Culture

Shift-work and irregular work schedules can cause several health-related issues and affect our defence against infection, according to new research from the University of Waterloo.

These health-related issues occur because the body's natural clock, called the circadian clock, can be disrupted by inconsistent changes in the sleep-wake schedule and feeding patterns often caused by shift work. To study this, researchers at Waterloo developed a mathematical model to look at how a disruption in the circadian clock affects the immune system in fighting off illness.

"Because our immune system is affected by the circadian clock, our ability to mount an immune response changes during the day," said Anita Layton, professor of Applied Mathematics, Computer Science, Pharmacy and Biology at Waterloo. "How likely are you to fight off an infection that occurs in the morning than midday? The answer depends on whether you are a man or a woman, and whether you are among quarter of the modern-day labour force that has an irregular work schedule."

The researchers created new computational models, separately for men and women, which simulate the interplay between the circadian clock and the immune system. The model is composed of the core clock genes, their related proteins, and the regulatory mechanism of pro- and anti-inflammatory mediators. By adjusting the clock, the models can simulate male and female shift-workers. 

The results of these computer simulations conclude that the immune response varies with the time of infection. Model simulation suggests that the time before we go to bed is the "worst" time to get an infection. That is the period of the day when our body is least prepared to produce the pro- and anti-inflammatory mediators needed during an infection. Just as importantly, an individual's sex impacts the severity of the infection.

"Shift work likely affects men and women differently," said Stéphanie Abo, a PhD candidate in Waterloo's Department of Applied Mathematics. "Compared to females, the immune system in males is more prone to overactivation, which can increase their chances of sepsis following an ill-timed infection."

The Endangered dryas monkey (Cercopithecus dryas), endemic to the Democratic Republic of the Congo, is one of Africa's most mysterious primates. The discovery of the dryas monkey killed by a hunter in the buffer zone of Lomami National Park in 2014 has prompted field research of this small species (5-7 pounds). However, they are difficult to detect because they live in dense vegetation in secondary forest thickets.

Using non-invasive research and no-flash camera traps from 2014 to 2019, scientists from Florida Atlantic University in collaboration with researchers from the FZS-Lomami Project, Democratic Republic of the Congo, now have picture-perfect details on this elusive species. They have confirmed the occurrence of the dryas monkey at seven locations in both Lomami National Park and its buffer zone spanning a total area of 3,453 square kilometers, based on opportunistic reports provided by local village residents and park patrols.

Their findings, published in Oryx--The International Journal of Conservation, indicate that Lomami National Park and its buffer zone contain the greatest extent of the species' known range, and Lomami is the only national park with a confirmed population.

Although camera traps - a method for capturing wild animals on film when researchers are not present - are widely used to detect and survey cryptic species, the FAU scientists had to develop specific camera trap methods and placements to reliably detect the dryas monkeys.

Daniel Alempijevic, M.S., first author and a doctoral student at FAU, and Kate Detwiler, Ph.D., senior author and an associate professor in the Department of Anthropology in FAU's Dorothy F. Schmidt College of Arts and Letters, developed a species-specific multi-strata (0 to 29 meters) camera-trap technique to detect the species with a placement of three camera traps at each survey point, one each monitoring the ground, understory and canopy.

Alempijevic positioned the camera traps on game paths (0.2 to 0.5 meters above ground), shrubs and liana tangles (1.5 to 10 meters), and horizontal limbs (14.9 to 29 meters) forming pathways to adjacent tree crowns. He used a single rope technique to access the canopy, and a double-rope technique to move to the desired camera-trap location when needed. With the solicited information on the dryas monkeys from the residents of villages, he selected specific sites for camera-trap surveillance.

"We selected Bafundo Forest in the buffer zone for camera-trap surveillance, starting at the location where the first reported dryas monkey was killed by a hunter," said Detwiler. "We established the second survey site 40 kilometers west of Bafundo Village, at Camp Bartho in Lomami National Park after a ranger patrol team saw a dryas monkey there in 2014."

Camera traps accumulated 1,742 trap days on the ground, 2,821 trap days in the understory and 2,927 trap days in the canopy. Understory camera traps recorded 32 dryas monkey events, canopy camera traps detected a single event, and dryas monkeys were not detected by camera traps at ground level. The cameras that detected the species most frequently were those in the lower strata of the canopy and understory, at 2 to 10 meters above ground. At least 365 trap days are required to achieve a 95 percent detection probability, although dryas monkeys may be detected sooner in suitable habitats.

"Our camera-trap placements detected dryas monkeys almost exclusively in the understory across all surveys, regardless of canopy structure, which supports our hypothesis that the species appear to prefer structurally complex understories and forest edges," said Alempijevic. "Because our camera traps on the ground did not detect dryas monkeys, it seems unlikely that they travel on the ground. Only one camera trap in the canopy detected a dryas monkey, suggesting that they rarely travel in the upper canopy."

The researchers note that high heterozygosity and low inbreeding measures from genomic analysis of a hunter-killed dryas monkey (collected on Oct. 26, 2014) from Bafundo Forest suggest that it was a representative of a larger contiguous population.

"We recommend that researchers and conservationists working in the central basin of the Democratic Republic of the Congo mobilize local knowledge to identify other areas where the dryas monkey occurs and confirm any reports using our species-specific camera-trap placement technique," said Detwiler.

