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      Building a better indoor herb garden

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      Randall Briggs ’09, SM ’18 didn’t set out to build indoor gardens when he arrived at MIT. The winner of the 2010 2.007 robot competition class, he was excited to work on designing fighter planes one day.

      But in 2016, halfway through his studies for his master’s degree in mechanical engineering, Briggs’s father passed away unexpectedly. “It was a big blow to me. My motivation took a big hit, so it was hard for me to keep working on my research,” Briggs shares.

      Briggs ordered a home hydroponic garden in the hopes that growing herbs inside his apartment could bring him some positivity. “There is something healing about seeing something organic and beautiful grow and develop,” Briggs says.

      When the garden arrived, Briggs found that many aspects of the design fell short. The plants weren’t getting enough light because the LEDs were dispersing light throughout the room and not focusing it on the plants. “It’s just not very pleasing aesthetically when it’s, like, a fluorescent color of light, and it just fills your room,” Briggs says.

      He set forth to create a better indoor garden. Briggs turned his spare bedroom into a hydroponics lab, testing herbs growing under various lighting conditions and with different nutrient solutions. He read every book and article he could find on the subject. “The same seed pods that I had used in that cheap garden, when I moved them over to my garden, they grew way faster and way healthier and more fragrant and full of flavor,” he says.

      Working on this project became a daily source of joy for Briggs. “Every day when you come home, you want to see if it’s growing a little bit more or to see how they’re doing. I think that made me happy, too.”

      Briggs saw the potential for his garden to improve the well-being of others. “I thought if people had fresh herbs at home, they might be more inspired to cook for themselves instead of always just eating out, as it’s normally a lot healthier to cook your own food at home.”

      After much research and experimentation, GardenByte was born in 2017: a tabletop indoor herb garden that is nearly 3 feet wide with almost 2 feet of height for the plants to grow, which is quite a bit larger than most models on the market. With Briggs’s hydroponics technology, the plants grow three times faster than they would grow outdoors. His garden allows anyone to grow fresh herbs in a wide range of settings. And since plants have a longer shelf life than cut herbs, they also cut down on food waste.

      Briggs was determined to make something that grows plants well and is attractive in a variety of settings. The outer case is handcrafted from solid hardwood from a local Massachusetts lumber yard, ensuring both durability and a visually pleasing aesthetic that seamlessly integrates into any kitchen or restaurant setting. The light bar, crafted from a single piece of crystal-clear acrylic, maintains an unobtrusive and ethereal appearance. This choice complements the overall design while allowing the LED lights to emit a powerful simulation of full sunshine. To ensure a smooth transition from daytime growth to evening, four different types of LEDs were incorporated. Polymer lenses focus the light directly onto the plants, preventing any wastage or unnecessary light spillage in the room. A light and color sensor on top detect the lighting conditions in the room and automatically adjust the lighting in the garden to match, enhancing plant growth. The grid tray is designed to accommodate up to 39 plants at once, offering ample space for an array of herbs. To simplify plant care, the garden is connected to a mobile app that will allow you to care for your plants while you’re away.

      The herb garden contains computer numerical control (CNC) machined-aluminum parts, in contrast with the flimsier plastic most products use. The heat flow capacity of aluminum disperses the heat from all the LEDs and the aluminum grid tray helps keep it compact and thin but rigid, so users can lift the plants up without it bending.

      Briggs received his foundation in machining as an undergrad at the MIT Edgerton Center, where he was on the MIT Motorsports team and MIT Electric Vehicle Team. He learned how to use the CNC machines in the student machine shop at the Area 51 garage under the tutelage of Instructor Pat McAtamney and Briggs’s teammates.

      Building an electric motorcycle on the Electric Vehicle Team for the Isle of Man TT Race in 2011 helped prepare Briggs for creating a robust product for production. The race took place on city streets, raising the potential for deadly crashes. “When we were building that motorcycle, the head of our team, Lennon Rodgers, kept reiterating to us, ‘you got to think aircraft quality, like aircraft quality. This is actually a life-or-death project.’ Seeing the way that he led, and the way that he really set the bar for quality and for execution and kind of kept things moving, was really helpful for me.”

      “My hope in the future is to make a more mass-market version that’s a little bit cheaper and more available to everybody,” Briggs shares.

      The feedback from his first customers has all been positive. After delivering the product to a chef in Boston, Briggs says, “He told me that the whole first evening he was sitting at home with his boyfriend and he just kept staring at it, and he’s like, ‘it is so beautiful. It is so beautiful.’”

      “I feel like something that my dad taught me was that sometimes to do hard things, it does take hard work, and that it’s not always going to be exciting, necessarily,” Briggs shares. “It’s good to be inspired, it’s good to be passionate, but it’s not always going to get you through. And sometimes it’s just hard work that you got to press through the tough parts.” More

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      Microbes could help reduce the need for chemical fertilizers

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      Production of chemical fertilizers accounts for about 1.5 percent of the world’s greenhouse gas emissions. MIT chemists hope to help reduce that carbon footprint by replacing some chemical fertilizer with a more sustainable source — bacteria.

      Bacteria that can convert nitrogen gas to ammonia could not only provide nutrients that plants need, but also help regenerate soil and protect plants from pests. However, these bacteria are sensitive to heat and humidity, so it’s difficult to scale up their manufacture and ship them to farms.

      To overcome that obstacle, MIT chemical engineers have devised a metal-organic coating that protects bacterial cells from damage without impeding their growth or function. In a new study, they found that these coated bacteria improved the germination rate of a variety of seeds, including vegetables such as corn and bok choy.

