Lessons from the lobster

God gave lobsters hard outer armor to protect them from predators and a segmented tail to propel them quickly through the water. So far, engineers have yet to develop a material as flexible, yet sturdy, as the one God designed for the lobster tail. Massachusetts Institute of Technology (MIT) researchers recently set up a series of experiments to explore how the translucent membrane that covers lobster tail joints allows the creature flexibility without leaving it vulnerable. They believe their discovery may aid in the design of body armor that is more flexible and offers freer movement of elbows and knees and may assist in better designs for soft robotics.

The researchers found that the hydrogel membrane, a gel-like substance consisting mostly of water, provides as much strength as industrial rubber composites used in car tires, garden hoses, and conveyor belts. It resists the cuts and scrapes a lobster’s underside endures as it scurries along the rocky ocean floor. The researchers found they could cut as much as halfway through the membrane and still pull it as far as an uncut piece without breaking it.

Additionally, when the membrane reached about twice its natural length, it stiffened and became progressively tougher, a unique feature in the world of biomaterials. “For many other tough hydrogels, the more you stretch, the softer they are,” Ming Guo, co-author of the study, said in a statement. “This strain-stiffening behavior could allow lobsters to flexibly move, but when something bad happens, they can stiffen and protect themselves.”

Though only about a quarter of a millimeter thick, the membrane contains tens of thousands of layers. Each single layer contains untold numbers of chitin fibers, the main component in most shells. All of them are oriented at the same angle, exactly 36 degrees offset from the layer of fibers above it. The researchers found that a membrane composed of randomly ordered fibers would quickly fracture when stretched. But when they imitated the lobster’s membrane, with precisely oriented fibers, it could withstand much greater stretching.

The researchers credited evolution with the design of the lobster tail. But lead researcher Zhao Qin described the development of the fibers as a “guided” architecture. “One mystery is how the chitin fibers can be guided to assemble into such a unique, layered architecture to form the lobster membrane,” he said.

Wouldn’t the “guided” architectural feature require a guiding Architect, or Designer?

Timothy Ray Brown Associated Press/Photo by Manuel Valdes

Second person appears cured of HIV

A second person has achieved sustained remission from HIV, according to reports issued last week.

In 2007, Berlin resident Timothy Ray Brown became HIV-free after undergoing treatment for leukemia. The treatment killed nearly all his immune cells with radiation and drugs and replaced them with stem cells from a donor who carried a natural mutation in a gene called CCR5, which causes resistance to HIV.

Now, more than 10 years later, scientists announced a second case of sustained HIV remission. The case report, published March 5 in Nature, describes an HIV-positive man in London. Doctors treated him for Hodgkin lymphoma using a bone marrow transplant from a donor who carried the CCR5 mutation. Sixteen months later, the patient stopped taking the antiviral drugs that kept HIV at bay. Now, 18 months later, he remains HIV-free. Although the results appear very promising, his doctors caution it is too early to declare him cured.

Researchers also announced a hopeful third case on March 5 at the Conference on Retroviruses and Opportunistic Infections in Seattle, New Scientist reported. Biopsies from the gut and lymph nodes of an HIV patient in Germany who received a bone marrow transplant from a donor with the CCR5 mutation showed no HIV infection after the patient was off of antiviral drugs for three months.

A lifetime of antiviral drugs currently offers the only treatment option available for 37 million people with HIV around the world, and some strains of the virus are becoming drug-resistant.

HIV is particularly difficult to treat because it integrates into the patient’s white blood cells, which are made in the bone marrow. Doctors can’t perform bone marrow transplants for people with HIV who don’t have cancer because the transplants carry a risky degree of chemotherapy toxicity. Physicians use them only as a last resort. But the researchers hope these cases will inspire other strategies that might one day offer a cure for HIV, such as using gene editing to mutate the CCR5 gene in a patient’s own cells. —J.B.

Timothy Ray Brown Associated Press/Photo by Manuel Valdes

Polly want a poppy?

Addicted parrots are overtaking opium poppy farms in India. In Madhya Pradesh, parrots feed on poppy plants 30 to 40 times a day, a poppy farmer told NDTV.

India is one of the few countries that legally grows opium poppies, and the central government permits and regulates the cultivation of the plants for medical and scientific purposes. Morphine and codeine are naturally occurring derivatives of the plants.

The farmers say they are incurring massive losses and their government has not responded to requests for help. Narendra Singh, an opium farmer from Pratapgarh Verma, told the Indian publication DNA that the birds destroy up to 10 to 15 percent of his crop. Some farmers try unsuccessfully to frighten the birds away with loudspeakers or firecrackers.

A video posted on the Newsflare website shows how some parrots tear into unripe poppy pods that contain opium-rich milk and others use their beaks and claws to snip off entire intact pods and fly away with them.

According to DNA, the addicted birds often wait on nearby trees and attack the plants at daybreak. After ingesting the opium in the pods, intoxicated birds fly in wobbly, disoriented patterns and often end up crashing into trees or lying dazed in the fields. Some of the birds even know how to swoop in silently to make sure they get their fix, Live Science reported. —J.B.

Healing soil?

According to a recent study, soil found in Northern Ireland harbors a previously unknown strain of bacteria that effectively kills four of the top six antibiotic-resistant superbugs, including methicillin-resistant Staphylococcus aureus (MRSA).

An international team of researchers discovered the bacterial strain, which they call Streptomyces sp. myrophorea, in soil samples from an area in Northern Ireland known for its alkaline grassland. Their study appears in the Oct. 16, 2018, issue of Frontiers in Microbiology. The discovery could help in the development of new treatments for multidrug-resistant bacteria, the researchers said.

Folk medicine practitioners have long held that the soil in the region has healing properties. They would wrap a small amount of the soil in cotton cloth and use it to treat ailments such as toothaches and throat and neck infections.

The World Health Organization lists antibiotic superbugs as one of the biggest threats to current global health, food security, and development.

“It seems that part of the answer to this very modern problem might lie in the wisdom of the past,” researcher Gerry Quinn said in a statement. —J.B.

Green icebergs in Antarctica

Most icebergs appear blue or white, but icebergs that break off the Amery Ice Shelf in Antartica have a mysterious green hue. A study published in the Jan. 10 issue of the Journal of Geophysical Research suggests these unusual icebergs get their color from iron dust that the glacier grinds up from the Antarctic bedrock as it moves. The iron gives the ice its color and produces emerald icebergs when chunks break away.

If the researchers are right, green icebergs serve a far greater purpose than aesthetic appeal: They ferry iron for phytoplankton, microscopic plants that support almost all marine life. —J.B.