradient and determined the nutritional quality of organisms in each lake by measuring valuable omega-3 fatty acids, EPA and DHA, from primary producer algae communities to top predators.

Researchers found major differences in the clear and murky water communities. Increasing temperature and productivity increased biomass of algal and cyprinid fish communities.

Professor Kimmo Kahilainen from University of Helsinki, Lammi Biological Station, coordinated this lake research program.

"What we find in these food webs was community shift from clear water to murky lakes. We get a lot of fish from blue-green algal covered lakes, but there were no salmonid fishes anymore and the fish catch consisted almost exclusively of roach" says Kahilainen.

Changes in fatty acid producing algal communities

Biomass in lake food webs is largely composed of water, carbohydrates, proteins and lipids. Part of lipids are nutritionally very important including essential omega-3 fatty acids, such as EPA and DHA, which are efficiently produced by certain algae, such as diatoms in subarctic regions.

Invertebrates consume these algal basal producers and their EPA and DHA are transferred through the food web.
Researchers measured EPA and DHA content from whole food web from algae to carnivorous fish in each lake.

"Algal community changed from diatoms to blue-green algae and their quality decreased from clear to murky lakes, similar decreasing quality was also observed in invertebrates", says the lead author of study Mr Ossi Keva, a PhD student from University of Jyväskylä.

Despite decreasing prey item quality, the hypothesised cascading effects on fish was not observed. Instead, increasing fish biomass in murky lakes actually led to an increase in total fatty acids.

"Food webs in warmer and more productive environment do contain more fish and fatty acids, while the fish species itself shift from highly valued salmonids towards cyprinid dominated communities. Northern Finnish pristine subarctic lakes are not getting clearer in future, the change is more likely towards warmer and murky lakes modifying food web communities as well", Keva summarises.

Researchers from the University of Kent, the Goethe-University in Frankfurt am Main (Germany), and the Hannover Medical School (Germany) have identified a drug with the potential to provide a treatment for COVID-19.

The international team led by Professor Martin Michaelis, Dr Mark Wass (both School of Biosciences, University of Kent), and Professor Jindrich Cinatl (Institute of Medical Virology, Goethe-University) found that the approved protease inhibitor aprotinin displayed activity against SARS-CoV-2, the coronavirus that causes COVID-19, in concentrations that are achieved in patients. Aprotinin inhibits the entry of SARS-CoV-2 into host cells and may compensate for the loss of host cell protease inhibitors that are downregulated upon SARS-CoV-2 infection.

Aprotinin aerosols are approved in Russia for the treatment of influenza and could be readily tested for the treatment of COVID-19.

Professor Martin Michaelis said: 'The aprotinin aerosol has been reported to be tolerated extremely well in influenza patients. Hence, it may have a particular potential to prevent severe COVID-19 disease when applied early after diagnosis.'

Optical barcodes enable detection and tracking via unique spectral fingerprints. They've been widely applied in areas ranging from multiplexed bioassays and cell tagging to anticounterfeiting and security. Yu-Cheng Chen of the Bio+Intelligent Photonics Laboratory at Nanyang Technological University notes that the concept of optical barcodes typically refers to a fixed spectral pattern corresponding to a single target.

"Optical barcodes have lacked the capability to characterize dynamic changes in response to analytes through time," says Chen. Thanks to Chen's research, that's about to change.

Chen's group recently developed bioresponsive dynamic barcodes, introducing the concept of resonance energy transfer at the interface of the microcavity. As reported in Advanced Photonics, the team demonstrated the barcode experimentally to detect molecules in a droplet. The radiative energy from a single microdroplet is transferred to binding biomolecules, converting dynamic biomolecular information into more than trillions of distinctive photonic barcodes.

Cavity-enhanced radiative energy transfer

The system is based on a whispering-gallery mode resonator (WGMR). The majority of WGMRs are classified as passive. As such, they require evanescent wave coupling and operate based on mode changes induced by perturbations. "In contrast," explains Chen, "active resonators that utilize the analyte as a gain medium can support free-space excitation and collection to acquire more biological information from emission signals."

