HIV budding out of a T-cell
Image: Dr. Tom Folks/NIH

In HIV infection populations of immune system cells are devastated, but researchers have found one immune cell type that survives the onslaught.

These surviving cells prevent inflammation, but they do so by suppressing the immune system. This new finding raises the question of whether their survival during HIV infection helps the body or the attacking virus.

The cells, called T regulators, may be useful because they normally prevent a hyperactive immune system which leads to its exhaustion.

But in the case of HIV infection their role of suppression could be disastrous, if this effect means the immune system causes its own demise by shutting itself down in a time of crisis. Knowing the difference could eventually help develop new HIV treatments, and this will be a central question guiding future research.

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Golden Orb-weaver
Photo: Adam Myhill

Spiders can fend off ants by coating their web with the predators’ own alarm chemical, reports a new study of Singapore spiders and ants.

Only spiders whose webs are thick enough for ants to crawl on seem to use the chemical, suggesting that different spider species may have evolved targeted chemical weaponry.

The insect world is full of mysteries, and spiders and ants were the center of this one. Spider webs are made of silk, a biomaterial whose strength and elasticity make an efficient trap for catching prey. But staying on or near the web makes the spider a sitting duck for potential predators, including wasps as well as ants. Yet ants steer clear of webs.

Spiders are known for the defenses they have evolved for escaping wasps, their main flying predator: “leaf-refuges” for hiding; camouflage silk decorations to make the spider look threatening; “drag-lines” to drop from the web, and the ability to color-shift, as octopi sometimes do in corral reefs. But little was known about spider defenses against ants—or how a particular spider species’ weapons might adapt to its specific predators.

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The red-tinted hair and bloated abdomens of these three
young girls in Madagascar are typical signs of kwashiorkor,
a type of malnutrition that occurs when there is not enough
protein in the diet. (Photo by Christopher Golden)

Eating bushmeat decreases incidences of anemia in children, according to a recent study conducted in Madagascar.

Bushmeat, or wildlife meat, is often the most affordable kind of meat in developing countries such as Madagascar, but its supplies are threatened by overhunting and its access is limited by conservation laws.

The study, published in the Proceedings of the National Academy of Sciences, demonstrated that children who eat less bushmeat are more likely to be iron-deficient and thus have anemia, a condition where the body is low on hemoglobin, an iron-containing molecule found in red blood cells that helps transport oxygen around the body.

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Emergency hospital during influenza epidemic
Camp Funston, Kansas
National Museum of Health and Medicine

You’re far more likely to get the flu from breathing in the virus when you’re around someone who has it than you are from touching infected items around your house, say researchers from Great Britain.

Most household materials can’t sustain enough influenza—the virus which causes the common disease we call “the flu”—to infect another person by physical contact after only a few hours. These results confirmed what most scientists suspected: the influenza virus is quite fragile.

To test the survival of the virus on household items, researchers deposited small amounts of influenza on items like light switches, toys, kitchen counters, keyboards, and window glass in a laboratory setting. Then they measured the amount of viable virus (meaning a large enough quantity to lead to an infection) at set times.

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H. Pylori
Courtesy Yutaka Tsutsumi, M.D.

Researchers have been able to disable bacteria that cause ulcers by removing the bacteria’s ability to get close to the stomach wall.

This new knowledge about how the immune system responds to H. pylori infections could be used to screen for patients more susceptible to stomach ulcers and cancer, and perhaps to create more targeted therapies for those already affected.

In order to both survive and cause inflammation in the stomach, bacteria need to get to the side of the stomach “and set up shop there, living adjacent to your stomach cells, in a little kind of cozy home,” says Karen Ottemann, whose study was published this week in the early online edition of the Proceedings of the National Academy of Sciences. Unlike the acidic middle of the stomach, “the pH is closer to neutral and there’s food coming out of the cells,” she notes.

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Courtesy of Robert Anemone
The Great Divide Basin, a 4,000-square-mile stretch of
rocky desert in Wyoming.

Picks and chisels may soon have a powerful new companion in paleontologists’ toolkits: artificial intelligence can help find fossils.

Scientists have shown that a computer program called a neural network can be trained to look at images of landscapes and pick out areas likely to be fossil beds. This is the first time paleontologists have used neural networks to locate fossils. The procedure may prove to be an effective addition to established methods, say scientists.

