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Let’s Talk about Ebola Survivors and Sex
As more patients recover from the infection, what risk do they pose to their sexual partners?
October 31, 2014 |By Dina Fine Maron

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Credit: Flickr/Peachy92

Wear a condom: That has been the standard—and strong—advice from public health officials trying to thwart the spread of HIV or syphilis. The U.S. Centers for Disease Control and Prevention has spent decades trying to get people to put them on. But now health workers are pushing the latex prophylactic for a different reason: Ebola recovery.

People are surviving the disease. Doctors Without Borders, which oversees many Ebola clinics in west Africa, is sending home recovered Ebola patients with a stack of condoms, and health workers are urging them to only engage in protected sex for at least three months after recovery. The virus has been found in the semen and vaginal fluids of convalescents for weeks or ...

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Anarchic Autism Genetics Gain a Touch of Clarity
By Gary Stix | October 30, 2014 |

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Two new studies demonstrate the promise and pitfalls of the industrial-scale gene-processing technologies that define the meaning of the much-ballyhooed Big Data.

Bad news first. One of the two reports published in Nature provided a four-digit estimate of the number of genes involved with autism. [I’m obligated to break here to say that Scientific American is part of the Nature Publishing Group.]

My science skeptic friends would say that this is also ...

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The Philosophical Implications of the Urge to Urinate
The state of our body affects how we think the world works
November 4, 2014 |By Daniel Yudkin

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Are we truly free?
Credit: thegreekphotoholic via Thinkstock

If one thing’s for sure, it’s that I decided what breakfast cereal to eat this morning. I opened the cupboard, Iperused the options, and when I ultimately chose the Honey Bunches of Oats over the Kashi Good Friends, it came from a place of considered judgment, free from external constraints and predetermined laws.

Or did it? This question—about how much people are in charge of their own actions—is among the most central to the human condition. Do we have free will? Are we in control of our destiny? Do we choose the proverbial Honey Bunches of Oats? Or does the cereal—or some other mysterious force in the vast and unknowable universe—choose us?

The Greek playwright Sophocles ...

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How the Brain Creates a Chronology of Consciousness
Several brain structures contribute to “mind time,” organizing our experiences into chronologies of remembered events
By Antonio Damasio

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DAVID MUIR Getty Images

We wake up to time, courtesy of an alarm clock, and go through a day run by time—the meeting, the visitors, the conference call, the luncheon are all set to begin at a particular hour. We can coordinate our own activities with those of others because we all implicitly agree to follow a single system for measuring time, one based on the inexorable rise and fall of daylight. In the course of evolution ...

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New Experiment Aims to Crack Neutrino Mass Mystery
These particles should not have mass, but they do. By sending neutrinos through the ground from Illinois to Minnesota, physicists hope to learn why
November 4, 2014 |By Clara Moskowitz

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A 50-foot-square block of the NOvA far detector is pivoted at the laboratory in Ash River, Minnesota, where it will detect oscillating neutrinos.
Fermilab

Neutrinos are everywhere in the universe, but we cannot see them or feel them and can almost never stop them. They stream through our bodies by the trillions every second, flitting through the spaces between our atoms with nary a collision. These ghostly particles were created in abundance during the big bang, and stars like the sun pump out more all the time. Yet for all their plentitude, neutrinos may be the most mysterious particles in the cosmos.

For decades physicists thought neutrinos weighed nothing, and they were shocked in 1998 to discover that the particles do have very small, but nonzero, masses. Exactly how much mass they have ...

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Crash Analysis: How SpaceShipTwo’s Feathered Tails Work
By Clara Moskowitz | November 3, 2014 | Comments6

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Virgin Galactic's SpaceShipTwo in its "feathered" configuration, with tails upright. Credit: Virgin Galactic

The cause of the deadly crash of Virgin Galactic’s SpaceShipTwo on Friday remains unknown, but the commercial spaceplane’s feathered reentry system looks to have been involved. Investigators at the National Transportation Safety Board (NTSB) determined that the vehicle’s copilot moved a lever to “unlock” the feather system earlier than planned, and two seconds after the feathers deployed, the spacecraft disintegrated.