      This coating could make it much easier for farmers to deploy microbes as fertilizers, says Ariel Furst, the Paul M. Cook Career Development Assistant Professor of Chemical Engineering at MIT and the senior author of the study.

      “We can protect them from the drying process, which would allow us to distribute them much more easily and with less cost because they’re a dried powder instead of in liquid,” she says. “They can also withstand heat up to 132 degrees Fahrenheit, which means that you wouldn’t have to use cold storage for these microbes.”

      Benjamin Burke ’23 and postdoc Gang Fan are the lead authors of the open-access paper, which appears in the Journal of the American Chemical Society Au. MIT undergraduate Pris Wasuwanich and Evan Moore ’23 are also authors of the study.

      Protecting microbes

      Chemical fertilizers are manufactured using an energy-intensive process known as Haber-Bosch, which uses extremely high pressures to combine nitrogen from the air with hydrogen to make ammonia.

      In addition to the significant carbon footprint of this process, another drawback to chemical fertilizers is that long-term use eventually depletes the nutrients in the soil. To help restore soil, some farmers have turned to “regenerative agriculture,” which uses a variety of strategies, including crop rotation and composting, to keep soil healthy. Nitrogen-fixing bacteria, which convert nitrogen gas to ammonia, can aid in this approach.

      Some farmers have already begun deploying these “microbial fertilizers,” growing them in large onsite fermenters before applying them to the soil. However, this is cost-prohibitive for many farmers.

      Shipping these bacteria to rural areas is not currently a viable option, because they are susceptible to heat damage. The microbes are also too delicate to survive the freeze-drying process that would make them easier to transport.

      To protect the microbes from both heat and freeze-drying, Furst decided to apply a coating called a metal-phenol network (MPN), which she has previously developed to encapsulate microbes for other uses, such as protecting therapeutic bacteria delivered to the digestive tract.

      The coatings contain two components — a metal and an organic compound called a polyphenol — that can self-assemble into a protective shell. The metals used for the coatings, including iron, manganese, aluminum, and zinc, are considered safe as food additives. Polyphenols, which are often found in plants, include molecules such as tannins and other antioxidants. The FDA classifies many of these polyphenols as GRAS (generally regarded as safe).

      “We are using these natural food-grade compounds that are known to have benefits on their own, and then they form these little suits of armor that protect the microbes,” Furst says.

      For this study, the researchers created 12 different MPNs and used them to encapsulate Pseudomonas chlororaphis, a nitrogen-fixing bacterium that also protects plants against harmful fungi and other pests. They found that all of the coatings protected the bacteria from temperatures up to 50 degrees Celsius (122 degrees Fahrenheit), and also from relative humidity up to 48 percent. The coatings also kept the microbes alive during the freeze-drying process.

      A boost for seeds

      Using microbes coated with the most effective MPN — a combination of manganese and a polyphenol called epigallocatechin gallate (EGCG) — the researchers tested their ability to help seeds germinate in a lab dish. They heated the coated microbes to 50 C before placing them in the dish, and compared them to fresh uncoated microbes and freeze-dried uncoated microbes.

      The researchers found that the coated microbes improved the seeds’ germination rate by 150 percent, compared to seeds treated with fresh, uncoated microbes. This result was consistent across several different types of seeds, including dill, corn, radishes, and bok choy.

      Furst has started a company called Seia Bio to commercialize the coated bacteria for large-scale use in regenerative agriculture. She hopes that the low cost of the manufacturing process will help make microbial fertilizers accessible to small-scale farmers who don’t have the fermenters needed to grow such microbes.

      “When we think about developing technology, we need to intentionally design it to be inexpensive and accessible, and that’s what this technology is. It would help democratize regenerative agriculture,” she says.

      The research was funded by the Army Research Office, a National Institutes of Health New Innovator Award, a National Institute for Environmental Health Sciences Core Center Grant, the CIFAR Azrieli Global Scholars Program, the MIT J-WAFS Program, the MIT Climate and Sustainability Consortium, and the MIT Deshpande Center. More

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      “Move-in day is kind of like our Superbowl”

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      The academic year has officially begun at MIT, and the halls are once again filled with the energy and excitement that only students can bring. But MIT’s campus does not come to life automatically.

      The flurry of activity happening around campus this week was preceded by a lot of hard work by thousands of staff members committed to getting the school year off to a seamless start.

      “Getting MIT ready to welcome new and returning students is a real team effort, and much of the work goes on over the summer or behind the scenes when many students are away from campus,” says Suzy Nelson, vice chancellor and dean for student life. “I’m grateful to all of the staff members in the Division of Student Life and across the Institute whose dedication to their job and exceptional efforts help to make the MIT experience so special from the moment students arrive on campus.”

      Describing all of those efforts would require a book-length article, but here we highlight a few examples of the behind-the-scenes work that ushers in the new academic year.

      Housing and Residential Services

      One might think the team responsible for housing at MIT gets a break in June and July when undergraduates leave for the summer. But the housing team stays busy year-round. Summer months offer openings for renovations, planning, and events like summer programs and conferences (some of which provide housing). In fact, team members say the planning alone is nearly a year-round job.

      “We start planning for students coming back in May because first-year students are confirming attendance and starting to indicate their preferences for where they want to live, and housing works really closely with student leaders in each of the undergrad residences because our student leaders are very involved with room assignments,” explains Rich Hilton, associate dean and director for residential services and operations. “On the graduate side, grads typically move in Aug. 1, and departing grad students move out at the end of July, or sometimes earlier, so in those early summer months there’s a lot of transitioning happening.”

      Of course, move-in day for undergraduates and the subsequent Welcome Week are an important time for the Housing and Residential Services team to help the MIT community’s newest members settle in.

