Tech

Why do we become more positive as we grow older? Why are adolescents so sensitive to negative social cues?

These are a few of the questions addressed in "Emotion Sensitivity Across the Lifespan: Mapping Clinical Risk Periods to Sensitivity to Facial Emotion Intensity," a new paper published in the Journal of Experimental Psychology: General. The paper presents findings from a groundbreaking study examining how people of all ages detect subtle changes in social cues. McLean Hospital's Lauren A. Rutter, PhD, Laura Germine, PhD, Ipsit Vahia, MD, Brent P. Forester, MD, MSc, and Kerry J. Ressler, MD, PhD, are among the papers authors.

For the study, researchers created a digital test of emotion sensitivity that was completed by nearly 10,000 men and women, ranging in age from 10 to 85. The test allowed researchers to measure how much each person was able to detect subtle differences in facial cues of fear, anger, and happiness. The test also identified how people in different age groups displayed changes in their sensitivity to those facial emotions.

Rutter, the study's lead author and a research fellow at McLean Hospital's Laboratory for Brain and Cognitive Health Technology, explained that participants were tested using the web-based platform TestMyBrain.org. They were shown images of faces, presented in pairs, and were asked "Which face is more angry?," "Which face is more happy?," or "Which face is more fearful?" Rutter stated that the online platform helped the researchers tap into a "much larger and more diverse sample set" than previous studies. She also said that the novel testing method helped improve the accuracy of the results for decoding facial cues.

Germine, the study's senior author, said that the new testing method and the large sample size helped the researchers gain a deeper understanding into differences in emotion processing. "From studies and anecdotal evidence, we know that the everyday experiences of an adolescent is different from a middle aged or older person, but we wanted to understand how these experiences might be linked with differences in basic emotion understanding," said Germine, who is the technical director of the McLean Institute for Technology in Psychiatry and director of the Laboratory for Brain and Cognitive Health Technology. Rutter added that "the paper grew out of knowing that these differences existed and wanting to compare these differences across the emotion categories."

Through their study, the researchers also drilled down on the way emotion sensitivity develops during adolescence.

"We found that sensitivity to anger cues improves dramatically during early to mid-adolescence," said Rutter. "This is the exact age when young people are most attuned to forms of social threat, such as bullying. The normal development of anger sensitivity can contribute to some of the challenges that arise during this phase of development."

On the other end of the life span, the study showed that sensitivity to facial cues for fear and anger decrease as people age, but the ability to detect happiness cues stays the same. "It's well established that there is an age-related decline in the ability to decode emotion cues, in general, but here we see very little decline in the ability to detect differences in happiness," Germine said. This is even though the study was designed to be sensitive to differences in happiness sensitivity with age, based on principles from psychometrics and signal detection theory.

"What's remarkable is that we see declines in many visual perceptual abilities as we get older, but here we did not see such declines in the perception of happiness," she said. "These findings fit well with other research showing that older adults tend to have more positive emotions and a positive outlook."

Now, the researchers are building on this study by conducting new work that examines how emotion sensitivity is related to differences in aspects of mental health, such as anxiety. The team is also looking at how sensitivity to anger and happiness cues might be related to the development of poorer mental health after trauma.

Researchers at Tokyo Institute of Technology (Tokyo Tech) report a unipolar n-type transistor with a world-leading electron mobility performance of up to 7.16 cm2 V-1 s-1. This achievement heralds an exciting future for organic electronics, including the development of innovative flexible displays and wearable technologies.

Researchers worldwide are on the hunt for novel materials that can improve the performance of basic components required to develop organic electronics.

Now, a research team at Tokyo Tech's Department of Materials Science and Engineering including Tsuyoshi Michinobu and Yang Wang report a way of increasing the electron mobility of semiconducting polymers, which have previously proven difficult to optimize. Their high-performance material achieves an electron mobility of 7.16 cm2 V-1 s-1, representing more than a 40 percent increase over previous comparable results.

In their study published in the Journal of the American Chemical Society, they focused on enhancing the performance of materials known as n-type semiconducting polymers. These n-type (negative) materials are electron dominant, in contrast to p-type (positive) materials that are hole dominant. "As negatively-charged radicals are intrinsically unstable compared to those that are positively charged, producing stable n-type semiconducting polymers has been a major challenge in organic electronics," Michinobu explains.

The research therefore addresses both a fundamental challenge and a practical need. Wang notes that many organic solar cells, for example, are made from p-type semiconducting polymers and n-type fullerene derivatives. The drawback is that the latter are costly, difficult to synthesize and incompatible with flexible devices. "To overcome these disadvantages," he says, "high-performance n-type semiconducting polymers are highly desired to advance research on all-polymer solar cells."

The team's method involved using a series of new poly(benzothiadiazole-naphthalenediimide) derivatives and fine-tuning the material's backbone conformation. This was made possible by the introduction of vinylene bridges[1] capable of forming hydrogen bonds with neighboring fluorine and oxygen atoms. Introducing these vinylene bridges required a technical feat so as to optimize the reaction conditions.

Overall, the resultant material had an improved molecular packaging order and greater strength, which contributed to the increased electron mobility.

Using techniques such as grazing-incidence wide-angle X-ray scattering (GIWAXS), the researchers confirmed that they achieved an extremely short π-π stacking distance[2] of only 3.40 angstrom. "This value is among the shortest for high mobility organic semiconducting polymers," says Michinobu.

There are several remaining challenges. "We need to further optimize the backbone structure," he continues. "At the same time, side chain groups also play a significant role in determining the crystallinity and packing orientation of semiconducting polymers. We still have room for improvement."

Wang points out that the lowest unoccupied molecular orbital (LUMO) levels were located at -3.8 to -3.9 eV for the reported polymers. "As deeper LUMO levels lead to faster and more stable electron transport, further designs that introduce sp2-N, fluorine and chlorine atoms, for example, could help achieve even deeper LUMO levels," he says.