The details of how or why this happened are still unclear. The feather system is normally used after SpaceShipTwo has already climbed to the peak of its parabolic flight path and begun to descend, to help the vehicle slow down and stabilize as it flies back to Earth. In fact, the design was one of ...

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Science Research Needs an Overhaul
The current incentive structure often leads to dead-end studies—but there are ways to fix the problem
November 3, 2014 |By John P. A. Ioannidis

SA Forum is an invited essay from experts on topical issues in science and technology.

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It will take a concerted effort by scientists and other stakeholders to fix this problem.
Credit: Kseniya Ragozina via Thinkstock

Earlier this year a series of papers in The Lancet reported that 85 percent of the $265 billion spent each year on medical research is wasted. This is not because of fraud, although it is true that retractions are on the rise. Instead, it is because too often absolutely nothing happens after initial results of a study are published. No follow-up investigations ensue to replicate or expand on a discovery. No one uses the findings to build new technologies.

The problem is not just what happens after publication—scientists often have trouble choosing the right questions and properly designing studies to answer them. Too many neuroscience studies test too few subjects ...

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Fracking Threatens to Crack Politics
Divisions within Colorado highlight a long-term political issue that affects many states
November 3, 2014 |By David Biello

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Courtesy of USGS

The city of Boulder wants to block fracking in the Rocky Mountain state. The liberal enclave has banned the combination of directional drilling and cracking subterranean rock with high-pressure fluids known as fracking within its city limits. And local Democratic U.S. Rep. Jared Polis wanted to enable other communities in Colorado to follow suit. He began collecting signatures for a ballot measure that would have vested authority in municipalities to enact their own fracking regulations, no matter what the state as a whole decides, to control the controversial practice that frees more oil and gas. For good measure, the Democrat also wanted to ...

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NASA's Plan to Visit an Asteroid Faces a Rocky Start
America's keystone human spaceflight mission for the next decade may be over before it begins
November 10, 2014 |By Lee Billings

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In this artist's rendition, a spacewalking astronaut prepares to retrieve samples from a captured asteroid in high lunar orbit as part of NASA's Asteroid Redirect Mission concept.
Credit: NASA

NASA’s next vehicle designed to carry astronauts to space is set to launch early next month atop a trusty Delta 4 rocket for a crewless test flight. Current plans call for a piloted flight in the new Orion spacecraft in the mid-2020s, when the vehicle will ride atop a new NASA heavy-lift rocket to take astronauts beyond Earth orbit for the first time in a half-century. What’s far less certain in the post–space shuttle era is where they’ll go from there.

If the Obama administration and NASA have their way, the astronauts will be visiting a small asteroid that will have been nudged by a solar-powered robotic probe into a high, stable lunar orbit. During the monthlong mission the astronauts will rendezvous with the asteroid, perform spacewalks to gather samples and then return to Earth. The target asteroid has yet to be announced ...

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New Type of More Problematic Mosquito-Borne Illness Detected in Brazil
A second form of the painful chikungunya virus has appeared in Brazil—one that could more easily spread, including to the U.S.
November 4, 2014 |By Dina Fine Maron

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Aedes albopictus mosquito
Credit: Centers for Disease Control and Prevention

When a mosquito-borne disease first arrived in the Western Hemisphere last year, humans were relatively lucky. The disease, which causes crippling joint pain persisting for weeks or even months and for which there is no known therapy or vaccine, hopscotched from the Caribbean islands to eventually land in the U.S. and the rest of the Americas. But the type of chikungunya creeping across the region then was one that could only readily spread via Aedes aegypti, a mosquito that is uncommon in the U.S.

That ecological happenstance provided some modicum of protection. Chikungunya spread by bites from Aedes aegypti was first detected in Saint Martin last year and in the U.S. this summer. ...