The researchers behind the pioneering effort—Glenn Conroy of Washington University in St. Louis, and Robert Anemone and Charles Emerson of Western Michigan University—explain that modern paleontologists do their work in much the same way as their predecessors of the last century and a half. “A hundred and fifty years ago, when the science was just beginning,” says Anemone, “people ended up walking long distances out in the badlands of the West. Today we have geological and topographical maps, but we still just go out to these areas and walk around looking for [fossils].”

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Drosophila (fruit fly)
Image: Wikimedia Commons

Fruit fly researchers have found the master control switch—a gene called spalt—that turns walking muscles into flight muscles.

Flies deprived of spalt grew up unable to fly. Their flight muscles were tubular and slow-moving, like leg muscles, instead of fibrillar and fast-moving as they should have been. And when the scientists switched on spalt where it didn’t belong, leg muscles developed a fibrillar structure like the one normally found in flight muscles.

This discovery could shed light on muscle development all the way up to humans. The cardiac muscle of mammals is very similar to insect flight muscle, not only in its fibrillar structure, but also in the way that it contracts. Furthermore, mammalian hearts are known to express two spalt-like genes. A mutation in one of these genes causes the heart abnormalities seen in Townes-Brocks syndrome.

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Black rat
Image: Wikimedia Commons

Invasive rats and birds in New Zealand have partially taken over the important role of the pollinators they ousted, complicating eradication of these invaders according to a recent study.

While it was already known that invasive species occasionally help the ecosystems they invade, this study quantified that effect. The results highlight one of the complexities of dealing with invasive species: sometimes removing them can harm the already-damaged ecosystem.

In the study, researchers took advantage of the unique ecology of New Zealand. On the North Island, invasive species have pushed out the endemic pollinators; but on small islands off the coast, scientists have managed to eradicate these invaders, and native fauna are flourishing, effectively giving researchers a window into the ecology of 18th century New Zealand.

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Dr. Augustus Riley
Image courtesy Kathy McCoy
www.rileyscrossing.com

The patient came to Boston City Hospital in fall 1929 after two weeks of difficulty urinating, when he noticed “a watery foul-smelling pus coming from an opening just above the pubis.” The patient was a 52-year-old African-American man, likely poor in money and education, who arrived in the urologist’s office pale and weak, reeking of urine and rotting flesh. The doctor, the same age as his patient, was a urologist and Harvard professor, graduate of Oberlin College ’03 and Harvard Medical School ’07. Dr. Augustus Riley lived at a posh address in Boston, 857 Beacon Street, and went golfing on weekends with other physicians. Dr. Riley would publish an account of this surgery in The New England Journal of Medicine.

A surgical photo shows the scrotum of this African-American male. Dr. Riley’s paper doesn’t mention the race of his patient, but you can tell from the dark pigmentation of his hand, holding up the hospital gown to expose his “gangrenous peritoneum.” In the black-and-white photograph, now in the archives at Harvard’s Countway Medical Library, the patient’s abdomen is punctured with holes, his penis attached to the catheter that saved his life. The nasty-looking gashes to the right of the patient’s belly-button are the surgical treatment for urinary extravasacation: incisions of the abdominal wall to drain urine that has leaked out of the vasa, or tubes, poisoning the abdomen. The resulting gangrene, without the aid of modern antibiotics, almost certainly killed him, according to present-day surgeon Dr. Norman McGowin. But such cases nevertheless required documentation and attempts at treatment.

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WWII Soldiers eating in mess tent
Harold Edgerton, Courtesy MIT Museum

In September 1943, a flurry of activity surrounded MIT’s biological engineering research labs. In the midst of battle in North Africa, twenty German prisoners had been taken by American forces. They were first shipped to a holding facility in Cameron, Virginia, and then to researchers in building 35 at MIT. Starting up spectrometers and microscopes, the scientists eagerly examined their captives: twenty samples of German rations—ingredients, main courses, and desserts—begging for a thorough analysis.

Just down the street from physics labs creating battle-winning radar technology and chemistry labs churning out isotopes for atomic bombs, a quieter wartime project was underway. From July 1942 to October 1945, the Office of the Quartermaster General in the U.S. War Department commissioned scientists at MIT to research and design rations for soldiers in the Second World War.

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On February 1962 at the upper reaches of the atmosphere, a cosmic ray raced towards Earth from space. It collided with the atomic nucleus of an air molecule. They both shattered, initiating a cascade of further collisions and disintegrations until an invisible shower of about fifty billion subatomic particles fell onto a stretch of New Mexico desert called Volcano Ranch.

