Aurelia Butler

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    in Computers Math

    Single model predicts trends in employment, microbiomes, forests

    Researchers report that a single, simplified model can predict population fluctuations in three unrelated realms: urban employment, human gut microbiomes and tropical forests. The model will help economists, ecologists, public health authorities and others predict and respond to variability in multiple domains, the researchers say.
    The new findings are detailed in the Proceedings of the National Academy of Sciences.
    The model, which goes by the acronym SLRM, does not predict exact outcomes, but generates a narrow distribution of the most likely trajectories, said James O’Dwyer, a professor of plant biology at the University of Illinois Urbana-Champaign who developed the model with postdoctoral researcher Ashish George in the Carl R. Woese Institute for Genomic Biology at the U. of I. George is now a computational scientist at the Broad Institute in Cambridge, Massachusetts.
    “The model incorporates random events, so it predicts a range of outcomes. But the data fall right in the middle of that range of outcomes,” O’Dwyer said.
    The model divides each population into discrete sectors — for example job types such as healthcare, agriculture or retail trade — and assigns a “generation time” to each.
    “Generation time is the lifetime of a tree or microbe, or the time a person spends in a given employment sector,” George said. “It is measured in hours for microbes, years for job types, and decades for forests.” Analyzing the systems in terms of generation time for each sector revealed similarities in how all three systems behave.
    The scientists relied on decades of research tracking changes in each of the different domains over time. For the employment analysis, they focused on the number of people employed in different economic sectors over time. This data came from the North American Industry Classification System and included monthly updates for 383 U.S. cities over a period of 17 years. More

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    in Heart

    Pumping cold water into rivers could act as ‘air conditioning’ for fish

    PITTSBURGH — Salmon may now have their own version of human air conditioning.  

    This past summer, hundreds of fish in the Wrights River in Nova Scotia, Canada, found reprieve from the heat in human-generated plumes of cold water, civil engineer Kathryn Smith reported October 17 at the Geological Society of America meeting. The work, though only proof of concept, could aid efforts to conserve cold-water species amid the widespread warming of rivers due to climate change (SN: 10/20/22).

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    When water temperatures get too hot, fish can become stressed or even die. In rivers, Atlantic salmon and other cold-water species sometimes escape the heat by flocking to cooler areas, which often arise near groundwater springs or relatively cool tributaries.

    Lots of work has been done to preserve and augment these naturally occurring refuges, said Smith, of Dalhousie University in Halifax, Canada, “but there hasn’t really been an emphasis or focus on if we can create cold-water habitat.”

    So she and her colleagues pumped groundwater that was about 9° Celsius (or about 48° Fahrenheit) from a nearby well into the river, manifesting an artificial plume of water that could be as much as 20 degrees Celsius cooler than the surrounding water.

    Researchers pumped groundwater into the Wrights River during the summer to create a plume of cooler water that fish could shelter in (image on the left). A thermal image (right) shows the effect: Cooler water appears darker purple while warmer water and sun-baked rocks are orange and yellow.Kathryn Smith

    The plume attracted several hundred fish of varying life stages and species, including Atlantic salmon and brown trout. Most were alevins — juvenile fish still attached to yolk sacs — that occupied the plume throughout the tests. But when a heat wave brought on maximum water temperatures of about 30° C, more mature fish also took shelter in the plume.

    For a pump-free approach, the team also rerouted some water from the river into an underground trench, where it cooled before reentering the river. Though this method lowered the water temperature by only a few degrees Celsius, fish were observed frequenting the passively cooled flow throughout the summer.