Protons are the next big thing when it comes to fuel cell technology. The subatomic exchange produces power on a scale that challenges contemporary solid-state fuel cell technology, used to help power space shuttles. To realize the proton-based technology sooner, an international team of researchers have developed a hybrid material that effectively transports protons at high temperatures and humidity -- two major challenges in past attempts.

The results were published on April 19 in ACS Applied Materials & Interfaces, a journal of the American Chemical Society.

The team, led by the University of Tokyo in Japan, focused on a material called polyoxometalates (POMs), which they previously fabricated into a composite with another polymer and compounds to help provide structural stability.

"POMs are attractive as building blocks for the design and synthesis of new materials with desirable properties and functions -- they can efficiently transport protons, for example, but only at low temperatures and in low humidity," said paper author Masahiro Sadakane, professor in the Graduate School of Advanced Science and Engineering, Hiroshima University. "Unfortunately, a huge problem remained to be solved is that our composite decomposed at higher temperatures and humidity."

To solve this problem, the researchers investigated how to better tune the composite by encapsulating positively charged ions in the material's internal cavities. Positive ions, known as cations, help balance negatively charged ions, known as anions, to stabilize conductivity in a material.

They settled on incorporating europium, a metallic element that is solid at room temperature, into the material. Europium is particularly attractive to water molecules, which brings external oxygen into the material. Protons move through the system by attaching to the oxygen. The more oxygen, the more proton-conductive the process is.

"Our goal is to produce stable high proton-conductive materials," said paper author Sayaka Uchida, associate professor in the Department of Basic Science, School of Arts and Sciences, The University of Tokyo. "Through fine control of the components, we produced such a material."

The material continued to demonstrate high proton conductivity at temperatures of 368 degrees Kelvin (202.73 degrees Fahrenheit) and 50% humidity. The researchers plan to increase the stability and proton conductivity further.

"We plan to increase the stability and proton conductivity so that this material can be used as an electrolyte in fuel cells, enhancing their performance," Sadakane said. "This work could provide guidance for the design of solid-state proton conductors."

A new Portland State study challenges the idea that youth with cognitive disabilities are unable or lack potential to pursue a career in science, technology, engineering and mathematics.

In a study using national data on more than 15,000 adolescents, the researchers found that undergraduates with medicated ADHD or autism appear to be more likely to major in STEM than youth without cognitive disabilities, and youth with autism have the most positive STEM attitudes.

Dara Shifrer, the lead author and an associate professor of sociology at PSU, says that increasing access to STEM fields for youth with disabilities depends not only on encouraging them to pursue STEM majors but also to enroll in college because STEM occupations often require bachelor's degrees at higher rates.

"We need a diverse STEM workforce so innovation and technologies are meeting the needs of the whole populace," she said.

Shifrer said the findings counter the notion that all youth with cognitive disabilities lack potential and ability. Instead, she says their potential often remains untapped due to inconsistent and subjective disability classifications, placement in lower-level courses, and lower expectations that are then likely to lead to self-fulfilling prophecies of poorer academic achievement and attitudes.

Both achievement and attitudes are important for postsecondary STEM outcomes, she said. The study found that if a student identifies as a math or science person, feels efficacious in their abilities and perceives math and science as useful for their goals, they're more likely to major in STEM. While achievement is important for college enrollment, attitudes are more strongly associated with pursuing a degree in a STEM field.

"People don't feel like they belong in STEM classes even in high school and it impacts their likelihood of choosing a STEM major, persisting in STEM and choosing a STEM job," Shifrer said. "STEM faculty and STEM employers write off lack of representation of people with cognitive disabilities as inevitable, perceiving them as having no potential, but they don't consider the roles of attitudes and don't consider their contributions to those attitudes. They're part of the reason why people don't feel like they belong."

Results showed that higher levels of high school achievement typically mattered more than STEM-positive attitudes for increasing the likelihood that a student enrolls in college, regardless of disability status and type. In contrast, STEM-positive attitudes mattered more than achievement for increasing the likelihood that a student majors in STEM, regardless of disability status and type.

The findings were published in the journal Socius: Sociological Research for a Dynamic World. Shifrer and her co-author, Ph.D. student Daniel Mackin Freeman, are now looking into what explains why some youth with cognitive disabilities are high-achieving and others are low-achieving.

"Often in research and policy, people with disabilities are treated as a monolithic category but that's problematic," Mackin Freeman said.

Osaka, Japan - Catalysts lie at the heart of a greener and more sustainable future for chemical production. However, many of the catalysts currently in widespread use have limitations that affect their efficiency. Researchers from Osaka University have reported a stable and reusable nickel phosphide nanoalloy catalyst for the hydrogenation of maltose to maltitol that outperforms conventional catalysts. Their findings are published in ACS Sustainable Chemistry & Engineering.

Maltitol is a sugar alcohol that is widely used as a sweetener and food additive. It can be produced by hydrogenating maltose; however, the reaction must be selective to avoid generating unwanted side products such as glucose. Ruthenium catalysts have been found to be efficient for this conversion, but are expensive, while cheaper nickel alternatives have low activity and are difficult to handle and reuse.

The researchers have now reported a nickel phosphide nanoalloy catalyst on a hydrotalcite (HT) support (nano-Ni2P/HT) that shows high activity for the selective hydrogenation of maltose to maltitol. The catalyst is also stable in air making it easy to handle.

"Our catalyst outperformed conventional catalysts for maltitol synthesis, showing high activity even at ambient temperature," says study first author Sho Yamaguchi. "The HT support was found to be key to the enhanced performance. In fact, the turnover number of the supported catalyst was more than 300 times higher than that of the same catalyst without a support."

