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Gene Expression in Neurons Solves a Brain Evolution Puzzle

The neocortex is the seat of human intellect. New data suggests that mammals created it with new types of cells only after their evolutionary split from reptiles.
Source: Gene Expression in Neurons Solves a Brain Evolution Puzzle
MIT Research / How cell mechanics influences everything
« Last post by feeds on March 25, 2023, 11:10:49 PM »
How cell mechanics influences everything

High in the treetops of a Chinese rainforest, Ming Guo began to explore the influence of a single cell.

A student in China’s Tsinghua University, Guo was studying the mechanical properties of plant cells. As part of his master’s thesis he took on an intriguing question: Does a cell’s physical integrity — its size, shape, squishiness, or stiffness — have anything to do with how tall a tree grows?

In search of an answer, Guo visited forests across the Yunnan province, collecting leaves from the tallest trees, some towering over 200 feet — too high for Guo himself to climb. So, he enlisted the help of a student in the university’s rock climbing club, who scaled the trees and retrieved leaves at various heights along their length.

After analyzing the individual plant cells within each leaf, Guo observed a pattern: The higher the leaves, the smaller the cells. And, more interesting still, the size of a single cell could more or less predict how tall a tree can grow.

This early work in tree cells made one thing clear in Guo’s mind: A cell’s physical form can play a role in the development of an entire organism. This realization motivated him to study cell mechanics, in plant and eventually animal cells, to see what more a cell’s physical properties can reveal about how cells, tissues, organs, and whole organisms grow.

“People study cells in the context of their biology and biochemistry, but cells are also simply physical objects you can touch and feel,” Guo says. “Just like when we construct a house, we use different materials to have different properties. A similar rule must apply to cells when forming tissues and organs. But really, not much is known about this process.”

His work in cell mechanics led him to MIT, where he recently received tenure and is the Class of ’54 Career Development Associate Professor in the Department of Mechanical Engineering.

At MIT, Guo and his students are developing tools to carefully poke and prod cells, and observe how their physical form influences the growth of a tissue, organism, or disease such as cancer. His research bridges multiple fields, including cell biology, physics, and mechanical engineering, and he is working to apply the insights from cell mechanics to engineer materials for biomedical applications, such as therapies to halt the growth and spread of diseased and cancerous cells.

“MIT is a perfect place for that in the long run,” Guo says. “It’s cross-disciplinary and always very inspiring, and by interacting with different people outside of the field, you get more ideas. It’s more likely that you can dig up something useful.”

The nature of physical objects

Guo grew up in Shijiazhuang, a city that is a two-hour train ride from Beijing. Both his parents were engineers — his father worked at the local factory, and his mother built teaching models of traffic systems at a vocational school. His parents worked hard, and like most factory families, they did not have the luxury of looking after their child when school was out.

“In the summers, they had to go to work, and they would just lock me at home. I’d throw my keys outside to someone to unlock the door so I could go play with them,” Guo recalls.

He and his friends would head to a cluster of residential buildings near the factory, and spent their days climbing.

“I liked to climb short buildings and towers and look at how they were structured,” Guo recalls. “There was also a small river where we tried to catch fish. Most families didn’t have much savings at the end of the year and didn’t spend much effort on education. But I remember as a kid having a lot of fun.”

School, and science, came more into focus in high school, when Guo had the chance to visit a cousin who was attending Tsinghua University. He remembers being particularly drawn to a textbook on his cousin’s shelf, on the structural mechanics of bridges. The short stay inspired him to apply to the university — one of the top two schools in the country. Once accepted, he headed to Tsinghua for a degree in mechanics.  

After a brief foray into the mechanics of fluids, and a project involving simulations of an artificial blood pump, Guo decided to pivot, and focus instead on the mechanics of cells, plant cells in particular. Inspired by his advisor, he took up the topic of how a plant cell’s mechanical integrity influences how tall a tree can grow. The project grew into a master’s thesis as Guo stayed on at Tsinghua as a master’s student.

