Tech

Thermal-imaging sensors that detect and capture images of the heat signatures of human bodies and other objects have recently sprung into use in thermostats to check facial temperatures in a contactless attempt to screen for COVID-19 at several building entrances. Under these circumstances, the smartphone industry is actively considering the incorporation of such sensors as portable features to create the add-on function of measuring temperature in real time. Additionally, the application of such technology to autonomous vehicles may facilitate safer autonomous driving.

A research team lead by Dr. Won Jun Choi at the Center for Opto-Electronic Materials and Devices in the Korea Institute of Science and Technology (KIST) has announced the development of a thermal-imaging sensor that overcomes the existing problems of price and operating-temperature limitations through convergence research with the team of Prof. Jeong Min Baik from Sungkyunkwan University (SKKU). The sensor developed in this work can operate at temperatures upto 100 °C without a cooling device and is expected to be more affordable than standard sensors on the market, which would in turn pave the way for its application to smartphones and autonomous vehicles.

To be integrated with the hardware of smartphones and autonomous vehicles, sensors must operate stably without any difficulties at high temperatures of 85 °C and 125 °C, respectively. For conventional thermal-imaging sensors to meet this criterion, an independent cooling device would be required. However, high-end cooling devices that promise quality come at a price of over two million Korean won; even such devices do not make the sensor suitable for operations at temperatures as high as 85 °C. Therefore, the conventional thermal-imaging sensors have not been applied in these fields.

A joint research team from KIST and SKKU has developed a device using a vanadium dioxide (VO2)-B film that is stable at 100 °C. This device detects and converts the infrared light generated by heat into electrical signals; this eliminates the need for cooling devices, which account for over 10% of the cost of thermal-imaging sensors and consume large amounts of electricity. The device was able to obtain the same level of infrared signals at 100 °C as at room temperature. Furthermore, as a result of fabricating and using an infrared absorber that can absorb as much external infrared light as possible, heat signatures were detected with three times more sensitivity and converted into electrical signals. The device shows around 3 milliseconds of response time even at 100 °C, which is about 3~4 times faster than conventional ones. Such high response speeds enable the device to capture thermal images at 100 frames per second, far exceeding the conventional level of 30-40 frames per second. This makes the device an interesting candidate for use in autonomous vehicles, as well.

Dr. Choi of the KIST said, "By means of our work with convergence research in this study, we have developed a technology that could dramatically reduce the production cost of thermal-imaging sensors. Our device, when compared to more conventional ones, has superior responsivity and operating speed. We expect this to accelerate the use of thermal-imaging sensors in the military supply, smartphone, and autonomous vehicle industries."

The feeling of a needle piercing skin is familiar to most people, especially recently as COVID-19 vaccinations gain momentum. But what exactly happens when a needle punctures skin? The answer is revealed in a new paper published recently in the Journal of the Mechanics and Physics of Solids.

Mattia Bacca, assistant professor at the University of British Columbia, often looks to the natural world for answers when he's faced with a mechanical engineering problem--like the way a gecko can cling to a surface with the pads on its toes, or an ant can cut through a leaf many times its size.

Bioinspired engineering helped Dr. Bacca, along with PhD candidate Stefano Fregonese, to answer the previously unsolved question of how the mechanics of piercing works on soft materials, like skin.

"Cutting is ubiquitous in our survival and daily lives," Bacca explains. "When we chew food, we cut tissue to make it digestible. Almost every species in the animal kingdom evolved with the ability to cut tissue to feed and defend, hence have acquired remarkable morphological and physical features to allow this process efficiently."

They created a mechanical theory to determine the critical force required for needle insertion--the pivotal phenomenon of puncture. Their work provides a simple, semi-analytical model to describe the process, from dimensional arguments to finite element analysis.

Mechanisms involved in cutting soft tissue have only gained attention in engineering over the last several decades, initially with investigations into the properties of rubber. Previous approaches determined the force needed to insert a needle in tissue after its initial puncture, using physical experiments that couldn't fully measure the deformations and complex failure mechanisms involved in breaking through the surface of a soft material.

In contrast, the new model created by Fregonese and Bacca can finally predict the puncture force and validate this with previous experiments. They discovered that the needle insertion force is proportional to the toughness of tissue and scales inversely with the radius of the needle--meaning thinner needles require less force. Albeit both these observations are intuitive, they provided quantitative prediction. What is counterintuitive, however, is the role of material rigidity in this process. Tissue rigidity scales inversely with puncture force, with softer tissue requiring higher force (at same toughness). The UBC team is currently performing additional experiments and model refinements to get "deeper" into the physics of this problem.