      “Move-in day is kind of like our Superbowl,” Hilton says. “All the summer projects we work on are to prepare and maintain the residence halls for new and returning students to be living in the residence halls. The ramp-up involves making sure the residences are refreshed and ready, and the welcome efforts include providing moving bins, materials, and moving assistance. For students who have never been to campus before, residential staff are often the first people they meet, so we want to put a really good impression out there. We pull out all the stops to make sure that welcome efforts are top-notch.”

      Hilton says the atmosphere is always special on move in day.

      “The students are a wonderful motivation,” Hilton says. “It’s great seeing the new students come in with their families. Students are coming from all corners of the world, from different backgrounds, and more often than not the parents are just beaming with pride, so being able to greet them and even reassure them if needed is really rewarding.”

      In all, MIT Housing and Residential Services employs more than 200 people focused on assignments, maintenance, cleaning, residential security, and more, to make living on campus as enjoyable as possible.

      “Housing truly is 24/7, 365,” Hilton says. “Our team members are on campus keeping our residents safe and happy and serving them 24 hours a day. They’re here rain or shine, and it’s nice to keep them in mind.”

      Dining

      MIT Dining works with students to offer healthy, affordable, and culturally meaningful food in environments that promote social connections, sustainability, and innovation. The department oversees nine different third-party contractors to provide services across 20+ locations — and MIT’s own dining staff consists of just two people: Director of Campus Dining Mark Hayes and Assistant Director of Dining Operations Heather Ryall.

      Typical summer months provide an opportunity for the small team to look at food trends, work with dieticians and food allergy specialists, review menus, and explore ways to improve operations. This summer was even busier thanks to renovations at the Stratton Student Center and Maseeh Hall and the introduction of new food stations in CommonWealth Kitchen and at Forbes Café.

      In August, MIT Dining makes sure it has established open lines of communication with new student leaders and other groups around campus

      “We interact with a lot of student groups this time of year,” Hayes says. “It’s exciting to start with a new group of students and get feedback, collaborating and sharing ideas. It reminds us of what we’re here for: students. If things are working, that’s great! If they’re not working, let’s collaborate and figure out what can we do better — let’s make it a pset [problem set]. What are we not doing that we should be? I’ve been lucky in that students at MIT are really engaged.”

      “August is when everyone wants to get together and make sure we’re starting off on the right foot,” Hayes says. “That two-way flow of information is what it’s all about, and it’s really strong here.”

      Some dining locations stay open through the summer to support grad students, faculty and staff, but residential dining halls shut down. By August, some international students and athletes begin moving back to campus. Then Welcome Week begins for first-year students. Then pretty much everyone else returns over Labor Day Weekend.

      “In a way, you go from almost zero to 100,” Hayes says.

      This academic year, DSL will undertake a thorough review of the residence hall dining program, gathering student and community input on enhancements. This follows a similar review of campus retail dining operations completed in December 2022.

      Student Support and Wellbeing

      The Student Support and Wellbeing team, co-led by Associate Dean and Senior Director Jimmy Doan, offers a slate of resources to make it easy for students to seek help if they need it, and to encourage students to take care of themselves throughout their time at MIT. The team also coordinates with faculty, staff, and student groups across the Institute to foster an environment where students’ sense of belonging and well-being is prioritized.

      Ahead of the new school year, team members have been sharing with faculty best practices for fostering student well-being in the classroom and labs, including presenting workshops to new faculty members to inform them of resources to use when they’re concerned about students.

      They have also been connecting with student leaders so they can help their peers prioritize well-being. “Come early August, we’re facilitating a lot of trainings and gearing up for new student orientation programs.” Doan says. “We’re working with a lot of student leaders this time of year. We know students learn as much from each other as they do from us.”

      New student orientation offers a chance to provide a week’s worth of programming to incoming first-year students. In one of those sessions, Dear Future Me, older students share their perspectives on prioritizing well-being and accessing support at MIT.

      “We try to normalize students getting help at MIT when they need it,” Doan says. “Starting from day one of orientation we tell them getting help is for everybody.”

      One office where nearly 80 percent of undergraduate students seek out help before they graduate is Student Support Services, more commonly known as “S3” or “S-Cubed.” The staff in S3 are preparing for the start of the year by revamping their virtual drop-in hours for students, which students can access from the S3 website.

      “We want the ways that students reach out for help to be as accessible as possible,” Doan says. More

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      Tiny magnetic beads produce an optical signal that could be used to quickly detect pathogens

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      Getting results from a blood test can take anywhere from one day to a week, depending on what a test is targeting. The same goes for tests of water pollution and food contamination. And in most cases, the wait time has to do with time-consuming steps in sample processing and analysis.

      Now, MIT engineers have identified a new optical signature in a widely used class of magnetic beads, which could be used to quickly detect contaminants in a variety of diagnostic tests. For example, the team showed the signature could be used to detect signs of the food contaminant Salmonella.

      The so-called Dynabeads are microscopic magnetic beads that can be coated with antibodies that bind to target molecules, such as a specific pathogen. Dynabeads are typically used in experiments in which they are mixed into solutions to capture molecules of interest. But from there, scientists have to take additional, time-consuming steps to confirm that the molecules are indeed present and bound to the beads.

      The MIT team found a faster way to confirm the presence of Dynabead-bound pathogens, using optics, specifically, Raman spectroscopy. This optical technique identifies specific molecules based on their “Raman signature,” or the unique way in which a molecule scatters light.

      The researchers found that Dynabeads have an unusually strong Raman signature that can be easily detected, much like a fluorescent tag. This signature, they found, can act as a “reporter.” If detected, the signal can serve as a quick confirmation, within less than one second, that a target pathogen is indeed present in a given sample. The team is currently working to develop a portable device for quickly detecting a range of bacterial pathogens, and their results will appear in an Emerging Investigators special issue of the Journal of Raman Spectroscopy.