    More work lies ahead to determine how many of these sites would need to be constructed and sustained to significantly benefit fish populations, and how to do so while keeping energy costs low, says John Ackerman, a consulting engineer based in Hazleton, Pa., who was not involved in the research. But the researchers are demonstrating that these solutions can work, he says. “The concept is solid.” More

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    in Computers Math

    Bitcoin mining has ‘very worrying’ impacts on land and water, not only carbon

    As bitcoin and other cryptocurrencies have grown in market share, they’ve been criticized for their heavy carbon footprint: Cryptocurrency mining is an energy-intensive endeavor. Mining has massive water and land footprints as well, according to a new study that is the first to detail country-by-country environmental impacts of bitcoin mining. It serves as the foundation for a new United Nations (UN) report on bitcoin mining, also published today.
    The study reveals how each country’s mix of energy sources defines the environmental footprint of its bitcoin mining and highlights the top 10 countries for energy, carbon, water and land use.* The work was published in Earth’s Future, which publishes interdisciplinary research on the past, present and future of our planet and its inhabitants.
    “A lot of our exciting new technologies have hidden costs we don’t realize at the onset,” said Kaveh Madani, a Director at United Nations University who led the new study. “We introduce something, it gets adopted, and only then do we realize that there are consequences.”
    Madani and his co-authors used energy, carbon, water and land use data from 2020 to 2021 to calculate country-specific environmental impacts for 76 countries known to mine bitcoin. They focused on bitcoin because it’s older, popular and more well-established/widely used than other cryptocurrencies.
    Madani said the results were “very interesting and very concerning,” in part because demand is rising so quickly. But even with more energy-efficient mining approaches, if demand continues to grow, so too will mining’s environmental footprints, he said.
    Electricity and carbon
    If bitcoin mining were a country, it would be ranked 27th in energy use globally. Overall, bitcoin mining consumed about 173 terawatt hours of electricity in the two years from January 2020 to December 2021, about 60% more than the energy used for bitcoin mining in 2018-2019, the study found. Bitcoin mining emitted about 86 megatons of carbon, largely because of the dominance of fossil fuel-based energy in bitcoin-mining countries. More

  • 113 Shares199 Views

    in Computers Math

    Smartphone attachment could increase racial fairness in neurological screening

    Engineers at the University of California San Diego have developed a smartphone attachment that could enable people to screen for a variety of neurological conditions, such as Alzheimer’s disease and traumatic brain injury, at low cost — and do so accurately regardless of their skin tone.
    The technology, published in Scientific Reports, has the potential to improve the equity and accessibility of neurological screening procedures while making them widely available on all smartphone models.
    The attachment fits over a smartphone’s camera and improves its ability to capture clear video recordings and measurements of the pupil, which is the dark center of the eye. Recent research has shown that tracking pupil size changes during certain tasks can provide valuable insight into an individual’s neurological functions. For example, the pupil tends to dilate during complex cognitive tasks or in response to unexpected stimuli.
    However, tracking pupil size can be difficult in individuals with dark eye colors, such as those with darker skin tones, because conventional color cameras struggle to distinguish the pupil from the surrounding dark iris.
    To enhance the visibility of the pupil, UC San Diego engineers equipped their smartphone attachment with a specialized filter that selectively permits a certain range of light into the camera. That range is called far-red light — the extreme red end of the visible spectrum located just before infrared light. Melanin, the dark pigment in the iris, absorbs most visible wavelengths of light but reflects longer wavelengths, including far-red light. By imaging the eye with far-red light while blocking out other wavelengths, the iris appears significantly lighter, making it easier to see the pupil with a regular camera.
    “There has been a large issue with medical device design that depends on optical measurements ultimately working only for those with light skin and eye colors, while failing to perform well for those with dark skin and eyes,” said study senior author Edward Wang, an electrical and computer engineering professor in The Design Lab at UC San Diego, where he is the director of the Digital Health Technologies Lab. “By focusing on how we can make this work for all people while keeping the solution simple and low cost, we aim to pave the way to a future of fair access to remote, affordable healthcare.”
    Another feature of this technology that makes it more accessible is that it is designed to work on all smartphones. Traditionally, pupil measurements have been performed using infrared cameras, which are only available in high-end smartphone models. Since regular cameras cannot detect infrared light, this traditional approach limits accessibility to those who can afford more expensive smartphones. By using far-red light, which is still part of the visible spectrum and can be captured by regular smartphone cameras, this technology levels the playing field. More

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    in Heart

    Berkley Walker wants to revamp photosynthesis for a changing climate

    Berkley Walker didn’t plan on becoming a scientist; he wanted to be an entrepreneur. And he got started early on that goal: In high school in Portland, Ore., he started a granola bar company, which helped pay for his bachelor’s degree in microbiology.