So far, their results come from various inquiries into animal solutions. At first, Fregonese joined Dr. Bacca's Micro & Nano Mechanics Lab for a project related to the mechanics of adhesion in animals like geckos. Exploring overlaps with this area and the problem of cutting, they began to investigate fundamentals of cutting and the link to the morphological evolution of animals, with an international collaboration >studying leafcutter ants with animal biomechanics expert Dr. David Labonte (Imperial College), and muscle physiology expert Dr. Natalie Holt (University of California). They also collaborated with UBC Okanagan's Dr. Kevin Golovin and mechanical engineering colleague Dr. Gwynn Elfring to research the interaction between ballistics and gels.

Their new theoretical model may help engineers developing various applications such as protective equipment, automation processes involving food and the emerging technology of robotic surgery.

It may also impact how people experience injections in the future, something top of mind for people who've recently lined up to receive their COVID-19 vaccination. For example, future technology could provide options like self-administered disposable pads armed with microneedles--like the ones designed by UBC's Dr. Boris Stoeber--designed to pierce skin at the right depth and with the right force.

Even in the absence of bark beetle outbreaks and wildfire, trees in Colorado subalpine forests are dying at increasing rates from warmer and drier summer conditions, found recent University of Colorado Boulder research.

The study, published in the May print issue of the Journal of Ecology, also found that this trend is increasing. In fact, tree mortality in subalpine Colorado forests not affected by fire or bark beetle outbreaks in the last decade has more than tripled since the 1980s.

"We have bark beetle outbreaks and wildfires that cause very obvious mortality of trees in Colorado. But we're showing that even in the areas that people go hiking in and where the forest looks healthy, mortality is increasing due to heat and dry conditions alone," said Robert Andrus, lead author of the study and postdoctoral researcher at Washington State University. "It's an early warning sign of climate change."

These deaths are not only affecting larger trees, thus reducing forests' carbon storage, but hotter and drier conditions are making it difficult for new trees to take root across the southern Rockies in Colorado, southern Wyoming and northern parts of New Mexico.

It's well known that rising temperatures and increasing drought are causing tree deaths in forests around the globe. But here in Colorado, researchers found that heat and drought alone are responsible for over 70% of tree deaths in the 13 areas of subalpine forest they measured over the past 37 years. That's compared with about 23% of tree deaths due to bark beetles and about 5% due to wind damage.

"It was really surprising to see how strong the relationship is between climate and tree mortality, to see that there was a very obvious effect of recent warmer and drier conditions on our subalpine forests," said Andrus, who conducted this research while completing his graduate degree in physical geography at CU Boulder. "The rate of increasing mortality is alarming."

With temperatures in Colorado having risen by about 2 degrees Fahrenheit since the 1980s and increasing more quickly at higher elevations, estimates of another possible 2.5 or more degrees of warming in the next few decades due to climate change indicate that the rate of tree deaths will only increase.

Seeing the forest for the trees

Subalpine forests cover over 10,000 square miles in Colorado and are best known by those who ski or recreate in the mountains. Subalpine fir and Engelmann spruce dominate the area above the Peak to Peak Highway in the Front Range, and if you go over any mountain pass in Colorado, you're going into the subalpine zone, according to Andrus.

Previous research at CU Boulder has shown how wildfire, beetle kill and the two combined can affect the mortality and health of Rocky Mountain subalpine forests. This new research isolated the effects of those two common stressors from those of heat and moisture to find out how much of an effect climate change is having on these tree populations.

"As trees die in increasing numbers due to fire, bark beetles and drought, the warmer and drier climate is making it much less likely that new tree seedlings can establish and replace the dead adult trees," said Tom Veblen, co-author of the study and professor emeritus of geography.

Launched by Veblen when he arrived on campus in 1982, this is the longest running study of tree mortality in Colorado with remeasurements made frequently enough to identify the factors causing tree death. Every three years since, graduate students, postdoctoral researchers and undergraduate field assistants have diligently returned to the more than 5,000 marked trees on Niwot Ridge just west of Boulder. In these 13 subalpine forest plots, they recorded that more trees died during summers with higher maximum temperatures and greater moisture deficits.

They found that tree mortality increased from .26% per year during 1982 to 1993, to .82% per year during 2008 to 2019--more than tripling within 40 years.

"It is really challenging because it's not very visually obvious to the casual observer," said Andrus. "But the thing to keep in mind is that while warmer, drier conditions are also causing more fire and bark beetle outbreaks, these slow and gradual changes are also important."

Tokyo, Japan - Researchers from Tokyo Metropolitan University have developed a new technology which allows non-contact manipulation of small objects using sound waves. They used a hemispherical array of ultrasound transducers to generate a 3D acoustic fields which stably trapped and lifted a small polystyrene ball from a reflective surface. Although their technique employs a method similar to laser trapping in biology, adaptable to a wider range of particle sizes and materials.

