It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, February 28, 2023
Super-fast insect urination powered by the physics of superpropulsion
IMAGE: A SHARPSHOOTER INSECT FORMING A URINE DROPLET BEFORE IT CATAPULTING IT HIGH ACCELERATION.view more
CREDIT: GEORGIA INSTITUTE OF TECHNOLOGY
Saad Bhamla was in his backyard when he noticed something he had never seen before: an insect urinating. Although nearly impossible to see, the insect formed an almost perfectly round droplet on its tail and then launched it away so quickly that it seemed to disappear. The tiny insect relieved itself repeatedly for hours.
It’s generally taken for granted that what goes in must come out, so when it comes to fluid dynamics in animals, the research is largely focused on feeding rather than excretion. But Bhamla, an assistant professor in the School of Chemical and Biomolecular Engineering at the Georgia Institute of Technology, had a hunch that what he saw wasn’t trivial.
“Little is known about the fluid dynamics of excretion, despite its impact on the morphology, energetics, and behavior of animals,” Bhamla said. “We wanted to see if this tiny insect had come up with any clever engineering or physics innovations in order to pee this way.”
Bhamla and Elio Challita, a bioengineering graduate student, investigated how and why glassy-winged sharpshooters – tiny pests notorious for spreading disease in crops – excrete the way they do. By using computational fluid dynamics and biophysical experiments, the researchers studied the fluidic, energetic, and biomechanical principles of excretion, revealing how an insect smaller than the tip of a pinky finger performs a feat of physics and bioengineering – superpropulsion. Their research, published in Nature Communications, is the first observation and explanation of this phenomenon in a biological system.
Small but Mighty: Observing Insect Excretion
The researchers used high-speed videos and microscopy to observe precisely what was happening on the insect’s tail end. They first identified the role played by a very important biophysical tool called an anal stylus, or, as Bhamla termed, a “butt flicker.”
Challita and Bhamla observed that when the sharpshooter is ready to urinate, the anal stylus rotates from a neutral position backward to make room as the insect squeezes out the liquid. A droplet forms and grows gradually as the stylus remains at the same angle. When the droplet approaches its optimal diameter, the stylus rotates farther back about 15 degrees, and then, like the flippers on a pinball machine, launches the droplet at incredible speed. The stylus can accelerate more than 40Gs – 10 times higher than the fastest sportscars.
“We realized that this insect had effectively evolved a spring and lever like a catapult and that it could use those tools to hurl droplets of pee repeatedly at high accelerations,” Challita said.
Then, the researchers measured the speed of the anal stylus movement and compared them to the speed of the droplets. They made a puzzling observation: the speed of the droplets in air was faster than the anal stylus that flicked them. They expected the droplets to move at the same speed as the anal stylus, but the droplets launched at speeds 1.4 times faster than the stylus itself. The ratio of speed suggested the presence of superpropulsion – a principle previously shown only in synthetic systems in which an elastic projectile receives an energy boost when its launch timing matches the projectile timing, like a diver timing their jump off a springboard.
Upon further observation, they found the stylus compressed the droplets, storing energy due to surface tension just before launch. To test this, the researchers placed the water droplets on an audio speaker, using vibrations to compress them at high speeds. They discovered that, at tiny scales, when water droplets are launched, they store energy due to inherent surface tension. And if timed just right, droplets can be launched at extremely high speeds.
But the question of why sharpshooters urinate in droplets was still unanswered. A sharpshooter’s almost zero-calorie diet consists only of plant xylem sap – a nutrient-deficient liquid containing only water and a trace of minerals. They drink up to 300 times their body weight in xylem sap per day and are therefore required to constantly drink and efficiently excrete their fluid waste, which is 99% water. Different insects, on the other hand, also feed exclusively on xylem sap but can excrete in powerful jets.
The team sent sharpshooter samples to a specialized lab. Micro CT scans enabled Bhamla and Challita to study the sharpshooter’s morphology and take measurements from inside the insects. They used the information to calculate the pressure required for a sharpshooter to push the fluid through its very small anal canal, determining how much energy was required for a sharpshooter to urinate.
Their research reveals that superpropulsive droplet ejection serves as a strategy for sharpshooters to conserve energy per feeding-excretion cycle. Sharpshooters face major fluid dynamic challenges due to their small size and energy constraints, and urinating in droplets is the most energy efficient way for them to excrete.
