Computers Math

As a first-year college student in an introductory chemistry class sits down for their midterm, which might be their first stepping stone toward a career in academia, research or medicine, a thought may swirl through their head alongside valence numbers, molar masses and oxidation states — an anxiety that forms itself into a supposition: “Maybe people like me don’t belong in this class.”
That thought is called belonging uncertainty, a feeling of social insecurity related to a person’s identity. New research from the University of Utah shows that belonging insecurity in a STEM course, specifically a first-year chemistry course, can affect a student’s midterm scores, which can then feed back into the student’s belonging uncertainty. For students in groups that are underrepresented in STEM, there’s a danger that such a feedback loop could cause them to decide that science isn’t for them, deterring potential scientists from even entering a STEM field.
“Students in these early STEM courses face many struggles and challenges, such as learning to adjust their study strategies, that are normal for this academic transitional period from high school to college,” says chemistry professor Gina Frey. “The concern is that a student with a high belonging uncertainty has a less stable sense of belonging and will believe the struggles they encounter in these courses are due to their identities as opposed to a normal part of the academic transition that everyone faces in their early years at college.”
The research is published in the Journal of Chemical Education in a special issue on diversity, equity, inclusion and respect in chemistry education research and practice.
Sense of belonging and belonging uncertainty
Belonging uncertainty is different than simply a sense of belonging. A sense of belonging is an individual feeling, Frey says, (i.e. “Do I belong here?”) while belonging uncertainty is tied to the groups in which a person identifies. More

Scientists have launched a unique software that is able to perform highly complex simulations of a variety of biological processes.
Agent-based simulations (ABS) are powerful computational tools that help scientists understand complex biological systems. These simulations are an inexpensive and efficient way to quickly test hypotheses about the physiology of cellular tissues, organs, or entire organisms. However, many ABS do not take full advantage of available computational power, and the majority of ABS platforms on the market are designed with a particular use case in mind.
In a paper published by Bioinformatics, a consortium that includes the University of Surrey, CERN, Newcastle University, GSI Helmholtz Centre, University of Cyprus, University of Geneva, SCImPULSE Foundation and Immunobrain Checkpoint, unveil their open-source, multi-disciplinary simulation platform called BioDynaMo.
In the paper, the consortium details how BioDynaMo can simulate complex medical cases in neuroscience, oncology, and epidemiology, thanks to its ability to utilise multi-core CPUs and offload computations to hardware accelerators.
The team’s results show that BioDynaMo performs up to 945 times faster than current state-of-the-art baselines. The advances make it feasible to simulate each use case with one billion cells on a single server, showcasing the potential BioDynaMo has for computational biology research.
Dr Roman Bauer from the University of Surrey, co-founder of the BioDynaMo initiative and senior author of the study, said:
“I believe that if we are ever to tackle highly complex health issues such as Alzheimer, computer simulation tools like BioDynaMo will be critical for scientists moving forward.
“In this paper, we have shown that BioDynaMO’s excellent features and performance. It will help the scientists of tomorrow pitting hypotheses against each other to study their subtle or less so divergences. And more importantly, it will help biomedical research become a truly interdisciplinary field of the 21st century.”
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Using the internet during your retirement years can boost your cognitive function, a new study has found.
Researchers from Lancaster University Management School, the Norwegian University Science and Technology and Trinity College Dublin examined the cognitive function of more than 2,000 retired people from across Europe, and found that post-retirement internet usage is associated with substantially higher scores on tests.
The study, published in the Journal of Economic Behavior and Organization, uses data drawn from the Survey of Health, Ageing and Retirement in Europe (SHARE) that collects information about the health, employment history and socio-economic status of older people.
Focusing on a sample of 2,105 older people from Austria, Belgium, Denmark, France, Germany, Italy, Israel, Spain, Sweden and Switzerland who have been retired since 2004, researchers examined retirees’ cognitive function in both 2013 and 2015. They specifically focused on a word recall test, where individuals were asked to recall a list of 10 words immediately, and then again five minutes later.
Results found that, on average, people who used the internet after they retired were able to recall 1.22 extra words in the recall test compared to non-internet users. However, retirees who used the internet were also more likely to be male, younger, better educated, and have been retired for a shorter period. They also appear to be in better health — even though they drink and smoke more.
Dr Vincent O’Sullivan, a co-author from Lancaster University Management School said: “Our results reveal that using the internet, post-retirement, leads to a marked reduction in the rate of cognitive decline. More

Researchers from the University of Basel have developed an augmented reality app for smartphones in order to help people reduce their fear of spiders. The app has already shown itself to be effective in a clinical trial, with subjects experiencing less fear of real spiders after completing just a few training units with the app at home.
