Engineers devise a recipe for improving any autonomous robotic system

by Jennifer Chu, Massachusetts Institute of Technology

A new general-purpose optimization tool can improve the performance of many 

autonomous robotic systems. Shown here is a hardware demonstration in which

 the tool automatically optimizes the performance of two robots working together

 to move a heavy box. Credits: Courtesy of the researchers

Autonomous robots have come a long way since the fastidious Roomba. In recent years, artificially intelligent systems have been deployed in self-driving cars, last-mile food delivery, restaurant service, patient screening, hospital cleaning, meal prep, building security, and warehouse packing.

Each of these robotic systems is a product of an ad hoc design process specific to that particular system. In designing an autonomous robot, engineers must run countless trial-and-error simulations, often informed by intuition. These simulations are tailored to a particular robot's components and tasks, in order to tune and optimize its performance. In some respects, designing an autonomous robot today is like baking a cake from scratch, with no recipe or prepared mix to ensure a successful outcome.

Now, MIT engineers have developed a general design tool for roboticists to use as a sort of automated recipe for success. The team has devised an optimization code that can be applied to simulations of virtually any autonomous robotic system and can be used to automatically identify how and where to tweak a system to improve a robot's performance.

The team showed that the tool was able to quickly improve the performance of two very different autonomous systems: one in which a robot navigated a path between two obstacles, and another in which a pair of robots worked together to move a heavy box.

Credit: Charles Dawson

The researchers hope the new general-purpose optimizer can help to speed up the development of a wide range of autonomous systems, from walking robots and self-driving vehicles, to soft and dexterous robots, and teams of collaborative robots.

The team, composed of Charles Dawson, an MIT graduate student, and ChuChu Fan, assistant professor in MIT's Department of Aeronautics and Astronautics, will present its findings later this month at the annual Robotics: Science and Systems conference in New York.

Inverted design

Dawson and Fan realized the need for a general optimization tool after observing a wealth of automated design tools available for other engineering disciplines.

"If a mechanical engineer wanted to design a wind turbine, they could use a 3D CAD tool to design the structure, then use a finite-element analysis tool to check whether it will resist certain loads," Dawson says. "However, there is a lack of these computer-aided design tools for autonomous systems."

Normally, a roboticist optimizes an autonomous system by first developing a simulation of the system and its many interacting subsystems, such as its planning, control, perception, and hardware components. She then must tune certain parameters of each component and run the simulation forward to see how the system would perform in that scenario.

Only after running many scenarios through trial and error can a roboticist then identify the optimal combination of ingredients to yield the desired performance. It's a tedious, overly tailored, and time-consuming process that Dawson and Fan sought to turn on its head.

"Instead of saying, 'Given a design, what's the performance?' we wanted to invert this to say, 'Given the performance we want to see, what is the design that gets us there?'" Dawson explains.

The researchers developed an optimization framework, or a computer code, that can automatically find tweaks that can be made to an existing autonomous system to achieve a desired outcome.

The heart of the code is based on automatic differentiation, or "autodiff," a programming tool that was developed within the machine learning community and was used initially to train neural networks. Autodiff is a technique that can quickly and efficiently "evaluate the derivative," or the sensitivity to change of any parameter in a computer program. Dawson and Fan built on recent advances in autodiff programming to develop a general-purpose optimization tool for autonomous robotic systems.

"Our method automatically tells us how to take small steps from an initial design toward a design that achieves our goals," Dawson says. "We use autodiff to essentially dig into the code that defines a simulator, and figure out how to do this inversion automatically."

Building better robots

The team tested their new tool on two separate autonomous robotic systems, and showed that the tool quickly improved each system's performance in laboratory experiments, compared with conventional optimization methods.

The first system comprised a wheeled robot tasked with planning a path between two obstacles, based on signals that it received from two beacons placed at separate locations. The team sought to find the optimal placement of the beacons that would yield a clear path between the obstacles.

They found the new optimizer quickly worked back through the robot's simulation and identified the best placement of the beacons within five minutes, compared to 15 minutes for conventional methods.