Promising Applications for Insect Superpropulsion
By combining biology, physics, and engineering, the research has implications for several fields. Understanding the role of excretion in animal behavior, size, and evolution can have applications for ecology and population dynamics. For example, sharpshooters are a major agriculture pest in California and Florida as they spread diseases in vineyards and citrus crops, causing millions of dollars of damage. Sharpshooter excretion could potentially serve as a vector surveillance tool as the issue will likely get worse with climate change. The team’s analysis also stresses the importance of studying excrement processes as they can reveal a multifaceted perspective about an organism’s behavior.
Studying how sharpshooters use superpropulsion can also provide insights into how to design systems that overcome adhesion and viscosity with lower energy. One example is low-power water-ejection wearable electronics, such as a smart watch that uses speaker vibrations to repel water from the device.
“The subject of this study may seem whimsical and esoteric, but it’s from investigations like this that we gain insight into physical processes at size scales outside of our normal human experience,” said Miriam Ashley-Ross, a program director in the Directorate for Biological Sciences at the U.S. National Science Foundation, which partially funded the work. “What the sharpshooters are dealing with would be like us trying to fling away a beachball-sized globe of maple syrup that was stuck to our hand. The efficient method these tiny insects have evolved to solve the problem may lead to bio-inspired solutions for removing solvents in micro-manufacturing applications like electronics or shedding water rapidly from structurally complex surfaces.”
The mere fact that insects urinate is compelling on its own, mostly because people don’t often think about it. But by applying the lens of physics to an everyday miniature biological process, the researchers’ work reveals new dimensions for appreciating small behaviors beyond what meets the eye.
“This work reinforces the idea of curiosity-driven science being valuable,” Challita said. “And the fact that we discovered something that is so interesting – superpropulsion of droplets in a biological system and heroic feats of physics that have applications in other fields – makes it even more fascinating.”
A sharpshooter insect uses its anal stylus to catapult a urine droplet at high acceleration (slow motion GIF).
Two sharpshooters on a plant, urinating in droplets (full-speed GIF).
Sharpshooters on a basil plant.
CREDIT
Georgia Institute of Technology
Citation: Elio J. Challita, Prateek Sehgal, Rodrigo Krugner & M. Saad Bhamla. “Droplet superpropulsion in an energetically constrained insect,” Nature Communications (2023).
The Georgia Institute of Technology, or Georgia Tech, is one of the top public research universities in the U.S., developing leaders who advance technology and improve the human condition. The Institute offers business, computing, design, engineering, liberal arts, and sciences degrees. Its more than 46,000 students, representing 50 states and more than 150 countries, study at the main campus in Atlanta, at campuses in France and China, and through distance and online learning. As a leading technological university, Georgia Tech is an engine of economic development for Georgia, the Southeast, and the nation, conducting more than $1 billion in research annually for government, industry, and society.
About The Study: In this study of National Institutes of Health (NIH) investigators from 1991 to 2020, researchers found a growing gap among NIH investigators that created a cohort of highly funded NIH investigators. Importantly, there were persistent gender, ethnic, and racial inequities among this elite class of super principal investigators (investigators receiving three or more research project grants). As the NIH develops critical initiatives and reforms to promote equity among its investigators, consideration of the persistent gender and ethnic and racial gaps in this elite class and the influence they have is critical for meaningful reform.
Authors: Mytien Nguyen, M.S., of the Yale School of Medicine in New Haven, Connecticut, is the corresponding author.
(doi:10.1001/jamanetworkopen.2023.0855)
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About JAMA Network Open:JAMA Network Open is an online-only open access general medical journal from the JAMA Network. On weekdays, the journal publishes peer-reviewed clinical research and commentary in more than 40 medical and health subject areas. Every article is free online from the day of publication.
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JUST IN TIME FOR SHARK WEEK
Jurassic shark – Shark from the Jurassic period was already highly evolved
New phylogenetic tree provides new insights into the evolutionary history of sharks and rays
IMAGE: FOSSIL OF THE LATE JURASSIC SHARK PROTOSPINAX ANNECTANS FROM SOLNHOFEN AND EICHSTÄTT, GERMANYview more
CREDIT: C: SEBASTIAN STUMPF
Cartilaginous fish have changed much more in the course of their evolutionary history than previously believed. Evidence for this thesis has been provided by new fossils of a ray-like shark, Protospinax annectans, which demonstrate that sharks were already highly evolved in the Late Jurassic. This is the result of a recent study by an international research group led by palaeobiologist Patrick L. Jambura from the Department of Palaeontology at the University of Vienna, which was recently published in the journal Diversity.
Cartilaginous fishes (sharks, rays, and ratfish) are an evolutionarily very old group of animals that already lived on earth before the dinosaurs more than 400 million years ago and have survived all five mass extinctions. Their fossil remains can be found in large numbers all over the world - however, usually only the teeth remain, while the cartilaginous skeleton decays together with the rest of the body and does not fossilize.