In future, the researchers will also aim to improve the air stability of n-channel transistors -- a crucial issue for realizing practical applications that would include complementary metal-oxide-semiconductor (CMOS)-like logic circuits, all-polymer solar cells, organic photodetectors and organic thermoelectrics.

Tokyo - Materials that have a disordered structure with no regular repeating pattern are described as amorphous. Such materials can be found in nature and also have a variety of applications in technology. However, the disordered nature of these materials makes them more challenging to characterize than crystalline structures.

Now, researchers at The University of Tokyo Institute of Industrial Science have shown that the structure of a particular class of liquids and amorphous materials, known as tetrahedral glass formers, can be understood from experimental measurements. Their findings were published in Science Advances.

When a crystalline material scatters X-rays or neutrons, it produces a well-defined pattern as a result of its structure. In contrast, the patterns produced by liquids and amorphous materials show broad peaks that do not provide the same degree of information. However, liquids and amorphous materials that have a tendency to form a network, such as silica and silicon, are known to exhibit a feature called the first sharp diffraction peak (FSDP).

Many theories linking the properties of the FSDP to the structure of the related material have been presented; however, there is still no accepted consensus on what gives rise to these features. Now researchers have demonstrated that the FSDP is a result of the tetrahedral nature of the local ordering of atoms in the liquid.

"The covalent nature of the bonding in the liquids we studied results in a certain degree of organization on a local level, although the order does not extend over a long range," study corresponding author Hajime Tanaka explains. "We focused on the tetrahedral unit structure that forms in the materials, and as a result have established a model that is able to support a range of experimental findings."

The researchers tested their tetrahedron model using simulated and experimental data for numerous oxide, halide, chalcogenide, and monoatomic materials in the liquid or amorphous states. The findings were able to explain the origin of the FSDP as well as other higher wavenumber peaks and features.

"We have shown direct evidence of a two-state structure in which order and disorder coexist in the same network forming liquid," First author Rui Shi explains. "We hope that our findings will lead to an improved understanding of the properties of tetrahedral liquids and glasses, and consequently have an impact on areas such as earth science and semiconductor materials."

The direct link between data that can be acquired using standard techniques and quantitative structural information on the degree and range of local order demonstrates the practical significance and potential of the presented model.

CAMBRIDGE, Mass. -- Spider silk, already known as one of the strongest materials for its weight, turns out to have another unusual property that might lead to new kinds of artificial muscles or robotic actuators, researchers have found.

The resilient fibers, the team discovered, respond very strongly to changes in humidity. Above a certain level of relative humidity in the air, they suddenly contract and twist, exerting enough force to potentially be competitive with other materials being explored as actuators -- devices that move to perform some activity such as controlling a valve.

The findings are being reported today in the journal Science Advances, in a paper by MIT Professor Markus Buehler, head of the Department of Civil and Environmental Engineering, along with former postdoc Anna Tarakanova and undergraduate student Claire Hsu at MIT; Dabiao Liu, an associate professor at Huazhong University of Science and Technology in Wuhan, China; and six others.

Researchers recently discovered a property of spider silk called supercontraction, in which the slender fibers can suddenly shrink in response to changes in moisture. The new finding is that not only do the threads contract, they also twist at the same time, providing a strong torsional force. "It's a new phenomenon," Buehler says.

"We found this by accident initially," Liu says. "My colleagues and I wanted to study the influence of humidity on spider dragline silk." To do so, they suspended a weight from the silk to make a kind of pendulum, and enclosed it in a chamber where they could control the relative humidity inside. "When we increased the humidity, the pendulum started to rotate. It was out of our expectation. It really shocked me."

The team tested a number of other materials, including human hair, but found no such twisting motions in the others they tried. But Liu said he started thinking right away that this phenomenon "might be used for artificial muscles."

"This could be very interesting for the robotics community," Buehler says, as a novel way of controlling certain kinds of sensors or control devices. "It's very precise in how you can control these motions by controlling the humidity."

Spider silk is already known for its exceptional strength-to-weight ratio, its flexibility, and its toughness, or resilience. A number of teams around the world are working to replicate these properties in a synthetic version of the protein-based fiber.

While the purpose of this twisting force, from the spider's point of view, is unknown, researchers think the supercontraction in response to moisture may be a way to make sure a web is pulled tight in response to morning dew, perhaps protecting it from damage and maximizing its responsiveness to vibration for the spider to sense its prey.

"We haven't found any biological significance" for the twisting motion, Buehler says. But through a combination of lab experiments and molecular modeling by computer, they have been able to determine how the twisting mechanism works. It turns out to be based on the folding of a particular kind of protein building block, called proline.

Investigating that underlying mechanism required detailed molecular modeling, which was carried out by Tarakanova and Hsu. "We tried to find a molecular mechanism for what our collaborators were finding in the lab," Hsu explains. "And we actually found a potential mechanism," based on the proline. They showed that with this particular proline structure in place, the twisting always occurred in the simulations, but without it there was no twisting.

"Spider dragline silk is a protein fiber," Liu explains. "It's made of two main proteins, called MaSp1 and MaSp2." The proline, crucial to the twisting reaction, is found within MaSp2, and when water molecules interact with it they disrupt its hydrogen bonds in an asymmetrical way that causes the rotation. The rotation only goes in one direction, and it takes place at a threshold of about 70 percent relative humidity.

"The protein has a rotational symmetry built in," Buehler says. And through its torsional force, it makes possible "a whole new class of materials." Now that this property has been found, he suggests, maybe it can be replicated in a synthetic material. "Maybe we can make a new polymer material that would replicate this behavior," Buehler says.

