Study: For food-waste recycling, policy is key

Food scraps. Okay, those aren’t the first words that come to mind when you think about the environment. But 22 percent of the municipal solid waste dropped into landfills or incincerators in the U.S. is, in fact, food that could be put to better use through composting and soil enrichment.Moreover, food-scrap recycling programs, while still relatively uncommon, are having a growth moment in the U.S.; they’ve roughly doubled in size since 2010. Now, a national study by MIT researchers provides one of the first in-depth looks at the characteristics of places that have adopted food recycling, revealing several new facts in the process.

How we recall the past

When we have a new experience, the memory of that event is stored in a neural circuit that connects several parts of the hippocampus and other brain structures. Each cluster of neurons may store different aspects of the memory, such as the location where the event occurred or the emotions associated with it.Neuroscientists who study memory have long believed that when we recall these memories, our brains turn on the same hippocampal circuit that was activated when the memory was originally formed. However, MIT neuroscientists have now shown, for the first time, that recalling a memory requires a “detour” circuit that branches off from the original memory circuit.

Researchers clarify mystery about proposed battery material

Battery researchers agree that one of the most promising possibilities for future battery technology is the lithium-air (or lithium-oxygen) battery, which could provide three times as much power for a given weight as today’s leading technology, lithium-ion batteries. But tests of various approaches to creating such batteries have produced conflicting and confusing results, as well as controversies over how to explain them.Now, a team at MIT has carried out detailed tests that seem to resolve the questions surrounding one promising material for such batteries: a compound called lithium iodide (LiI). The compound was seen as a possible solution to some of the lithium-air battery’s problems, including an inability to sustain many charging-discharging cycles, but conflicting findings had raised questions about the material’s usefulness for this task. The new study explains these discrepancies, and although it suggests that the material might not be suitable after all, the work provides guidance for efforts to overcome LiI’s drawbacks or find alternative materials.

Case study suggests new approach to urban water supply

If you live in the developed world, safe water is usually just a faucet-turn away. And yet, global warming, drought conditions, and population growth in coming decades could change that, ushering in an era of uncertain access to water.Now an MIT-based research team has evaluated those potential problems and, based on a case study in Australia, suggested an alternate approach to water planning. In a new paper, the researchers find there is often a strong case for building relatively modest, incremental additions to water infrastructure in advanced countries, rather than expensive larger-scale projects that may be needed only rarely.

Study: Indian monsoons have strengthened over past 15 years

An MIT study published today in Nature Climate Change finds that the Indian summer monsoons, which bring rainfall to the country each year between June and September, have strengthened in the last 15 years over north central India.This heightened monsoon activity has reversed a 50-year drying period during which the monsoon season brought relatively little rain to northern and central India. Since 2002, the researchers have found, this drying trend has given way to a much wetter pattern, with stronger monsoons supplying much-needed rain, along with powerful, damaging floods, to the populous north central region of India.

Study predicts heart cells' response to dwindling oxygen

Time is of the essence when treating a patient undergoing a heart attack. Cardiac surgeons attempt to quickly stabilize the heart by applying reperfusion, a technique that restores oxygen to the heart by opening up blocked vessels with balloons and stents. While reperfusion can restore cardiac function, such sudden infusions of oxygen can also further injure severely depleted regions of the heart.“It’s a double-edged sword,” says Anthony McDougal, a graduate student in MIT’s Department of Mechanical Engineering. “The rapid return of oxygen is necessary for the heart to survive, but it could also overwhelm the heart.”

Finding leaks while they're easy to fix

Access to clean, safe water is one of the world’s pressing needs, yet today’s water distribution systems lose an average of 20 percent of their supply because of leaks. These leaks not only make shortages worse but also can cause serious structural damage to buildings and roads by undermining foundations.Unfortunately, leak detection systems are expensive and slow to operate — and they don’t work well in systems that use wood, clay, or plastic pipes, which account for the majority of systems in the developing world.

Harnessing the right amount of sunshine

Photosynthesis, which allows energy from the sun to be converted into life-sustaining sugars, can also be hazardous to green plants. If they absorb too much sunlight, the extra energy destroys their tissue.To combat this, green plants have developed a defense mechanism known as photoprotection, which allows them to dissipate the extra energy. Researchers from MIT and the University of Verona have now discovered how the key protein in this process allows moss and green algae to protect themselves from too much sun.

Preventing severe blood loss on the battlefield or in the clinic

In a tiny room in the sub-basement of MIT’s Building 66 sits a customized, super-resolution microscope that makes it possible to see nanoscale features of a red blood cell. Here, Reginald Avery, a fifth-year graduate student in the Department of Biological Engineering, can be found conducting research with quiet discipline, occasionally fidgeting with his silver watch.He spends most of his days either at the microscope, taking high-resolution images of blood clots forming over time, or at the computer, reading literature about super-resolution microscopy. Without windows to approximate the time of day, Avery’s watch comes in handy. Not surprisingly for those who know him, it’s set to military time.

Underwater mountains help ocean water rise from abyss

At high latitudes, such as near Antarctica and the Arctic Circle, the ocean’s surface waters are cooled by frigid temperatures and become so dense that they sink a few thousand meters into the ocean’s abyss.Ocean waters are thought to flow along a sort of conveyor belt that transports them between the surface and the deep in a never-ending loop. However, it remains unclear where the deep waters rise to the surface, as they ultimately must. This information would help researchers estimate how long the ocean may store carbon in its deepest regions before returning it to the surface.