A unique window into the past
In the Solnhofen archipelago, a so-called "Konservat Lagerstätte" in Bavaria, Germany, skeletal remains and even imprints of skin and muscles of Late Jurassic vertebrates (including cartilaginous fishes) have been preserved due to special preservation conditions. The research team used this circumstance to take a closer look at the previously unclear role of the already extinct species Protospinax annectans in the evolution of sharks and rays, also with the help of modern genetic evidence.
"Protospinax carried features that are found in both sharks and rays today," explains study author Patrick L. Jambura. Protospinax lived some 150 million years ago and was a 1.5-m-long, dorso-ventrally flattened cartilaginous fish with expanded pectoral fins and a prominent fin spine in front of each dorsal fin. Although known from well preserved fossils, the phylogenetic position of Protospinax has puzzled researchers ever since it was first described in 1918. "Of particular interest," Jambura continued, "is whether Protospinax represents a transition between sharks and rays as a 'missing link' - a hypothesis that has gained considerable appeal among experts over the past 25 years." Alternatively, Protospinax could have been a very primitive shark, an ancestor of rays and sharks, or an ancestor of a certain group of sharks, the Galeomorphii, which includes the great white shark today - all of which are exciting ideas whose plausibility has now been clarified by scientists.
One mystery solved, another one remains
Incorporating the latest fossil finds, Jambura and his international team reconstructed the family tree of extant sharks and rays using genetic data (mitochondrial DNA) and embedded fossil groups - including Protospinax annectans - using morphological data. The results of the analysis were startling: Protospinax was neither a "missing link" nor a ray nor a primitive shark - but a highly evolved shark. "We tend to think of evolution like a hierarchical, ladder-like system, in which older groups are at the base, while humans, as a very young species in Earth history, are at the top. In truth, however, evolution has never stopped even for these primitive representatives, but they continue to evolve day by day via changes in their DNA, just as we do. This is the only way they have been able to adapt to constantly changing environments and survive to this day," says Jambura.
Even though cartilaginous fishes as a group have survived to this day, most species disappeared during its evolution, including Protospinax. Why Protospinax became extinct at the Jurassic-Cretaceous boundary some 145 million years ago and why there is no comparable shark species today, while the ecologically similarly adapted rays exist relatively unchanged to this day, remains a mystery at this point.
Palaeoreconstruction of the Solnhofen Archipelago 150 million years ago showing Protospinax annectans and the Jurassic ray Asterodermus platypterus
Systematics and Phylogenetic Interrelationships of the Enigmatic Late Jurassic Shark Protospinax annectans Woodward, 1918 with Comments on the Shark-Ray Sister Group Relationship.
'Informal carers’ experienced mental health decline ‘akin to divorce’ during COVID lockdowns
UK people who became carers during COVID-19 by helping family members, friends or neighbours in need experienced a sharp decline in their own mental health, new research from Lancaster University reveals.
People who became carers during Covid-19 by helping family members, friends or neighbours in need experienced a sharp decline in their own mental health, new research from Lancaster University reveals.
Using the General Health Questionnaire (GHQ) scale – a psychometrically validated and widely used index of psychological distress – researchers studied individual responses to the UK Household Longitudinal Study (Understanding Society).
They looked at 4698 participants from a total of 11 surveys - three before COVID-19 and eight collected between April 2020 and March 2021.
They carefully focused on three groups of people – ‘existing carers’ (totalling 349 people who had caring responsibilities for people outside of their home before the pandemic), ‘new carers’ who started helping and continually provided care during the pandemic (1655 individuals), and a group of ‘never-carers’ (2694 respondents).
Results found that the most statistically significant “moments of distress” for new caregivers occurred when national lockdowns were in place. Existing carers within the sample experienced a 0.48 point increase in mental deterioration during the third national lockdown, imposed by the Government in January 2021. This measurement indicates worse mental ill-health than men who lose their jobs (measured at 0.41 points on the GHQ scale – for unemployed women, it’s 0.60 points), while the death of a partner leads to worse mental health by 0.51 points for women, and 0.53 for men.
Overall, the study finds mental health in the UK fluctuated according to the social restrictions imposed by Government, but the mental health of those who started providing care informally during the pandemic was consistently worse than those who did not provide any informal care at all.
“Our evidence suggests that while social restrictions were put in place to curb infection rates and protect the public from Covid-19, the mental toll this had on informal caregivers was sizeable,” explains Chiara Costi, a PhD student from Lancaster University Management School and lead author of the study. “This is the first time, to our knowledge, there has been any focus on the mental health of the vast number of people who became informal carers during Covid-19 in the UK.