    After college, Walker went to work as a product manager at an instrumentation company in Washington state, planning to go to business school and then into biotech. But a class on environmental biophysics at nearby Washington State University in 2009 changed his trajectory.  

    The course was about using mathematics to model physical systems in nature. “Working that math out to understand how energy and matter exchange within the environment,” Walker says — that was all it took. He decided to pursue a career as a plant scientist. “I wanted to have some kind of usefulness to the world,” Walker says. “Feeding people is where I settled.”

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    Amazing but inefficient plants

    Today, at Michigan State University, Walker wants to understand the intricate details of how photosynthesis works, with the ultimate aim of improving it.

    He remains deeply fascinated by plants: “You just take this little seed, you put it in the dirt and then you get this plant,” he says. “And it spreads these leaves out. And those leaves just take the sun, and they scrub carbon dioxide out of the atmosphere, and they use that to make the food that we eat, the clothes that we wear, the air that we breathe, energy that we consume. And that’s just miraculous.”

    But as impressive as photosynthesis is, it is surprisingly inefficient. A leaf converts just around 1 percent of the sun’s light into usable energy, Walker says. In part that’s because of mistakes in the first step of photosynthesis. The enzyme that captures CO2 molecules and sticks them to sugar makes a lot of mistakes, often grabbing oxygen instead. Those mistakes result in a compound that actually inhibits photosynthesis. Photorespiration, a kind of recycling process, gets rid of that compound — but photorespiration requires a lot of energy.

    Losses due to this recycling in the American Midwest over an average wheat and soybean growing season add up to about 148 trillion dietary calories, Walker says. “If you were to convert these calories into doughnut equivalents,” he says, “you would have a stack of doughnuts that would go to the moon and back about 11 times.”

    Any efficiency gain could make a huge difference in agricultural productivity. But first scientists have to better understand how photorespiration works.

    To that end, Walker came up with an innovative technique to trace carbon molecules in leaves, research reported in a 2022 paper in Nature Plants. The researchers were using flux analysis, which reveals the movements of molecules through plants’ metabolic network. But they needed a better way to freeze the metabolism of a plant. The problem was, there was no way to spray liquid nitrogen into the instrument chamber that held the leaves.

    After talking to engineers at the company that makes the instrument, Walker decided to drill a hole in the chamber so his team could insert a nozzle to spray in liquid nitrogen and hit the leaf surface instantaneously. “That’s a really critical step,” says Xinyu Fu, who has been a postdoc in Walker’s lab for the past four years. A lot could change in the 10 seconds it would take to open the chamber and take the leaf out.

    Xinyu Fu, a postdoc in Berkley Walker’s lab, prepares to rapidly freeze a leaf for metabolic analysis.Chelsea Mamott/Wisconsin Energy Institute

    The work revealed that up to about 40 percent of the carbon-bearing amino acid serine that is produced during photorespiration gets diverted by the plant to be used for something — perhaps protein synthesis — rather than going all the way through the recycling process. That suggests optimizing photorespiration in the context of climate change could result in more nutritious, protein-rich crops. But, “as we’re trying to change it,” Walker says, “we need to understand what trade-offs there might be.”

    A generosity of spirit

    Colleagues who know Walker best point to his eagerness to collaborate as one of his strengths, along with his generosity of spirit.