Cosmic rays, made of energetic particles (usually protons), hit the Earth all the time, creating a continual stream of particle showers. The higher the energy of the cosmic ray, the more particles shower out of it. At the time, the February 1962 event was the highest energy cosmic ray ever seen, and it remained so until 1991.

It was also the third in a string of record-breaking cosmic rays discovered at Volcano Ranch. The first was detected in 1960 and the second in 1961, but the February 1962 event outstripped them all. The fifty billion particles that rained down on the cosmic ray detectors at Volcano Ranch were created by a single particle with an energy of 10²⁰ eV, a hundred billion billion electron volts. That’s comparable to the energy of a golf ball dropped off the top of the Leaning Tower of Pisa shortly before it hits the ground.

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Lt. Henry Hawthorne
Courtesy, MIT Archives

Boston, 1892 — The MIT freshmen hustled along Irvington Street, fastening buttons and straightening collars. They were on their way to the South Armory to pick up their rifles, so that by 2:20 pm they could assemble, uniformed and armed, for their mandatory weekly military drill instruction.

Under the terms of the Morrill Land-Grant Act of 1862, signed into law by Abraham Lincoln, each state was provided federal land and funds for land-grant colleges, focused on agriculture, science, and engineering. But under the terms of the Act, these schools also had to include mandatory military training in the curriculum. MIT, founded in 1861 but waylaid by the start of the Civil War, was designated a land-grant college, and so when the war drew to a close and MIT began holding its first classes in 1865, military instruction was a core component of student life.

In June of 1893, Lieutenant Henry Hawthorne was looking back on his first year as Professor of Military Science and Tactics at MIT. Dismayed at the school’s poor job of maintaining the program’s records (he couldn’t even find out who all of his predecessors were), he first committed to paper the history of his department, as best as he was able. And all the while he lamented the school’s seeming disregard and even disdain for him and his program. Regarding the beginnings of his department’s “ill-starred course,” he wrote,

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Sonar instrument field-testing, Charles River 1972
© 2010 Massachusetts Institute of Technology.
Courtesy of MIT Museum

Harold “Doc” Edgerton was a man accustomed to testing sonar devices wherever there was water. Tanks, swimming pools, the open ocean: no aquatic body was safe from his “pingers,” “boomers,” and “thumpers.” Some of Edgerton’s keenest disappointments and most spectacular successes played out in the Charles River, right in his backyard at MIT.

Edgerton’s sonar experiments were an outgrowth of his compulsion to turn invisible things into visible ones. As an MIT graduate student in the 1920s and 30s, he embarked on a long and famed career of using strobe photography to “slow down” fast-moving objects, like speeding bullets and hummingbird wings. He took dozens of photos at the MIT Alumni Pool, capturing the motion of divers twisting in the air between the board and the water. As early as 1941, Edgerton was also taking underwater photos of these divers as they plunged below the surface. Underwater photography spurred him to address a whole new array of technological challenges, from waterproofing the equipment to coping with limited light.

One day in 1952, an obscure French explorer dropped in on Edgerton (now a full professor) to ask for advice on underwater flash photography. Within a couple of hours, Jacques Cousteau was in the MIT pool with flippers and a scuba tank, trying out Edgerton’s equipment. So began a long friendship and collaboration between the two men, during which Edgerton accompanied many of Cousteau’s expeditions and was christened “Papa Flash.”

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Memory bank in Whirlwind
Picture used with the permission of
The MITRE Corporation.
Copyright ©The MITRE Corporation.
All Rights Reserved.

The Whirlwind computer was a nudist. In contrast, today’s computers come sheathed in plastic; we’re unaware of and unconcerned with the electrons zipping through their wires, hidden as they are behind matte gray or glossy white cases. These are prudish machines.

The Whirlwind, on the other hand, let it all hang out. Photographs of the computer, circa its 1950s heyday in MIT’s Barta Building at the corner of Massachusetts Avenue and Smart Street in Cambridge, show its innards on brazen display: transistors the size of double-A batteries, wiring snaking across circuit boards like roots seeking water. Like all others of its day, the Whirlwind was massive—covering some 3,100 square feet of floor space—with dozens of banks of circuitry cooled by huge air conditioners. This superficial chaos masked a sea change, though, a fundamental shift in the way computers compute. The Whirlwind was the granddaddy of nearly every computer in existence today.