“While each group of informal carers we focused on is different, it is important to note that all respondents had similar levels of mental health before providing informal care.
“When you look at our data, the stay-at-home orders during Covid most certainly harmed the mental health of carers across the UK, but had a particularly severe affect on those who took on additional caring roles purely as a result of the pandemic.
“The effect on those who had been caring for people before the pandemic started is also very interesting. While existing carers were coping relatively well with the pandemic at the beginning, imposing the third lockdown almost one year after the start of the pandemic looks to have really impacted their mental health when you look at the sharp decline in scores in January 2021.”
Data taken from the informal carers’ responses for the study also shows:
Existing carers are older, on average, than those who have never provided informal care for others, while the new informal carers are the youngest group
Existing carers are less likely to be single or live alone, and are more likely to be widowed or divorced when compared to new carers or never carers
New carers tend to have more dependent children and are more likely to be employed
Existing caregivers have poorer physical health with greater functional limitations and long-standing illnesses
White people generally have better mental health than other ethnicities (a decrease of 1.19 GHQ points for existing carers and 0.81 points for new carers on the GHQ scale)
Amongst existing carers, women tend to have better mental health than men (a decrease of 0.71 GHQ compared to men on the scale)
Being in paid employment is correlated with better mental health (0.36 GHQ points)
“While all groups we studied have similar demographics in terms of gender, ethnicity and education, existing carers are older on average, when compared to new carers”, said co-author, Dr Vincent O’Sullivan from the University of Limerick. “This could mean that existing carers may have started to provide care earlier to support older parents or relatives, hence having better mental health at the start of the pandemic when compared to those who just started care-giving.”
Researchers say their findings should be helpful for policymakers who may look to provide psychological support for new informal care givers.
Co-author, Dr Eugenio Zucchelli from Autonoma University of Madrid, added: “Our evidence would suggest it is important to look at other forms of support for caregivers that goes beyond financial or respite care.”
“Hopefully we won’t see a pandemic like the last for quite some time, but for any future public health crisis, it would be important to not overlook those who may be picking up caring duties for the first time – especially if they may be socially isolated and therefore lacking any in-person support or network,” adds co-author Professor Bruce Hollingsworth from Lancaster University.
The paper, Does caring for others affect our mental health? Evidence from the COVID-19 pandemic, is published in the Social Science and Medicine journal, and is written by Chiara Costi from Lancaster University Management School; Professor Bruce Hollingsworth from Lancaster University; Dr Vincent O’Sullivan from the University of Limerick, and Dr Eugenio Zucchelli from Autonoma University of Madrid and the Madrid Institute for Advanced Study.
Does caring for others affect our mental health? Evidence from the COVID-19 pandemic
CU School of Medicine researchers part of national team that identified a new dietary approach to treatment for eosinophilic esophagitis
The research published in Lancet Gastroenterology and Hepatology shows that eliminating dairy alone is as effective as the six-food elimination diet that is standard for the condition.
Research by a team that includes two faculty members from the University of Colorado School of Medicine may change the treatment paradigm for patients with eosinophilic esophagitis (EoE), an allergic condition that causes chronic inflammation in the esophagus that can lead to esophageal narrowing and dysfunction.
Glenn Furuta, MD, professor of pediatric gastroenterology, hepatology, and nutrition, and Paul Menard-Katcher, MD, associate professor of gastroenterology, helped lead the National Institutes of Health (NIH)-funded, multisite study that shows that a single-food elimination diet — one in which dairy products are eliminated — is just as effective as the standard six-food elimination diet for achieving remission in eosinophilic esophagitis. The paper was published today in Lancet Gastroenterology and Hepatology.
“Eosinophilic esophagitis is a chronic disease that affects children and adults,” Furuta says. “It causes significant problems with eating dysfunction in young children, and in adults it causes problems with food getting stuck and food impactions, as well as problems with swallowing. EoE is classically thought of as an allergic disease sparked by food allergens, so there’s a lot of interest in trying to remove foods from the diet to treat it.”
The problem with that approach, Furuta says, is that there is no test to easily identify which food allergen causes EoE in any given patient. Gastroenterologists typically start treatment by removing the six most common food allergens — dairy, wheat, eggs, soy, fish/shellfish, and peanuts/tree nuts — then reintroducing them one by one to see which sparks the inflammation. It’s an approach that necessitates multiple endoscopies to pinpoint the precise cause of EoE, and one that presents a significant decrease in quality of life for patients who must severely limit their diet in addition to undergoing a series of invasive tests.