"Silk's unique propensity to undergo supercontraction and exhibit a torsional behavior in response to external triggers such as humidity can be exploited to design responsive silk-based materials that can be precisely tuned at the nanoscale," says Tarakanova, who is now an assistant professor at the University of Connecticut. "Potential applications are diverse: from humidity-driven soft robots and sensors, to smart textiles and green energy generators."

It may also turn out that other natural materials exhibit this property, but if so this hasn't been noticed. "This kind of twisting motion might be found in other materials that we haven't looked at yet," Buehler says. In addition to possible artificial muscles, the finding could also lead to precise sensors for humidity.

Princeton University researchers are gaining new insights into the causes and characteristics of diseases by harnessing machine learning to analyze molecular patterns across hundreds of diseases simultaneously. Demonstrating a new tool now available to researchers worldwide, the team of computer scientists and biologists has already uncovered and experimentally confirmed previously unknown contributions of four genes to a rare form of cancer that primarily affects babies and young children.

The team, which includes collaborators at Michigan State University and the University of Oslo, introduced the system and demonstrated its abilities in a paper published in the Feb. 23 issue of the journal Cell Systems.

While previous approaches focused on genes associated with specific diseases or types of cancer, the new technique uses machine learning to find unique patterns of gene activity by looking at more than 300 different diseases simultaneously, including cancers, heart disease, metabolic disorders and many others. In doing so, it reveals distinctions between diseases and tissue types, including fine-tuned differences between related diseases that were not possible to discern with other techniques.

The researchers believe that, with further development, the tool will be useful to clinicians in diagnosing disease, tailoring and tracking the effectiveness of therapies, and finding new treatment approaches.

The system, called Unveiling RNA Sample Annotation for Human Diseases, or URSA(HD), incorporates information about the activity of genes from publicly available records of about 8,000 biopsies taken from healthy and diseased tissues of thousands of patients. Going forward, researchers may submit new samples to the tool, via a web interface, and receive an analysis of possible associations with diseases and tissue types.

"The real innovation is comparing all samples to every other sample," said Chandra Theesfeld, one of the lead researchers along with Young-Suk Lee, who earned his Ph.D. at Princeton in 2016.

Theesfeld likened the idea to humans' ability to recognize nuanced differences between behaviors based on having seen a wide variety of examples. Watching soccer players, for example, might reveal the characteristics of a kicking action, but watching soccer players and ballet dancers at the same time reveals details and context for a similar action with a very different style and purpose.

"Studying them together provides a way to distinguish unique aspects," said Theesfeld, a research scientist in the lab of Olga Troyanskaya of Princeton and the Simons Foundation, who led the team. That viewpoint provides an unbiased way "to learn new things about disease that aren't possible to find with the one-disease-at-a-time approach -- and potentially identify new targets for therapies or even discover new aspects of disease that weren't appreciated."

In making its comparisons, the algorithm gives more weight to differences in gene activity that uniquely define the distinct tissues and diseases. It de-emphasizes information about gene activity common to related diseases, much of which already is well studied. In the soccer-dancing analogy, it's like setting aside the large-scale action of lifting a leg in a kick and finding many details, such the angle of a foot, that taken together constitute a signature set of characteristics that reliably identifies one action or the other.

"Our method is driven by the disease information in the patient sample, so it's not biased toward the popular disease genes that always get studied," Theesfeld said. "We can track patterns of changes in data without knowing exactly what each change means."

Theesfeld noted that 90 percent of studies of genes look at just 10 percent of human genes. URSA(HD) looks at the entire human genome and creates a genome-wide model or signature for each disease.

This approach could be particularly powerful for rare diseases, for which the researchers can now create a model with just a few samples. In the case of neuroblastoma, the pediatric cancer, the researchers found four genes that particularly contributed to the disease and for which there was no previous information in the scientific literature. To confirm the findings, Theesfeld performed laboratory tests on human cells, manipulating the gene activity and observing their effects on cancer-related processes in the cells.

Rather than looking at DNA itself, URSA(HD) looks at RNA, the product that cells create as they transcribe the information in DNA into working molecules that build and run cells and transmit signals from cell to cell. In this way, the system looks beyond mutations (scrambling in the genes themselves) and instead focuses on the downstream transcription products, which can be dysregulated in ways that cause problems even if the original gene is normal.

The research is part of longstanding work in Troyanskaya's lab to integrate massive collections of dissimilar datasets to extract information necessary to make precise biological predictions and to direct laboratory experiments to accelerate discovery. A wide range of data science at Princeton brings together computing and biology to develop foundational tools and insights with potential to have a broad impact for health and humanity.

"Interdisciplinary approaches that merge sophisticated data science with deep knowledge of biology are key to deciphering biomedical puzzles necessary to realize the promise of precision medicine," said Troyanskaya.

SAN DIEGO -- Experimental photonic switches tested by researchers at the University of California, Berkeley, U.S.A., show promise toward the goal of fully optical, high-capacity switching for future high-speed data transmission networks. The switch developed and tested for this research demonstrated capabilities not seen before in photonic switches.

In a paper to be presented at OFC: The Optical Fiber Communications Conference and Exhibition, to be held 3-7 March in San Diego, Calif., U.S.A., researchers Tae Joon Seok and colleagues will report successful scale up of a 240x240 integrated silicon photonic switch. The device is so-named because it accepts 240 optical communication input channels and sends them into 240 output channels.

Using experimental photonic switches manufactured at the Marvell Nanofabrication Laboratory at UC Berkeley, the research team demonstrated signal loss lower than any previously reported, said Seok, who is assistant professor at the Gwangju Institute of Science and Technology in South Korea and a visiting scholar at UC Berkeley.

Addressing industry needs with advanced optical switching

The telecommunications industry long ago embraced fiber-optic technology as a better solution to meet exploding demand for higher speeds and greater capacity data transmission over the electrical copper wires of old. Now a similar revolution is occurring at the points where the messages transmitted over long-haul fibers are sent and received. Instead of power-hungry electrical switches that require optical-electrical-optical conversions and cause signal loss, researchers are developing and deploying photonic switches to improve transmission quality and link a single transmission to tens and sometimes thousands of servers.