    Don Ort, a plant scientist at the University of Illinois Urbana-Champaign and Walker’s postdoc adviser for nearly three years, says Walker is a committed teacher and colleague. “Being involved in the education of graduate students and postdocs is a passion for him,” Ort says. “He’s very passionate about what he does. He does it with a very high level of enthusiasm and a very high level of optimism. And it’s infectious to people around him.”

    Walker sees plant science as one big community that is trying to solve two big problems: How to make crops more productive to feed a growing population, and how to do it in a changing climate, which may pose any number of challenges to agriculture. And he believes we’ll start seeing solutions in the coming decades, whether they come out of his lab or someone else’s.

    “Whoever comes up with those, and if they’re shown to work and work repeatedly in a lot of crops, then that’s a really big deal,” he says. “That’s the kind of idea that we’re chasing.” More

  • 100 Shares149 Views

    in Computers Math

    Plant-based materials give ‘life’ to tiny soft robots

    A team of University of Waterloo researchers has created smart, advanced materials that will be the building blocks for a future generation of soft medical microrobots.
    These tiny robots have the potential to conduct medical procedures, such as biopsy, and cell and tissue transport, in a minimally invasive fashion. They can move through confined and flooded environments, like the human body, and deliver delicate and light cargo, such as cells or tissues, to a target position.
    The tiny soft robots are a maximum of one centimetre long and are bio-compatible and non-toxic. The robots are made of advanced hydrogel composites that include sustainable cellulose nanoparticles derived from plants.
    This research, led by Hamed Shahsavan, a professor in the Department of Chemical Engineering, portrays a holistic approach to the design, synthesis, fabrication, and manipulation of microrobots. The hydrogel used in this work changes its shape when exposed to external chemical stimulation. The ability to orient cellulose nanoparticles at will enables researchers to program such shape-change, which is crucial for the fabrication of functional soft robots.
    “In my research group, we are bridging the old and new,” said Shahsavan, director of the Smart Materials for Advanced Robotic Technologies (SMART-Lab). “We introduce emerging microrobots by leveraging traditional soft matter like hydrogels, liquid crystals, and colloids.”
    The other unique component of this advanced smart material is that it is self-healing, which allows for programming a wide range in the shape of the robots. Researchers can cut the material and paste it back together without using glue or other adhesives to form different shapes for different procedures.
    The material can be further modified with a magnetism that facilitates the movement of soft robots through the human body. As proof of concept of how the robot would maneuver through the body, the tiny robot was moved through a maze by researchers controlling its movement using a magnetic field.
    “Chemical engineers play a critical role in pushing the frontiers of medical microrobotics research,” Shahsavan said. “Interestingly, tackling the many grand challenges in microrobotics requires the skillset and knowledge chemical engineers possess, including heat and mass transfer, fluid mechanics, reaction engineering, polymers, soft matter science, and biochemical systems. So, we are uniquely positioned to introduce innovative avenues in this emerging field.”
    The next step in this research is to scale the robot down to submillimeter scales.
    Shahsavan’s research group collaborated with Waterloo’s Tizazu Mekonnen, a professor from the Department of Chemical Engineering, Professor Shirley Tang, Associate Dean of Science (Research), and Amirreza Aghakhani, a professor from the University of Stuttgart in Germany. More