According to Chen, the trouble when considering molecular detection is the mode occupation factor of the analyte outside the cavity: It is only a few tenths from that inside the cavity, leading to a reduced effective Q-factor and unsatisfactory signal-to-noise ratio. The concept of resonant energy transfer separates donor molecules and acceptor molecules at the cavity interface, where radiative energy transfer happens. Radiative energy transfer is accompanied by electromagnetic radiation (unlike conventional non-radiative fluorescence resonance energy transfer, known as FRET). Because of that radiation, energy transfer can occur even in situations where the donor and acceptor are separated.

"In the presence of cavity-enhanced mechanisms, efficient energy transfer and coupling between donors and acceptors may lead to enhanced light-matter interactions and signal-to-noise ratio," says Chen.

The developed system takes advantage of an effect whereby the high concentration of dye (donor) inside the microdroplet triggers a cavity-enhanced energy transfer to excite the molecules (acceptor) attached to the cavity interface.

"When biomolecules bind to the cavity interface, the number of binding molecules alters the amount of energy transfer, resulting in distinctive modulated fluorescence emission peaks," says Chen. Dynamic spectral barcoding was achieved by a significant improvement in the signal-to-noise ratio upon binding to target molecules.

According to the authors, this biomolecular encoding system illuminates a beacon for real-time intermolecular interaction and can greatly increase the complexity of an encoding system. They believe the concept can be widely applied in many biosensing applications and optical encryption.

Read the open-access, peer reviewed research article by Yunke Zhou et al., "Dynamic photonic barcodes for molecular detection based on cavity-enhanced energy transfer." Adv. Photonics 2(6), 066002 , doi 10.1117/1.AP.2.6.066002.

Boston - While current antiretroviral treatments for HIV are highly effective, data has shown that people living with HIV appear to experience accelerated aging and have shorter lifespans - by up to five to 10 years - compared to people without HIV. These outcomes have been associated with chronic inflammation, which could lead to the earlier onset of age-associated diseases, such as atherosclerosis, cancers, or neurocognitive decline. A new study led by researchers at Boston Medical Center examined what factors could be contributing to this inflammation, and they identified the inability to control HIV RNA production from existing HIV DNA as a potential key driver of inflammation. Published in The Journal of Infectious Diseases, the results underscore the need to develop new treatments targeting the persistent inflammation in people living with HIV in order to improve outcomes.

After infection, HIV becomes a part of an infected person's DNA forever, and in most cases, infected cells are silent and do not replicate the virus. Occasionally, however, RNA is produced from this HIV DNA, which is a first step towards virus replication. Antiretroviral treatments help prevent HIV and AIDS-related complications, but they do not prevent the chronic inflammation that is common among people with HIV and is associated with mortality.

"Our study set out to identify a possible association between HIV latently infected cells with chronic inflammation in people with HIV who have suppressed viral loads," said Nina Lin, MD, a physician scientist at Boston Medical Center (BMC) and Boston University School of Medicine (BUSM).

For this study, researchers had a cohort of 57 individuals with HIV who were treated with antiretroviral therapy. They compared inflammation in the blood and various virus measurements among younger (age less than 35 years) and older (age greater than 50 years) people living with HIV. They also compared the ability of the inflammation present in the blood to activate HIV production from the silent cells with the HIV genome. Their results suggest that an inability to control HIV RNA production even with antiretroviral drugs correlates with inflammation.

"Our findings suggest that novel treatments are needed to target the inflammation persistent in people living with HIV," said Manish Sagar, MD, an infectious diseases physician and researcher at BMC and the study's corresponding author. 'Current antiretroviral drugs prevent new infection, but they do not prevent HIV RNA production, which our results point as a potential key factor driving inflammation in people living with HIV."

According to the Centers for Disease Control and Prevention, it is estimated that 1.2 million Americans are living with HIV; however, approximately 14 percent of these individuals are not aware that they are infected. Another CDC reporter found that of those diagnosed and undiagnosed with HIV in 2018, 76 percent had received some form of HIV care; 58 percent were retained in care; and 65 percent had undetectable or suppressed HIV viral loads. Antiretroviral therapy prevents HIV progression and puts the risk of transmission almost to zero.

The authors note that these results need to be replicated in larger cohorts. "We hope that our study results will serve as a springboard for examining drugs that stop HIV RNA production as a way to reduce inflammation," added Sagar, also an associate professor of medicine and microbiology at BUSM.