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The Rise of All-Purpose Antidepressants
Doctors are increasingly prescribing SSRIs to treat more than just depression
Oct 16, 2014 |By Julia Calderone

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Antidepressant use among Americans is skyrocketing. Adults in the U.S. consumed four times more antidepressants in the late 2000s than they did in the early 1990s. As the third most frequently taken medication in the U.S., researchers estimate that 8 to 10 percent of the population is taking an antidepressant. But this spike does not necessarily signify a depression epidemic. Through the early 2000s pharmaceutical companies were aggressively testing selective serotonin reuptake inhibitors (SSRIs), the dominant class of depression drug, for a variety of disorders—the timeline below shows the rapid expansion of FDA-approved uses.

As the drugs' patents expired, companies stopped funding studies for official approval. Yet doctors have continued ...

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Dark Matter Black Holes Could Be Destroying Stars at the Milky Way’s Center
If dark matter comes in both matter and antimatter varieties, it might accumulate inside dense stars to create black holes
November 10, 2014 |By Clara Moskowitz

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NASA

Dark matter may have turned spinning stars into black holes near the center of our galaxy, researchers say. There, scientists expected to see plenty of the dense, rotating stars called pulsars, which are fairly common throughout the Milky Way. Despite numerous searches, however, only one has been found, giving rise to the so-called “missing pulsar problem.” A possible explanation, according to a new study, is that dark matter has built up inside these stars, causing the pulsars to collapse into black holes. (These black holes would be smaller than the supermassive black hole that is thought to lurk at the very heart of the galaxy.)

The universe appears to be teeming with invisible dark matter, which can neither be seen nor touched, but nonetheless exerts a gravitational pull on regular matter. Scientists have several ideas for what dark matter might be made of ...

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Lander Stable on Comet, for Now
The Philae lander settled atop the “head” of the rubber duck–shaped object despite trouble with systems designed to secure the probe to the comet
November 12, 2014 |By Lee Billings

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Philae's primary landing site from 30 km
Credit: ESA

After more than a decade of careful planning and hours of nail-biting tension, this morning an emissary from Earth made history’s first soft landing on a comet. The European Space Agency’s dishwasher-size Philae lander touched down on the craggy surface of Comet 67P/Churyumov–Gerasimenko shortly after 10:30 A.M. Eastern time, after being released seven hours earlier from its mother ship, the Rosetta orbiter.

“We are there. We are sitting on the surface. Philae is talking to us,” said Philae lander manager Stephan Ulamec during a live Webcast of the landing. “We are on the comet.” The lander seems to be fully operational, ready to begin its unprecedented ...

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Everything You Need to Know about the U.S.–China Climate Change Agreement
A turning point has been reached in the world's bid to curb global warming
November 12, 2014 |By David Biello

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HISTORIC AGREEMENT: President Obama's visit to Beijing has yielded a pact to cut greenhouse gas pollution from the world's two biggest emitting nations.
Official White House Photo by Chuck Kennedy

The presidents of the world's two most polluting nations agree: something should be done about climate change. And they're just the leaders to do it, per the terms of what President Barack Obama called a "historic agreement" announced November 12 between the U.S. and China. Although neither country has plans to stop burning coal or oil in the near future, both countries now have commitments to reduce the greenhouse gases that result.

"As the world's two largest economies, energy consumers and emitters of greenhouse gases, we have a special responsibility to lead the global effort against climate change," said Obama in a ...

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Ethanol Scheme to Clean Air in Billions of Kitchens Goes Up in Smoke
An effort to build a scheme involving crop rotation, ethanol and clean cookstoves in Mozambique was defeated by bad roads, old trucks, slow carbon credits, civil unrest and tradition
November 11, 2014 |By David Biello

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CLEANER COOKING: The clean cookstove pictured here burning ethanol proved popular in Mozambique, but unsustainable.
Courtesy of Novozymes

In Mozambique, as in much of the world, people cook with charcoal. The dirty fuel causes smoke and soot to billow into their homes. As a result, cardiovascular and lung diseases are rampant from breathing such smoky indoor air—a problem that kills at least two million people worldwide prematurely every year, primarily women and children. Burning charcoal to cook exacerbates pneumonia, emphysema, tuberculosis and even low intelligence, among other human health issues. To solve the problem in the capital city of Maputo, Danish enzyme-maker Novozymes and its partners, like many before them, wanted to introduce a cleaner cookstove.