The catalyst and support were found to work together in so-called cooperative catalysis. The nickel sites on the nano-Ni2P are thought to activate the hydrogen gas, while the HT is believed to be an electron donor and to activate the maltose.

nano-Ni2P/HT could be filtered from the reaction mixture and reused directly, without the need for time-consuming regeneration steps. The same amount of maltitol was produced on the fifth use as when the catalyst was fresh, showing that the activity and selectivity were conserved after multiple uses.

The catalyst even achieved high yields when the reaction mixture had a high maltose concentration (>50 wt%), which indicates that it would be appropriate for use on an industrial scale.

"The cooperative role of the support in the high activity of nano-Ni2P/HT is particularly exciting because this area has not been widely explored," study corresponding author Takato Mitsudome explains. "We believe that this mechanism, supported by the excellent properties we have demonstrated, means our catalyst is perfectly positioned to make a significant contribution to the sustainable production of maltitol."

INDIANAPOLIS -- Patients who suffer from traumatic brain injuries (TBI) often need a great deal of healthcare services after the injury, but the extent of care utilization is unknown. A new study from research scientists affiliated with the U.S. Department of Veterans Affairs (VA), Regenstrief Institute and IUPUI is one of the first to analyze how much care TBI patients use and identify areas of unmet need.

"There is not a lot of information about traumatic brain injury care utilization available," said primary study author Johanne Eliacin, PhD, a Regenstrief research scientist and core investigator at the VA Health Services Research and Development Center for Health Information at Richard L. Roudebush VA Medical Center. "In fact, until a few years ago, TBI was viewed as a one-time event. The goal of this study was to look at the care sought by survivors in order to understand the struggles they face and address them."

The study used the Indiana TBI registry for its cohort. The registry, funded by the Indiana Department of Health, contains all individuals diagnosed with mild, moderate and severe TBI listed in the Indiana Network for Patient Care (INPC), which is managed by Indiana Health Information Exchange. The research team looked at patients who were hospitalized with a TBI from 2005 through 2014 and examined healthcare utilization data for one year after the TBI event. That data was broken down into three categories: emergency department, inpatient and outpatient care.

Researchers found that many TBI survivors needed extensive healthcare services in the year after their injury, and a quarter of them were super-utilizers, having three or more emergency department visits or inpatient encounters or more than 26 outpatient visits during the year.

The results indicate that health insurance impacted the amount and type of care utilized, as did race, gender and residency status. Study authors say these potential disparities are an important area to focus on in future research.

"Because this is one of the first studies looking at these data, we are just beginning to identify patterns," said Dr. Eliacin. "More work is needed to dig into the social determinants of health that impact a TBI survivor's outcomes and to understand the struggles faced by those who are high utilizers of the healthcare system."

A previous qualitative study published by Dr. Eliacin presented some of the challenges patients and caregivers reported, which included the struggle to understand what care was available and where to access it.

"The Indiana TBI registry is an important resource to be able to understand the healthcare journeys of TBI patients," said study author Brian Dixon, PhD, MPA, Regenstrief and Indiana University Richard M. Fairbanks School of Public Health at IUPUI director of public health informatics. "We can leverage these data to identify population needs and develop interventions to improve quality of life as well as the access to and utility of their care."

"Characterizing health care utilization following hospitalization for a traumatic brain injury: a retrospective cohort study" was published in the journal Brain Injury.

In addition to Drs. Eliacin and Dixon, authors on the paper are Ziyi Yang, M.S. of IUPUI and Jacob Kean, PhD, of the VA Salt Lake City Health Care System and the University of Utah School of Medicine.

This work was supported, in part, by the Indiana Spinal Cord & Brain Injury Research Fund from the Indiana Department of Health. It was also supported by a VA Rehabilitation Research and Development Career Development Award IK2RX000879 to Dr. Kean.

IHIE is a non-profit, software development organization that operates the INPC -- the nation's largest inter-organizational clinical data repository which houses more than 14 billion pieces of patient data from 95% of Indiana.

UNIVERSITY PARK, Pa. -- Have you recently turned to your mobile device or computer to find out if your cough, sniffle or fever could be caused by COVID-19?

The online symptom checker you used may have advised you to stay home and call your medical provider if symptoms worsen, or perhaps told you that you may be eligible for COVID-19 testing. But why did it make the recommendation it did? And how should you know if you can trust it?

Those are questions that researchers at the Penn State College of Information Sciences and Technology recently explored through a project in which they augmented online symptom checkers by offering explanations of how the system generated its probable diagnoses and suggestions -- while also studying users' perceptions of those recommendations.

"People are confused about why online symptom checkers ask certain questions and how they make certain recommendations and decisions," said Chun-Hua Tsai, assistant research professor and first author on the research paper. "These interactions are not very transparent, which is OK if you just have a common cold, but with COVID it could be pretty serious."

Tsai explained that current online symptom checkers, which are powered by machine learning algorithms, use information that users provide to guide the checker in its next steps toward a possible diagnosis. However, the AI-driven systems' lack of transparency and comprehensible language could result in unintended -- and potentially tragic -- consequences if a user does not fully understand the recommendations it provides.

For example, if an online symptom checker simply recommended that a user get tested for COVID-19 based on the user's input, it could cause undue worry or unnecessary trips to a medical facility. Conversely, if a user learned from an online symptom checker that they could possibly have the coronavirus, it could lead them to make a poor medical decision such as taking medication on their own instead of being tested or seeking proper medical treatment.