“As I worked on plants, I realized that animal cells were also very interesting,” Guo says. “The nature of different materials, especially biological materials, and how to understand them simply as physical objects, was fascinating to me.”

“A profound impact”

As he wrapped up his work with tree cells, Guo read up on animal cell research, gravitating to work by David Weitz, a Harvard University physicist who specializes in soft matter, including the mechanical properties of living cells. Weitz’s work motivated Guo to apply to Harvard’s graduate program in applied physics.

In 2007, he arrived on the Cambridge campus — the first time he’d ever ventured outside China — and felt lost amid a new and foreign landscape.

“I had filled half my suitcase with ramen, and the first week I just ate ramen because I didn’t know where to eat,” Guo recalls. “I also couldn’t understand anything in some of my classes, because the type of English I learned in China was not the way people actually talk here.”

After time, Guo found his footing and dove into work in Weitz’s lab, where he focused his PhD thesis on understanding the “nonequilibrium behavior,” or the physical motions in a single cell, and investigating where the energy to generate such motions originates.

“That work really shifted my direction,” Guo says. “I knew what I wanted to do: keep understanding how cell mechanics — in multicellular systems like organs and tissues — influence everything.”

In 2015, he made the move to MIT, where he accepted a junior faculty position in the Department of Mechanical Engineering. At the Institute, he has shaped his research goals around developing new tools and techniques to better study living cells and how their physical and mechanical properties influence how cells move, respond, deform, and function.

“In the last few years, we’ve made some big insights on how, if you change a cell’s mechanical environment, such as their stiffness or their water content, that has a major impact on some fundamental biochemistry, such as transcription and cell signaling, which in turn regulates multicellular growth,” Guo says. “So, cell mechanics can have a really profound impact on biology.”

In addition to his research, Guo also enjoys teaching MIT students, most recently in 2.788 (Mechanical Engineering and Design of Living Systems), a class that challenges students to apply the mechanics of cells to design novel systems and machines. In a recent class, students have been using cardiac muscle cells to pump liquid through a microfluidic chip. A previous class amplified the natural voltage inside a plant to power a small wheel.

“The most energetic and happy moments I have are in talking to students,” Guo says. “They often give me surprises or new ideas that I love and most look forward to.”

In recent years, Guo’s research and teaching have expanded to consider not just the mechanics of single cells, but also multicellular systems — a shift he credits with the arrival of his daughter.

“She was born in 2016, and at that time, my entire group was working on single cells,” Guo says. “But seeing how she’s developed, I feel that understanding something that complex is much more interesting. So, we have also started working on exploring the mechanics and mechanobiology of more complex systems such as tissues and embryos.”

Source: How cell mechanics influences everything
Wired - Science / California’s Atmospheric Rivers Are Getting Worse
« Last post by feeds on March 25, 2023, 01:08:10 PM »
California’s Atmospheric Rivers Are Getting Worse

As climate change makes storms warmer and wetter, the state’s flood control system is struggling to keep up.
Source: California’s Atmospheric Rivers Are Getting Worse
JPL - NASA / NASA Invites Media to See Mars Habitat Before Crew Enters for One Year
« Last post by feeds on March 24, 2023, 07:34:46 PM »
NASA Invites Media to See Mars Habitat Before Crew Enters for One Year

Media are invited to visit NASA’s simulated Mars habitat on Tuesday, April 11, at the agency’s Johnson Space Center in Houston. This summer, four volunteers will begin a yearlong Mars mission in the ground-based habitat, helping NASA prepare for human exploration of Mars for the benefit of humanity.
Source: NASA Invites Media to See Mars Habitat Before Crew Enters for One Year
JPL - NASA / NASA Coverage Set for Uncrewed Soyuz Undocking, Departure
« Last post by feeds on March 24, 2023, 07:34:46 PM »
NASA Coverage Set for Uncrewed Soyuz Undocking, Departure

The uncrewed Roscosmos Soyuz MS-22 spacecraft will undock from the International Space Station on Tuesday, March 28.
Source: NASA Coverage Set for Uncrewed Soyuz Undocking, Departure
BBC Technology & Environment / Have we found the 'animal origin' of Covid?
« Last post by feeds on March 24, 2023, 07:34:44 PM »
Have we found the 'animal origin' of Covid?