Whirlwind’s chaotic appearance was reflected in its origins. Times of war often warrant rapid innovation, and the deepest years of World War II were no different. Prior to 1939 fewer than 6,000 aircraft were produced per year in the United States. By 1945 more than 300,000 had been built, 275,000 of them after Pearl Harbor. These new aircraft were unprecedented in their complexity, from the B-29 Superfortress heavy bomber—one of the largest aircraft to fly during the war—to the venerable P-51 Mustang fighter.

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Coffee rust
Image: Howard Schwartz, Colorado State University

Here’s news to researchers studying coffee rust, a fungal disease that has devastated coffee crops around the world for more than a hundred years: It was always assumed the coffee fungus reproduced asexually—meaning its cells split instead of fused with other cells from another host. But new research confirms they also reproduce sexually.

Coffee rust is the most economically damaging disease affecting coffee crops worldwide (estimated to cost the global coffee industry up to $3 billion a year). This new insight into the personal life of coffee fungus could help control the spread of the deadly disease in coffee and other plant life as well, including wheat grain and pine trees, which also suffer from different forms of rust fungi.

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Psychiatrists in Germany have found a difference in brain arousal that marks men most vulnerable to sexual dysfunction upon taking antidepressant drugs.

By showing pornographic film clips to eighteen young men in a brain scanner, after a week of antidepressant treatment and sexual-function surveys, the researchers determined what goes wrong when these drugs cause sexual problems.

Men who showed high impulsiveness on a personality test were more likely to have trouble getting aroused and to show the weakened brain response to erotic movies. Psychiatrists may use this factor to predict depressed patients at risk for sex problems and to treat them.

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N. American Porcupine and plant stems
National Park Service

Inspired by plant stems and porcupine quills, tissue engineers have developed a new material to speed tendon regeneration.

Made of a collagen “scaffold” surrounded by a dense shell, their invention is both strong and compatible with living cells—two requirements that are difficult to achieve simultaneously.

The new material, so far confined to the test tube, faces years of testing in animals before it can be considered for clinical use. But it could eventually become an effective tool for healing tendon and ligament injuries, which make up half of all musculoskeletal injuries in the United States each year.

“Tendon is a tough tissue to mimic,” says Brendan Harley of the University of Illinois. Since its job is to connect muscle and bone, “there’s a lot of tensile load that gets applied to the material.”

A scaffold for tendon regeneration must be very strong to withstand such force. However, it must also be porous enough so that living cells can infiltrate its interior and begin forming new tissue. Since high porosity makes for a weak scaffold, this double requirement is the bane of tendon-tissue engineers.

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Horseshoe bat

Some bat species can dramatically change the size and shape of their ears faster than humans can blink an eye, researchers have shown.

Scientists already knew that bats could change the direction of their ears depending on where a sound was coming from, like shining a flashlight around a room. New data now show that bats can also reshape their outer ears, stretching their ears to pick up sound from a wide field and then focusing back to tiny targets very quickly.

Rapidly switching back and forth from one ear shape to another can help the bat simultaneously learn about its environment and chase down an insect for dinner. Rolf Mueller, a researcher at Virginia Tech whose study was recently published in Physical Review Letters, hopes that the finding can be used to create more sophisticated sonar technology.

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Neuron complex, Wikimedia Commons

Researchers at MIT have designed a computer chip that emulates brain synapses—the junctions between neurons—at a new level of detail.

Recently, they’ve used these chips as a model to study how the connections between neurons strengthen over time, a process thought to be integral to learning and memory, according to a paper published in the Proceedings of the National Academy of Sciences.

But beyond helping us understand the brain, these chips could eventually be part of brain-machine interfaces used by amputees to control artificial limbs, says Chi-Sang Poon, senior author of the paper. Someday he believes they could even build prosthetic brain parts to replace damaged brain tissue—or to augment users’ natural abilities.

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Amazon rainforest, Wikimedia Commons

A type of logging called “reduced-impact” logging can minimize the effects of rainforest tree-cutting on the climate, according to a study conducted in the Brazilian Amazon.

The study, published in the Proceedings of the National Academy of Sciences, is the first to show that reduced-impact logging, when compared to deforestation and conventional logging, has only a small and temporary effect on a forest’s carbon cycles. A change in a forest’s carbon cycle (for example, an alteration of a forest’s emission and absorption of carbon dioxide into and out of the atmosphere) would affect regional and global climate.

Reduced-impact logging, which one of the paper’s authors, Michael Goulden of the University of California, Irvine, likens to “common sense” logging, was developed about two decades ago to counter the negative effects of logging in forests.

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