The ability to move objects without touching them might sound like magic, but in the world of biology and chemistry, technology known as optical trapping has been helping scientists use light to move microscopic objects around for many years. In fact, half of the 2018 Nobel Prize for Physics, awarded to Arthur Ashkin (1922-2020) was in recognition of the remarkable achievements of this technology. But the use of laser light is not without its failings, particularly the limits placed on the properties of the objects which can be moved.

Enter acoustic trapping, an alternative which uses sound instead of optical waves. Sound waves may be applied to a wider range of object sizes and materials, so much so that successful manipulation is possible for millimeter-sized particles. Though they haven't been around for as long as their optical counterparts, acoustic levitation and manipulation show exceptional promise for both lab settings and beyond. But the technical challenges that need to be surmounted are big. In particular, it is not easy to individually and accurately control vast arrays of ultrasound transducers in real-time, and get the right sound fields to lift objects far from the transducers themselves, particularly near surfaces that reflect sound.

Now, Researcher Shota Kondo and Associate Professor Kan Okubo from Tokyo Metropolitan University have come up with a new approach to lift millimeter-sized objects off a reflective surface using a hemispherical array of transducers. Their method of driving the array does not involve complex addressing of individual elements. Instead, they split the array into manageable blocks and use an inverse filter that finds the best phase and amplitude to drive them to make a single trap at some distance from the transducers themselves. By adjusting how they drive the blocks over time, they can change the position of their target field and move the particle they have trapped. Their findings are supported by simulations of the 3D acoustic fields that are created by the arrays, and of course, by their experiments with a polystyrene ball, which speak for themselves (see the video).

Though challenges remain in keeping particles trapped and stable, this exciting new technology promises big advances towards transforming acoustic trapping from a scientific curiosity to a practical tool in the lab and in industry.

New York, NY (July 23, 2021) -- Mount Sinai researchers have developed a therapeutic agent that shows high effectiveness in vitro at disrupting a biological pathway that helps cancer survive, according to a paper published in Cancer Discovery, a journal of the American Association for Cancer Research, in July.

The therapy is an engineered molecule, named MS21, that causes the degradation of AKT, an enzyme that is overly active in many cancers. This study laid out evidence that pharmacological degradation of AKT is a viable treatment for cancers with mutations in certain genes.

AKT is a cancer gene that encodes an enzyme that is frequently abnormally activated in cancer cells to stimulate tumor growth. Degradation of AKT reverses these processes and inhibits tumor growth.

"Our study lays a solid foundation for the clinical development of an AKT degrader for the treatment of human cancers with certain gene mutations," said Ramon Parsons, MD, PhD, Director of The Tisch Cancer Institute and Ward-Coleman Chair in Cancer Research and Chair of Oncological Sciences at the Icahn School of Medicine at Mount Sinai. "Examination of 44,000 human cancers identified that 19 percent of tumors have at least one of these mutations, suggesting that a large population of cancer patients could benefit from therapy with an AKT degrader such as MS21."

MS21 was tested in human cancer-derived cell lines, which are models used in laboratories to study the efficacy of cancer therapies. Mount Sinai is looking to develop MS21 with an industry partner to open clinical trials for patients.

"Translating these findings into effective cancer therapies for patients is a high priority because the mutations and the resulting cancer-driving pathways that we lay out in this study are arguably the most commonly activated pathways in human cancer, but this effort has proven to be particularly challenging," said Jian Jin, PhD, Mount Sinai Professor in Therapeutics Discovery and Director of the Mount Sinai Center for Therapeutics Discovery at Icahn Mount Sinai. "We look forward to an opportunity to develop this molecule into a therapy that is ready to be studied in clinical trials."

EVANSTON, Ill., --- One of the keys to a long life may lie in your net worth.

In the first wealth and longevity study to incorporate siblings and twin pair data, researchers from Northwestern University analyzed the midlife net worth of adults (mean age 46.7 years) and their mortality rates 24 years later. They discovered those with greater wealth at midlife tended to live longer.

The researchers used data from the Midlife in the United States (MIDUS) project, a longitudinal study on aging. Using data from the first collection wave in 1994-1996 through a censor date of 2018, the researchers used survival models to analyze the association between net worth and longevity.

To tease apart factors of genetics and wealth, the full sample was segmented into subsets of siblings and twins.

In the full sample of 5,400 adults, higher net worth was associated with lower mortality risk. Within the data set of siblings and twin pairs (n=2,490), they discovered a similar association with a tendency for the sibling or twin with more wealth to live longer than their co-sibling/twin with less. This finding suggests the wealth-longevity connection may be causal, and isn't simply a reflection of heritable traits or early experiences that cluster in families.