In particular, silicon-based photonic switches using advanced complementary metal-oxide semi-conductor (CMOS) technology are drawing a lot of attention from researchers as a powerful platform due to their low cost and high capacity. They have the potential to replace electrical switches, which will soon face scalability limits in performance and energy efficiency. In order to realize this potential, researchers are now working to overcome limitations related to the size of today's silicon photonic chips and improve their performance.

"Recently, many research groups competitively reported silicon photonic switches with large input/ouput port counts," said Seok. However, the physical size of a silicon photonic chip has been limited to 2 to 3 cm because of the limitations of the lithography tools necessary to etch the required geometric patterns on the silicon wafers used as a base for the integrated chips.

Seok and his colleagues overcame this limitation by using a process known as lithography stitching, creating a wafer-scale 240x240 silicon photonic switch by stitching together nine 80x80 switch blocks in a 3x3 array, with three input and three output coupler blocks. The switches developed as part of the experiment coupled light coming in and out of the chip through grating couplers. The switch cells were actuated by electrical probes.

The resulting switch area was 4 cm x 4 cm--nearly doubling the size of existing silicon photonic switches. "To the best of our knowledge, this is the largest integrated photonic switch ever reported on any platform," Seok said.

Measured results from the experimental switch also broke records. "The on-chip loss to port-count ratio (0.04 dB/port) is the lowest demonstrated," Seok added.

"This technology can be applied not only to silicon photonic switches but also to any silicon photonics applications that require ultra-large-scale devices such as programmable photonic processors, and so on," Seok said.

Brain tumors vary widely in how they respond to treatment. However, early assessment of therapy response is essential in order to choose the best possible treatment for the patient. Scientists from the German Cancer Research Center (DKFZ) have now been able to show in a study using non-invasive high-resolution 7-Tesla MRI scans that the protein content of tumors correlates with response to treatment and survival.

Glioma is the most common type of brain tumor in adults. This non-neuronal type of tumor arises from glial cells - the cells that support and nourish neurons. The term "glioma" comprises a whole number of brain tumors that vary widely in grade. Some are benign and can be removed completely by surgery. In others, chemotherapy and/or radiotherapy is necessary in addition to surgical removal.

In about half of all glioma patients, an extremely malignant form of the tumor is diagnosed. "Malignant gliomas respond very diversely to treatment," says Daniel Paech from the German Cancer Research Center (DKFZ). "In some of the cases, postoperative radiotherapy and chemotherapy are more effective than in others. And whether the tumor has in fact responded to treatment cannot be told before the first follow-up care exam six weeks after treatment ends."

In order to choose the best possible treatment strategy for the patient right from the start, it would be advantageous to be able to assess a brain tumor's aggressiveness and future response to therapy already at the time of diagnosis.

In their present study, Paech and his colleagues from Heidelberg University Hospital have now shown that this look into the future, which is so critical for individual therapy planning for glioma patients, in fact seems possible. They used an extremely powerful 7-Tesla MRI scanner to image proteins in the brains of glioma patients. To do so, they exploited the so-called CEST effect, a chemical exchange effect between the proteins and free water in tissue. No contrast agents are needed for this examination.

Paech explains: "Cancer cells grow in an uncontrolled manner, producing proteins along the way in an equally uncontrolled manner. Our study shows that the protein signal measured in the MRI image is a biomarker that is associated with survival as well as with treatment response of patients: The stronger the protein signal, the poorer the prognosis."

If the MRI image at diagnosis shows that the tumor has a tendency to grow rapidly, it would be possible to choose, depending on other factors such as the patient's age, a more intensive therapy from the start in order to improve the patient's chances.

7-Tesla MRI machines of the type that was used for the present study are only available at a small number of research locations. Fewer than 100 of these scanners, which weigh 25 tons and cost over €10 million, are running worldwide. They generate a magnetic field with a strength of 7 Tesla. Conventional MRI scanners used in hospitals have a strength of 1.5 or 3 Tesla. Paech and his DKFZ colleagues from the groups led by Heinz-Peter Schlemmer, Mark Ladd and Peter Bachert are therefore already planning the next study. In a prospective study, they plan to examine in a larger patient group whether protein measurement is also possible using a less powerful MRI scanner. "If a 3-Tesla MRI machine can equally measure the elevated protein expression in the tumor, then our results may be used broadly to enhance diagnostics in glioma patients, because 3-Tesla machines are available in many hospitals," says Paech.

Researchers have developed an algorithm that safeguards hardware from attacks to steal data. In the attacks, hackers detect variations of power and electromagnetic radiation in electronic devices' hardware and use that variation to steal encrypted information.

Researchers with the University of Wyoming and the University of Cincinnati recently published their work in the Institute of Engineering and Technology Journal.

Electronic devices appear more secure than ever before. Devices that used to rely on passwords now use Touch ID, or even face recognition software. Unlocking our phones is like entering a 21st century Batcave, with high-tech security measures guarding the entry.

But protecting software is only one part of electronic security. Hardware is also susceptible to attacks.

"In general, we believe that because we write secure software, we can secure everything," said University of Wyoming assistant professor Mike Borowczak, Ph.D., who graduated from UC. He and his advisor, UC professor Ranga Vemuri, Ph.D., led the project.

"Regardless of how secure you can make your software, if your hardware leaks information, you can basically bypass all those security mechanisms," Borowczak said.

Devices such as remote car keys, cable boxes and even credit card chips are all vulnerable to hardware attacks, typically because of their design. These devices are small and lightweight and operate on minimal power. Engineers optimize designs so the devices can work within these low-power constraints.

"The problem is if you try to absolutely minimize all the time, you're basically selectively optimizing," Borowczak said. "You're optimizing for speed, power, area and cost, but you're taking a hit on security."