      “This technique would be useful in a situation where a doctor is trying to narrow down the source of an infection in order to better inform antibiotic prescription, as well as for the detection of known pathogens in food and water,” says study co-author Marissa McDonald, a graduate student in the Harvard-MIT Program in Health Sciences and Technology. “Additionally, we hope this approach will eventually lead to expanded access to advanced diagnostics in resource-limited environments.”

      Study co-authors at MIT include Postdoctoral Associate Jongwan Lee; Visiting Scholar Nikiwe Mhlanga; Research Scientist Jeon Woong Kang; Tata Professor Rohit Karnik, who is also the associate director of the Abdul Latif Jameel Water and Food Systems Lab; and Assistant Professor Loza Tadesse of the Department of Mechanical Engineering.

      Oil and water

      Looking for diseased cells and pathogens in fluid samples is an exercise in patience.

      “It’s kind of a needle-in-a-haystack problem,” Tadesse says.

      The numbers present are so small that they must be grown in controlled environments to sufficient numbers, and their cultures stained, then studied under a microscope. The entire process can take several days to a week to yield a confident positive or negative result.

      Both Karnik and Tadesse’s labs have independently been developing techniques to speed up various parts of the pathogen testing process and make the process portable, using Dynabeads.

      Dynabeads are commercially available microscopic beads made from a magnetic iron core and a polymer shell that can be coated with antibodies. The surface antibodies act as hooks to bind specific target molecules. When mixed with a fluid, such as a vial of blood or water, any molecules present will glom onto the Dynabeads. Using a magnet, scientists can gently coax the beads to the bottom of a vial and filter them out of a solution. Karnik’s lab is investigating ways to then further separate the beads into those that are bound to a target molecule, and those that are not. “Still, the challenge is, how do we know that we have what we’re looking for?” Tadesse says.

      The beads themselves are not visible by eye. That’s where Tadesse’s work comes in. Her lab uses Raman spectroscopy as a way to “fingerprint” pathogens. She has found that different cell types scatter light in unique ways that can be used as a signature to identify them.

      In the team’s new work, she and her colleagues found that Dynabeads also have a unique and strong Raman signature that can act as a surprisingly clear beacon.

      “We were initially seeking to identify the signatures of bacteria, but the signature of the Dynabeads was actually very strong,” Tadesse says. “We realized this signal could be a means of reporting to you whether you have that bacteria or not.”

      Testing beacon

      As a practical demonstration, the researchers mixed Dynabeads into vials of water contaminated with Salmonella. They then magnetically isolated these beads onto microscope slides and measured the way light scattered through the fluid when exposed to laser light. Within half a second, they quickly detected the Dynabeads’ Raman signature — a confirmation that bound Dynabeads, and by inference, Salmonella, were present in the fluid.

      “This is something that can be used to rapidly give a positive or negative answer: Is there a contaminant or not?” Tadesse says. “Because even a handful of pathogens can cause clinical symptoms.”

      The team’s new technique is significantly faster than conventional methods and uses elements that could be adapted into smaller, more portable forms — a goal that the researchers are currently working toward. The approach is also highly versatile.

      “Salmonella is the proof of concept,” Tadesse says. “You could purchase Dynabeads with E.coli antibodies, and the same thing would happen: It would bind to the bacteria, and we’d be able to detect the Dynabead signature because the signal is super strong.”

      The team is particularly keen to apply the test to conditions such as sepsis, where time is of the essence, and where pathogens that trigger the condition are not rapidly detected using conventional lab tests.

      “There are a lot cases, like in sepsis, where pathogenic cells cannot always be grown on a plate,” says Lee, a member of Karnik’s lab. “In that case, our technique could rapidly detect these pathogens.”

      This research was supported, in part, by the MIT Laser Biomedical Research Center, the National Cancer Institute, and the Abdul Latif Jameel Water and Food Systems Lab at MIT. More

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      System tracks movement of food through global humanitarian supply chain

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      Although more than enough food is produced to feed everyone in the world, as many as 828 million people face hunger today. Poverty, social inequity, climate change, natural disasters, and political conflicts all contribute to inhibiting access to food. For decades, the U.S. Agency for International Development (USAID) Bureau for Humanitarian Assistance (BHA) has been a leader in global food assistance, supplying millions of metric tons of food to recipients worldwide. Alleviating hunger — and the conflict and instability hunger causes — is critical to U.S. national security.

      But BHA is only one player within a large, complex supply chain in which food gets handed off between more than 100 partner organizations before reaching its final destination. Traditionally, the movement of food through the supply chain has been a black-box operation, with stakeholders largely out of the loop about what happens to the food once it leaves their custody. This lack of direct visibility into operations is due to siloed data repositories, insufficient data sharing among stakeholders, and different data formats that operators must manually sort through and standardize. As a result, accurate, real-time information — such as where food shipments are at any given time, which shipments are affected by delays or food recalls, and when shipments have arrived at their final destination — is lacking. A centralized system capable of tracing food along its entire journey, from manufacture through delivery, would enable a more effective humanitarian response to food-aid needs.

      In 2020, a team from MIT Lincoln Laboratory began engaging with BHA to create an intelligent dashboard for their supply-chain operations. This dashboard brings together the expansive food-aid datasets from BHA’s existing systems into a single platform, with tools for visualizing and analyzing the data. When the team started developing the dashboard, they quickly realized the need for considerably more data than BHA had access to.

      “That’s where traceability comes in, with each handoff partner contributing key pieces of information as food moves through the supply chain,” explains Megan Richardson, a researcher in the laboratory’s Humanitarian Assistance and Disaster Relief Systems Group.