Looking for less-drastic options
Working with the Consortium of Eosinophilic Gastrointestinal eosinophiLic disease Researchers (CEGIR) led jointly by the CU School of Medicine and Cincinnati Children’s Hospital Medical Center, Furuta and Menard-Katcher began looking for a less-drastic dietary treatment option for EoE. Knowing that dairy is the most common allergen responsible for the disease, they constructed a clinical trial for adults ages 18 to 60 with active EoE. Half of the participants were assigned the standard six-food elimination diet for six weeks, and half eliminated only dairy products over the same timeframe.
At the end of the almost three-year trial, the researchers discovered that histological remission was statistically the same in both groups. Thirty-four percent of participants had remission from eliminating dairy alone, indicating that method as an acceptable initial dietary therapy for EoE.
“We started off by saying, ‘Do we have to have so many foods eliminated? Is it necessary to go all the way to removing the six foods, or can we just start with the most common allergen first, and then if that’s not effective, move up to the six-food elimination diet?’” says Furuta, who is working with other CEGIR researchers on a similar study in pediatric EoE patients. “It was taking a very practical approach to addressing a very concerning problem.”
Alternative to medications
Other treatments for EOE include proton pump inhibitors, topical steroids, and expensive biologic medications, all of which come with side effects. Dietary therapy is preferred, Menard-Katcher says, but eliminating six foods can be intimidating, especially for children. Working with patient-advocacy groups as well as the NIH, the researchers strived to create a patient-friendly trial that would result in an easier path toward remission for more patients.
“We have a lot of patients who would love to do dietary therapy, if that enables them to avoid the use of chronic medications,” Menard-Katcher says. “But the six-food elimination diet has a lot of drawbacks. You’re talking about eliminating a lot of foods that people eat really commonly. Then you add to that the burden of repeated endoscopies to try and identify the trigger or triggers, knowing that you also might not identify those triggers. It’s much easier for a patient to hear that they might have to try eliminating dairy as a first-line therapy rather than dairy, wheat, eggs, soy, tree nuts, and seafood.”
Strength in gastrointestinal research
The new study not only is a boon for patients with EoE and the physicians who treat them; it’s also evidence of the strengths in research and treatment for EoE and similar gastrointestinal diseases on the CU Anschutz Medical Campus. That includes the Gastrointestinal Eosinophilic Diseases Program at Children’s Hospital Colorado, a multidisciplinary program that currently sees patients from around 40 states who travel to the clinic for research studies and multidisciplinary care.
“We feel very fortunate because just across campus, Dr. Menard-Katcher and his team are there on the adult side for us to transition our local patients to,” says Furuta, director of the Gastrointestinal Eosinophilic Diseases Program and section head of the Digestive Health Institute at Children’s Colorado. “Institutionally, on this campus, we have a fantastic team that is helping to shape the field.”
BU researchers receive $1.3m EPA grant to advance climate resilience among Mystic River communities
The three-year project aims to identify and address the cumulative impacts of chemical hazards and climate change that affect the 21 communities surrounding the Mystic River Watershed.
BU Researchers Receive $1.3M EPA Grant to Advance Climate Resilience among Mystic River Communities
The three-year project aims to identify and address the cumulative impacts of chemical hazards and climate change that affect the 21 communities surrounding the Mystic River Watershed.
The 21 communities that surround Greater Boston’s Mystic River Watershed are exposed to many of the central threats of climate change, including urban heat islands and coastal and inland flooding, while also confronting multiple chemical exposures.
Now, with a new grant from the US Environmental Protection Agency (EPA), a team of Boston University School of Public Health (BUSPH) researchers are collaborating with the Greater Boston-based Mystic River Watershed Association (MyRWA) and other local community organizations to better understand how communities are affected by these chemical and climate stressors, and how they can become more resilient to the current and future impacts of climate change.
Dr. Jonathan Levy, chair and professor of environmental health at BUSPH, and Dr. Amruta Nori-Sarma, assistant professor of environmental health at BUSPH, will serve as co-principal investigators of the award, titled Advancing Community Resilience to Cumulative Climate Impacts in the Mystic River Watershed (ACRES). The grant totals $1.3 million over three years and is part of broader efforts by the EPA to support projects that advance environmental justice in underserved and overburdened communities across the country. A majority of MyRWA’s neighboring communities include residents who are low-income and people of color. The communities include Arlington, Belmont, Boston (Charlestown & East Boston), Burlington, Cambridge, Chelsea, Everett, Lexington, Malden, Medford, Melrose, Reading, Revere, Somerville, Stoneham, Wakefield, Watertown, Wilmington, Winchester, Winthrop, and Woburn.