When something like a cable box first turns on, it's decoding and encoding specific manufacturer information tied to its security. This decoding and encoding process draws more power and emits more electromagnetic radiation than when all of the other functions are on. Over time, these variations in power and radiation create a pattern unique to that cable box, and that unique signature is exactly what hackers are looking for.

"If you could steal information from something like a DVR early on, you could basically use it to reverse engineer and figure out how the decryption was happening," Borowczak said.

Hackers don't need physical access to a device to take this information. Attackers can remotely detect frequencies in car keys and break into a car from more than 100 yards away.

To secure the hardware in these devices, Vemuri and Borowczak went back to square-one: these devices' designs.

Borowczak and Vemuri aim to restructure the design and code devices in a way that doesn't leak any information. To do this, they developed an algorithm that provides more secure hardware.

"You take the design specification and restructure it at an algorithmic level, so that the algorithm, no matter how it is implemented, draws the same amount of power in every cycle," Vemuri said. "We've basically equalized the amount of power consumed across all the cycles, whereby even if attackers have power measurements, they can't do anything with that information."

What's left is a more secure device with a more automated design. Rather than manually securing each hardware component, the algorithm automates the process. On top of that, a device created using this algorithm only uses about 5 percent more power than an insecure device, making the work commercially viable.

Software and hardware security is an ongoing game of cat and mouse: As security technologies improve, hackers eventually find ways around these barriers. Hardware security is further complicated by the expanding network of devices and their interactivity, also known as the Internet of Things.

Innovative research like the work by Vemuri and Borowczak can give people an extra layer of safety and security in a world of connected devices.

SYRACUSE, N.Y. - Researchers in the Syracuse University College of Engineering and Computer Science have developed a material--a new kind of shape memory polymer (SMP)--that could have major implications for health care.

SMPs are soft, rubbery, "smart" materials that can change shape in response to external stimuli like temperature changes or exposure to light. They can hold each shape indefinitely and turn back when triggered to do so.

SMPs have many potential biomedical applications. For example, they are ideal as cardiovascular stents because they can be one shape for surgical insertion and another once positioned in a blood vessel. The warmth of the patient's body is all that is required to trigger the shape change.

Along with collaborators at Bucknell University, Syracuse University researchers have designed an SMP that can change its shape in response to exposure to enzymes and is compatible with living cells. It requires no additional trigger, such as a change in temperature. Given these properties, it can respond to cellular activity like healing.

"The enzymatic sensitivity of the material allows it to respond directly to cell behavior," explains biomedical engineering Ph.D. candidate Shelby L. Buffington. "For instance, you could place it over a wound, and as the tissue remodeled and degraded it, the SMP would slowly pull the wound closed. It could be adapted to play a role in treating infections and cancer by adjusting the material's chemistry."

The research team includes Buffington, Justine E. Paul '18, bioengineering junior Mark M. Macios, Professor James H. Henderson and Bucknell's Patrick T. Mather and Matthew M. Ali Ph.D. '18. Their research, "Enzymatically triggered shape memory polymers," was published in Acta Biomaterialia this year.

The team created the material using a process called dual electrospinning, in which a high-voltage current is applied to two needle tips pumping two separate polymer solutions. The voltage draws out the polymer fibers, and they are blended into a fiber polymer mat. The proper combination of fibers gives the material its shape memory qualities.

Detailed in their paper, the teams analyzed the material's properties, shape memory performance and cytocompatibility. Their experiments successfully demonstrated that the SMP's original shape could be recovered through a degree of reversal, or degradation, of the shape-fixing phase.

Today, the research team is examining their SMP in cancer and macrophage cell cultures. They hope that with additional research, they will uncover practical uses for their material using lower concentrations of enzymes, produced by less extreme cellular activity.

"We anticipate that the materials we're developing could have broad application in health care. For example, our SMPs could be used in drugs that only activate when the target cells or organ are in the desired physiological state, in scaffolds that guide tissue regeneration in response to the behavior of the regenerating tissue itself, and in decision-making biosensors that guide patient treatment more effectively," Henderson says. "We're very excited to have achieved these first enzymatically responsive SMPs."

Gardeners commonly use nematodes to naturally get rid of harmful soil-dwelling insects. A new study published today in the journal Functional Ecology revealed that these insect-killing nematodes also produce distinctive chemical cues, which deter Colorado potato beetles and make potato leaves less palatable to them.

The Colorado potato beetle is a devastating pest of potato leaves in home and fresh-market gardens, and feeds on tomato, pepper, eggplant and other plants in the nightshade family (Solanaceae) as well. A now widespread species in North America, continental Europe and Asia, control of the Colorado potato beetle often fails due to its ability to rapidly develop resistance to insecticides.

In a project funded by the United States Department of Agriculture, entomologists from Texas A&M University and Penn State University investigated whether Colorado potato beetles and potato plants responded to the presence of entomopathogenic nematodes (EPNs).

Although Colorado potato beetles feed on plant leaves above the ground, they can come in contact with EPNs as they move along the soil to a new host plant and when their larvae burrow themselves in the ground to pupate.

"We know from previous research that predators and parasites are attracted to odours that help them locate their prey. Here, we wanted to flip things around to see whether insects and plants can sense, or "smell", the chemical signatures of a predator", said Dr Anjel Helms at Texas A&M University, who led the research.

Nematodes and their symbiotic bacteria attack and kill insects in the soil. They can be used to control a wide variety of insect pests, providing a natural and effective alternative to chemical pesticides, without harming ladybugs, earthworms and other beneficial garden insects.

To determine whether Colorado potato beetles respond to the chemical cues emitted by EPNs, the researchers allowed beetles to choose potato plants with or without nematode-infected insects in the surrounding soil.