Genetic data released by China three years after it was gathered has provided 'the best evidence' of how the pandemic started, scientists say.
Source: Have we found the 'animal origin' of Covid?
A novel combination therapy for treating vancomycin-resistant bacterial infections

Researchers have developed a novel combination therapy using the anticancer agent mitoxantrone (MTX), together with an antibiotic, vancomycin, for treating bacteria that are resistant to the vancomycin, which are also known as vancomycin-resistant Enterococcus faecalis or VRE. The therapy uniquely targets both VRE and the host, stimulating the host immune system to more effectively clear bacterial infections and accelerate infected wound healing. The work was led by scientists at the Antimicrobial Resistance (AMR) interdisciplinary research group at Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, in collaboration with Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, MIT, and University of Geneva.

Antimicrobial resistance is a significant global health concern, causing 4.95 million deaths from infections associated with or attributed to antimicrobial resistance in 2019 alone. By 2050, the Asia-Pacific region is forecast to account for 47 percent of AMR-related deaths worldwide if immediate and coordinated actions are not taken to avert a potential drug-resistance crisis. In response to this aggravating health threat, new and innovative approaches to treating bacterial infections are being developed, including the use of antimicrobials that can overcome resistance mechanisms and host-directed therapies that enhance the innate human immune system to combat bacterial infections.

VRE is a "hard-to-kill" bacterium due to its increasing antibiotic resistance. It can cause serious infections, including urinary tract, bloodstream, and wound infections associated with catheters or surgical procedures. The treatment of VRE infections has posed a significant challenge as the bacteria exhibit resistance to vancomycin — an antibiotic commonly used to treat endocarditis, skin, stomach, and intestine infections caused by Gram-positive bacteria — and other commonly used antibiotics.

In this research, the team tested MTX’s effectiveness and antibiotic activity against VRE, both in vitro and in vivo. Despite VRE’s resistance to vancomycin, MTX was found to inhibit the growth of VRE more effectively when used in the presence of vancomycin. This outcome is due to the synergistic relationship between MTX and vancomycin, which makes VRE more sensitive to vancomycin by lowering the vancomycin concentration required to kill VRE. The research also demonstrated that MTX improved wound healing by enhancing the ability of macrophages — a type of white blood cell that kills microorganisms, removes dead cells, and stimulates the action of other immune cells — to fight off VRE infections, and by recruiting more immune cells to the site of infection.

MIT co-authors on a paper about the work include professor of biology Jianzhu Chen and visiting professor Guangan Hu, both of whom are affiliated with the Koch Institute for Integrative Cancer Research.

SMART was established by MIT in partnership with the National Research Foundation of Singapore (NRF) in 2007. SMART is the first entity in the Campus for Research Excellence and Technological Enterprise (CREATE) developed by NRF. SMART serves as an intellectual and innovation hub for cutting-edge research interactions between MIT and Singapore. SMART currently comprises an Innovation Centre and five interdisciplinary research groups: AMR, Critical Analytics for Manufacturing Personalized-Medicine, Disruptive and Sustainable Technologies for Agricultural Precision, Future Urban Mobility, and Low Energy Electronic Systems.

The AMR interdisciplinary research group is a translational research and entrepreneurship program that tackles the growing threat of antimicrobial resistance. By leveraging talent and convergent technologies across Singapore and MIT, we aim to tackle AMR head-on by developing multiple innovative and disruptive approaches to identify, respond to, and treat drug-resistant microbial infections. Through strong scientific and clinical collaborations, our goal is to provide transformative, holistic solutions for Singapore and the world.