The project is timely, as many cities are ramping upefforts to address the global climate crisis and protect their local communities against climate hazards.
The researchers will work closely with the Resilient Mystic Collaborative (RMC), a voluntary group among the Mystic River Watershed communities that builds regional climate resilience, to identify community concerns related to climate change and to develop candidate solutions that highlight health protection and equity alongside sustainability. They will connect this information with a geolocated database and mapping tool that will be used to identify places and populations at higher risk, allowing the RMC to prioritize climate-resilient policies and investments that can decrease and prevent chemical exposures and improve climate resilience among vulnerable populations over time.
“At the heart of the project, we are trying to understand how we can best protect vulnerable people and neighborhoods from chemical exposures given the growing effects of climate change,” says Dr. Levy. His team will support the MyRWA/RMC and other organizations actively engaged in this work with quantitative and qualitative analyses that will provide useful insight on how to best protect these high-risk communities.
“These communities are often also disproportionately burdened due to systemic issues such as historical redlining, which have important implications for development that stretch into present-day,” Dr. Nori-Sarma says. Climate change solutions may also lead to climate gentrification in urban communities where residents can no longer afford to live in their neighborhood due to the costs of green infrastructure and sustainability, she says. “The impact of exposure to all of these issues is likely to be greater than the sum of its parts.”
The researchers are eager to learn more about how to reduce the impact of multiple climate hazards on vulnerable residents.
“In addition to risks from flooding, storm surges, and heat islands, many communities also have a lot of industrial facilities as well as a lot of traffic and other sources of air pollution,” Dr. Levy says. “So we're trying to understand how to best address the cumulative burden that these communities are experiencing as they face different climate and chemical stressors simultaneously.”
“As we advance climate justice, it must be founded on community-engaged research,” says David Cash, EPA regional administrator for New England. “The work conducted under this grant will help target climate-related challenges facing the disadvantaged communities in the Mystic Watershed that have been overburdened by environmental pollution. This project will yield tangible benefits for people living in the Mystic Watershed and provide policy guidance for EPA nationwide.”
The team hopes the project will underscore the need for health equity to be centered in climate resilience planning, and provide a framework that can be applied in other communities across the US.
“Our project intends to meet these communities where they are, assess the challenges that they face and understand the interrelated nature of climate exposures and impacts on health, and provide communities with the tools that they need to advocate for themselves and their local environments,” says Dr. Nori-Sarma.
“As a student at BUSPH, I learned that community power can be built through research,” says Mariangelà EchevarrÃa-Ramos, Climate Resilience Manager at MyRWA, a graduate of the school’s Master of Public Health program. “One of our community leaders often says, ‘No one knows everything, together we know a lot.’ What an exciting opportunity to blend top-notch academic research with on-the-ground lived experiences to help people stay safe from chemical exposures.”
**
About Boston University School of Public Health
Founded in 1976, Boston University School of Public Health is one of the top five ranked private schools of public health in the world. It offers master's- and doctoral-level education in public health. The faculty in six departments conduct policy-changing public health research around the world, with the mission of improving the health of populations—especially the disadvantaged, underserved, and vulnerable—locally and globally.
Artificial intelligence with a human touch
New project creates next-gen AI to improve diagnostics
IMAGE: HIEN VAN NGUYEN, UNIVERSITY OF HOUSTON ASSOCIATE PROFESSOR OF ELECTRICAL AND COMPUTER ENGINEERING, IS DEVELOPING NEXT-GEN ARTIFICIAL INTELLIGENCE TO IMPROVE MEDICAL DIAGNOSTICS.view more
CREDIT: UNIVERSITY OF HOUSTON
Despite the remarkable progress in artificial intelligence (AI), several studies show that AI systems do not improve radiologists' diagnostic performance. In fact, diagnostic errors contribute to 40,000 - 80,000 deaths annually in U.S. hospitals. This lapse creates a pressing need: Build next-generation computer-aided diagnosis algorithms that are more interactive to fully realize the benefits of AI in improving medical diagnosis.
That’s just what Hien Van Nguyen, University of Houston associate professor of electrical and computer engineering, is doing with a new $933,812 grant from the National Cancer Institute. He will focus on lung cancer diagnostics.
“Current AI systems focus on improving stand-alone performances while neglecting team interaction with radiologists,” said Van Nguyen. “This project aims to develop a computational framework for AI to collaborate with human radiologists on medical diagnosis tasks.”
That framework uses a unique combination of eye-gaze tracking, intention reverse engineering and reinforcement learning to decide when and how an AI system should interact with radiologists.