They found that the nematode-infected insect cadavers produced characteristic odours different from those of uninfected dead insects. Female Colorado potato beetles laid around 30% fewer eggs on plants surrounded by infected cadavers compared to control plants, indicating that they detect EPNs as a potential threat to the performance and survival of their offspring.

Beetle larvae voraciously feed on potato leaves, before entering the soil to pupate and resurfacing as adult beetles.

"It is becoming increasingly difficult to manage these noxious beetles with conventional methods particularly with their ability to rapidly develop resistance to pesticides.

Nematodes, however, could be added to the soil to target them directly and, as our research demonstrates, could also increase plant resistance to the insects by slowing their development and reducing their attraction to plants", said co-author Dr Jared Ali from Penn State University.

Interestingly, the potato plants also seemed to respond to the presence of these predatory nematodes, or their odours, by increasing their defences. As a result, Colorado potato beetle larvae feeding on these plants consumed less leaf tissue and were about 40% smaller than those feeding on control plants, which could have further consequences for their development and fitness.

Helms commented: "One explanation could be that plants perceive the presence of nematodes as a warning of the danger of herbivorous insects, so they mount their defences as a precaution. It's better to be safe than sorry."

While nematodes will likely not provide the only solution to Colorado potato beetles, these tiny worms can offer growers a natural alternative to existing methods and target soil-dwelling insect pests.

"Nematodes may prove more useful than previously thought. Not only do they directly kill insects in the soil, we found they also produce chemical cues that offer plants additional protection", Helms concluded.

Many modern laptops and an increasing number of desktop computers are much more vulnerable to hacking through common plug-in devices than previously thought, according to new research.

The research, to be presented today (26 February) at the Network and Distributed Systems Security Symposium in San Diego, shows that attackers can compromise an unattended machine in a matter of seconds through devices such as chargers and docking stations.

Vulnerabilities were found in computers with Thunderbolt ports running Windows, macOS, Linux and FreeBSD. Many modern laptops and an increasing number of desktops are susceptible.

The researchers, from the University of Cambridge and Rice University, exposed the vulnerabilities through Thunderclap, an open-source platform they have created to study the security of computer peripherals and their interactions with operating systems. It can be plugged into computers using a USB-C port that supports the Thunderbolt interface and allows the researchers to investigate techniques available to attackers. They found that potential attacks could take complete control of the target computer.

The researchers, led by Dr Theodore Markettos from Cambridge's Department of Computer Science and Technology, say that in addition to plug-in devices like network and graphics cards, attacks can also be carried out by seemingly innocuous peripherals like chargers and projectors that correctly charge or project video but simultaneously compromise the host machine.

Computer peripherals such as network cards and graphics processing units have direct memory access (DMA), which allows them to bypass operating system security policies. DMA attacks abusing this access have been widely employed to take control of and extract sensitive data from target machines.

Current systems feature input-output memory management units (IOMMUs) which can protect against DMA attacks by restricting memory access to peripherals that perform legitimate functions and only allowing access to non-sensitive regions of memory. However, IOMMU protection is frequently turned off in many systems and the new research shows that, even when the protection is enabled, it can be compromised.

"We have demonstrated that current IOMMU usage does not offer full protection and that there is still the potential for sophisticated attackers to do serious harm," said Brett Gutstein, a Gates Cambridge Scholar, who is one of the research team.

The vulnerabilities were discovered in 2016 and the researchers have been working with technology companies such as Apple, Intel and Microsoft to address the security risks. Companies have begun to implement fixes that address some of the vulnerabilities that the researchers uncovered; several vendors have released security updates in the last two years.

However, the Cambridge research shows that solving the general problem remains elusive and that recent developments, such as the rise of hardware interconnects like Thunderbolt 3 that combine power input, video output and peripheral device DMA over the same port, have greatly increased the threat from malicious devices, charging stations and projectors that take control of connected machines. The researchers want to see technology companies taking further action, but also stress the need for individuals to be aware of the risks.

"It is essential that users install security updates provided by Apple, Microsoft and others to be protected against the specific vulnerabilities we have reported," said Markettos. "However, platforms remain insufficiently defended from malicious peripheral devices over Thunderbolt and users should not connect devices they do not know the origin of or do not trust."

They're neither white and gold or black and blue. But in an optical puzzle akin to The Dress, colourful snails are causing scientists at the University of Nottingham to turn to technology to definitively decide whether some snails' shells are pink or brown.

The beautifully-hued Cepaea nemoralis - commonly known as grove snails - are found all over Europe in a range of colours, from yellow to pink to brown, with some also having 'humbug' style banding patterns.

But new research published in the academic journal Heredity, shows that differences in the way that the humans see and categorise colour, often makes it tricky to be sure about the colour of snail shells, leading to heated debate among scientists.

The problem of how to classify the colours has important implications for the study of the evolution of snails shell colour in response to factors including warming climate and hiding from predators.

Dr Angus Davison, Associate Professor and Reader in Evolutionary Genetics in the University's School of Life Sciences, who led the study, said: "The shell patterns and colour are hugely variable - almost like a snail fingerprint. As scientists, to ensure the accuracy of our studies and the subsequent interpretation, it is important that we have a reproducible measure of colour."

"The problem is that there are obvious differences in how humans perceive and categorise their colour, making it very difficult to compare the different types".

Over the past century, the study of animal colour has been critical in helping us to understand the principles of biology, particularly in relation to genetics and evolution. Studies on the distribution and the impact of colour on how predators may identify their prey have shaped our understanding of how natural and sexual selection operate in wild populations and the impact of climate change.

These snails - which are the second most common large snail in UK, and often found in gardens and hedgerows - have also been used in an "Evolution Megalab" experiment in which citizen scientists collect the snails and record the colour. Scientists compare the colour over time - there is a clear indication that the proportions of the different shell types are changing. But these citizen scientists face the same problem in classifying the colours.

