In the Heat for a Moment: The Male Giant Panda's Sex Drive Fluctuates to Match the Female's Short-Lived Libido

There is perhaps no mammal that is less often in the mood for sex than the female giant panda. Each spring, female pandas enter estrous (aka "heat") for only 24 to 72 hours. If male pandas do not make their move during that brief window of time, they miss their chance to mate. Although researchers initially struggled to breed pandas in captivity , they achieved recent success by closely studying the females' reproductive behaviors. But what about the males? It now seems that male pandas have a reproductive cycle of their own, knowledge of which could strengthen the growing captive panda population by improving both breeding strategies and artificial insemination techniques . From the summer through the fall, male pandas are not interested in sex at all. But each winter and early spring, sex hormones flood the males' bodies, plump up their testes and fire up their sperm factories in preparation for a very brief mating season. [More]


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What Thawed the Last Ice Age?

Roughly 20,000 years ago the great ice sheets that buried much of Asia, Europe and North America stopped their creeping advance. Within a few hundred years sea levels in some places had risen by as much as 10 meters--more than if the ice sheet that still covers Greenland were to melt today. This freshwater flood filled the North Atlantic and also shut down the ocean currents that conveyed warmer water from equatorial regions northward. The equatorial heat warmed the precincts of Antarctica in the Southern Hemisphere instead, shrinking the fringing sea ice and changing the circumpolar winds. As a result--and for reasons that remain unexplained--the waters of the Southern Ocean may have begun to release carbon dioxide, enough to raise concentrations in the atmosphere by more than 100 parts per million over millennia--roughly equivalent to the rise in the last 200 years. That CO2 then warmed the globe, melting back the continental ice sheets and ushering in the current climate that enabled humanity to thrive.

Consciousness Does Not Reside Here

What is the relation between selective attention and consciousness? When you strain to listen to the distant baying of coyotes over the sound of a campsite conversation, you do so by attending to the sound and becoming conscious of their howls. When you attend to your sparring opponent out of the corner of your eye, you become hyperaware of his smallest gestures. Because of the seemingly intimate relation between attention and consciousness, most scholars conflate the two processes.

100 Years Ago: Loss of the Titanic

April 1962

Infectious Selflessness: How an Ant Colony Becomes a Social Immune System

In the 2011 blockbuster thriller Contagion , a virus infects and kills 26 million people around the world. But even those who evade the virus are infected with something else: crippling fear . To contain the outbreak, the military imposes a quarantine. People stay indoors, refusing to interact with anyone outside their families. Touching anyone or anything becomes a risk, because the virus lingers everywhere. [More]


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YouTube Winner Sends Spiders To Space

The first YouTube Space Lab contest has announced its winners. Young people entered by creating a short video of their idea for an experiment to be done in space. I was a judge.

Why Some Pain Relievers Cause Intense Itching

Millions of patients benefit from opioids such as morphine and codeine, but the pain relief they provide often comes with intense itching. In some cases, the irritation is so bad that patients will opt to cut back on painkillers. Now a study in the October 14 issue of Cell has found a possible explanation--the first step to creating drugs that will not make patients choose between experiencing itchiness and pain.

100 Years Ago: Loss of the Titanic

April 1962

Dengue Virus Makes Mosquitoes Better Spreaders

The dengue virus depends on mosquitoes to get around. But the virus may have evolved a way to speed its spread--by manipulating the behavior of its mosquito hosts. It makes them more bloodthirsty, and quicker to find a blood meal, than their uninfected counterparts. So says a study in the journal Public Library of Science Pathogens . [Shuzhen Sim, Jose L. Ramirez and George Dimopoulos, Dengue Virus Infection of the Aedes aegypti Salivary Gland and Chemosensory Apparatus Induces Genes that Modulate Infection and Blood-Feeding Behavior ]

How Useful Is Whole Genome Sequencing to Predict Disease?

A $1,000 genome sequence is close to being available. What will your sequence tell you about your actual risk for certain diseases?

World Repository of Human Genetics Will Move to Amazon's Cloud

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Readers Respond to "The Death of Preschool"--and More

DREAM STATES [More]


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Fossil Free: Microbe Helps Convert Solar Power to Liquid Fuel

A new " bioreactor " could store electricity as liquid fuel with the help of a genetically engineered microbe and copious carbon dioxide. The idea--dubbed " electrofuels " by a federal agency funding the research--could offer electricity storage that would have the energy density of fuels such as gasoline. If it works, the hybrid bioelectric system would also offer a more efficient way of turning sunlight to fuel than growing plants and converting them into biofuel .

Microbial Mules: Scientists Experiment With Engineering Bacteria to Transport Nanoparticles and Drugs

Tiny robots that swim through our blood vessels attacking viruses and malignant cells have not quite crossed the line that separates science fiction from science--but there might be a way to jump-start their development. [More]


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Food Poisoning's Hidden Legacy

Colette Dziadul struggled for years to understand her daughter’s joint problems. Dana, who is now 14 years old, complained from toddlerhood that her knees and ankles hurt. The aches kept her up at night, made her wake her parents to ask for painkillers and forced her to sit out school sports. Nevertheless, two pediatricians and an orthopedist diagnosed the problem as “growing pains” that would fade as she grew older.

Bots of Burden: U.S. Army Recruiting an Array of Animal-Inspired Robots to Assist Battlefield Troops [Video]

Three of the U.S. military's newest recruits reported for duty this week at the Army Test and Evaluation Command . These troops are different from normal soldiers in several ways--for starters, each has six feet. And they are robots designed to look and move like cockroaches. Aside from those details, the Army is hoping its new Boston Robotics RHex bots will soon join grunts in Afghanistan. [More]


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Thyme Kills Acne Bacteria

Compounds found in the herb thyme have antibiotic properties. Now scientists have demonstrated that thyme might have a future role in fighting acne.

Primeval Precipitation: What Fossil Imprints of Rain Reveal about Early Earth

Some 2.7 billion years ago in what is now Omdraaisvlei farm near Prieska, South Africa, a brief storm dropped mild rain on a new layer of ash laid down by a recent volcanic eruption (not unlike ash from the 2010 Eyjafjallajökull eruptio n in Iceland) forming tiny craters. Additional ash subsequently buried the craters and, over eons, hardened to become rock known as tuff. Closer to the present, other rainstorms eroded the overlying tuff, exposing a fossil record of raindrops from the Archean eon, and may now have revealed the density of early Earth's atmosphere.

Pupfish, Downfish: Subterranean Tsunami Gives Vertical Shakes to the Water-Hole Home of Endangered Fishes

On March 20 a National Park Service biologist named Jeffrey Goldstein and I descended a rocky incline into the mouth of Devils Hole, a collapsed cave in the Nevada desert 40 miles south of the visitor’s center in Death Valley. Thirty feet down, an arm of water extends out from a deep pool to cover a rock shelf the size of a Ping-Pong table with up to two and a half feet of hot water. This shallow recess is home to 100 much-studied adult Devils Hole pupfish, or Cyprinodon diabolis . Living nowhere else on the planet, the pupfish receive protection from human harm by force of federal law and padlocked gates.