      Richardson and the rest of the team have been working with BHA and their partners to scope, build, and implement such an end-to-end traceability system. This system consists of serialized, unique identifiers (IDs) — akin to fingerprints — that are assigned to individual food items at the time they are produced. These individual IDs remain linked to items as they are aggregated along the supply chain, first domestically and then internationally. For example, individually tagged cans of vegetable oil get packaged into cartons; cartons are placed onto pallets and transported via railway and truck to warehouses; pallets are loaded onto shipping containers at U.S. ports; and pallets are unloaded and cartons are unpackaged overseas.

      With a trace

      Today, visibility at the single-item level doesn’t exist. Most suppliers mark pallets with a lot number (a lot is a batch of items produced in the same run), but this is for internal purposes (i.e., to track issues stemming back to their production supply, like over-enriched ingredients or machinery malfunction), not data sharing. So, organizations know which supplier lot a pallet and carton are associated with, but they can’t track the unique history of an individual carton or item within that pallet. As the lots move further downstream toward their final destination, they are often mixed with lots from other productions, and possibly other commodity types altogether, because of space constraints. On the international side, such mixing and the lack of granularity make it difficult to quickly pull commodities out of the supply chain if food safety concerns arise. Current response times can span several months.

      “Commodities are grouped differently at different stages of the supply chain, so it is logical to track them in those groupings where needed,” Richardson says. “Our item-level granularity serves as a form of Rosetta Stone to enable stakeholders to efficiently communicate throughout these stages. We’re trying to enable a way to track not only the movement of commodities, including through their lot information, but also any problems arising independent of lot, like exposure to high humidity levels in a warehouse. Right now, we have no way to associate commodities with histories that may have resulted in an issue.”

      “You can now track your checked luggage across the world and the fish on your dinner plate,” adds Brice MacLaren, also a researcher in the laboratory’s Humanitarian Assistance and Disaster Relief Systems Group. “So, this technology isn’t new, but it’s new to BHA as they evolve their methodology for commodity tracing. The traceability system needs to be versatile, working across a wide variety of operators who take custody of the commodity along the supply chain and fitting into their existing best practices.”

      As food products make their way through the supply chain, operators at each receiving point would be able to scan these IDs via a Lincoln Laboratory-developed mobile application (app) to indicate a product’s current location and transaction status — for example, that it is en route on a particular shipping container or stored in a certain warehouse. This information would get uploaded to a secure traceability server. By scanning a product, operators would also see its history up until that point.   

      Hitting the mark

      At the laboratory, the team tested the feasibility of their traceability technology, exploring different ways to mark and scan items. In their testing, they considered barcodes and radio-frequency identification (RFID) tags and handheld and fixed scanners. Their analysis revealed 2D barcodes (specifically data matrices) and smartphone-based scanners were the most feasible options in terms of how the technology works and how it fits into existing operations and infrastructure.

      “We needed to come up with a solution that would be practical and sustainable in the field,” MacLaren says. “While scanners can automatically read any RFID tags in close proximity as someone is walking by, they can’t discriminate exactly where the tags are coming from. RFID is expensive, and it’s hard to read commodities in bulk. On the other hand, a phone can scan a barcode on a particular box and tell you that code goes with that box. The challenge then becomes figuring out how to present the codes for people to easily scan without significantly interrupting their usual processes for handling and moving commodities.” 

      As the team learned from partner representatives in Kenya and Djibouti, offloading at the ports is a chaotic, fast operation. At manual warehouses, porters fling bags over their shoulders or stack cartons atop their heads any which way they can and run them to a drop point; at bagging terminals, commodities come down a conveyor belt and land this way or that way. With this variability comes several questions: How many barcodes do you need on an item? Where should they be placed? What size should they be? What will they cost? The laboratory team is considering these questions, keeping in mind that the answers will vary depending on the type of commodity; vegetable oil cartons will have different specifications than, say, 50-kilogram bags of wheat or peas.

      Leaving a mark

      Leveraging results from their testing and insights from international partners, the team has been running a traceability pilot evaluating how their proposed system meshes with real-world domestic and international operations. The current pilot features a domestic component in Houston, Texas, and an international component in Ethiopia, and focuses on tracking individual cartons of vegetable oil and identifying damaged cans. The Ethiopian team with Catholic Relief Services recently received a container filled with pallets of uniquely barcoded cartons of vegetable oil cans (in the next pilot, the cans will be barcoded, too). They are now scanning items and collecting data on product damage by using smartphones with the laboratory-developed mobile traceability app on which they were trained. 

      “The partners in Ethiopia are comparing a couple lid types to determine whether some are more resilient than others,” Richardson says. “With the app — which is designed to scan commodities, collect transaction data, and keep history — the partners can take pictures of damaged cans and see if a trend with the lid type emerges.”

      Next, the team will run a series of pilots with the World Food Program (WFP), the world’s largest humanitarian organization. The first pilot will focus on data connectivity and interoperability, and the team will engage with suppliers to directly print barcodes on individual commodities instead of applying barcode labels to packaging, as they did in the initial feasibility testing. The WFP will provide input on which of their operations are best suited for testing the traceability system, considering factors like the network bandwidth of WFP staff and local partners, the commodity types being distributed, and the country context for scanning. The BHA will likely also prioritize locations for system testing.

      “Our goal is to provide an infrastructure to enable as close to real-time data exchange as possible between all parties, given intermittent power and connectivity in these environments,” MacLaren says.