"The within-family association provides strong evidence that an association between wealth accumulation and life expectancy exists, because comparing siblings within the same family to each other controls for all of the life experience and biology that they share," said corresponding author Eric Finegood, a postdoctoral fellow in the Institute for Policy Research at Northwestern.

The researchers also considered the possibility that previous health conditions, such as heart disease or cancer, could impact an individual's ability to accrue wealth due to activity limitations or healthcare costs -- possibly confounding any association between wealth and longevity. To address this, they re-analyzed the data using only individuals without cancer or heart disease. However, even within this sub-group of healthy individuals, the within-family association between wealth and longevity remained.

The study's senior author is Greg Miller, the Louis W. Menk Professor of Psychology and faculty fellow at the Institute for Policy Research at Northwestern. Co-authors of the study include other Northwestern faculty and trainees (Edith Chen, Daniel Mroczek, Alexa Freedman) as well as researchers from the University of Illinois, Urbana-Champaign; West Virginia University; Purdue University; and the University of Minnesota.

"Far too many American families are living paycheck to paycheck with little to no financial savings to draw on in times of need, said Miller. "At the same time, wealth inequality has skyrocketed. Our results suggest that building wealth is important for health at the individual level, even after accounting for where one starts out in life. So, from a public health perspective, policies that support and protect individuals' ability to achieve financial security are needed."

WESTMINSTER, Colorado - July 23, 2021 - Horseweed is a serious threat to both agricultural crops and natural landscapes around the globe. In the U.S., the weed is prolific and able to emerge at any time of the year.

Fall emerging horseweed overwinters as a rosette, while spring emerging horseweed skips the rosette stage and grows upright. In some instances, both rosette and upright plants emerge simultaneously in mid-summer. These unpredictable growth patterns create challenges for growers as they try to develop an appropriate weed management plan.

In a study featured in the journal Weed Science, a team from Michigan State University explored whether environmental cues could be used to predict horseweed growth type. They found that variations in temperature, photoperiod, competition, shading, and soil moisture resulted only in the rosette growth type. Upright plants emerged, though, when seeds were exposed to dry conditions, followed by a prolonged cooling.

Researchers also determined that upright horseweed plants from known glyphosate-resistant populations are three- to four-fold less sensitive to glyphosate than their rosette siblings, which makes them much harder to control.

"Our results suggest that when horseweed populations shift from winter to summer annual lifecycles, concurrent increases can be expected in glyphosate resistance," says researcher John Schramski of Michigan State University.

When can we say that a certain property of a system is robust? Intuitively, robustness implies that, even under the effect of external perturbations on the system, no matter how strong or random, said property remains unchanged. In mathematics, properties of an object that are robust against deformations are called topological. For example, the letters s, S, and L can be transformed into each other by stretching or bending their shape. The same holds true for letters o, O, and D. However, it is impossible to turn an S into an O without a discontinuous operation, such as cutting the O apart or sticking the two ends of the S together. Therefore, we say that the letters s, S and L have the same topology - as do the letters o, O and D - whereas the two groups of letters have different topologies. But how does topology relate to biology?

"During the last decades, physicists have discovered that certain properties of quantum systems depend only on the topology of some underlying feature of the system, such as the phase of its wave function or its energy spectrum" explains Evelyn Tang, co-first author of the study. "We wanted to know if this model can also be applied to biochemical systems to better describe and understand processes out of equilibrium." As topology is insensitive to continuous perturbations - like the stretching or bending of letters in the example above - properties linked to topology are extremely robust. They will remain unchanged unless a qualitative change to the system occurs, such as cutting apart or sticking together the letters above. The scientists Evelyn Tang, Jaime Agudo-Canalejo and Ramin Golestanian now demonstrated that the same concept of topological protection may be found in biochemical systems, which ensures the robustness of the corresponding biochemical processes.

Flowing along the edges

One of the most famous observations regarding topology in quantum systems is the quantum Hall effect: This phenomenon occurs when a two-dimensional conducting material is subjected to a perpendicular magnetic field. In such a setting, the electrons in the material begin to move in tiny circles known as cyclotron orbits, which overall do not lead to any net current in the bulk of the material. However, at the material's edges, the electrons will bounce off before completing an orbit, and effectively move in the opposite direction, resulting in a net flow of electrons along these edges. Importantly, this edge flow will occur independently of the shape of the edges, and will persist even if the edges are strongly deformed, highlighting the topological and thus robust nature of the effect.

The researchers noticed a parallel between such cyclotron orbits in the quantum Hall effect and an observation in biochemical systems termed "futile cycles": directed reaction cycles that consume energy but are useless, at least at first sight. For example, a chemical A may get converted to B, which gets converted to C, which subsequently gets converted back to A. This raised the question: is it possible that, like for cyclotron orbits in the quantum Hall effect, futile cycles can cause edge currents resulting in a net flow in a two-dimensional biochemical reaction network?