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    in Computers Math

    Simulating cold sensation without actual cooling

    The perception of persistent thermal sensations, such as changes in temperature, tends to gradually diminish in intensity as our bodies become accustomed to the temperature. This phenomenon leads to a shift in our perception of temperature when transitioning between different scenes in a virtual environment. Researchers at the University of Tsukuba developed a technology to generate a virtual cold sensation via a non-contact method without physically altering the skin temperature.
    Our skin plays a key role in perceiving temperature and the surroundings. For instance, we perceive the chill of the outdoors when our cheeks blush with cold, and we sense the onset of spring when our skin warms up gradually. However, getting exposed to the same stimuli repeatedly, makes us accustomed to the stimuli, making it challenging to sense new sensations. This process, known as “temperature acclimatization,” can interfere with our ability to gauge temperature changes in a virtual reality (VR) environment while switching scenes.
    In this study, the researchers have developed a non-contact technology for simulating a cold sensation that continually generates thermal experiences while maintaining nearly constant skin temperature. This innovative approach leverages human body’s natural sensitivity to rapid temperature changes. The technology employs a combination of cold air flow and a light source to instantly switch between a quick cold and a gentle warm stimulus, inducing a cold sensation while maintaining the skin temperature fluctuations close to zero. Evaluation results have demonstrated that this system can provide a virtual cold sensation without any actual change in temperature. Moreover, the researchers have succeeded in replicating a cold sensation of the same intensity as one would experience with continuous skin temperature changes.
    This breakthrough technology offers a novel perspective on simulating skin sensations without altering the body’s physical state. It has the potential to enable immersive experiences in the world of VR, including the Metaverse, by offering not only instantaneous thermal sensations like a sudden cold breeze but also persistent thermal experiences over extended periods, akin to those encountered during international travel.
    This work was supported in part by grants from JSPS KAKENHI (JP21H03474, JP21K19778) and in part by JST SPRING (JPMJSP2124). More

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    in Computers Math

    Adaptive optical neural network connects thousands of artificial neurons

    Scientists headed by physicists Prof. Wolfram Pernice, Prof. Martin Salinga and computer specialist Prof. Benjamin Risse, all from the University of Münster (Germany), developed a so-called event-based architecture, using photonic processors. In a similar way to the brain, this makes possible the continuous adaptation of the connections within the neural network.
    Modern computer models — for example for complex, potent AI applications — push traditional digital computer processes to their limits. New types of computing architecture, which emulate the working principles of biological neural networks, hold the promise of faster, more energy-efficient data processing. A team of researchers has now developed a so-called event-based architecture, using photonic processors with which data are transported and processed by means of light. In a similar way to the brain, this makes possible the continuous adaptation of the connections within the neural network. This changeable connections are the basis for learning processes. For the purposes of the study, a team working at Collaborative Research Centre 1459 (“Intelligent Matter”) — headed by physicists Prof. Wolfram Pernice and Prof. Martin Salinga and computer specialist Prof. Benjamin Risse, all from the University of Münster — joined forces with researchers from the Universities of Exeter and Oxford in the UK. The study has been published in the journal “Science Advances.”
    What is needed for a neural network in machine learning are artificial neurons which are activated by external excitatory signals, and which have connections to other neurons. The connections between these artificial neurons are called synapses — just like the biological original. For their study, the team of researchers in Münster used a network consisting of almost 8,400 optical neurons made of waveguide-coupled phase-change material, and the team showed that the connection between two each of these neurons can indeed become stronger or weaker (synaptic plasticity), and that new connections can be formed, or existing ones eliminated (structural plasticity). In contrast to other similar studies, the synapses were not hardware elements but were coded as a result of the properties of the optical pulses — in other words, as a result of the respective wavelength and of the intensity of the optical pulse. This made it possible to integrate several thousand neurons on one single chip and connect them optically.
    In comparison with traditional electronic processors, light-based processors offer a significantly higher bandwidth, making it possible to carry out complex computing tasks, and with lower energy consumption. This new approach consists of basic research. “Our aim is to develop an optical computing architecture which in the long term will make it possible to compute AI applications in a rapid and energy-efficient way,” says Frank Brückerhoff-Plückelmann, one of the lead authors.
    Methodology: The non-volatile phase-change material can be switched between an amorphous structure and a crystalline structure with a highly ordered atomic lattice. This feature allows permanent data storage even without an energy supply. The researchers tested the performance of the neural network by using an evolutionary algorithm to train it to distinguish between German and English texts. The recognition parameter they used was the number of vowels in the text. More