The second system was more complex, comprising two wheeled robots working together to push a box toward a target position. A simulation of this system included many more subsystems and parameters. Nevertheless, the team's tool efficiently identified the steps needed for the robots to accomplish their goal, in an optimization process that was 20 times faster than conventional approaches.

"If your system has more parameters to optimize, our tool can do even better and can save exponentially more time," Fan says. "It's basically a combinatorial choice: As the number of parameters increases, so do the choices, and our approach can reduce that in one shot."

The team has made the general optimizer available to download, and plans to further refine the code to apply to more complex systems, such as robots that are designed to interact with and work alongside humans.

"Our goal is to empower people to build better robots," Dawson says. "We are providing a new building block for optimizing their system, so they don't have to start from scratch."A policy to enable the use of general-purpose manipulators in high-speed robot air hockey

More information: Paper: roboticsconference.org/program/papers/037/

Provided by Massachusetts Institute of Technology 

ROBOTS DON'T REVOLT

Increased army mechanization reduces the risk of a coup d'état

by Universitat Pompeu Fabra - Barcelona

Credit: Pixabay/CC0 Public Domain

A state's risk of a coup is negatively associated with its army's degree of mechanization, understood as the extent to which militaries depend on tanks and armored vehicles in relation to personnel.

This is the main conclusion of a study involving Abel Escribà-Folch, a senior lecturer with the UPF Department of Political and Social Sciences, together with Ioannis Choulis from the University of Essex (United Kingdom), Marius Mehrl, from the University of Munich (Germany), and Tobias Böhmelt, also from the University of Essex.

"While we do not necessarily question the tenet that mechanization strengthens the military, we show that more powerful militaries do not necessarily represent a greater threat to incumbent governments."

The study, recently published in the journal Comparative Political Studies, is one of the first to theoretically and empirically link the structure of military forces with the way coups arise, as well as the degree of mechanization of the army with states' civil-military relations.

According to the authors, in a coup d'état, the higher degree of mechanization of the armed forces increases their potential execution costs and hinders coordination, thus deterring potential conspirators.

Research challenging the logic of the 'guardianship dilemma'

The cornerstone of civil-military relations is the so-called guardianship dilemma: dependence on the armed forces to protect from external and internal threats places militaries in a fundamental position that they can use to take power. Therefore, the dilemma means that a stronger army should pose a greater threat to a state. The paradox lies in the fact that the very institution created to protect the political system is given enough power to become a threat to the system itself.

"Our research examines the practical implications of this dilemma and, under some circumstances, challenges the notion that more powerful militaries represent a greater threat to incumbent governments", the authors state. And they add: "While we do not necessarily question the tenet that mechanization strengthens the military, we show that more powerful militaries do not necessarily represent a bigger threat to incumbent governments".

Having tanks, vehicles and weaponry would help keep militaries content with the status quo and reduce incentives for staging a coup.

Having tanks, vehicles and weaponry would help keep militaries content with the status quo and reduce incentives for staging a coup. But, as the authors suggest, this would not be the only mechanism: militaries prioritize avoiding fratricidal conflicts between members of the army, and mechanization can increase the risks of confrontation and the costs derived from it and from the lack of coordination between units. In contexts of uncertainty and high potential execution costs in urban contexts, a coup becomes less likely.

For their study, the authors performed a quantitative analysis and used different prediction and prognostication techniques, and robustness controls, a country-level aggregate database on mechanization levels and coups over four decades (1979-2019) of all military organizations in the world, including democracies. They focused on ground combat forces, since in the vast majority of cases, they are the ones that stage coups.

Mechanization can harm the state's counterinsurgency

One offshoot from the study is that structural changes in armies' organization and equipment, including mechanization, can lead to indirect negative consequences. "The result we have reached complements or relates to those of other authors, who have found that higher levels of mechanization reduce the counterinsurgent capacity of the armed forces, that is, their ability to confront domestic armed insurgencies, which translates into longer civil wars and a lower proportion of government victory in these conflicts," Abel Escribà-Folch notes.