The authors thus modelled biochemical processes that occur in a two-dimensional space. One simple example are the assembly dynamics of a biopolymer that is composed of two different subunits X and Y: A clockwise futile cycle would then correspond to adding a Y subunit, adding an X subunit, removing a Y subunit, and removing an X subunit, which would bring the system back to the initial state. Now, such a two-dimensional space will also have "edges", representing constraints in the availability of subunits. As anticipated, the researchers found that counterclockwise currents along these edges would indeed arise spontaneously. Jaime Agudo-Canalejo, co-first author of the study, explains: "In this biochemical context, edge currents correspond to large-scale cyclic oscillations in the system. In the example of a biopolymer, they would result in a cycle in which first all X subunits in the system are added to the polymer, followed by all Y subunits, then first all X and finally all Y subunits are again removed, so the cycle is completed."

The power of topology

Like in the quantum Hall system, these biochemical edge currents appear robust to changes in the shape of the system's boundaries or to disorder in the bulk of the system. Thus the researchers aimed to investigate whether topology indeed sits at the heart of this robustness. However, the tools used in quantum systems are not directly applicable to biochemical systems, which underlie classical, stochastic laws. To this end, the researchers devised a mapping between their biochemical system and an exotic class of systems known as non-Hermitian quantum systems. Evelyn Tang, who has a background in topological quantum matter, recalls: "Once this mapping was established, the whole toolbox of topological quantum systems became available to us. We could then show that, indeed, edge currents are robust thanks to topological protection. Moreover, we found that the emergence of edge currents is inextricably linked to the out-of-equilibrium nature of the futile cycles, which are driven by energy consumption."

A new realm of possibilities

The robustness arising from topological protection, coupled to the versatility inherently present in biochemical networks, results in a multitude of phenomena that can be observed in these systems. Examples include an emergent molecular clock that can reproduce some features of circadian systems, dynamical growth and shrinkage of microtubules (proteins of the cell skeleton) and spontaneous synchronization between two or more systems that are coupled through a shared pool of resources. Ramin Golestanian, co-author of the study and Director of the Department of Living Matter Physics at MPI-DS, is optimistic for the future: "Our study proposes, for the first time, minimal biochemical systems in which topologically-protected edge currents can arise. Given the wealth of biochemical networks that exists in biology, we believe it is only a matter of time until examples are found in which topological protection sensitively control the operations in such systems."

Scientists have identified five new plant species in the Bolivian Andes.

The species are all part of the genus Jacquemontia, which are twining or trailing plants with pretty blue flowers.

With rapid biodiversity loss taking place across South America and worldwide, identifying plant species is a vital step towards protecting them.

The new study, which classifies and describes the 28 Jacquemontia species now known to live in Bolivia and Peru, was carried out by the universities of Exeter and Oxford, and the Royal Botanic Gardens, Kew.

"Many plant species have not been identified and classified, especially in the tropics," said Rosie Clegg, of the University of Exeter and Kew.

"If you don't know what a species is, you can't conserve it.

"Working with local collaborators in Bolivia, we have identified five new Jacquemontia species - and our work so far suggests most of them are relatively rare."

Jacquemontia plants often grow in open, bushy or grassy habitats, however, even widespread species are often scattered in their distribution and some species are highly specialised, growing even on bare rock with very little soil or water, while some require fire to stimulate seed germination.
The researchers now want to discover more about these species, and where each can be found as - at present - some are only known to exist in a single location.
Plants limited to a small area are highly vulnerable to threats such as the arrival of invasive species and habitat destruction for agriculture, mining and road and reservoir construction.
Clegg's current work focusses on rock outcrops, where some Jacquemontia species are found, although the new species described in the paper are found on Andean slopes.
"Rock outcrops come in many forms across South America, with different geologies and different plants living on them," she said.
"As well as identifying plants, we want to learn more about these habitats and the role they play in wider ecosystems.
"Jacquemontia and other plants on rock outcrops are able to survive in very harsh conditions, so through them we can learn more about how plants might respond and adapt to climate change."

John Wood, of the University of Oxford and Kew, said: "Collaboration between UK institutions working alongside colleagues in Bolivia is important for the identification and conservation of species and their habitats."

Clegg's research at the University of Exeter is funded by the NERC GW4+ Doctoral Training Programme.

The five newly described species are named: Jacquemontia boliviana, Jacquemontia cuspidata, Jacquemontia longipedunculata, Jacquemontia mairae and Jaquemontia chuquisacensis.

The paper, published in the journal Kew Bulletin, is entitled: "Jacquemontia (Convolvulaceae) in Bolivia and Peru."

