God’s knitting mechanism

In Psalm 139, David poetically described his fetal development as God knitting him together in his mother’s womb. Until now, the process in which embryonic cells knit into tissues and organs has mystified researchers. But scientists at the University of California, Santa Barbara, believe they have solved the mystery.

“In a nutshell, we discovered a fundamental physical mechanism that cells use to mold embryonic tissues into their functional 3-D shapes,” Otger Campàs, the lead researcher, said in a statement.

In the study, published in the journal Nature, the researchers observed the embryonic development of zebrafish, which grow similar to human embryos. They discovered that cells coordinate by exchanging biochemical signals.

But some embryonic cells either latch onto or push away from certain other cells in order to form organs such as eyes, lungs, and heart. Cells in certain locations display a higher activity level than others. When cells push and tug at one another, heat builds up, which melts foamy tissue into a liquid. When the liquid cools down and begins to solidify again, it does so in a controlled manner to form into the appropriate organ shape, somewhat like pouring warm liquid Jell-O into a mold and then popping it in the fridge to set up. The researchers likened the process to glass molding or 3-D printing.

The scientists hope their study will help researchers engineer better 3-D organs or understand how cancerous tumors form and invade surrounding tissues. Researchers know cancer switches from a solidlike tissue state to a fluidlike state, Alessandro Mongera, one of the researchers, explained. “The present study can help elucidate the mechanisms underlying this switch and highlight some of the potential druggable targets to hinder it,” he said.

But, whatever new discoveries may come of this study, it serves as one more example that we are “fearfully and wonderfully made.”

Upside-down filter

We put filters in our coffeemakers in order to allow the small water molecules flow through while holding back the gritty grounds we don’t want to drink in our morning cup of java. But in a new study, published in Science, researchers turned the purpose of a filter upside down. They created a membrane that allows larger objects to pass through but holds back smaller particles. For example, the filter can hold back gases but allow solids to flow through.

The researchers got their inspiration from nature. Membranes that allow large particles to pass through while retaining small ones must possess the ability to “self-heal,” similar to liquids. Plunge a stick into a puddle of water and the water will automatically close as soon as you remove the stick—the hole in the water does not remain. The new membrane retains objects based on their speed, not size. Bigger objects move slower, so they readily go through, and then the filter self-heals and retains smaller, faster objects.

The researchers envision many applications for their new filter, such as an invisible barrier to contaminants in surgical procedures. It could keep bacteria and dust particles out of an open surgical site while allowing instruments to go through, as well as allowing surgeons to pull tissue back out. The filter could also act as a barrier to insects and pollens or to trap odors in a waterless toilet. —J.B.

Cleaning up the ocean

Twenty-four-year old inventor and entrepreneur Boyan Slat, who founded the Ocean Clean-up organization headquartered in the Netherlands, has designed a partially solar-powered device that he hopes can clean out some of the more than 8 million metric tons of plastic that enters ocean waters every year.

A ship recently towed the 2,000-foot-long cleaning mechanism, System 001, through the San Francisco Bay to a testing site. If all goes well with testing, it will then head out to the Great Pacific Garbage Patch, the world’s largest accumulation of ocean plastic, located between Hawaii and California, Business Insider reported. The crew hopes the system can collect 50 tons of plastic in the first year. Based on test models, Slat believes a full deployment of 60 systems could remove half of the plastic in the garbage-patch within five years.

But, scientists who study plastics noted the system cannot reach pieces that have begun to break up and sink. Critics also warn the apparatus could negatively impact marine wildlife and may not stand up to harsh ocean conditions. They also fear the system could distract policymakers from stopping the overall use of plastic or implementing management plans to prevent it from entering the ocean in the first place.

Creation of the system cost about $23 million, but the design team estimates the manufacture of future arrays will cost under $6 million. —J.B.

Air pollution affects cognitive functioning

Much research has shown that breathing polluted air can negatively affect health and contribute to conditions such as heart and lung disease and even cancer. But now researchers in China found it also interferes with cognitive ability as people age.

The longitudinal study, published in Proceedings of the National Academy of Sciences, compared the levels of nitrogen and sulfur dioxide air pollution to the language and arithmetic test scores of 20,000 Chinese citizens living in the polluted areas between 2010 and 2014, The Guardian reported. Statistical analysis showed a significant drop in test scores, equivalent to losing one year of education, that corresponded to high pollution levels. The greatest drop occurred for men over the age of 64 and people with less education. —J.B.