The ambition did not stop there. Novozymes hoped to bring an entire bio-based economy to the southeast African nation, starting with improved crop rotations that would allow farmers to grow excess cassava. The cassava in turn would be fed to a donated ethanol-brewing facility, built in the town of Dondo. The ethanol would be the fuel in cookstoves, burning ...

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Dark Matter Black Holes Could Be Destroying Stars at the Milky Way’s Center
If dark matter comes in both matter and antimatter varieties, it might accumulate inside dense stars to create black holes
November 10, 2014 |By Clara Moskowitz

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NASA

Dark matter may have turned spinning stars into black holes near the center of our galaxy, researchers say. There, scientists expected to see plenty of the dense, rotating stars called pulsars, which are fairly common throughout the Milky Way. Despite numerous searches, however, only one has been found, giving rise to the so-called “missing pulsar problem.” A possible explanation, according to a new study, is that dark matter has built up inside these stars, causing the pulsars to collapse into black holes. (These black holes would be smaller than the supermassive black hole that is thought to lurk at the very heart of the galaxy.)

The universe appears to be teeming with invisible dark matter, which can neither be seen nor touched, but nonetheless exerts a gravitational pull on regular matter. Scientists have several ideas for what dark matter might be made of, but none have been proved. A leading option suggests ...

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A High-Flying Web May Catch the Beginning of Time
This winter an airborne experiment named Spider will probe the earliest remnants of the universe
November 12, 2014 |By Dan Falk

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SPIDER with all of its focal planes installed, in Antarctica in November.
Credit: Jon Gudmundsson

When searching for clues about the physics of the early universe, one has to aim high—and a balloon-borne telescope array known as Spider, set to soar over Antarctica this winter, may succeed where a highly publicized ground-based experiment fell short.

Physicists working on that earthbound experiment, known as BICEP2, announced several months ago that they had found evidence for primordial gravitational waves—ripples in the fabric of space itself, dating back to the universe’s earliest moments. The finding made headlines around the world. After further analysis, however, they admitted their data was inconclusive. The signal they detected could just as likely have been caused by interstellar dust as by the much-sought-after gravitational waves. Scientists working with Spider believe ...

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Mind-Blowing Fossil Preserves Tiny Horse Carrying Unborn Foal
By Kate Wong | November 11, 2014 | Comments2

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Extraordinary 48 million-year-old fossil of a Eurohippus messelensis mare and fetus from Messel, Germany. Imag

BERLIN: The former oil shale mining site of Messel, near Frankfurt, Germany, is well known for its spectacular fossils of organisms that lived between 47 million and 48 million years ago, during the Eocene epoch. But a fossil of the early horse species Eurohippus messelensis, described at this year’s Society of Vertebrate Paleontology meeting in Berlin, stands out even in that illustrious company.

The tiny specimen—full grown, Eurohippus was about the size of a modern fox terrier–preserves a mare and her unborn foal (circled in the image above) in exquisite detail, with many of the bones in anatomical position. Also visible are parts of the uterus, including the placenta and the so-called broad ligament that attaches the uterus to the mare’s lumbar vertebrae and helps support the fetus. The soft tissue is not preserved directly, but as images formed by the ...

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Next Wave of U.S. Supercomputers Could Break Up Race for Fastest
National Labs are now collaborating, not competing, to make the fastest supercomputers, which should enable new types of science to model everything from climate change to materials science to nuclear-weapons performance
November 17, 2014 |By Alexandra Witze and Nature magazine

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The Titan system at Oak Ridge National Laboratory in Tennessee will soon be surpassed as the fastest supercomputer in the United States.
Credit: OLCF

Once locked in an arms race with each other for the fastest supercomputers, US national laboratories are now banding together to buy their next-generation machines.

On November 14, the Oak Ridge National Laboratory (ORNL) in Tennessee and the Lawrence Livermore National Laboratory in California announced that they will each acquire a next-generation IBM supercomputer that will run at up to 150 petaflops. That means that the machines can perform 150 million billion floating-point operations per second, at least five times as fast as the current leading US supercomputer, the Titan system at the ORNL.

The new supercomputers, which together will cost $325 million, should ...

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