After gaining world attention by 'unboiling' egg protein, Flinders University scientists have now used an Australian-made novel thin film microfluidic device to manipulate Beta-lactoglobulin (β-lactoglobulin), the major whey protein in cow's, sheep's and other mammals milk.

The so-called Vortex Fluidic Device has previously been used in an array of experiments to successfully 'un-boil' egg protein and even break the molecular bonds of one of the world's hardest material, carbon nanotubes.

In the latest application, published in Molecules, College of Science and Engineering experts have combined the capabilities of the VFD with a new form of biosensor called TPE-MI, which is an aggregation-induced emission luminogen (AIEgen).

"In the human body, protein folding is a regular process which in some cases may involve misfolding and aggregation such as in gene mutation, which can upset the balance," says Professor Youhong Tang, whose research focuses on expanding AIEgen technologies.

"One is example is the buildup of amyloid proteins, which is associated with diseases such as Alzheimer's, Parkinson's and Huntington's. Finding ways to monitor these protein levels - and even reversing high levels of these cellular aggregations - could lead to future therapies."

SA Scientist of the Year Professor Colin Raston, who designed the VFD, says the combination of both technologies produced some promising results in fields of medical discovery.

"In this latest study, we showed how vital proteins can be manipulated - unfolded and refolded - using β-lactoglobulin, which is a relatively simple, low molecular weight protein.

"Combining VFD and AIE technologies provides a fully capable and robust method for controlling and monitoring the progress of protein denaturation and renaturation."

The research team will now use the technology combination on other proteins, focusing on those highly related to Alzheimer's disease, Parkinson's disease, and Huntington's disease.

As Xi'an Jiaotong-Liverpool University researchers completed their research on coloured architectural concrete, they found a surprising result--green pigmented cement had impurities that produced porous, poor quality concrete. Meanwhile, red and blue pigments had little effect.

The research was conducted by Mehreen Heerah, a graduate of XJTLU's Department of Civil Engineering, Dr Graham Dawson of XJTLU's Department of Chemistry, and Isaac Galobardes of Mohammed VI Polytechnic University.

Pigmented architectural concrete is used as a visually appealing alternative to grey concrete, such as in Barcelona's Ciutat de la Justícia, explains Dr Dawson. As the demand for pigmented architectural concrete grows, so does the importance of this research.

Not easy being green

"The characteristics of red and blue pigments used in the study were established in the existing research literature. However, the characteristics of the green pigment was not usual," says Dawson.

"The results for the red and blue pigments were quite close to our expectation," Heerah says. "On the other hand, we did not expect the drastic effect of green pigment on the properties of the mortar. In fact, we expected that a greater increment in strength with the green pigment compared to the other two."

That's because green pigment in products is based upon chromium oxide, which increases the strength of the mix when hydrated.

So why was green concrete found to be substandard?

The answer lies in how it was produced with damaging impurities, says Dr Dawson.

"Chemical products are used to produce pigments," he explains. "Sometimes, pigments present simple chemical components and other combinations of them to obtain different colours."

The offending impurity that weakened the green concrete was muscovite; a mineral used to produce green pigment for other industrial uses. When hydrated with cement, muscovite generated significant quantities of a component that causes excessive porousness, which results in a reduction in strength and longevity.

"However, other studies have found that there is no adverse effect when using green pigment consisting solely of chromium (III) oxide, with no muscovite," says Heerah.

Mix it up

The cement samples were produced with three different pigments--blue cobaltous aluminate, green chromium oxide and red iron oxide pigment--at three different levels: 1, 5 and 10%.
The researchers tested two types of cement to understand how these admixtures and by-products affect the properties of the resulting concrete.

The four-part experiment first tested water absorption to evaluate the change in physical properties, and then determined the hydration properties of the samples.

Next, the kinetics of hydration were studied through the evolution of the temperature of each mix. Finally, the researchers examined the flexural and compressive strength to understand the effect of pigment on mechanical strength.

The research established that the morphology of hydration products and kinetics was related to the samples' compressive strength.

The poor performance of the green pigment stood out compared to the minimal effects of the red and blue.

The research also discovered that the cobaltous aluminate oxide (blue) and iron (III) oxide (red) pigments could be used with both Portland and Portland Composite cement without weakening the concrete's strength.

Less impact

Researchers also improved upon an existing equation used for estimating the real-time compressive strength of the pigmented mortar, Heerah says.

Dr Galobardes explains: "Using this equation avoids making the destructive tests used to estimate the mechanical properties of concrete.

"This eliminates waste and lowers carbon dioxide emissions and costs related to the production of the samples used in the tests."

While pigments themselves do not reduce carbon emissions produced by concrete, the research indicates that they are safe to use with eco-cements.

Cement mixes such as Portland Composite Cement, which includes ground granulated blast-furnace slag (GGBS) and fly ash are expected to achieve reduced carbon emissions in coming years.