To maximize time efficiency and minimize the amount of distraction on the clinical work, Van Nguyen is designing a user-friendly and minimally interfering interface for radiologist-AI interaction.
The project evaluates the approaches on two clinically important applications: lung nodule detection and pulmonary embolism. Lung cancer is the second most common cancer, and pulmonary embolism is the third most common cause of cardiovascular death.
“Studying how AI can help radiologists reduce these diseases' diagnostic errors will have significant clinical impacts,” said Van Nguyen. “This project will significantly advance the knowledge of the field by addressing important, but largely under-explored questions.”
The questions include when and how AI systems should interact with radiologists and how to model radiologist visual scanning process.
“Our approaches are creative and original because they represent a substantive departure from the existing algorithms. Instead of continuously providing AI predictions, our system uses a gaze-assisted reinforcement learning agent to determine the optimal time and type of information to present to radiologists,” said Van Nguyen.
“Our project will advance the strategies for designing user interfaces for doctor-AI interaction by combining gaze-sensing and novel AI methodologies.”
Blue whale foraging and reproduction are related to environmental conditions, study shows
IMAGE: A NEW ZEALAND BLUE WHALE SURFACES IN THE SOUTH TARANAKI BIGHT.view more
CREDIT: DAWN BARLOW, MARINE MAMMAL INSTITUTE, OREGON STATE UNIVERSITY
NEWPORT, Ore. – A new study of New Zealand blue whales’ vocalizations indicates the whales are present year-round in the South Taranaki Bight and their behavior is influenced by environmental conditions in the region.
The findings are a significant advancement in researchers’ understanding of the habitat use and behavior of this population of blue whales, which Oregon State University researchers first identified as genetically distinct from other blue whale populations less than a decade ago.
“We went from not knowing 10 years ago whether this was a distinct population to now understanding these whales’ ecology and their response to changing environmental conditions,” said the study’s lead author, Dawn Barlow, a postdoctoral scholar in OSU’s Marine Mammal Institute. “These findings can inform conservation management of this blue whale population and their habitat.”
The patterns and intensity of the whales’ calls and songs over two years showed strong seasonality in their foraging and breeding behavior, and the vocalizations changed based on environmental conditions such as a documented marine heatwave, Barlow said.
“During the marine heatwave, feeding-related calls were reduced, reflecting poor foraging conditions during that period,” Barlow said. “But we also saw changes in vocalizations in the next breeding period, an indication that they put less effort into reproduction following a period of poor feeding conditions.”
The study was just published in the journal Ecology and Evolution. Barlow conducted the research as a doctoral student in the Geospatial Ecology of Marine Megafauna Laboratory at Hatfield Marine Science Center in Newport, led by associate professor Leigh Torres, a co-author of the new paper.
Blue whales are the largest of all whales and are found in all oceans except the Arctic. Their populations were depleted due to commercial whaling in the early 1900s, and today they are listed as endangered under the International Union for Conservation of Nature’s Red List of Threatened Species.
The New Zealand whales’ habitat overlaps with a wide range of commercial activities, including oil and gas exploration and extraction, vessel traffic, fisheries, wind energy development and possible seabed mining.
Torres first hypothesized in 2013 that the South Taranaki Bight, between New Zealand’s North and South Islands, was an undocumented blue whale feeding ground. Following comprehensive data collection efforts, and using multiple lines of evidence, Torres, Barlow and colleagues were able to document in 2018 that the population in this region was genetically distinct from other blue whale populations.
Previous research was primarily based on observations researchers made during visits to the region in the summer months. But the researchers wanted to know more about the whales’ behavior during other parts of the year. They placed five hydrophones – a type of underwater microphone – that recorded continuously between January 2016 and February 2018, with only brief gaps to retrieve data every six months.
“Unlike many other baleen whales, this population stays in this region year-round,” Barlow said. “That means we can monitor what they are doing from one location. Listening is an effective way to do that.”
The hydrophone recordings showed that the whales’ “D” calls were strongly correlated with oceanographic conditions related to upwelling in the spring and summer. Upwelling is a process where deeper, cooler water is pushed toward the surface; the nutrient-rich water supports aggregations of krill that the blue whales feed on. The whales’ D calls were more intense during periods of strong upwelling.
The recordings also showed that the whales’ song vocalizations, which are produced by males and associated with breeding behavior, followed a highly seasonal pattern, with peak intensity in the fall. That timing aligns with past whaling records’ estimates of conception, Barlow said.
The hydrophone evidence of the breeding behavior and the whales’ presence in the region year-round can influence the animals’ national threat classification status, which impacts management practices, the researchers said.