Fear of spiders is one of the most common phobias and leads to a variety of limitations in everyday life, as those affected seek to avoid situations involving spiders. For example, sufferers are known to avoid social occasions outdoors, visits to the zoo or certain travel destinations — or to excessively check rooms for spiders or avoid certain rooms, such as basements or lofts, altogether. One effective treatment for a fear of spiders is “exposure therapy,” in which patients are guided through therapeutic exposure to the situations they fear in order to gradually break down their phobia. This treatment is rarely used, however, because those affected are reluctant to expose themselves to real spiders.
To remedy this situation, the interdisciplinary research team led by Professor Dominique de Quervain has developed a smartphone-based augmented reality app called Phobys. Writing in the Journal of Anxiety Disorders, the researchers have reported promising results with this app designed to tackle the fear of spiders.
Phobys is based on exposure therapy and uses a realistic 3D spider model that is projected into the real world. “It’s easier for people with a fear of spiders to face a virtual spider than a real one,” explains Anja Zimmer, lead author of the study.
Effectiveness verified in a study
Zimmer and her colleagues analyzed the effectiveness of Phobys in a clinical trial involving 66 subjects. Over the course of two weeks, the participants — who all suffered from a fear of spiders — either completed six half-hour training units with Phobys or, in the case of the control group, were offered no intervention. Before and after treatment, the subjects approached a real spider in a transparent box as closely as their fear of spiders allowed. The group that had trained using Phobys showed significantly less fear and disgust in the real-life spider situation and was able to get closer to the spider than the control group.
The Phobys app offers nine different levels so that subjects can get closer to — and even interact with — the virtual spider. With each level, the tasks become more intensive and therefore more difficult. Each level ends with an assessment of one’s own fear and disgust, and the app decides whether the level should be repeated or the user can move on to the next one. The app also makes use of game elements, such as rewarding feedback, animation and sound effects, to maintain a high level of motivation.
Phobys is available in app stores
Following refinement with the help of GeneGuide AG (specifically, the MindGuide Division), a spin-off from the University of Basel, the app is now available in the app stores for iPhones and Android smartphones. People suffering from mild forms of a fear of spiders can use the app on their own. In the case of people who suffer from a serious fear of spiders, the researchers recommend that the app only be used with the supervision of a professional. The app allows users to test whether they are afraid of a virtual spider for free, while the training to reduce their fear of spiders can be purchased in the app.
The current study is one of several projects in progress at the Transfaculty Research Platform for Molecular and Cognitive Neurosciences, led by Professor Andreas Papassotiropoulos and Professor Dominique de Quervain, with the aim of improving the treatment of mental disorders through the use of new technologies and making these treatments widely available.
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Physics researchers at the University of Bath in the UK discover a new physical effect relating to the interactions between light and twisted materials — an effect that is likely to have implications for emerging new nanotechnologies in communications, nanorobotics and ultra-thin optical components.
In the 17th and 18th centuries, the Italian master craftsman Antonio Stradivari produced musical instruments of legendary quality, and most famous are his (so-called) Stradivarius violins. What makes the musical output of these musical instruments both beautiful and unique is their particular timbre, also known as tone colour or tone quality. All instruments have a timbre — when a musical note (sound with frequency fs) is played, the instrument creates harmonics (frequencies that are an integer multiple of the initial frequency, i.e. 2fs, 3fs, 4fs, 5fs, 6fs, etc.).
Similarly, when light of a certain colour (with frequency fc) shines on materials, these materials can produce harmonics (light frequencies 2fc, 3fc, 4fc, 5fc, 6fc, etc.). The harmonics of light reveal intricate material properties that find applications in medical imaging, communications and laser technology.
For instance, virtually every green laser pointer is in fact an infrared laser pointer whose light is invisible to human eyes. The green light that we see is actually the second harmonic (2fc) of the infrared laser pointer and it is produced by a special crystal inside the pointer.
In both musical instruments and shiny materials, some frequencies are ‘forbidden’ — that is, they cannot be heard or seen because the instrument or material actively cancels them. Because the clarinet has a straight, cylindrical shape, it supresses all of the even harmonics (2fs, 4fs, 6fs, etc.) and produces only odd harmonics (3fs, 5fs, 7fs, etc.). By contrast, a saxophone has a conical and curved shape which allows all harmonics and results in a richer, smoother sound. Somewhat similarly, when a specific type of light (circularly polarised) shines on metal nanoparticles dispersed in a liquid, the odd harmonics of light cannot propagate along the direction of light travel and the corresponding colours are forbidden.
Now, an international team of scientists led by researchers from the Department of Physics at the University of Bath have found a way to reveal the forbidden colours, amounting to the discovery of a new physical effect. To achieve this result, they ‘curved’ their experimental equipment.