Alexandria, Va., USA - Hiba Nasir, Wayzata High School, Plymouth, Minn., presented the poster "Oral-Health Impact Profile 5: Analyzing A Private Practice Adult Population's Distribution" at the virtual 99th General Session & Exhibition of the International Association for Dental Research (IADR), held in conjunction with the 50th Annual Meeting of the American Association for Dental Research (AADR) and the 45th Annual Meeting of the Canadian Association for Dental Research (CADR), on July 21-24, 2021.

Nasir, a high school student, along with Sheila Riggs, University of Minnesota, Minneapolis, USA, performed an observational study to understand the distribution of the Oral-Health Impact Profile (OHIP5) scores in a general adult population that seeks care in a private, suburban dental clinic. Participants were adult patients seeking care in a clinic who were administered the OHIP5 survey upon arrival. This survey was filled out as a paper copy and additionally included demographic questions (race, ethnicity, gender and age) for additional analysis.

A chi-square test for homogeneity was performed and determined that there was not a difference between the score distributions between females and males. Understanding the distribution of OHIP5 scores between men and women of an adult population seeking care in a private, suburban dental clinic allows for dental practitioners to further improve the care that they provide and allows for them to enhance their treatment plans.

New research from the University of Otago debunks a long-held belief about our ancestors' eating habits.

For more than 60 years, researchers have believed Paranthropus, a close fossil relative of ours which lived about one to three million years ago, evolved massive back teeth to consume hard food items such as seeds and nuts, while our own direct ancestors, the genus Homo, is thought to have evolved smaller teeth due to eating softer food such as cooked food and meats.

However, after travelling to several large institutes and museums in South Africa, Japan and the United Kingdom and studying tooth fractures in more than 20,000 teeth of fossil and living primate species, Dr Ian Towle, an Otago biological anthropologist, working with Dr Carolina Loch, of the Faculty of Dentistry, says this "neat picture is far more complex than once thought".

"By individually studying each tooth and recording the position and size of any tooth fractures, we show tooth chipping does not support regular hard food eating in Paranthropus robustus, therefore potentially putting an end to the argument that this group as a whole were hard food eaters," he says.

Dr Towle says the findings challenge our understanding of dietary and behavioural changes during human evolution.

"The results are surprising, with human fossils so far studied - those in our own genus Homo - showing extremely high rates of tooth fractures, similar to living hard object eating primates, yet Paranthropus show extremely low levels of fracture, similar to primates that eat soft fruits or leaves.

"Although in recent years there has been a slow acceptance that another species of Paranthropus, Paranthropus boisei, found in East Africa, was unlikely to have regularly eaten hard foods, the notion that Paranthropus evolved their large dental apparatus to eat hard foods has persisted. Therefore, this research can be seen as the final nail in the coffin of Paranthropus as hard object feeders."

The fact that humans show such contrasting chipping patterns is equally significant and will have "knock on" effects for further research, particularly research on dietary changes during human evolution, and why the human dentition has evolved the way it has, he says.

"The regular tooth fractures in fossil humans may be caused by non-food items, such as grit or stone tools. However, regardless of the cause, these groups were subjected to substantial tooth wear and fractures. So, it raises questions to why our teeth reduced in size, especially compared to groups like Paranthropus."

Dr Towle's research will now focus on if our dentition evolved smaller due to other factors to allow other parts of the skull to expand, leading to evolution then favouring other tooth properties to protect it against wear and fracture, instead of increased tooth size.

"This is something we are investigating now, to see if tooth enamel may have evolved different characteristics among the great apes. Our research as a whole may also have implications for our understanding of oral health, since fossil human samples typically show immaculate dental health.

"Since extreme tooth wear and fractures were the norm, our ancestors likely evolved dental characteristics to not just cope with but actually utilise this dental tissue loss. For example, without substantial tooth wear our dentitions can face all sorts of issues, including impacted wisdom teeth, tooth crowding and even increased susceptibility to cavities."

Elderly patients with neurological conditions are significantly more likely to develop delirium shortly after they are hospitalised.

A new study has discovered that a delayed transfer to a hospital floor is associated with greater short-term risk of delirium among patients aged 65 and over, and for those who arrive to the Emergency Department (ED) on days with higher risk of prolonged lengths of stay - found to be Sunday and Tuesday.

Delirium is an acute cognitive disorder characterised by altered awareness, attentional deficits, confusion, and disorientation. Current estimates of new-onset delirium highlight the fact that delirium overwhelmingly develops in medical settings (as high as 82 per cent in intensive care settings) compared to the community at large (between one per cent and two per cent). Research has shown that between 30 per cent and 40 per cent of all delirium cases are preventable.