Source: A novel combination therapy for treating vancomycin-resistant bacterial infections
MIT Research / A design tool to democratize the art of color-changing mosaics
« Last post by feeds on March 24, 2023, 07:34:44 PM »
A design tool to democratize the art of color-changing mosaics

A colorful new design tool developed by MIT researchers allows individuals to create polarized light mosaics that can be printed on cellophane to make data visualizations, passive light displays, mechanical animations, fashion accessories, educational science and design tools, and more.

Ticha Melody Sethapakdi, a PhD student in electrical engineering and computer science and affiliate of the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL), is leading the use of regenerated cellulose to make what she calls Polagons, machine-made color-changing mosaics that use polarized light to inform and delight. Such polarized light mosaics have previously been crafted by hand, and Sethapakdi was inspired by artists such as Austine Wood Comarow, whose innovative “polage art” is based on the same physics principles. The new computational Polagon design system, however, enables a fabrication process based on laser cutting and welding, all with minimal assembly by the user.

Users first import custom mosaic designs, and the system computes the feasible color palette given a user's cellophane supply. Uploading multiple designs to the interface allows users to create “morphing” mosaics that can transition from one image to another. Then, it’s on to logistics: Polagons optimizes the necessary constituent components for each scenario, like the type and number of sheets needed. Once the user finishes uploading designs, playing around with colors, and visualizing the color-changing behaviors, they can export the fabrication files and chop them up in a laser cutter.

What’s so special about cellophane, anyway? The sheets have a property called birefringence, meaning that when light passes through, the speed of light is different depending on the propagation angle. When the sheets get put into a “sandwich” of two polarizers (material that only lets certain polarities of light pass through while blocking others), they appear colored. The colors you see depend on different factors in the material, like thickness and the angle of the material relative to the two polarizers. To create that color-changing effect, you just need to rotate the image, or the polarizers, because then you’re changing the angle of light propagation.

“Perhaps, in the future, since these designs are non-electronic, they could enable interesting underwater applications, where you put these types of mosaics in places that might be difficult for electronics to stay in. That’s what’s special here, that all of these color-changing effects are mechanical,” says Sethapakdi.

One limitation of Polagons is the inability to represent every color on the rainbow in a continuous way. The team believes a potential solution could be changing the fabrication process to support a constant mode of building colors. This might mean 3D printing a birefringent material to access a more extensive palette and have more control over the colors. 

“In creating this system, I was mostly interested in democratizing this art form and helping preserve something that might only be accessible to skilled individuals. If something happens to the creator of this layering principle, Austine Wood Comarow’s family, does the art then die with them? If we didn’t have some way of preserving that or continuing it, then you would lose something that would be very precious to the world,” says Sethapakdi. “I think there is a real benefit to building these systems that democratize niche art forms. We hope this tool can expand the community of modern polarized light mosaicists. Since we are making this process accessible to a larger group of users, it can add new programmable material to the palette of options in [human-computer interaction].”

Sethapakdi recently wrote a paper on Polagons alongside Laura Huang '21, former MIT mechanical engineering undergraduate and current mechanical engineer at Neocis; Vivian Chan, a master’s student at Brown University and Rhode Island School of Design; Mackenzie Leake, a postdoc at MIT CSAIL; Stefanie Mueller, associate professor in EECS at MIT and a CSAIL principal investigator; Lung-Pan Cheng, assistant professor at National Taiwan University; and Fernando Fuzinatto Dall’Agnol, professor at the Federal University of Santa Catarina. The research will be present at the 2023 Conference on Human Factors in Computing Systems (CHI 2023).

Source: A design tool to democratize the art of color-changing mosaics
Wired - Science / Can You Really Pump Water Without Any Electricity?
« Last post by feeds on March 24, 2023, 10:56:00 AM »
Can You Really Pump Water Without Any Electricity?

To see if those videos of people conjuring liquid without any external power actually hold water, you’ll need physics—and a straw.
Source: Can You Really Pump Water Without Any Electricity?
Claude Lorius: Pioneering French climate change scientist dies aged 91

His expeditions to Antarctica helped prove that humans were responsible for global warming.
Source: Claude Lorius: Pioneering French climate change scientist dies aged 91
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