      In subsequent pilots, the team will try to integrate their approach with existing systems that partners rely on for tracking procurements, inventory, and movement of commodities under their custody so that this information is automatically pushed to the traceability server. The team also hopes to add a capability for real-time alerting of statuses, like the departure and arrival of commodities at a port or the exposure of unclaimed commodities to the elements. Real-time alerts would enable stakeholders to more efficiently respond to food-safety events. Currently, partners are forced to take a conservative approach, pulling out more commodities from the supply chain than are actually suspect, to reduce risk of harm. Both BHA and WHP are interested in testing out a food-safety event during one of the pilots to see how the traceability system works in enabling rapid communication response.

      To implement this technology at scale will require some standardization for marking different commodity types as well as give and take among the partners on best practices for handling commodities. It will also require an understanding of country regulations and partner interactions with subcontractors, government entities, and other stakeholders.

      “Within several years, I think it’s possible for BHA to use our system to mark and trace all their food procured in the United States and sent internationally,” MacLaren says.

      Once collected, the trove of traceability data could be harnessed for other purposes, among them analyzing historical trends, predicting future demand, and assessing the carbon footprint of commodity transport. In the future, a similar traceability system could scale for nonfood items, including medical supplies distributed to disaster victims, resources like generators and water trucks localized in emergency-response scenarios, and vaccines administered during pandemics. Several groups at the laboratory are also interested in such a system to track items such as tools deployed in space or equipment people carry through different operational environments.

      “When we first started this program, colleagues were asking why the laboratory was involved in simple tasks like making a dashboard, marking items with barcodes, and using hand scanners,” MacLaren says. “Our impact here isn’t about the technology; it’s about providing a strategy for coordinated food-aid response and successfully implementing that strategy. Most importantly, it’s about people getting fed.” More

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      Exploring the links between diet and cancer

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      Every three to five days, all of the cells lining the human intestine are replaced. That constant replenishment of cells helps the intestinal lining withstand the damage caused by food passing through the digestive tract.

      This rapid turnover of cells relies on intestinal stem cells, which give rise to all of the other types of cells found in the intestine. Recent research has shown that those stem cells are heavily influenced by diet, which can help keep them healthy or stimulate them to become cancerous.

      “Low-calorie diets such as fasting and caloric restriction can have antiaging effects and antitumor effects, and we want to understand why that is. On the other hand, diets that lead to obesity can promote diseases of aging, such as cancer,” says Omer Yilmaz, the Eisen and Chang Career Development Associate Professor of Biology at MIT.

      For the past decade, Yilmaz has been studying how different diets and environmental conditions affect intestinal stem cells, and how those factors can increase the risk of cancer and other diseases. This work could help researchers develop new ways to improve gastrointestinal health, either through dietary interventions or drugs that mimic the beneficial effects of certain diets, he says. 

      “Our findings have raised the possibility that fasting interventions, or small molecules that mimic the effects of fasting, might have a role in improving intestinal regeneration,” says Yilmaz, who is also a member of MIT’s Koch Institute for Integrative Cancer Research.

      A clinical approach

      Yilmaz’s interest in disease and medicine arose at an early age. His father practiced internal medicine, and Yilmaz spent a great deal of time at his father’s office after school, or tagging along at the hospital where his father saw patients.

      “I was very interested in medicines and how medicines were used to treat diseases,” Yilmaz recalls. “He’d ask me questions, and many times I wouldn’t know the answer, but he would encourage me to figure out the answers to his questions. That really stimulated my interest in biology and in wanting to become a doctor.”

      Knowing that he wanted to go into medicine, Yilmaz applied and was accepted to an eight-year, combined bachelor’s and MD program at the University of Michigan. As an undergraduate, this gave him the freedom to explore areas of interest without worrying about applying to medical school. While majoring in biochemistry and physics, he did undergraduate research in the field of protein folding.

      During his first year of medical school, Yilmaz realized that he missed doing research, so he decided to apply to the MD/PhD program at the University of Michigan. For his PhD research, he studied blood-forming stem cells and identified new markers that allowed such cells to be more easily isolated from the bone marrow.

      “This was important because there’s a lot of interest in understanding what makes a stem cell a stem cell, and how much of it is an internal program versus signals from the microenvironment,” Yilmaz says.

      After finishing his PhD and MD, he thought about going straight into research and skipping a medical residency, but ended up doing a residency in pathology at Massachusetts General Hospital. During that time, he decided to switch his research focus from blood-forming stem cells to stem cells found in the gastrointestinal tract.

      “The GI tract seemed very interesting because in contrast to the bone marrow, we knew very little about the identity of GI stem cells,” Yilmaz says. “I knew that once GI stem cells were identified, there’d be a lot of interesting questions about how they respond to diet and how they respond to other environmental stimuli.”

      Dietary questions

      To delve into those questions, Yilmaz did postdoctoral research at the Whitehead Institute, where he began investigating the connections between stem cells, metabolism, diet, and cancer.

      Because intestinal stem cells are so long-lived, they are more likely to accumulate genetic mutations that make them susceptible to becoming cancerous. At the Whitehead Institute, Yilmaz began studying how different diets might influence this vulnerability to cancer, a topic that he carried into his lab at MIT when he joined the faculty in 2014.

      One question his lab has been exploring is why low-calorie diets often have protective effects, including a boost in longevity — a phenomenon that has been seen in many studies in animals and humans.

      In a 2018 study, his lab found that a 24-hour fast dramatically improves stem cells’ ability to regenerate. This effect was seen in both young and aged mice, suggesting that even in old age, fasting or drugs that mimic the effects of fasting could have a beneficial effect.