Blue whales in New Zealand had been classified as migrant, but as a result of the research by Torres, Barlow and colleagues, the classification of has changed from migrant to data deficient. If the whales are reclassified as a resident population, that could impact management practices, but evidence of breeding in New Zealand is needed for that change to occur, the researchers said.
“Although no one has actually documented blue whales mating – it is hard to observe that directly – the increase in song during the expected time of mating is a strong indication of breeding in New Zealand waters,” Torres said. “Our study adds more evidence that these are resident New Zealand blue whales.”
Once the researchers were able to make the link between the whales’ behavior and their calls, they could then look at the calls and behavior relative to environmental patterns. Specifically, they noted how the whales’ foraging and breeding behavior changed during and after a 2016 marine heatwave.
During the marine heatwave, there were fewer aggregations of krill for the whales to feed on, which the researchers documented in a previous study. The reduction in foraging behavior correlated to less intense D calls during that period, and in the next breeding season, the breeding songs were also less intense.
The findings raise additional questions about how changing ocean conditions and human activity in the region are impacting the New Zealand blue whale population and reinforce the need for continued monitoring, the researchers said.
“We have come so far in 10 years in our knowledge of these blue whales - from not knowing this population existed to now understanding their year-round use of this region for feeding, mating and nursing,” Torres said. “New Zealanders should be excited and proud that their country is home to its own unique population of blue whales. We hope our work helps Kiwis manage and protect these whales.”
Additional coauthors are Holger Klinck, director of the Cornell University K. Lisa Yang Center for Conservation Bioacoustics, who also is affiliated with OSU’s Marine Mammal Institute; Dimitri Ponirakis of Cornell; and Trevor Branch of the University of Washington. The Marine Mammal Institute is part of Oregon State’s College of Agricultural Sciences.
New Zealand blue whale
CREDIT
Leigh Torres, Marine Mammal Institute, Oregon State University
Americans are drinking more caffeinated beverages than ever before, but Rutgers researchers found one group that tops the charts in caffeine consumption: adult smokers with mental illness.
In a study published online ahead of print in the January issue of the journal Psychiatry Research, Jill M. Williams, director of the division of addiction psychiatry at Rutgers Robert Wood Johnson Medical School, found not only do adult smokers with bipolar disorder and schizophrenia drink the most caffeine, they are at the highest risk of negative health consequences.
“Caffeine is generally considered safe and even has some health benefits,” said Williams. “But we just don't understand the cognitive and psychiatric effects of high caffeine intake, especially among smokers with mental illness.”
Caffeine is one of the most widely used psychoactive drugs in the United States, with the main effects increased alertness, attention and vigilance. While it’s considered safe for most healthy adults to consume up to 400 milligrams of caffeine per day – the equivalent of about four cups of brewed coffee – consuming more than 600 milligrams isn’t recommended and can lead to anxiety, insomnia, excess stomach acid and heartburn.
Little is known about caffeine’s influence on executive functions, such as reasoning and decision making, and the studies that have been done have mostly included healthy adults without mental illness, Williams said. Even less is known about how high caffeine intake may impact psychiatric symptoms or sleep in adults with serious mental illness who smoke.
To address these gaps, Williams and colleagues from the Rutgers Department of Psychology and the University of California San Francisco School of Medicine analyzed data from 248 adult smokers recruited during a previous study. Participants were either outpatient smokers with schizophrenia or bipolar disorder or from a control group with no psychiatric diagnoses. All participants were pack-a-day smokers.
At the beginning of the study, participants completed surveys on smoking history, caffeine use, physical health and psychological symptoms. The researchers also collected blood samples to measure serum caffeine levels.
They found caffeine intake was highest among participants with bipolar disorder, followed by adults with schizophrenia. The control group consumed the least amount of caffeine.
Williams said there are several theories to explain the relationship between caffeine intake and mental illness. One is a well-established association between caffeine and smoking: People with mental illnesses smoke at rates two to three times higher than the general population, and because the tars in cigarette smoke increase the metabolism of caffeine, it takes more caffeine to achieve stimulating effects.
Another theory links high caffeine intake to adenosine receptors and supports a possible self-medication effect among people with mental illness, said Williams. People with mental illnesses also seem to have vulnerabilities to all types of addictive substances, putting them at higher risk for excess intake and more negative consequences. Additionally, the researchers found evidence that mood is linked to caffeine intake, especially bad mood.
Each of these explanations warrants further investigation, Williams said.
“Today, people consume huge amounts of caffeine in more concentrated forms – like energy drinks or double shots of espresso – far more than when our participants were surveyed,” she said. “And yet, the effects of high caffeine intake remain widely understudied. This is particularly true for people with mental illness.”