Previous studies on grove snails have revealed that they can be sorted into roughly three colour groups - yellow, brown and pink.

It might be sensible to assume that yellow snails are found in dry, arid grasses where they can effectively blend into the background while their brown counterparts may stick to darker woodland environments to camouflage them. The snails uses their colour to evade predators - i.e. as camouflage - and to avoid overheating in open environments.

But surveys of the snails have shown that it's not always that simple - different coloured snails are found across a range of environments.

The colour may also have a role in how predators, particularly birds like song thrushes, choose their prey. Birds develop a preference for the commonest colour of snail over time, and so the rarer types escape predation.

To enable scientists to study the nuances of these issues accurately, they need a way of accurately sorting them into colour groups.

In the Nottingham study, grove snails from Britain and mainland Europe were categorised by Dr. Davison and PhD student Hannah Jackson, by eye.

The same snails were then analysed using a spectrometer, a machine that aims light at the snails, and measures the spectrum of light reflected from the shells.

Using these methods, the scientists were able to cluster the snails into brown, pink and yellow groups and this was compared to how the scientists had categorised the same snails by the naked eye.

The results showed that humans were largely capable of accurately categorising yellow snails but were less successful in identifying which snails were brown or pink. They also disagreed amongst themselves which were pink and which were brown.

The work provides scientists with a baseline measure for further studies into animal colour and the genes which underpin these variations.

After the birth of the first child mothers' and fathers' sleep duration and satisfaction don't recover to levels before pregnancy up to six years after giving birth

Mothers' sleep an hour less in the first 3 months after giving birth, and fathers' slept 15 minutes less researchers at the University of Warwick have found.

Six years after birth mothers slept 20 minutes less and fathers were still deprived of 15 minutes.

Higher household income and psychosocial factors such as dual vs. single parenting did not appear to protect against these changes in sleep after childbirth.

The birth of a child has drastic short-term effects on new mothers' sleep, particularly during the first three months after birth. Researchers at the University of Warwick have also found sleep duration and satisfaction is decreased up to six years after giving birth for both parents.

A new study by researchers from the University of Warwick shows that after birth of the first child and up to 6 years after birth mothers and fathers sleep duration and sleep satisfaction do not fully recover to the levels before pregnancy.

In the paper 'Long-term effects of pregnancy and childbirth on sleep satisfaction and duration of first-time and experienced mothers and fathers', a collaboration with the German Institute for Economic Research and the West Virginia University studied sleep in 4,659 parents who had a child between 2008 and 2015.

During these years parents also reported on their sleep in yearly interviews. In the first 3 months after birth mothers slept on average 1 hour less than before pregnancy while fathers sleep duration decreased by approximately 15 minutes.

Dr Sakari Lemola, from the Department of Psychology at the University of Warwick comments:

"Women tend to experience more sleep disruption than men after the birth of a child reflecting that mothers are still more often in the role of the primary caregiver than fathers"

However, when the children were 4-6 years old sleep duration was still about 20 minutes shorter in mothers and 15 minutes shorter in fathers compared to their sleep duration before pregnancy. A similar time course was also observed for their satisfaction with sleep.

Sleep effects were more pronounced in first-time parents compared with experienced parents. In the first half a year after birth the sleep effects were also somewhat stronger in breastfeeding compared with bottle-feeding mothers.

Higher household income and psychosocial factors such as dual vs. single parenting did not appear to protect against these changes in sleep after childbirth.

Dr Sakari Lemola, from the Department of Psychology at the University of Warwick comments:

"While having children is a major source of joy for most parents it is possible that increased demands and responsibilities associated with the role as a parent lead to shorter sleep and decreased sleep quality even up to 6 years after birth of the first child."

'The Last-Time Buyer: housing and finance for an ageing society'
A CSFI report by Professor Les Mayhew

Incentives to downsize would ease the housing crisis

Housing policy is too concentrated on first-time buyers and should be refocused towards 'last-time buyers' to encourage those aged 55+ to downsize, according to a new report for the Centre for the Study of Financial Innovation (CSFI).

The report, by Professor Les Mayhew, of Cass Business School, also highlights the role of the financial services industry in expanding mortgage offerings and insurance policies to enable older people to monetise their housing wealth. This would not only help them fund retirement but also cover the rising cost of care.

The UK's housing crisis is the result of a growing population and an inadequate supply of new homes. Demographic analysis suggests that the demand for accommodation could add the equivalent of two new towns, each with 100,000 homes, every year for 25 years.

The trend has been fed by shrinking household size, linked to the ageing population. If there were still 2.48 people per dwelling, as in 1980, rather than today's 2.36, the UK would have 1.3m more homes available, according to the report supported by Cass and Aldermore, the challenger bank.

But this is not just a numbers game. Professor Mayhew finds that, on paper at least, the UK is not short of housing; rather, it is short of the right sort of housing. Too many older people are stuck in houses that no longer suit them with a lack of affordable alternatives of suitable quality and size.

The evidence suggests that the government should refocus policy on 'last-time buyers' to encourage downsizing, including via the planning system and tax incentives. A more efficient approach could reduce the requirement for new homes by up to quarter each year.

House prices set to fall

The report uses a new concept called the Dwelling Index, which combines demographics with data on household composition and housing supply to analyse past, present and future housing needs.

It predicts large rises in couple households in their 60s and one-person households in their 70s and 80s. It also predicts that prices will fall in the 2020s, as the 'baby boomers' start to pass their homes to the next generations.

Although this will alleviate some supply-side issues, it does not help those trying to get on the housing ladder now or who are stuck in homes that are too large. More needs to be done - for example, building suitable properties for people to downsize into and creating more social housing for young families.

Financial innovation to free up housing wealth

The role of the financial services is crucial to helping people monetise their housing wealth. This applies not only to the growing market for equity release mortgages - about £4bn of lending in 2018 - but also to greater flexibility in housing-backed lending to people from their 50s onwards.