Professor Ventsislav Valev, who led the research, said: “The idea that the twist of nanoparticles or molecules could be revealed through even harmonics of light was first formulated over 42 years ago, by a young PhD student — David Andrews. David thought his theory was too elusive to ever be validated experimentally but, two years ago, we demonstrated this phenomenon. Now, we discovered that the twist of nanoparticles can be observed in the odd harmonics of light as well. It’s especially gratifying that the relevant theory was provided by none other than our co-author and nowadays well-established professor — David Andrews!
“To take a musical analogy, until now, scientists who study twisted molecules (DNA, amino acids, proteins, sugars, etc) and nanoparticles in water — the element of life — have illuminated them at a given frequency and have either observed that same frequency or its noise (inharmonic partial overtones). Our study opens up the study of the harmonic signatures of these twisted molecules. So, we can appreciate their ‘timbre’ for the first time.
“From a practical point of view, our results offer a straightforward, user-friendly experimental method to achieve an unprecedented understanding of the interactions between light and twisted materials. Such interactions are at the heart of emerging new nanotechnologies in communications, nanorobotics and ultra-thin optical components. For instance, the ‘twist’ of nanoparticles can determine the value of information bits (for left-handed or right-handed twist). It is also present in the propellers for nanorobots and can affect the direction of propagation for a laser beam. Moreover, our method is applicable in tiny volumes of illumination, suitable for the analysis of natural chemical products that are promising for new pharmaceuticals but where the available material is often scarce.
PhD student Lukas Ohnoutek, also involved in the research, said: “We came very close to missing this discovery. Our initial equipment was not ‘tuned’ well and so we kept seeing nothing at the third-harmonic. I was starting to lose hope but we had a meeting, identified potential issues and investigated them systematically until we discovered the problem. It is wonderful to experience the scientific method at work, especially when it leads to a scientific discovery!”
Professor Andrews added: ”Professor Valev has led an international team to a real first in the applied photonics. When he invited my participation, it led me back to theory work from my doctoral studies. It has been amazing to see it come to fruition so many years later.”
The research was funded by The Royal Society, the Science and Technology Facilities Council (STFC) and the Engineering and Physical Science Research Council (EPSRC). More

A UCLA-led team of engineers and chemists has taken a major step forward in the development of microbial fuel cells — a technology that utilizes natural bacteria to extract electrons from organic matter in wastewater to generate electrical currents. A study detailing the breakthrough was recently published in Science. 
“Living energy-recovery systems utilizing bacteria found in wastewater offer a one-two punch for environmental sustainability efforts,” said co-corresponding author Yu Huang, a professor and chair of the Materials Science and Engineering Department at the UCLA Samueli School of Engineering. “The natural populations of bacteria can help decontaminate groundwater by breaking down harmful chemical compounds. Now, our research also shows a practical way to harness renewable energy from this process.” 
The team focused on the bacteria genus Shewanella, which have been widely studied for their energy-generation capabilities. They can grow and thrive in all types of environments — including soil, wastewater and seawater — regardless of oxygen levels.  
Shewanella species naturally break down organic waste matter into smaller molecules, with electrons being a byproduct of the metabolic process. When the bacteria grow as films on electrodes, some of the electrons can be captured, forming a microbial fuel cell that produces electricity. 
However, microbial fuel cells powered by Shewanella oneidensis have previously not captured enough currents from the bacteria to make the technology practical for industrial use. Few electrons could move quickly enough to escape the bacteria’s membranes and enter the electrodes to provide sufficient electrical currents and power.
To address this issue, the researchers added nanoparticles of silver to electrodes that are composed of a type of graphene oxide. The nanoparticles release silver ions, which bacteria reduce to silver nanoparticles using electrons generated from their metabolic process and then incorporate into their cells. Once inside the bacteria, the silver particles act as microscopic transmission wires, capturing more electrons produced by the bacteria.
“Adding the silver nanoparticles into the bacteria is like creating a dedicated express lane for electrons, which enabled us to extract more electrons and at faster speeds,” said Xiangfeng Duan, the study’s other corresponding author and a professor of chemistry and biochemistry at UCLA. 
With greatly improved electron transport efficiency, the resulting silver-infused Shewanella film outputs more than 80% of the metabolic electrons to external circuit, generating a power of 0.66 milliwatts per square centimeter — more than double the previous best for microbial-based fuel cells.
With the increased current and improved efficiencies, the study, which was supported by the Office of Naval Research, showed that fuel cells powered by silver-Shewanella hybrid bacteria may pave the way for sufficient power output in practical settings.