Therefore, according to the authors, the fact that governments increase their investment in mechanization is useful to reduce the risk of coups d'état, but conversely, it can have harmful consequences for the counterinsurgent effectiveness of the militaries. "Investing in mechanization means that governments shift risk from coups to internal insurgencies, which are less frequent and have a lower success rate," they conclude.

Does U.S. military training incubate coups in Africa? The jury is still out

More information: Ioannis Choulis et al, How Mechanization Shapes Coups, Comparative Political Studies (2022). DOI: 10.1177/00104140221100194

Provided by Universitat Pompeu Fabra - Barcelona

RUSSIAN BOT SENT TO ISS

Typhoid-causing bacteria have become more resistant to essential antibiotics, spreading widely over past 30 years

by Lancet

Salmonella enterica serovar Typhi flagellar stain. Credit: Wikipedia, CC BY-SA 4.0

Bacteria causing typhoid fever are becoming increasingly resistant to some of the most important antibiotics for human health, according to a study published in The Lancet Microbe journal. The largest genome analysis of Salmonella enterica serovar typhi (S. typhi) also reveals that resistant strains—almost all originating in South Asia—have spread to other countries nearly 200 times since 1990.

Typhoid fever is a global public health concern, causing 11 million infections and more than 100,000 deaths per year. While it is most prevalent in South Asia—which accounts for 70% of the global disease burden—it also has significant impacts in sub-Saharan Africa, Southeast Asia, and Oceania, highlighting the need for a global response.

Antibiotics can be used to successfully treat typhoid fever infections, but their effectiveness is threatened by the emergence of resistant S. typhi strains. Analysis of the rise and spread of resistant S. typhi has so far been limited, with most studies based on small samples.

The authors of the new study performed whole-genome sequencing on 3,489 S. typhi isolates obtained from blood samples collected between 2014 and 2019 from people in Bangladesh, India, Nepal, and Pakistan with confirmed cases of typhoid fever. A collection of 4,169 S. typhi samples isolated from more than 70 countries between 1905 and 2018 was also sequenced and included in the analysis.

Resistance-conferring genes in the 7,658 sequenced genomes were identified using genetic databases. Strains were classified as multidrug-resistant (MDR) if they contained genes giving resistance to classical front-line antibiotics ampicillin, chloramphenicol, and trimethoprim/sulfamethoxazole. The authors also traced the presence of genes conferring resistance to macrolides and quinolones, which are among the most critically important antibiotics for human health.

The analysis shows resistant S. typhi strains have spread between countries at least 197 times since 1990. While these strains most often occurred within South Asia and from South Asia to Southeast Asia, East and Southern Africa, they have also been reported in the UK, U.S., and Canada.

Since 2000, MDR S. typhi has declined steadily in Bangladesh and India, and remained low in Nepal (less than 5% of typhoid strains), though it has increased slightly in Pakistan. However, these are being replaced by strains resistant to other antibiotics.

For example, gene mutations giving resistance to quinolones have arisen and spread at least 94 times since 1990, with nearly all of these (97%) originating in South Asia. Quinolone-resistant strains accounted for more than 85% of S. typhi in Bangladesh by the early 2000s, increasing to more than 95% in India, Pakistan, and Nepal by 2010. Mutations causing resistance to azithromycin—a widely used macrolide antibiotic—have emerged at least seven times in the past 20 years. In Bangladesh, strains containing these mutations emerged around 2013, and since then their population size has steadily increased. The findings add to recent evidence of the rapid rise and spread of S. typhi strains resistant to third-generation cephalosporins, another class of antibiotics critically important for human health.

Lead author Dr. Jason Andrews of Stanford University (U.S.) says, "The speed at which highly-resistant strains of S. typhi have emerged and spread in recent years is a real cause for concern, and highlights the need to urgently expand prevention measures, particularly in countries at greatest risk. At the same time, the fact resistant strains of S. typhi have spread internationally so many times also underscores the need to view typhoid control, and antibiotic resistance more generally, as a global rather than local problem."

