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Much like human soldiers in combat, members of a large, black, termite-eating ant species found in sub-Saharan Africa march in formation into battle and afterward retrieve wounded comrades and carry them back home to recover.

Scientists on Wednesday described the unique rescue behavior of the African Matabele ants, called Megaponera analis, after observing them in Ivory Coast’s Comoé National Park, but did not ascribe charitable motives to the insects.

“This is not an altruistic behavior,” said entomologist Erik Frank of the University of Würzburg in Germany, who led the research published in the journal Science Advances.

“The ants do not help the injured out of the goodness of their hearts. There is a clear benefit for the colony: these injured ants are able to participate again in future raids and remain a functioning member of the colony.”

The ants, which get up to almost three-quarters of an inch (2 cm) long, specialize in hunting termites and use a distinctive raiding strategy.

Scouts leave the nest in search of termite-foraging sites, then recruit up to 500 nest mates and lead them to the termites in a column formation. Ants injured while fighting with termites, sometimes losing limbs or becoming disabled when termites cling to them, excrete pheromone chemicals from their bodies to signal comrades for help.

Uninjured ants then hoist up the wounded and carry them, as well as the dead termites, back to the nest in the same column formation, sometimes as far as about 165 feet (50 meters).

Once back at the nest, other ants remove termites that may be grasping the injured ants. Ants that lost one or two of their six legs are able to adapt their locomotion, often regaining running speeds similar to a healthy ant within 24 hours.

Nearly all the rescued ants participated in subsequent raids, sometimes less than an hour after being injured.

Frank said he was surprised to find this behavior in an invertebrate species.

“It first sounded illogical to me why they should evolve this type of helping behavior,” Frank said. “After a closer look, we realized that the good of the individual, saving the injured, can also be for the good of the colony, and that individuals can be very valuable in ants.”

In addition to primates such as apes and monkeys, rescue behavior has been seen in certain other mammals including elephants, rats and dolphins, Frank said.
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Scientists are touting a discovery that they think might cure HIV infection. They’ve engineered an antibody that blocks the virus from entering and infecting key immune system cells.

The process, developed at the Scripps Researcher Institute in California, involves tethering an antibody, which fights infection, directly onto T cells, the immune system cells that are targeted by the AIDS virus. Eventually, if enough immune cells become infected and destroyed by HIV, the disease progresses to AIDS, which leads to certain death. The antibodies, however, block the receptor on the T cells that HIV uses to enter and destroy them.

It’s what immunochemist Richard Lerner called a form of “cellular vaccination.”  He said the genetic alteration of the T cells with tethered antibodies does not interfere with the immune cells’ ability to fight other pathogens.

Lerner is the senior author of a study describing the work in Proceedings of the National Academy of Sciences.

Experimental HIV vaccines attempt to stimulate an immune response, creating HIV-specific antibodies to attack and destroy infected cells. But Lerner says the concentration of antibodies flowing freely in the bloodstream is too low to reach every infected T cell.

‘Survival of the fittest’

This approach is different, protecting only some healthy T cells.

“You don’t really care about the rest of the body,” Lerner explained. “You would just like to shield those cells from viruses and a virus attack. So that’s the chemical principle. Never mind immunizing the whole body. Just immunize the cells that are the real victims.”

His team added a gene to T cells which instructed them to synthesize antibodies that would bind with the cellular receptor called CD4. That is the doorway to the cell for HIV. Having antibodies hanging on to the cell surface blocks that doorway.

It’s hoped that eventually in humans, these HIV-resistant cells will multiply into the millions, passing on the protective gene, as the unprotected, infected cells die off, eradicating the AIDS virus from the body and affording a long-lasting cure.

At least that’s what experiments in the laboratory suggested when both genetically engineered and unprotected human T cells were exposed to HIV.

Lerner said the engineered T cells would be introduced into a patient’s bone marrow, which would produce protective cells en masse.  

“We hope to, after securing their safety and so on and so forth, in a patient with HIV, [the engineered cells] can harm their [infected] cells with [the] resistance of ours, and … hopefully the good cells will be selected over the bad cells. And that will be the end of HIV in that patient,” Lerner said.

 It’s an approach that Lerner calls a Darwinian “survival of the fittest.”