Bocheng Cao, a UCLA doctoral student advised by both Huang and Duan, is the first author of the paper. Other UCLA senior authors are Gerard Wong, a professor of bioengineering; Paul Weiss, a UC Presidential Chair and distinguished professor of chemistry and biochemistry, bioengineering, and materials science and engineering; and Chong Liu, an assistant professor of chemistry and biochemistry. Kenneth Nealson, a professor emeritus of earth sciences at USC, is also a senior author. More

In metal alloys, behaviour at the atomic scale affects the material’s properties. However, the number of possible alloys is astronomical. Together with an international team of colleagues, Francesco Maresca, an engineer at the University of Groningen, developed a theoretical model that allows him to rapidly determine the strength of millions of different alloys at high temperatures. Experiments confirmed the model predictions. The findings were published in Nature Communications on 16 September.
The discovery that iron became much stronger with the addition of a little bit of carbon was one of the discoveries that heralded the Industrial Revolution. ‘Tweaking the composition of a base metal by adding different elements, thus creating an alloy, has been important in human history,’ says Francesco Maresca, assistant professor at the Engineering and Technology institute Groningen (ENTEG), at the University of Groningen. As a civil engineer, he likes large structures such as bridges. But he is now studying metals at an atomic scale to find the best alloys for specific applications.
Dislocation
Maresca is particularly interested in high-entropy alloys (HEAs), which were first proposed some twenty years ago. These are complex alloys with five or more elements that can have all kinds of useful properties. But how to find the best one? ‘There are around forty metallic elements that are not radioactive or toxic and are therefore suitable for use in alloys. This gives us roughly 1078 different compositions,’ he explains. It is impossible to test a large fraction of these by simply making them.
This is why Maresca wanted a good theory to describe important properties of HEAs. One of those properties is high-temperature strength, essential in various applications ranging from turbine engines to nuclear power plants. The strength of an alloy depends largely on defects in the crystal structure. ‘Perfect crystals are the strongest, but these do not exist in real life materials.’ A major determinant of strength at high temperatures in body-centred cubic alloys is thought to be a screw dislocation, a dislocation in the lattice structure of a crystal in which the atoms are rearranged into a helical pattern. ‘These dislocations are very hard to model at the atomic scale,’ explains Maresca.
Composition
Another type of defect is edge dislocation, where an extra atomic plane is inserted into part of the crystal structure. Maresca: ‘It was believed that these dislocations have no effect on strength at high temperatures, because that was shown experimentally in pure metals. However, we found that they can determine strength in complex alloys.’ Edge dislocations are much easier to model and Maresca created an atomic-scale model for this dislocation in HEAs, which he then translated into a MATLAB script that could predict the engineering-scale strength of millions of different alloys at high temperatures in a matter of minutes.
The result is a strength versus temperature relationship for these different alloys. ‘Using our results, you can find which compositions will give you a specific strength at, for example, 1300 Kelvin. This allows you to tweak the properties of such a high-temperature-resistant material.’ The theoretical results can be used to create alloys with new properties, or to find alternative compositions when one element in an alloy becomes scarce. The model was validated by creating two different alloys and testing their predicted ‘yield strength’, the amount of stress they can withstand at high temperatures without irreversible deformation. The importance of edge dislocation in this process was confirmed using different experimental techniques.
Surprise
‘We also made an atomic model for screw dislocations, which was too complicated for the high-throughput analysis used for the edge dislocation,’ says Maresca. This confirmed that screw dislocation was not the most important determinant of yield strength in these alloys. The finding that edge dislocation actually determines a large part of the yield strength of complex HEAs was a major surprise and one that has made a simple, theory-driven discovery of new complex alloys possible.
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You might think robots and other forms of workplace automation gain traction due to intrinsic advances in technology — that innovations naturally find their way into the economy. But a study co-authored by an MIT professor tells a different story: Robots are more widely adopted where populations become notably older, filling the gaps in an aging industrial work force.
“Demographic change — aging — is one of the most important factors leading to the adoption of robotics and other automation technologies,” says Daron Acemoglu, an MIT economist and co-author of a new paper detailing the results of the study.
The study finds that when it comes to the adoption of robots, aging alone accounts for 35 percent of the variation among countries. Within the U.S., the research shows the same pattern: Metro areas where the population is getting older at a faster rate are the places where industry invests more in robots.
“We provide a lot of evidence to bolster the case that this is a causal relationship, and it is driven by precisely the industries that are most affected by aging and have opportunities for automating work,” Acemoglu adds.
The paper, “Demographics and Automation,” has been published online by The Review of Economic Studies, and will be appearing in a forthcoming print edition of the journal. The authors are Acemoglu, an Institute Professor at MIT, and Pascual Restrepo PhD ’16, an assistant professor of economics at Boston University.
An “amazing frontier,” but driven by labor shortages
The current study is the latest in a series of papers Acemoglu and Restrepo have published about automation, robots, and the workforce. They have previously quantified job displacement in the U.S. due to robots, looked at the firm-level effects of robot use, and identified the late 1980s as a key moment when automation started replacing more jobs than it was creating. More