The authors acknowledge some limitations to their study. There remains an underrepresentation of S. typhi sequences from several regions, particularly many countries in sub-Saharan Africa and Oceania, where typhoid is endemic. More sequences from these regions are needed to improve understanding of timing and patterns of spread. Even in countries with better sampling, most isolates come from a small number of surveillance sites and may not be representative of the distribution of circulating strains. As S. typhi genomes only cover a fraction of all typhoid fever cases, estimates of resistance-causing mutations and international spread are likely underestimated. These potential underestimates highlight the need to expand genomic surveillance to provide a more comprehensive window into the emergence, expansion, and spread of antibiotic-resistant organisms.Tracing travelers' typhoid to get an early warning of emerging threats

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More information: The international and intercontinental spread and expansion of antimicrobial-resistant Salmonella Typhi: a genomic epidemiology study, The Lancet Microbe (2022). DOI: 10.1016/S2666-5247(22)00093-3

Provided by Lancet 

Researchers make virus-fighting face masks

by Katie Malatino, Rensselaer Polytechnic Institute

Graphical abstract. Credit: ACS Applied Materials & Interfaces (2022). DOI: 10.1021/acsami.2c04165

Rensselaer Polytechnic Institute researchers have developed an accessible way to make N95 face masks not only effective barriers to germs, but on-contact germ killers. The antiviral, antibacterial masks can potentially be worn longer, causing less plastic waste as the masks do not need to be replaced as frequently.

Helen Zha, assistant professor of chemical and biological engineering and a member of the Center for Biotechnology and Interdisciplinary Studies at Rensselaer (CBIS), collaborated with Edmund Palermo, associate professor of materials science and engineering and a member of the Center for Materials, Devices, and Integrated systems (cMDIS) at Rensselaer, to fight infectious respiratory disease and environmental pollution with the perfect recipe to improve face masks.

"This was a multifaceted materials engineering challenge with a great, diverse team of collaborators," Palermo said. "We think the work is a first step toward longer-lasting, self-sterilizing personal protective equipment, such as the N95 respirator. It may help reduce transmission of airborne pathogens in general."

In research recently published in ACS Applied Materials & Interfaces, the team successfully grafted broad-spectrum antimicrobial polymers onto the polypropylene filters used in N95 face masks.

"The active filtration layers in N95 masks are very sensitive to chemical modification," said Zha. "It can make them perform worse in terms of filtration, so they essentially no longer perform like N95s. They're made out of polypropylene, which is difficult to chemically modify. Another challenge is that you don't want to disrupt the very fine network of fibers in these masks, which might make them more difficult to breathe through."

Zha and Palermo, along with other researchers from Rensselaer, Michigan Technological Institute, and Massachusetts Institute of Technology, covalently attached antimicrobial quaternary ammonium polymers to the fiber surfaces of nonwoven polypropylene fabrics using ultraviolet (UV)-initiated grafting. The fabrics were donated by Hills Inc. courtesy of Rensselaer alumnus Tim Robson.

"The process that we developed uses a really simple chemistry to create this non-leaching polymer coating that can kill viruses and bacteria by essentially breaking open their outer layer," said Zha. "It's very straightforward and a potentially scalable method."

The team used only UV light and acetone in their process, which are widely available, to make it easy to implement. On top of that, the process can be applied to already manufactured polypropylene filters, rather than necessitating the development of new ones.

The team did see a decrease in filtration efficiency when the process was applied directly to the filtration layer of N95 masks, but the solution is straightforward. The user could wear an unaltered N95 mask along with another polypropylene layer with the antimicrobial polymer on top. In the future, manufacturers could make a mask with the antimicrobial polymer incorporated into the top layer.

Thanks to a National Science Foundation Rapid Response Research (RAPID) grant, Zha and Palermo started their research in 2020 when N95 face masks were in short supply.

Healthcare workers were even reusing masks that were intended to be single use. Fast forward to 2022 and face masks of all types are now widely available. However, COVID rates are still high, the threat of another pandemic in the future is a distinct possibility, and single use, disposable masks are piling up in landfills.