"Explanation in medical diagnosis interactions emphasizes the importance of pragmatics," said Jack Carroll, distinguished professor of information sciences and technology and one of the research paper's authors.

The team's work has potential application beyond COVID-19, said Xinning Gui, assistant professor of information sciences and technology and another collaborator on the project.

"Even before COVID-19, tens of millions of people have used symptom checkers to self-diagnose or self-triage for numerous health conditions," she said. "However, little attention is paid to critical issues such as legitimacy, safety, trust and transparency from a user's perspective. Our work is just the start to fill this gap."

In their work, the researchers reproduced a user's interaction with an online symptom checker and added explanations for why the chatbot asked certain questions and how the recommendations were generated -- for example, if the suggestion was drawn from Centers for Disease Control and Prevention guidelines.

"Based on these explanations, our findings showed that the users were more confident (in the accuracy of the symptom checker) when they received these recommendations," said Tsai. "Transparent symptom checkers could be really useful for people to understand their own situation to make a better medical decision. Potentially, this could [also] be a tool to use in responding to the pandemic public health crisis that we're facing today."

In their study, the researchers interviewed users of online symptom checkers to understand if explanations would improve their user experience and their trust in the online tools. The interviews yielded that users are often confused by the questions that chatbots ask and which symptoms and information led to the suggested diagnosis and advice.

"For the possible causes listed to me, (the chatbot) doesn't tell me why my symptoms have a match. It just says something in a statistical way, like how many people might have this cause. I think the app should show the relations, like explain why it thinks this might be a possible cause, which question it asked, and which answers I gave have led me to this diagnosis," said one survey participant, as published in the research paper.

Then, the researchers designed a COVID-19 online symptom checker to include three types of explanation styles: rationale-based, providing an explanation after each question the system promoted to the user; feature-based, offering a personalized summary based on the user's answers; and example-based, highlighting an identical example of a patient who received the same clinical recommendation as the user based on identical answers.

They found that the explanations not only could significantly improve the user experience, but also could facilitate medical decision-making and improve user trust in the diagnosis.

"Explanation could empower health consumers to make informed decisions," said Gui. "Without explanation about how the symptom checkers come to the results and the underpinning evidence, health consumers will face challenges in comprehending or trusting the diagnostic results."

She added, "Our study proves that providing suitable explanations can help users better interpret the results and make informed decisions."

The researchers' findings could inform future design of online symptom checkers, helping users to potentially navigate a number of medical issues beyond COVID-19.

"Our findings could advance the research area of health recommender systems and explainable AI [artificial intelligence] in terms of personal health care, fairness and user trust," said Tsai.

Astronauts who spend extended time in space face stressors such as isolation, confinement, lack of privacy, altered light-dark cycles, monotony and separation from family. Interestingly, so do people who work at international research stations in Antarctica, where the extreme environment is characterized by numerous stressors that mirror those present during long-duration space exploration.

To better understand the psychological hurdles faced by astronauts, University of Houston professor of psychology Candice Alfano and her team developed the Mental Health Checklist (MHCL), a self-reporting instrument for detecting mental health changes in isolated, confined, extreme (ICE) environments. The team used the MHCL to study psychological changes at two Antarctic stations. The findings are published in Acta Astronautica.

"We observed significant changes in psychological functioning, but patterns of change for specific aspects of mental health differed. The most marked alterations were observed for positive emotions such that we saw continuous declines from the start to the end of the mission, without evidence of a 'bounce-back effect' as participants were preparing to return home," reports Alfano. "Previous research both in space and in polar environments has focused almost exclusively on negative emotional states including anxiety and depressive symptoms. But positive emotions such as satisfaction, enthusiasm and awe are essential features for thriving in high-pressure settings."

Negative emotions also increased across the study, but changes were more variable and predicted by physical complaints. Collectively, these results might suggest that while changes in negative emotions are shaped by an interaction of individual, interpersonal and situational factors, declines in positive emotions are a more universal experience in ICE environments. "Interventions and counter measures aimed at enhancing positive emotions may, therefore, be critical in reducing psychological risk in extreme settings," said Alfano.

At coastal and inland Antarctic stations, Alfano and her team tracked mental health symptoms across a nine-month period, including the harshest winter months, using the MHCL. A monthly assessment battery also examined changes in physical complaints, biomarkers of stress such as cortisol, and the use of different emotion regulation strategies for increasing or decreasing certain emotions.

Study results also revealed that participants tended to use fewer effective strategies for regulating (i.e., increasing) their positive emotions as their time at the stations increased.

"Both the use of savoring - purposely noticing, appreciating, and/or intensifying positive experiences and emotions - and reappraisal - changing the way one thinks about a situation - decreased during later mission months compared to baseline. These changes likely help explain observed declines in positive emotions over time," said Alfano.

A mollusk and shrimp are two unlikely marine animals that are playing a very important role in engineering. The bodies of both animals illustrate how natural features, like the structures of their bones and shells, can be borrowed to enhance the performance of engineered structures and materials, like bridges and airplanes. This phenomenon, known as biomimetics, is helping advance structural topology research, where the microscale features found in natural systems are being mimicked.

In a recent paper published by researchers at the Georgia Institute of Technology and the Pontifical Catholic University of Rio de Janeiro (Brazil), a new approach to structural topology optimization is outlined that unifies both design and manufacturing to create novel microstructures, with potential applications ranging from enhanced facial implants for cranial reconstruction to improved ways to get materials into space for planetary exploration.