Authored by Valdery Moura Junior, an Executive PhD Research student at the Business School (formerly Cass), the study explores whether a combination of the care experienced at the ED and the delayed implementation of delirium prevention measures contribute to an increased risk of the disorder. For example, it is possible that the bright lights and high ambient noise level of the ED for 24 hours a day will contribute to increased short-term risk.

The findings showed that of the 858 patients who presented to the ED with a neurological emergency, delirium was documented in 234 (30 per cent) patients within the first 72 hours from ED arrival.

This study also found that there was a connection between the onset of delirium and the day in which the patient arrived in the ED. Those arriving on Sundays and Tuesdays were more likely to demonstrate symptoms in a shorter time. Casual factors suggested include fewer hospital beds, delayed floor admission - a waiting time greater than 13 hours - and a greater proportion of elective pre-surgical admissions.

Mr. Moura has outlined several measures which can be taken to help prevent the likelihood of the onset of delirium in these settings, as well as reduce spending. These include an earlier initiation of delirium prevention measures; a quicker transfer from the ED to the hospital bed; and improving communication across healthcare managers in primary care, emergency rooms, operating rooms, and post-acute services.

Valdery Moura Junior, who is also computer scientist and technical leader at the Mass General Brigham, a Boston-based non-profit hospital and physicians network that includes Brigham and Women's Hospital (BWH) and Massachusetts General Hospital (MGH), two of the Harvard Medical School's most prestigious teaching hospitals, said:

"New-onset delirium in older patients alone will mean a high price for the health care system and poses a global challenge for healthcare managers, providers, and payors. Managing hospital capacity has been an enormous challenge throughout the pandemic, with many admission processes reviewed as a result with the goal of improving patient outcomes. Our study may help to identify feasible targets to improve processes between ED and the rest of the hospital."

Professor Feng Li, Chair of Information Management at the Business School, said: "This is an excellent example where routine operational data in a hospital can be used to identify anomaly and improve patient outcomes. Valdery's research demonstrated that more systematic use of such data can lead to significant improvement in the management of hospital capacity and operational processes, and most of all, quality of patient care."

Electromagnetic (EM) waves in the terahertz (THz) regime contribute to important applications in communications, security imaging, and bio- and chemical sensing. Such wide applicability has resulted in significant technological progress. However, due to weak interactions between natural materials and THz waves, conventional THz devices are typically bulky and inefficient. Although ultracompact active THz devices do exist, current electronic and photonic approaches to dynamic control have lacked efficiency.

Recently, rapid developments in metasurfaces have opened new possibilities for the creation of high-efficiency, ultracompact THz devices for dynamic wavefront control. Ultrathin metamaterials formed by subwavelength planar microstructures (i.e., meta-atoms), metasurfaces enable tailored optical responses for control of EM wavefronts. By constructing metasurfaces that possess certain predesigned phase profiles for transmitted or reflected waves, scientists have demonstrated fascinating wave-manipulation effects, such as anomalous light deflection, polarization manipulation, photonic spin-Hall, and holograms.

Moreover, integrating active elements with individual meta-atoms inside passive metasurfaces allows for "active" metadevices that can dynamically manipulate EM wavefronts. While active elements in deep subwavelengths are easily found in the microwave regime (e.g., PIN diodes and varactors), and successfully contribute to active metadevices for beam-steering, programmable holograms, and dynamic imaging, they are difficult to create at frequencies higher than THz. This difficulty is due to size restrictions and significant ohmic losses in electronic circuits. Although THz frequencies can control THz beams in a uniform manner, they are typically unable to dynamically manipulate the THz wavefronts. This is ultimately due to deficiencies in the local-tuning capabilities at deep-subwavelength scales in this frequency domain. Therefore, developing new approaches that bypass reliance on local tuning is a priority.

As reported in Advanced Photonics, researchers from Shanghai University and Fudan University developed a general framework and metadevices for achieving dynamic control of THz wavefronts. Instead of locally controlling the individual meta-atoms in a THz metasurface (e.g., via PIN diode, varactor, etc.), they vary the polarization of a light beam with rotating multilayer cascaded metasurfaces. They demonstrate that rotating different layers (each exhibiting a particular phase profile) in a cascaded metadevice at different speeds can dynamically change the effective Jones-matrix property of the whole device, achieving extraordinary manipulations of the wavefront and polarization characteristics of THz beams. Two metadevices are demonstrated: the first metadevice can efficiently redirect a normally incident THz beam to scan over a wide solid-angle range, while the second one can dynamically manipulate both wavefront and polarization of a THz beam.

This work proposes an attractive alternative way to achieve low-cost dynamic control of THz waves. The researchers hope that the work will inspire future applications in THz radar, as well as bio- and chemical sensing and imaging.