"Hopefully, we are on the other side of the COVID pandemic," said Zha. "But this kind of technology will be increasingly important. The threat of diseases caused by airborne microbes is not going away. It's about time that we improved the performance and sustainability of the materials that we use to protect ourselves."

"Attaching chemical groups that kill viruses or bacteria on contact to polypropylene is a smart strategy," said Shekhar Garde, Dean of the School of Engineering at Rensselaer. "Given the abundance of polypropylene in daily life, perhaps this strategy is useful in many other contexts, as well."New study proposes a low cost, high efficiency mask design

More information: Mirco Sorci et al, Virucidal N95 Respirator Face Masks via Ultrathin Surface-Grafted Quaternary Ammonium Polymer Coatings, ACS Applied Materials & Interfaces (2022). DOI: 10.1021/acsami.2c04165

Journal information: ACS Applied Materials and Interfaces 

Provided by Rensselaer Polytechnic Institute 

Supporting teachers' mental health

by La Trobe University

Credit: Pixabay/CC0 Public Domain

La Trobe University research reveals an inexpensive "peer support" model used extensively by frontline health workers may be the solution to teacher burnout, which has left schools across the country unable to operate effectively.

Published in Teachers and Teaching, the study showed that of 40 educators who took part in the pilot program, all reported positive changes to their own mental health, better workplace culture and an increased ability to cope in the classroom.

La Trobe University Master of Education Coordinator, Dr. Anne Southall, said the need for mental health support structures for teachers was becoming increasingly clear.

"We know the pandemic put a lot of pressure on teachers—but, even before that, two thirds of educators experienced occupational stress, and over half identified as having anxiety," Dr. Southall said.

"Teachers are burning out and leaving the profession in droves, causing shortages across metro and regional schools. There is an urgent need to put structures in place to support them—and this model may prove critical,"

Dr. Southall said the trial showed that peer support in the form of "reflective circles" significantly improved teachers' ability to adapt to classroom challenges with a culture of openness, flexibility and compassion, allowing them to find solutions to complex problems together.

"The wonderful thing about this model is, once training has occurred, it is entirely self-supporting—schools don't have to employ a professional to run the program, and they can adapt the timing and structure to suit their needs," Dr. Southall said.

Over a three-year period at three regional Victorian schools, researchers trialed a peer supervision model, where critical reflection in a small group setting was used to generate strategies and solutions to complex challenges teachers were experiencing in the classroom—from disruptive students to unhelpful parents.

Associate Professor Fiona Gardner from La Trobe Rural Health School said systematic support structures such as reflective circles are a key pillar of allied health professions like social work and psychology, but the model was also well-suited to an education setting.

"We know that social workers and psychologists, who deal with incredibly complex, difficult and often traumatic circumstances, need peer support to ensure they can cope with the mental and emotional toll this takes on them," Associate Professor Gardner said.

"Teachers are finding they now have to take on similar roles in supporting their students, and the Reflective Circle Education Model can provide them with a space to develop a deeper understanding of their personal and professional interactions and encourage mutual support."

Co-Principal of St Peter's Primary School in Bendigo, Jen Roberts, said the model could make an enormous difference to the well-being of teachers at the school.

"Teaching is a complex and stressful profession, with teachers finding their roles are increasingly changing. With one in seven students experiencing mental health issues, teachers are often required to provide mental health support, while having no formal structures in place to safeguard their own emotional well-being," Co-Principal Mick Chalkley said.

Teachers taking part in the study reported that reflective circles generated significant mutual support between colleagues, helped them see things differently and build confidence and flexibility to better meet the needs of students.Teacher and principal stress running at twice the rate of general working public, hindering pandemic recovery

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More information: Fiona Gardner et al, Effectively supporting teachers: a peer supervision model using reflective circles, Teachers and Teaching (2022). DOI: 10.1080/13540602.2022.2062727

Provided by La Trobe University 

Tackling air quality and COVID-19 in the classroom

by Victoria University of Wellington

Credit: Pixabay/CC0 Public Domain

As the days get colder, teachers not only face the usual seasonal battle of keeping classrooms at a comfortable temperature but also trying to reduce the COVID-19 virus count in the environment. How to reduce virus spread is important knowledge for teachers—just as it was a century ago when the 1918 flu pandemic hit.