"With traditional structural topology optimization, we use algorithms to determine the ideal layout of a structure - one that maximizes structural efficiency and requires fewer material resources," said Emily Sanders, a Ph.D. student in the School of Civil and Environmental Engineering at Georgia Tech, and co-author of the paper. "Our new research takes that a step further by introducing structural hierarchy, microarchitectures, and spatially-varying mechanical properties to enable different types of functionality like those observed in the cuttlefish and mantis shrimp."

The properties of both animals inspired the new framework for designing hierarchical, spatially-varying microstructures and required the researchers to build on existing technologies used to create 3D-printed structures.

"In our recent work, we've developed technology that includes new algorithms and computations that are the enablers of a hierarchical microstructure," said Glaucio Paulino, Raymond Allen Jones chair and professor in the School of Civil and Environmental Engineering at Georgia Tech, co-author of the paper and recent inductee to the National Academy of Engineering. "We can then input that information into 3D printers and create structures with tremendous amounts of details. After studying the porous, layered cuttlefish bone that has extremely adaptive properties, we've been able to apply that to new structures and materials like the ones shown in our paper."

For Paulino and his team, he hopes this new research will be applied to his earlier work in cranial reconstruction on cancer patients and those who have had massive facial injuries and bone loss.

"Now, we can 3D print craniofacial implants that have been designed using topology optimization and provide the framework for tissue re-growth," said Paulino. "Ideally when combined with the spatially-varying microarchitectures we've recently developed, the implants would more closely mimic the porous nature of the human bone and would promote the growth of the bone itself inside the scaffold. As the bone grows, the scaffold biodegrades, and if everything goes well, in the end the scaffold is gone, and the patient has new bones in the right places."

Design and Manufacturing

As Sanders explains it, there are two aspects being investigated in this paper that advance the study of topology optimization: design and manufacturing. The first goal is to design an optimal macro geometry and at the same time, optimally distribute spatially-varying micro geometries within, in order to meet performance objectives. In this paper, the researchers were looking for maximally stiff parts with limited volume, much like the mantis shrimp hammer claw and they achieved a high level of complexity that mimics nature at both scales.

The second goal is related to the manufacturing needed to create the structures. With additive manufacturing - or 3D printing - researchers can manufacture structures with complex geometries. But with the research team's introduction of spatially-varying microstructures, the printing becomes increasingly difficult.

"The more complex 3D data that we would have to send to the printer is so enormous that it's prohibitive," said Sanders. "So, we had to find a new way to communicate that information to the printer. Now, we communicate only 2D information, embedding the microstructures directly in 2D slices of the structure. At the end, the printer combines the slices to get the structure. It's much more efficient."

"What Emily did with manufacturing closes the loop," said Paulino. "We deliver on the design, mathematics, and algorithms. And we connect topology optimization with the additive manufacturing at both macro and micro levels."

Future Applications

When considering the future of the advancements made to structural topology optimization in this paper, Paulino and Sanders both see applications in biomaterials, as well as magnetic properties designed for space exploration.

For Paulino's work that continues in cranial reconstruction, he envisions interdisciplinary collaborations between engineering, chemistry and biology to develop biocompatible materials and architectures for medical use.

"We're not there yet, but this work is a step in the right direction," said Paulino. "Eventually, we'll be able to print biocompatible materials. This research with spatially-varying microarchitectures should enable the optimal design and manufacturing for biomaterial applications."

Regarding space exploration, the research could impact the creation of synthetic structures and systems with functionality, like magnetic material assemblages that could be actuated on demand by means of applied magnetic fields.

"An important aspect of this work is that it opened up our design space so that we can have spatially-varying properties, which enables us to do things we couldn't before," said Sanders.

Paulino goes on to explain that with space travel, each pound of material sent into space has an enormous cost, so the amount of material and volume brought on space missions is very limited.

"The way I see our manufacturing working in space is you print in place, potentially using printing materials from the foreign planet itself," said Paulino. "You can bring the additive printing capabilities to Mars and print structures with the properties you need when you get there. You print only what you need versus bringing everything you think you might need. In space, you want everything you do to be optimized."

Inspired by animals and how they function in nature, Paulino and his team have evolved topology optimization once again, this time with the new design and manufacturing of spatially-varying, hierarchical structures. And, soon, practical applications in biomedicine and space exploration are sure to follow.

WASHINGTON, April 20, 2021 -- Fiber optic technology is the holy grail of high-speed, long-distance telecommunications. Still, with the continuing exponential growth of internet traffic, researchers are warning of a capacity crunch.

In AVS Quantum Science, by AIP Publishing, researchers from the National Institute of Standards and Technology and the University of Maryland show how quantum-enhanced receivers could play a critical role in addressing this challenge.

The scientists developed a method to enhance receivers based on quantum physics properties to dramatically increase network performance while significantly reducing the error bit rate (EBR) and energy consumption.

Fiber optic technology relies on receivers to detect optical signals and convert them into electrical signals. The conventional detection process, largely as a result of random light fluctuations, produces "shot noise," which decreases detection ability and increases EBR.

To accommodate this problem, signals must continually be amplified as pulsating light becomes weaker along the optic cable, but there is a limit to maintaining adequate amplification when signals become barely perceptible.