      On the flip side, Yilmaz is also interested in why a high-fat diet appears to promote the development of cancer, especially colorectal cancer. In a 2016 study, he found that when mice consume a high-fat diet, it triggers a significant increase in the number of intestinal stem cells. Also, some non-stem-cell populations begin to resemble stem cells in their behavior. “The upshot of these changes is that both stem cells and non-stem-cells can give rise to tumors in a high-fat diet state,” Yilmaz says.

      To help with these studies, Yilmaz’s lab has developed a way to use mouse or human intestinal stem cells to generate miniature intestines or colons in cell culture. These “organoids” can then be exposed to different nutrients in a very controlled setting, allowing researchers to analyze how different diets affect the system.

      Recently, his lab adapted the system to allow them to expand their studies to include the role of immune cells, fibroblasts, and other supportive cells found in the microenvironment of stem cells. “It would be remiss of us to focus on just one cell type,” Yilmaz says. “We’re looking at how these different dietary interventions impact the entire stem cell neighborhood.”

      While Yilmaz spends most of his time running his lab at MIT, he also devotes six to eight weeks per year to his work at MGH, where he is an associate pathologist focusing on gastrointestinal pathology.

      “I enjoy my clinical work, and it always reminds me about the importance of the research we do,” he says. “Seeing colon cancer and other GI cancers under the microscope, and seeing their complexity, reminds me of the importance of our mission to figure out how we can prevent these cancers from forming.” More

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      Ingestible “electroceutical” capsule stimulates hunger-regulating hormone

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      Hormones released by the stomach, such as ghrelin, play a key role in stimulating appetite. These hormones are produced by endocrine cells that are part of the enteric nervous system, which controls hunger, nausea, and feelings of fullness.

      MIT engineers have now shown that they can stimulate these endocrine cells to produce ghrelin, using an ingestible capsule that delivers an electrical current to the cells. This approach could prove useful for treating diseases that involve nausea or loss of appetite, such as cachexia (loss of body mass that can occur in patients with cancer or other chronic diseases).

      In tests in animals, the researchers showed that this “electroceutical” capsule could significantly boost ghrelin production in the stomach. They believe this approach could also be adapted to deliver electrical stimulation to other parts of the GI tract.

      “This study helps establish electrical stimulation by ingestible electroceuticals as a mode of triggering hormone release via the GI tract,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT, a gastroenterologist at Brigham and Women’s Hospital, and the senior author of the study. “We show one example of how we’re able to engage with the stomach mucosa and release hormones, and we anticipate that this could be used in other sites in the GI tract that we haven’t explored here.”

      Khalil Ramadi SM ’16, PhD ’19, a graduate of the Department of Mechanical Engineering and the Harvard-MIT Program in Health Sciences and Technology who is now an assistant professor of bioengineering at the New York University (NYU) Tandon School of Engineering and the director of the Laboratory for Advanced Neuroengineering and Translational Medicine at NYU Abu Dhabi, and James McRae, an MIT graduate student, are the lead authors of the paper, which appears today in Science Robotics.

      Electrical stimulation

      The enteric nervous system controls all aspects of digestion, including the movement of food through the GI tract. Some patients with gastroparesis, a disorder of the stomach nerves that leads to very slow movement of food, have shown symptomatic improvement after electrical stimulation generated by a pacemaker-like device that can be surgically implanted in the stomach.

      Doctors had theorized that the electrical stimulation would provoke the stomach into contracting, which would help push food along. However, it was later found that while the treatment does help patients feel better, it affected motility to a lesser degree. The MIT team hypothesized that the electrical stimulation of the stomach might be leading to the release of ghrelin, which is known to promote hunger and reduce feelings of nausea.

      To test that hypothesis, the researchers used an electrical probe to deliver electrical stimulation in the stomachs of animals. They found that after 20 minutes of stimulation, ghrelin levels in the bloodstream were considerably elevated. They also found that electrical stimulation did not lead to any significant inflammation or other adverse effects.

      Once they established that electrical stimulation was provoking ghrelin release, the researchers set out to see if they could achieve the same thing using a device that could be swallowed and temporarily reside in the stomach. One of the main challenges in designing such a device is ensuring that the electrodes on the capsule can contact the stomach tissue, which are coated with fluid. 

      Play video

      To create a drier surface that electrodes can interact with, the researchers gave their capsule a grooved surface that wicks fluid away from the electrodes. The surface they designed is inspired by the skin of the Australian thorny devil lizard, which uses ridged scales to collect water. When the lizard touches water with any part of its skin, water is transported by capillary action along the channels to the lizard’s mouth.

      “We were inspired by that to incorporate surface textures and patterns onto the outside of this capsule,” McRae says. “That surface can manage the fluid that could potentially prevent the electrodes from touching the tissue in the stomach, so it can reliably deliver electrical stimulation.”

      The capsule surface consists of grooves with a hydrophilic coating. These grooves function as channels that draw fluid away from the stomach tissue. Inside the device are battery-powered electronics that produce an electric current that flows across electrodes on the surface of the capsule. In the prototype used in this study, the current runs constantly, but future versions could be designed so that the current can be wirelessly turned on and off, according to the researchers.

      Hormone boost

      The researchers tested their capsule by administering it into the stomachs of large animals, and they found that the capsule produced a substantial spike in ghrelin levels in the bloodstream.

      “As far as we know, this is the first example of using electrical stimuli through an ingestible device to increase endogenous levels of hormones in the body, like ghrelin. And so, it has this effect of utilizing the body’s own systems rather than introducing external agents,” Ramadi says.

      The researchers found that in order for this stimulation to work, the vagus nerve, which controls digestion, must be intact. They theorize that the electrical pulses transmit to the brain via the vagus nerve, which then stimulates endocrine cells in the stomach to produce ghrelin.