Another big opportunity set out in the report is for housing equity to be earmarked for insurance to cover care costs. The idea is that payment for the policies could be deferred until the home is sold.

The peace of mind of knowing that care costs are covered would assist in inheritance planning and passing wealth down the generations. But housing wealth is not inexhaustible and the report cautions against reckless lending and unrealistic expectations.

The report's author, Professor Les Mayhew, said:

"The UK population is growing and also rapidly ageing thanks to improvements in life expectancy. By taking a long view, the research clearly shows the origins of today's housing crisis and what can be done to tackle it. A better alignment of the housing stock with housing needs, along with improved financial incentives, would significantly alleviate housing pressures to the benefit of all."

Sue Hayes, Group Managing Director - Retail Finance, Aldermore, said:

"People in the UK are living longer, healthier lives, providing greater opportunity for their retirement compared with previous generations. This creates new challenges for the way they manage their finances in later life and for the housing market overall, although the financial sector is moving rapidly to meet their diverse demands. Product innovation has extended to later life mortgages, financial advice is improving and specialist lenders are playing a vital role by investing time to assess individual circumstances, with high levels of customer care.

"The report provides many practical and achievable recommendations on how the UK can expand the options for older homeowners and support their financial freedom. This will require changing mind-sets and a collective refocus from government and the housing industry towards helping last-time buyers. The effect could have a substantial impact in tackling the wider housing crisis."

Read the report

Read 'The Last-Time Buyer: housing and finance for an ageing society' here.

Readers can find:

a summary of the main findings and recommendations on pages 1 - 3

information on demographics and household composition in chapter 1

a comparison of housing needs with the housing stock in chapter 2

house prices and Dwelling Index predictions in chapter 3

the impact of ageing on housing policy in chapter 4

the crucial role for financial services in chapter 5

Men with early stage testicular cancer can safely receive one course of chemotherapy or radiotherapy after surgery without it having a long-term effect on their sperm count, according to a study published in the leading cancer journal Annals of Oncology today (Monday).

Although it is known already that several rounds of chemotherapy or high doses of radiotherapy given to men with more advanced testicular cancer can reduce sperm count and concentration, it has been unclear whether a single cycle of chemotherapy or radiotherapy would have a similar effect in men with stage I disease.

Dr Kristina Weibring, a cancer doctor at the Karolinska University Hospital in Stockholm, Sweden, who led the study, said: "We wanted to examine in more detail if postoperative treatment, given to decrease the risk of recurrence after the removal of the tumorous testicle, would affect the sperm count and sperm concentration long term in testicular cancer patients with no spread of the disease. To our knowledge, no such study has been done before.

"This is important to find out, since treatment with one course of postoperative chemotherapy has been shown to decrease the risk of relapse substantially, thereby reducing the number of patients having to be treated with several courses of chemotherapy."

Testicular cancer is the most common cancer in young men between the ages of 15 and 40. When it is diagnosed, all patients have the testicle containing the tumour removed, a surgical procedure called orchiectomy.

In this study, 182 men aged between 18 and 50, diagnosed with stage I testicular cancer and who had had an orchiectomy within the past five years, took part in the study between 2001 and 2006. They were treated either in Stockholm or Lund. After surgery, they received radiotherapy (14 fractions of 1.8 Gy each, up to a total dose of 25 Gy) or one course of chemotherapy, or were managed by surveillance, meaning there was no postoperative treatment. They provided semen samples after orchiectomy but before further treatment, and then six months, one year, two years, three years and five years thereafter. From 2006 onwards, radiotherapy was no longer used as a standard treatment in Sweden because of the risk of causing secondary cancer.

"We found no clinically significant detrimental long-term effect in either total sperm number or sperm concentration, irrespective of the type of postoperative treatment received," said Dr Weibring. "Among men who received radiotherapy, there was a distinct decrease in average sperm number and concentration six months after treatment, though not in those who received chemotherapy. However, sperm number and concentration recovered in the radiotherapy group after six months, and continued to increase in all groups up to five years after treatment.

"I am very excited to see these results as I wasn't expecting sperm to recover so well after postoperative treatment. I didn't expect as negative an effect as if the patient had received many courses of chemotherapy, since it is much more toxic, but I was not sure how much the sperm would be affected by one course.

"With the results of this study we can give the patients more adequate information on potential side effects from postoperative treatment. Testicular cancer patients are often young men wanting to father children at some point, and we find, in many cases, that the patients are afraid of the potential risk of infertility caused by chemotherapeutic treatment. These findings should provide some reassurance to them."

A well-known problem for men diagnosed with testicular cancer is an impaired ability to create sperm. A condition called testicular dysgenesis syndrome, characterised by poor semen quality among other things, may play a role in this and is also associated with a higher risk of developing testicular cancer. In addition, the orchiectomy and the cancer itself may also affect sperm quality. The removal of one testicle does not necessarily affect a man's sperm count and concentration as the remaining testicle can compensate.

Dr Weibring concluded: "Our results are promising but more studies are needed, and we still recommend sperm banking before orchiectomy as a number of patients may have low sperm counts at the time of diagnosis that persists after postoperative treatment. In addition, the type of testicular cancer and whether or not it will need further treatments are unknown factors before the orchiectomy. Assisted reproductive measures may be necessary for these patients regardless of any treatment given."

Editor-in-chief of Annals of Oncology, Professor Fabrice André, Professor in the Department of Medical Oncology, Institut Gustave Roussy, Villejuif, France, commented: "This study, together with other research efforts, explores the paths to recovering a normal life after cancer. The finding that one course of chemotherapy has minimal impact on sperm count offers hope for thousands of patients worldwide, but we all must keep in mind that these data are preliminary and will require validation before we can use them in clinics. The next step will be to establish how to predict the toxic effects on sperm count of different chemotherapy regimens."