A physician at Columbia University Medical Center who recently travelled to Guinea to work with Doctors Without Borders has become the first case of Ebola in New York City. The New York Times says that there have been positive results in preliminary tests performed by city health authorities, although these await confirmation by the CDC. This would be the first US case outside of an initial cluster in Dallas, Texas.
The physician, who has been identified as Craig Spencer, posted photos of himself in full protective garb on Facebook in September. He returned from West Africa less than two weeks ago, and had been self-monitoring since. He apparently began feeling unwell several days ago, and developed a high fever on Thursday. As soon as health authorities were alerted, they brought him to Bellevue Hospital, which as been prepared for the isolation of Ebola patients and has trained staff for this contingency.
Unfortunately, the night prior to reporting his fever, Dr. Spencer took public transportation and a cab in order to go bowling in Brooklyn, according to the Times report. Authorities are now trying to identify people who might have had extensive contact with the patient, and have sealed off his home and quarantined his girlfriend, according to CNN.
Sex exists because it's evolutionarily useful—it makes it easier for a population to share genetic novelties and dilute out harmful mutations. But it's also subject to all sorts of additional evolutionary constraints, from the amount of resources devoted to offspring to the challenge of ensuring that a population ends up with a useful ratio of male and female individuals.
A paper in today's issue of Science suggests that some species of fern have evolved a rather novel solution to creating a good balance between the sexes: they discuss it as a community, with the discussion taking place via chemical signals. A team of Japanese researchers show that the earliest maturing sex organs in a group of ferns will invariably develop as females. Once they do, they start producing and exporting a chemical signal.
That signal is a chemically inactivated hormone. When it's received by an immature sex organ, it gets converted to the mature form, which then influences the development of the tissue, causing it to mature as a male. The trick to all this working is that an enzyme that's essential for activating the hormone is present in immature tissue, but the gene that encodes it gets shut down as the tissue matures.
Surfers love Hawaii’s waves, and many dream of catching “the big one.” For most people living in coastal areas vulnerable to tsunamis, though, “the big one” is a bad dream. We’ve seen many devastating events over the years, but our memory is not so long that Mother Nature can’t surprise us. The 2011 tsunami in Japan testified to that.
In 2001, sediment from a past tsunami was found in a sinkhole on the southeast side of the Hawaiian island of Kaua’i. The mouth of that sinkhole is about a hundred meters from the shoreline—and over seven meters above sea level. The largest tsunami measured in the area had been three meters, courtesy of Chile’s monstrous magnitude 9.55 earthquake in 1960. Could it be that an event was big enough to send tsunami waves over seven meters high to Hawaii in the past?
Researchers Rhett Butler, David Burney, and David Walsh simulated a variety of earthquakes around the Pacific to find out. They used a model that simulates the spread of tsunami waves, creating some virtual magnitude 9.0 to 9.6 earthquakes from Alaska to Kamchatka.
it seems like everywhere scientists look, they're finding dinosaurs. A new species is emerging at the astounding pace of one per week. And this trend continues with the announcement of perhaps the strangest dinosaur find over the past few years: the toothless, hump-backed, super-clawed omnivore Deinocheirus mirificus, which lived about 70 million years ago in what is now Mongolia.
Deinocheirus may even become a household name, thanks to spectacular new fossils from the Gobi Desert reported by South Korean paleontologist Young-Nam Lee and colleagues, who published their results in Nature. It is a one-of-a kind dinosaur—a creature so astoundingly weird that the world probably won't be able to avoid taking notice.Half a century of wild speculation
It has been a banner year for dinosaur discoveries. First it was the “chicken from hell” and a dwarf tyrannosaur announced in the spring, then the long-snouted carnivore “Pinocchio rex” and the feathery glider Changyuraptor came in the summer. Over the past couple of months, we have been awed by the 65-ton, long-necked behemoth Dreadnoughtus and wowed by remarkable new fossils of the sail-backed, shark-eating Spinosaurus from Africa.
Svante Pääbo's lab at the Max Planck Institute for Evolutionary Anthropology in Germany has mastered the process of obtaining DNA from ancient bones. With the techniques in hand, the research group has set about obtaining samples from just about any bones they can find that come from the ancestors and relatives of modern humans. In their latest feat, they've obtained a genome from a human femur found in Siberia that dates from roughly the time of our species' earliest arrival there. The genome indicates that the individual it came from lived at a time where our interbreeding with Neanderthals was relatively recent, and Europeans and Asians hadn't yet split into distinct populations.
The femur comes from near the town of Ust’-Ishim in western Siberia. It eroded out of a riverbank that contains a mixture of bones, some from the time where the sediments were deposited (roughly 30 to 50,000 years ago), and some likely older that had been washed into the sediments from other sites. The femur shows features that are a mixture of those of paleolithic and modern humans and lacks features that are typical of Neanderthal skeletons.
Two separate samples gave identical carbon radioisotope dates; after calibration to the 14C record, this places the bone at 45,000 years old, give or take a thousand years. That's roughly when modern humans first arrived in the region. That also turned out to be consistent with dates estimated by looking at the DNA sequence, which placed it at 49,000 years old (the 95 percent confidence interval was 30 to 65,000 years).
A new observation of the M82 galaxy has turned up a surprise—a previously discovered, incredibly bright object. was pulsing The object, called M82 X-2, is bright enough to be classified as an ultra-luminous X-ray source, or ULX. It sits close to its previously discovered sibling, M82 X-1, near the core of M82. The discovery, which was made by NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) and the Chandra X-ray Observatory, has provided new clues about the nature of that mysterious class of objects.
X-2 turns out to be the brightest pulsar ever discovered—so bright that it challenges current models of how pulsars work.
NuSTAR had initially been pointed toward M82 in the hope of observing a new supernova, and the team of researchers had no idea that they would happen upon this strange behavior in an ULX. To clarify which source was producing the pulsations, the Chandra X-ray Observatory observed the region, successfully separating X-2 from the noise.