In the same way that we expect people to understand the fundamentals of nutrition when planning a menu, we need a sound understanding of building science to get the healthiest, most productive and enjoyable environments in our buildings. How can teachers deal with classroom "fug" and COVID-19 this winter? Louise Starkey and Michael Donn explain.

The fug problem

A common approach in winter is to close classroom windows and turn on the heaters. However, if you walk into a crowded space that has been tightly closed for a time against the outdoor air, you will notice a distinct transition into what might politely be termed a fug.

This fug has high humidity and high carbon dioxide (CO2) levels, and is a natural product of people breathing. If this air is not removed and replaced with fresh air, CO2 levels will rise. And as this happens, stuffiness increases and the ability to concentrate drops significantly.

Building design typically aims for 1000 parts per million (ppm)—or fewer—of CO2 in the air. This standard was developed about 100 years ago and is based on diluting body odor to an acceptable level.

But body odor isn't the only worry.

For focused tasks, our ability to concentrate begins to decrease at CO2 levels above 1000 ppm and acute health symptoms start at concentrations over 5000 ppm.

Modern technology can now tell us when levels are too high: devices are being installed in New Zealand classrooms to alert schools when levels reach 800 ppm so they can act to reduce CO2.

COVID-19 in the mix

So, what can teachers and students do to lower CO2 as well as virus levels in the classroom?

In an era where heat pumps warm, cool and push air around a room, it is tempting to see the stuffiness as solvable by running the heat pump. Heat pumps may make the air feel fresher, but they're just circulating existing air without changing CO2 levels or removing virus contained within the air.

Therefore, these are not a good option to help concentration or reduce the risk of virus spread.

What about air purifiers? They are being installed in some classrooms. These devices recirculate the air in a space and "clean" it either through UV radiation or by filters. So they can help reduce virus levels in the air, but they do not lower CO2 and can only be half the answer.

Ventilation is the solution to lowering CO2 levels. Air ventilated from the outside into the classroom has lower CO2 levels than the air "polluted" by students and teachers breathing out CO2. One Danish research group found that "increased ventilation rates in classrooms have a positive effect on short-term concentration and logical thinking of children performing schoolwork."

Ventilation can be through open windows or a mechanical system that draws fresh air from the outside. For a classroom of 33 people, 0.5 square meters of open windows on opposite sides of the room provides adequate ventilation to keep CO2 levels down and concentration levels up by replacing the air about six times each hour.

This approach isn't new. Following the 1918 flu pandemic, "open air" classrooms were designed with windows on two sides of the room that could be opened to enable fresh air to flow through.

Ventilating the room with fresh air also reduces the virus count in the environment. Professor Richard Corsi, an air quality expert at the University of California Davis, estimates air in an enclosed space that has 700 to 800 ppm of CO2 might contain 0.8 to 1 percent COVID-19 virus during an outbreak when no one is wearing a mask. Masks reduce this risk further.

Opening windows may require increased heating—and noise distractions from outside the classroom will need to be managed. But this might be the price we have to pay to have comfortable and safe buildings in winter.

Poorly ventilated schools spread delta variant

Provided by Victoria University of Wellington 

Economic and psychosocial effects of the COVID-19 pandemic on the nations of the GCC

by David Bradley, Inderscience

Credit: Pixabay/CC0 Public Domain

A study in the Global Business and Economics Review looks at the economic and psychosocial effects of the COVID-19 pandemic on the nations of the GCC (the Gulf Cooperation Council).

Talla M. Aldeehani of the Department of Finance and Financial Institutions in the College of Business Administration at Kuwait University, in Kuwait, and Moid U. Ahmad of Scholeio Education in the National Capital Region (NCR), India, explain that they have investigated how government support may have ameliorated the detrimental psychosocial and economic effects of the pandemic on individuals and industry.