      Traverso’s lab now plans to explore using this approach in other parts of the GI tract, and the researchers hope to test the device in human patients within the next three years. If developed for use in human patients, this type of treatment could potentially replace or complement some of the existing drugs used to prevent nausea and stimulate appetite in people with cachexia or anorexia, the researchers say.

      “It’s a relatively simple device, so we believe it’s something that we can get into humans on a relatively quick time scale,” Traverso says.

      The research was funded by the Koch Institute Support (core) Grant from the National Cancer Institute, the National Institute for Diabetes and Digestive and Kidney Diseases, the Division of Engineering at New York University Abu Dhabi, a National Science Foundation graduate research fellowship, Novo Nordisk, and the Department of Mechanical Engineering at MIT. More

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      Scientists uncover the amazing way sandgrouse hold water in their feathers

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      Many birds’ feathers are remarkably efficient at shedding water — so much so that “like water off a duck’s back” is a common expression. Much more unusual are the belly feathers of the sandgrouse, especially Namaqua sandgrouse, which absorb and retain water so efficiently the male birds can fly more than 20 kilometers from a distant watering hole back to the nest and still retain enough water in their feathers for the chicks to drink and sustain themselves in the searing deserts of Namibia, Botswana, and South Africa.

      How do those feathers work? While scientists had inferred a rough picture, it took the latest tools of microscopy, and patient work with a collection of sandgrouse feathers, to unlock the unique structural details that enable the feathers to hold water. The findings appear today in the Journal of the Royal Society Interface, in a paper by Lorna Gibson, the Matoula S. Salapatas Professor of Materials Science and Engineering and a professor of mechanical engineering at MIT, and Professor Jochen Mueller of Johns Hopkins University.

      The unique water-carrying ability of sandgrouse feathers was first reported back in 1896, Gibson says, by E.G.B. Meade-Waldo, who was breeding the birds in captivity. “He saw them behaving like this, and nobody believed him! I mean, it just sounded so outlandish,” Gibson says.

      In 1967, Tom Cade and Gordon MacLean reported detailed observations of the birds at watering holes, in a study that proved the unique behavior was indeed real. The scientists found that male sandgrouse feathers could hold about 25 milliliters of water, or about a tenth of a cup, after the bird had spent about five minutes dipping in the water and fluffing its feathers.

      About half of that amount can evaporate during the male bird’s half-hour-long flight back to the nest, where the chicks, which cannot fly for about their first month, drink the remainder straight from the feathers.

      Cade and MacLean “had part of the story,” Gibson says, but the tools didn’t exist at the time to carry out the detailed imaging of the feather structures that the new study was able to do.

      Gibson and Mueller carried out their study using scanning electron microscopy, micro-computed tomography, and video imaging. They borrowed Namaqua sandgrouse belly feathers from Harvard University’s Museum of Comparative Zoology, which has a collection of specimens of about 80 percent of the world’s birds.

      Bird feathers in general have a central shaft, from which smaller barbs extend, and then smaller barbules extend out from those. Sandgrouse feathers are structured differently, however. In the inner zone of the feather, the barbules have a helically coiled structure close to their base and then a straight extension. In the outer zone of the feather, the barbules lack the helical coil and are simply straight. Both parts lack the grooves and hooks that hold the vane of contour feathers together in most other birds.
      Video of water spreading through the specialized sandgrouse feathers, under magnification, shows the uncoiling and spreading of the feather’s barbules as they become wet. Initially, most barbules in the outer zone of the feather form tubular features.Credit: Specimen #142928, Museum of Comparative Zoology, Harvard University © President and Fellows of Harvard College.

      When wetted, the coiled portions of the barbules unwind and rotate to be perpendicular to the vane, producing a dense forest of fibers that can hold water through capillary action. At the same time, the barbules in the outer zone curl inward, helping to hold the water in.

      The microscopy techniques used in the new study allowed the dimensions of the different parts of the feather to be measured. In the inner zone, the barb shafts are large and stiff enough to provide a rigid base about which the other parts of the feather deform, and the barbules are small and flexible enough that surface tension is sufficient to bend the straight extensions into tear-like structures that hold water. And in the outer zone, the barb shafts and barbules are smaller still, allowing them to curl around the inner zone, further retaining water.

      While previous work had suggested that surface tension produced the water retention characteristics, “what we did was make measurements of the dimensions and do some calculations to show that that’s what is actually happening,” Gibson says. Her group’s work demonstrated that the varying stiffnesses of the different feather parts plays a key role in their ability to hold water.

      The study was mostly driven by intellectual curiosity about this unique behavioral phenomenon, Gibson says. “We just wanted to see how it works. The whole story just seemed so interesting.” But she says it might lead to some useful applications. For example, in desert regions where water is scarce but fog and dew regularly occur, such as in Chile’s Atacama Desert, some adaptation of this feather structure might be incorporated into the systems of huge nets that are used to collect water. “You could imagine this could be a way to improve those systems,” she says. “A material with this kind of structure might be more effective at fog harvesting and holding the water.”

      “This fascinating and in-depth study reveals how the different parts of the sandgrouse’s belly feathers — including the microscopic barb shafts and barbules — work together to hold water,” says Mary Caswell Stoddard, an evolutionary biologist at Princeton University, who was not associated with this study. “By using a suite of advanced imaging techniques to describe the belly feathers and estimate their bending stiffnesses, Mueller and Gibson add rich new details to our understanding of the sandgrouse’s water-carrying feathers. … This study may inspire others to take a closer look at diverse feather microstructures across bird species — and to wonder whether these structures, as in sandgrouse, help support unusual or surprising functions.”

      The work was partly supported by the National Science Foundation and the Matoula S. Salapatas Professorship in Materials Science and Engineering at MIT. More