Quantum-enhanced receivers that process up to two bits of classical information and can overcome the shot noise have been demonstrated to improve detection accuracy in laboratory environments. In these and other quantum receivers, a separate reference beam with a single-photon detection feedback is used so the reference pulse eventually cancels out the input signal to eliminate the shot noise.

The researchers' enhanced receiver, however, can decode as many as four bits per pulse, because it does a better job in distinguishing among different input states.

To accomplish more efficient detection, they developed a modulation method and implemented a feedback algorithm that takes advantage of the exact times of single photon detection. Still, no single measurement is perfect, but the new "holistically" designed communication system yields increasingly more accurate results on average.

"We studied the theory of communications and the experimental techniques of quantum receivers to come up with a practical telecommunication protocol that takes maximal advantage of the quantum measurement," author Sergey Polyakov said. "With our protocol, because we want the input signal to contain as few photons as possible, we maximize the chance that the reference pulse updates to the right state after the very first photon detection, so at the end of the measurement, the EBR is minimized."

Researchers at Johannes Gutenberg University Mainz (JGU) in Germany and the Institute of Molecular Biology of Barcelona in Spain have discovered how the blood plasma protein fetuin-B binds to the enzyme meprin β and used a computer model to visualize their findings. These results could lead to the development of new drugs to treat serious diseases such as Alzheimer's and cancer. Meprin β releases proteins from cell membranes, thus controlling important physiological functions in the human body. However, a dysregulation of this process can trigger the development of Alzheimer's and cancer. Meprin β is regulated by fetuin-B binding to the enzyme when required, thereby preventing the release of other proteins. Presenting their findings in the journal "Proceedings of the National Academy of Sciences", the researchers are now the first to describe this binding in detail.

The team at Mainz University produced both meprin β and fetuin-B in insect cells and then allowed them to react with one other in a test tube. By means of measurement of enzyme kinetics and biophysical analyses, the researchers determined that this reaction resulted in an exceptionally stable, high-molecular-mass complex. Their colleagues in Barcelona subsequently managed to crystallize the complex and determine its three-dimensional structure using X-ray crystallography. This involved X-rays being fired at the protein crystals, which allowed the atomic structure of the crystals to be calculated from the diffraction of the X-rays. A computer model of the structure was then generated. "Thanks to the model, we can now see exactly how meprin β and fetuin-B bind together," said Professor Walter Stöcker, who conducted the research at JGU together with Dr. Hagen Körschgen and Nele von Wiegen. "This research represents an excellent starting point for gaining a better understanding of diseases such as Alzheimer's and for developing the drugs to combat them." Meprin β is already known to be involved in the formation of so-called beta-amyloid plaques, which are a characteristic feature of the condition. Moreover, people with Alzheimer's disease have relatively little fetuin-B in their blood, which in turn may lead to a lack of regulation of meprin β. "If it is possible to develop a drug that binds to the enzyme and inhibits it in a similar way to fetuin-B, this could be a new way of treating Alzheimer's," concluded Stöcker.

Earthquake early warnings can be delivered successfully using a small network of off-the-shelf smartphones attached to building baseboards, according to a study conducted in Costa Rica last year.

In his presentation at the Seismological Society of America (SSA)'s 2021 Annual Meeting, Ben Brooks of the U.S. Geological Survey said the ASTUTI (Alerta Sismica Temprana Utilizando Teléfonos Inteligentes) network of more than 80 stations performed comparably to scientific-grade warning systems.

During six months' of ASTUTI operation, there were 13 earthquakes that caused noticeable shaking in Costa Rica, including in the city of San Jose where the network was deployed. The system was able to detect and alert on five of these earthquakes, Brooks and his colleagues determined when they "replayed" the seismic events to test their network.

Alerts for the system are triggered when shaking exceeds a certain threshold, equivalent to slightly less than what would be expected for a magnitude 5 earthquake, as measured by the accelerometers that are already built into the phones, Brooks said.

In simulations of the magnitude 7.6 Nicoya earthquake that took place in 2012 in Costa Rica, ASTUTI would have delivered its first alerts on average nine to 13 seconds after the event.

"The performance level over the six months is encouraging," Brooks said. "Cascadia events in the Pacific Northwest are similar to the Costa Rican subduction zone, and latencies for ShakeAlert in Cascadia are about 10 seconds, so it's comparable."

ASTUTI demonstrates the possibilities of lower-cost earthquake early warning for regions that lack the scientific-grade network stations such as those behind ShakeAlert, he noted.

"I would imagine that would be attractive for countries with less resources to dedicate to earthquake early warning" Brooks said, "but the performance is also at a level that I imagine would interest even wealthier countries."

The accelerometers within smartphones are ideal for a low-cost network, Brooks and his colleagues suggested. "If you were to build your own sensors, there's a lot of cost in maintaining them, and the sensors will quickly become obsolete," Brooks said.

By using commercial technology, "we let the big telecommunications companies do the research and development and we just deploy it," he added.

The phones were deployed in the homes of researchers and staff at the Observatorio Vulcanologico y Sismologico de Costa Rica (OVSICORI). The phones were enclosed in a plastic protective box before being mounted to the baseboard with 3M adhesive tape. As a result, the phones sense an earthquake through the filter of the structures, rather than directly as is the case for buried seismometers.

During testing, the system did not issue any false alerts. The researchers' analysis suggests the system could deliver alerts to 15% to 75% of Costa Rica's population in enough time to carry out drop-cover-hold-on responses, if it alerted the entire country after detecting an earthquake.