The team surveyed citizens of the GCC states and used moderation-mediation techniques and other analytical tools to draw conclusions from the data obtained. The GCC, more formally the Cooperation Council for the Arab States of the Gulf is an intergovernmental political and economic union that comprises Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates (UAE).

The fundamental conclusion is that government support significantly reduced stress levels in individuals during the period studied, October to December 2020. Loss of earnings caused by the pandemic being a major stress factor for workers with men aged 50 and over being worst affected economically. This period coincided with the second wave of infection from the coronavirus, SARS-CoV-2, and would have seen enforced lockdowns, quarantine, hospitality closures, and other restrictions in place in many places in an attempt to reduce the spread of the virus.

The researchers say that the conclusions they have drawn might have relevance to nations beyond the GCC. They suggest that policymakers might best serve their citizens and businesses by putting in place a technological framework and other measures to ensure a more effective response to a future pandemic.Bahrain records first coronavirus death in GCC

More information: Talla M. Aldeehani et al, Economical and psychosocial effects of COVID-19: evidence from the GCC economies, Global Business and Economics Review (2022). DOI: 10.1504/GBER.2022.123283

Provided by Inderscience 

 New, fully biodegradable cellulose membrane proves effective in oil-water separation

by KeAi Communications Co

The closed loop process of the degradable cellulose oil-water separation membrane. Credit: Institute of Coal Chemistry (CAS)

Oil spills and industrial pollution pose a huge threat to the ecological environment. Concerns over safety have seen an increased focus on improving the filtration of oily wastewater; for example, during the treatment of sewage. Membrane separation technology offers a promising and efficient option for treating that wastewater, particularly with its low energy consumption. However, it remains a challenge to find low-cost, strong and environmentally-friendly composite membranes that can achieve a high level of separation.

A group of researchers at Shanxi Institute of Coal Chemistry (part of the Chinese Academy of Sciences—CAS) have developed a new and improved method using two different cellulose materials. Their process allows them to obtain membrane materials for oil-water separation that are "all cellulose" (cellulose with two or more different crystal forms).

Importantly, as they outline in their study results, published in Green Energy & Environment, their membrane is friendly to the environment.

According to Prof. Tiansheng Deng, the paper's corresponding author, "oil-water separation membrane materials that have been widely used in recent years include vinylidene fluoride (PVDF), polypropylene (PP), polyacrylonitrile (PAN), nylon or their composites. However, these polymers are non-biodegradable and put further pressure on the environment."

To solve this problem, Prof. Deng and his group chose degradable cellulose derived from plants as a raw material and then bonded it with commercial cellulose filter paper, which is low in price and porous. They found that a large number of nanopores appear in the modified cellulose filter paper, which improve the membrane's barrier against oil droplets. When their separation membrane comes into contact with water, a cellulose hydrogel is formed that effectively separates oil-water mixture and oil in water emulsion.

Prof. Deng adds that "cellulose chains are tightly bonded by a hydrogen bond, with few defects, and the mechanical properties of the material are greatly improved. The high dry and wet mechanical properties of the membrane extend the ways in which it can be applied and help it to remain stable when used in water. We believe this is an important step forward in the treatment of pollution."\

Bacterial film separates water from oil

More information: Chizhou Wang et al, Efficient oil-water separation by novel biodegradable all cellulose composite filter paper, Green Energy & Environment (2022). DOI: 10.1016/j.gee.2022.03.013

Provided by KeAi Communications Co

Novel synthetic polymers could lead to greater crop yields for farmers

by University of Birmingham

Credit: Unsplash/CC0 Public Domain

Scientists at the University of Birmingham have invented a new method to encourage bacteria to form growth-promoting ecosystems that could be used to coat the roots of plant seedlings, which is expected to result in stronger, healthier plants, and higher crop yields in agriculture.

In nature, the roots of seedlings form mutually beneficial relationships with communities of microbes (fungi, bacteria, viruses) in soil, and exchange nutrients, allowing both the plant and the microbes to flourish. This is particularly critical in the early stages of a plant's life when the seedling is in a race against time to reach self-sufficient growth before the nutrients and energy stores in the seed run out.