Scripps investigators are working with City of Hope, an independent research and comprehensive cancer treatment center in Duarte, California, that has a lot of experience with bone marrow transplantation. The center will carry out clinical trials of the engineered, HIV-resistant T cells with an eye toward advancing what scientists hope will be a cure for AIDS.
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Scientists have identified the oldest-known forerunner of the dinosaurs and are expressing surprise at how little it actually resembled one.

Researchers on Wednesday described fossils of a long-necked, four-legged, meat-eating reptile called Teleocrater rhadinus that reached up to 10 feet (3 meters) long and prowled a Tanzanian floodplain roughly 245 million years ago.

It lived during the Triassic Period millions of years before the first dinosaurs. Scientists called it a close cousin rather than a direct dinosaur ancestor.

Its appearance differed from what scientists had expected from the earliest representatives of the dinosaur evolutionary lineage. Teleocrater possessed an unexpected combination of crocodile-like and dinosaur-like characteristics.

“I’m surprised by the mosaic of features that it possesses,” said paleontologist Ken Angielczyk of the Field Museum in Chicago, one of the researchers in the study published in the journal Nature.

“In terms of how it shakes up our understanding of dinosaur evolution, Teleocrater shows that the earliest members of the dinosaur lineage were very unlike dinosaurs, and that many ‘typical’ features of dinosaurs accumulated in a step-wise fashion instead of all evolving at close to the same time.”

Dinosaurs belong to a larger group called archosaurs that about 250 million years ago cleaved into two branches: crocodilians in one and another that includes dinosaurs, extinct flying reptiles called pterosaurs, and birds, which evolved from feathered dinosaurs.

Teleocrater is the oldest-known member of the dinosaur-pterosaur-bird archosaur branch.

Scientists had expected such a dinosaur forerunner to be a smallish, two-legged predator resembling early dinosaurs such as Herrerasaurus, which lived about 231 million years ago in Argentina. While dinosaur predators were bipedal, Teleocrater instead was four-legged, looking superficially like a modern Komodo dragon.

Virginia Tech paleontologist Sterling Nesbitt, the study’s lead author, said fossils representing at least four individuals were found in southern Tanzania, representing about half the skeleton.

Much like a croc and unlike a dinosaur, Teleocrater’s ankle joints could rotate from side to side as well as flexing up and down, providing a crocodile-like gait.

It also boasted telltale dinosaur features such as characteristic depressions for jaw muscle attachment on the roof of the skull, extra surfaces for the backbones to attach to one another, and distinctive hip muscle attachments on the thigh bone.

Teleocrater’s remains were found in the same Tanzanian region as fossils of the two-legged meat-eater Nyasasaurus, which lived perhaps a couple of million years later. Some scientists regard Nyasasaurus as the earliest-known dinosaur.
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A Russian cosmonaut who has returned to Earth after a mission on the International Space Station said on Wednesday he had taken a relic of a Russian Orthodox saint with him.

Astronauts and cosmonauts routinely take small items such as their children’s toys or CDs with them as reminders of home.

Sergei Ryzhikov told Russian news agencies that he would give the tiny relic of St. Serafim of Sarov’s body, which he received from its home monastery last year, to an Orthodox church in Star City outside Moscow, home to the cosmonaut training center.

Serafim of Sarov, one of Russia’s most revered saints known for his hermitical lifestyle, died in the early 19th century.

Ryzhikov, who came back with two other crew members on Monday after six months in space, said he would celebrate the relic’s return at a church service in Star City on Thursday.

“We always wait for some sort of miracle, but the fact that a piece of the relics traveled to the orbit and blesses everything onboard and outside, including our planet, is a big miracle in itself,” he said.

Space exploration in atheist Soviet society was often portrayed as debunking the existence of God. A popular Soviet-era propaganda poster showed a cosmonaut floating in space and declaring: “There is no God!”

Russia has since experienced a religious revival, with the overwhelming majority of Russians now identifying themselves as Russian Orthodox.

In what would have seemed an absurdity to fiercely atheist Soviet space pioneers, Soyuz spacecraft now routinely receive pre-launch blessings from Orthodox priests and Russian cosmonauts have put up small icons at the Space Station.

Cosmonauts have taken tiny relics of at least six Orthodox saints and a piece of the Holy Cross into space with them.

Russia celebrates Space Day on April 12, exactly 56 years after Yuri Gagarin became the first human to travel into space.

 
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