Country-wide alerting might be a successful strategy for the network, since recent studies show that people tend to be more tolerant than previously suspected of receiving warnings even if they didn't feel shaking, especially if they live in hazard-prone regions such as Costa Rica, said Brooks.

The work was funded by the U.S. Agency for International Development Bureau for Humanitarian Assistance. Next steps for ASTUTI will be to develop an app to make it more user-friendly and to deploy it more widely throughout the country.

Low-cost networks like ASTUTI will be a growing trend in earthquake early warning over the next decade, Brooks predicted. "When your objective is warning, you don't necessarily need the fanciest equipment."

The lack of accountability, poor communication and insufficient planning plaguing the government’s response to the COVID-19 pandemic — especially in its early months — have roots in how the nation responded to 9/11, Hurricane Katrina and the H1N1 swine flu, a new study involving the University of Washington found.

Focusing on the way government agencies assemble and allocate resources – the procurement system – researchers said the successes and shortcomings of responses to other large-scale crises show that a more centralized approach can achieve goals faster and more effectively.

“In the moment of disasters, we prioritize saving lives, but if we also want to achieve other goals, like equity, we need to establish processes and relationships in advance,” said Ben Brunjes, an assistant professor of public policy at the UW and co-author of the study, published April 14 in the Journal of Emergency Management.

In theory, government procurement aims to acquire goods and provide services efficiently, equitably and at the lowest possible cost to the taxpayer. When seeking bids and proposals, agencies are supposed to prioritize spending with businesses owned by women and people of color. During an emergency, however, governments suspend many timelines and rules in the interest of speed.

The government’s approach to the pandemic, especially in the early months when personal protective equipment and medical supplies equipment were the priority, has been criticized as fragmented and politicized. States were generally left to compete on the open market for N95 masks and ventilators; a lack of information and, ultimately, supplies, plagued the Strategic National Stockpile; and even today, the rollout of COVID-19 vaccines has been inconsistent across states.

The highly infectious nature of the coronavirus, and the impact not only on the health care sector but also on most other areas of society, made the pandemic an almost unprecedented emergency for which few countries were prepared, the researchers point out. The United States, with a mostly privatized health care system and three levels of government (local, state and federal) involved in emergency response functions, faced a massive task in protecting the population.

But the Trump administration’s hands-off approach, researchers said, essentially pitted states against each other. Some states had too little and others too much or simply poor-quality supplies, and that opened the door to fraud in the contracting process.

These problems could have been avoided, Brunjes said, if the federal government had recognized and mitigated some of the issues that arose during past crises:

During 9/11, the lack of interagency radio capability thwarted rescue efforts. Emergency responders from different agencies were unable to communicate with each other throughout the 2001 disaster, which led to an effort among law enforcement and other aid agencies nationwide to improve radio systems over the next several years. In the years that followed, new emergency management policies and innovative technologies helped avoid similar problems in subsequent disasters.
The evacuation of millions of people during Hurricane Katrina in 2005 prompted the need for emergency shelters and other services, fast. Several federal agencies purchased temporary beds, trailers and portable school buildings that went unused or were overpriced. The U.S. Government Accountability Office criticized the overall response as vulnerable to “fraud, waste and abuse.” In the aftermath, new laws were passed to make emergency procurement more accountable.
The case most similar to the current pandemic — the H1N1 swine flu in 2009-2010 — showed how the response to COVID-19 might have been different if government had taken the issue seriously and acted quickly. As the H1N1 crisis continued, resources wore thin and coordination across states was stymied. In response, the federal government developed a dashboard to track and share information about critical supplies, aiding in the rapid distribution of vaccines.

In addition to the lessons of better communication and contracting accountability from Hurricane Katrina and 9/11, the government’s experience with H1N1, a smaller-scale pandemic than COVID-19, shows the importance of interagency planning and procurement throughout. That includes the use of existing, issue-specific resources, such as the pandemic guidebook and organizational structure that the federal government developed during H1N1.

“If the previous administration had retained human capital and not gotten rid of the pandemic team, this would have been a lot smoother. There was a lot of knowledge about how to go through this process,” said Brunjes, a former emergency policy analyst for the Department of Homeland Security’s research institute.

The new study was written early in the COVID-19 pandemic, he added, but nothing in the course of events would have changed the researchers’ recommendations. The Biden team has seen the need to take a more central role in communication and management of the response, Brunjes said, and though the administration acted quickly in rolling out a vaccine program, there remain significant equity concerns over who has received the shots. With vaccines alone — all the first and second doses still to be administered, not to mention any booster doses in the future — there should be an even more transparent supply chain and system for determining what agencies need, how much and when.

Co-authors on the study were Sawsan Abutabenjeh of Mississippi State University; Lachezar Anguelov of The Evergreen State College; Ana-Maria Dimand of Boise State University; and Evelyn Rodriguez-Plesa, who worked on the study while completing her doctorate at Florida International University and is the assistant to the city manager of the City of Sunny Isles Beach, Florida.

For more information, contact Brunjes at Brunjes@uw.edu.

Journal

Journal of Emergency Management

DOI

10.5055/jem.0549

The familiar murkiness of waters in the Gulf of Mexico can be off-putting for beachgoers visiting Galveston Island. Runoff from the Mississippi River makes its way to local beaches and causes downstream water to turn opaque and brown. Mud is one factor, and river runoff is another. However, concern tends to ratchet up a notch when pollution enters the river runoff discussion on a national scale, specifically when smaller, navigable intrastate bodies of water push pollution into larger interstate waters often involved in commerce (i.e. the Mississippi River, Great Lakes, Ohio River).