Dr. Tim Overton, an applied microbiologist from the University's School of Chemical Engineering, and Dr. Francisco Fernandez-Trillo from the School of Chemistry led a team to develop novel synthetic polymers that stimulate the formation of these bacterial communities in a way that mirrors a natural process known as biofilm formation.

A biofilm is a finely orchestrated community of microbes, supported by matrix of biological polymers that forms a protective micro-environment and holds the community together.

The researchers worked jointly on a four-year project on how polymers interact with bacteria, which resulted in the synthesis of a group of acylhydrazone-based polymers.

These new polymers were designed to act as an adhesive scaffold, "seeding" the formation of a microorganism-polymer complex to initiate and expedite biofilm formation. Once the biofilm is formed, the bacteria become a self-sufficient and self-organizing community, and produce their own matrix to allow the transmission of nutrients and water, and the discharge of waste products.

The project involved Ph.D. students Pavan Adoni and Omar Huneidi, who subsequently progressed research showing the polymers aggregate bacteria, and improve biofilm formation. Critically, they also showed the process is fully reversible, and the biofilm can be dispersed by changing the environmental conditions. The results of these experiments and further studies will be published in 2022.

Pavan Adoni commented, "We anticipate that the polymer will ultimately be used as a seed coating, perhaps in conjunction with bacteria such as B. Subtilis, which is naturally present in soil, increases the stress tolerance of plants, and is currently used as a soil inoculant. We envisage a more targeted approach that only treats the seed, so that when it germinates the bacteria are ready to grow in the safe harbor environment provided by a microorganism polymer complex. Ultimately this should result in stronger plants, which grow more quickly, and have greater resilience to disease."

University of Birmingham Enterprise has filed a broad-based patent application covering the novel polymers, the method of forming the biofilm and the method of polymer cleaving, and its use to promote growth of a biofilm with any microorganism including those that can produce or deliver chemical or biological molecules.

The patent has now been licensed to specialist life science company PBL Technology, which invests in, protects and promotes emerging innovations from public research sources worldwide. In agriculture, PBL's technologies include crop genetics, crop treatments, precision agriculture and promoters and R&D tools.Researchers propose new strategy for prevention and treatment of dental caries

Provided by University of Birmingham 

Examining the impact of herbicide-resistant crops on weed management

by Cambridge University Press

Integrated weed management (IWM) tactics are needed to manage glyphosate-resistant kochia (Bassia scoparia) in glyphosate-resistant soybeans (Glycine max L.). Credit: Vipan Kumar & Phil Stahlman.

Herbicide-resistant crops are now commonplace in the U.S. and Canada. With proper stewardship, these same crop-trait technologies can also play a key role in integrated weed management—reducing the intensity of herbicide use and the selection pressure on weed populations. But does this weed management potential match the reality in the field

A team of university researchers recently reviewed 25 years of data on the impact of herbicide-resistant crops on integrated weed management in the Great Plains, Pacific Northwest and Canadian Prairies. In an article featured in the latest issue of the journal Weed Science, they say herbicide-resistant weeds are now ubiquitous in areas where herbicide-resistant crops are grown. While the magnitude of the issue can vary by crop, resistance trait and where the crop is grown, it is largely influenced by whether growers resist the temptation to rely solely on herbicide-resistant crops.

"Slowing the evolution of herbicide-resistant weeds will require diverse crop rotation sequences involving multiple herbicide-resistant and nonherbicide-resistant crops," says Caio Brunharo of Oregon State University, a member of the research team. "Unfortunately, though, few growers and land managers are adopting this approach."

The authors recommend adding new teeth to registration requirements and industry stewardship plans—backed by comprehensive training for seed retailers, agronomists and growers. They also suggest the use of financial incentives to promote adoption of proper stewardship practices.Research validates new control tactic for herbicide-resistant weeds in US soybean crops

More information: Caio A. C. G. Brunharo et al, Western United States and Canada perspective: are herbicide-resistant crops the solution to herbicide-resistant weeds?, Weed Science (2022). DOI: 10.1017/wsc.2022.6

Provided by Cambridge University Press