A recently published research analysis in the journal Science, co-authored by Victor Flatt, Dwight Olds Chair in Law at the University of Houston Law Center, demonstrates how the supposed benefits of retracting federal oversight on these transboundary waters and defaulting that responsibility to individual states failed to account for economic and scientific evidence that said otherwise and violated the bounds of justifiable law.

In the article, "A water rule that turns a blind eye to transboundary pollution," Flatt contributed as the sole legal researcher, explaining how the 2020 Navigable Waters Protection Rule, which retracted federal oversight of interstate waters, did so with the overt assumption that state governments would fill in the oversight gap. Not only did the evidence point toward an alternate outcome but the rule's federalism rationale was incorrect, according to the researchers.

"New administrations get to implement new policies, but those policies have to be consistent with statutes, the Constitution and be logical," Flatt said. "The legal phrase is: 'they cannot be arbitrary and capricious.' An administration can only do what is allowed by the law and must be rational and logical. This fails that. This is a policy disagreement, but it is a policy disagreement that is out of the bounds of what is allowed by law."

The cleanliness of larger transboundary rivers falls under the responsibility of the federal government and under the 2015 Clean Water Rule (CWR) enacted during former President Barack Obama's administration. This included small wetlands and streams that could push pollution runoff to these larger rivers that bisect several states. In 2020, under the Navigable Waters Protection Rule (NWPR), the federal regulation of some of those smaller, linked bodies of water was withdrawn, leaving individual states with the responsibility to fill in the gaps. However, many states did not assert control over these waters as assumed by former President Donald Trump's administration, leaving room for pollution to make its way to interstate waters.

"One prominent example is 31 states' challenge to the 2015 CWR in court, arguing that it would impose excessive costs. Inexplicably, the NWPR's economics analysis projected that 14 of these states would now change their position," according to the Science article. As Flatt explains, this assumption was the misstep.

"The Army Corps and EPA said in their analysis that 31 states will move into the breach and help protect the wetlands that the federal government would no longer protect," Flatt said. "But best practices for economic analysis state that you cannot speculate about future state actions. When I looked at this, I found a lot of these states are even prohibited from enacting a rule more stringent than the federal government. Here, the data is flawed."

In March, President Joe Biden's administration proposed a $111 billion investment in water infrastructure. Flatt said that the implementation of the investment will include review of previous policy and research, including information uncovered in the Science article.

Mass extinctions are known as times of global upheaval, causing rapid losses in biodiversity that wipe out entire animal groups. Some of the doomed groups linger on before going extinct, and a team of scientists found these "dead clades walking" (DCW) are more common and long-lasting than expected.

"Dead clades walking are a pattern in the fossil record where some animal groups make it past the extinction event, but they also can't succeed in the aftermath," said Benjamin Barnes, a doctoral student in geosciences at Penn State. "It paints the pictures of a group consigned to an eventual extinction."

The scientists found 70 of the 134 orders of ancient sea-dwelling invertebrates they examined could be identified as DCW in a new statistical analysis of the fossil record.

"What really fascinated us was that over half of all the orders we looked at have this phenomenon and that it can look like many different things," said Barnes, who led a group of graduate students and a postdoctoral researcher on the study. "In some cases, you have a group that has a sudden drop in diversity and lasts for a few more million years before disappearing from the record. But we also found many orders straggled along sometimes for tens or hundreds of millions of years."

The findings, published in the journal Proceedings of the National Academy of Sciences, challenge the view of extinction as a sudden disappearance and suggest that the full impact of mass extinctions lag behind the events themselves longer than previously expected, the scientists said.

"I think it raises questions about how the so-called kill mechanism operates," Barnes said. "We think of mass extinctions as being these selective forces that cause large groups of animals to go extinct, but our results really show there are a lot of instances where it's not so sudden. It raises questions about why that's such a long delay."

Paleontologist David Jablonski first coined the term DCW more than 20 years ago, and since then it has been associated almost exclusively with mass extinctions. Using a wealth of new fossil record data made available over the last two decades, the study found DCW are also common around smaller, more localized background extinction stages, the scientists said.

"Our results suggest that rather than representing a rare, brief fossil pattern in the wake of mass extinction events, DCWs are actually a really diverse phenomenon and that there might be a lot of drivers that produce this pattern in the fossil record," Barnes said. "These DCWs may represent a major macroevolutionary pattern."

The scientists used a statistical technique called a Bayesian change point algorithm to analyze fossil records from the Paleobiology Database, a public record of paleontological data maintained by international scientists.

The method allowed the researchers to search time series data for significant points where the data deviated from the pattern. They were able to identify negative jagged shifts in diversity and rule out that the organism went extinct immediately but instead persisted.

"So you might be looking in the fossil record and you'll find tons of a type of brachiopod," Barnes said. "Each order has a handful of families and dozens of genera within those families. Then you might see a drop in diversity, and the majority of those genera disappear and perhaps there's only one family that continues to survive."

Those survivors can continue in their niche for millions of years, even into the present. But their lack of diversity makes them more susceptible to future environmental challenges or extinction events, the scientists said.

"I think these findings cause you to reexamine how you measure success," Barnes said. "It's quite possible for an animal group not to produce new families and new genera at a rate like it did before, but if it continues to survive for many millions of years, that's still some form of success. I think it raises a lot of questions about what it means to be successful as a fossil organism and what ultimately are the controls of origination."