- Meet Titanoceratops, the Hornier Ancestor of Triceratops
- ‘Love Hormone’ Arouses Suspicion, Too
- Ultracold Quantum ‘Bullets’ Make Pendulums Speed Up
- Bacterial Biofilms Beat Teflon in Repelling Liquids
Posted: 31 Jan 2011 01:56 PM PST
By Olivia Solon, Wired UK
The species weighed in at around 6,800 kilograms [15,000 pounds] and an enormous 8-foot skull — rivaling Triceratops for size. It is very similar to Triceratops, but with a thinner frill, longer nose and slightly bigger horns.
Titanoceratops lived in the American Southwest during the Cretaceous period, about 74 million years ago, and is the earliest known triceratopsin. Its discovery has signalled that the group evolved its large size about 5 million years earlier than previously thought.
The discovery was made by Nicholas Longrich, a palaeontologist at Yale University and will feature in the journal Cretaceous Research.
Longrich found signs of a new triceratopsin species when he came across a description of a partial skeleton of a dinosaur unearthed in New Mexico in 1941 in scientific papers. This dinosaur was wrongly identified as Pentaceratops and reconstructed for display in the Oklahoma Museum of Natural History.
Longrich noticed that the skeleton was too different from other Pentaceratops to be the same species, because it would have belonged to a creature that could have weighed double that of an adult Pentaceratops. Instead he believes that it is a predecessor of both Triceratops and Torosaurus.
In order to confirm the discovery, Longrich is hoping that other fossil skeletons will be found with the crucial frill intact, which will help make the differences between Titanoceratops and Pentaceratops clearer.
Images: Nicholas Longrich/Yale University
Posted: 31 Jan 2011 01:20 PM PST
SAN ANTONIO — Oxytocin, a hormone with a rosy reputation for getting people to love, trust and generally make nice with one another, can get down and dirty, according to evidence presented on Jan. 28 at the annual meeting of the Society for Personality and Social Psychology.
This brain-altering substance apparently amplifies whatever social proclivities a person already possesses, whether positive or negative, says psychologist Jennifer Bartz of Mount Sinai School of Medicine in New York City.
Previous work has shown that a nasal blast of the hormone encourages a usually trusting person to become more trusting (Science News Online: May 21, 2008), but now Bartz and her colleagues find that it also makes a highly suspicious person more uncooperative and hostile than ever.
"Oxytocin does not simply make everyone feel more secure, trusting and prosocial," Bartz says.
See recent Wired Science coverage of oxytocin's complicated effects.
These new results raise concerns about plans by some researchers to administer oxytocin to people with autism and other psychiatric conditions that include social difficulties, she adds.
Her team studied 14 people diagnosed with borderline personality disorder and 13 volunteers with no psychiatric conditions. Symptoms of borderline personality disorder include severe insecurity about relationships, fears of abandonment and constant, needy reassurance-seeking from partners.
Borderline personality disorder usually occurs in women, but Bartz's sample included four men. Her group of healthy participants included seven men.
Members of each group played a computer game with an experimenter posing as a research volunteer. In each of three rounds, volunteers had to predict whether their partner would cooperate with them, so that each player could make $6, or if the partner would leave the game in order to claim $4 alone.
Volunteers who suspected the partner of bad intent could leave the game early and claim $4 for themselves.
Borderline personality players of both sexes left the game early far more often after receiving an oxytocin nasal spray than after whiffing a placebo spray. Inhaling the hormone prodded their already high levels of hostile suspicion and depleted minimal reserves of trust, Bartz suggests.
Psychiatrically healthy players became more cooperative in the money game after getting oxytocin, relative to their placebo responses.
Nasally inhaling oxytocin also magnifies men's memories of their mothers as being either supportive or not, Bartz says. Her team had 31 men fill out surveys on the quality of their relationships with their mothers up to age 16.
Those who described good maternal relationships remembered mom as substantially more caring and supportive after receiving oxytocin, compared with after inhaling a placebo spray. Those whose early home life had been troubled remembered mom as much less caring and supportive after oxytocin, versus placebo.
Bartz's team initially described oxytocin's two-sided influence on men's maternal memories in the Dec. 14 Proceedings of the National Academy of Sciences.
These findings underscore that "oxytocin is not a love hormone; its effects vary in different people," remarks psychologist Greg Norman of Ohio State University in Columbus.
Norman and his colleagues have found that oxytocin stimulates the heart to beat more in sync with the breathing cycle in people with healthy social lives, but not in people who report constant loneliness.
Other researchers have recently reported that oxytocin stimulates greater trust of members of one's own ethnic group and greater suspicion of other ethnicities.
Posted: 31 Jan 2011 07:30 AM PST
Physicists have explained yet another quirk of the quantum world: why, if you swing a pendulum through a quantum fluid, it speeds up rather than slowing down. Tiny "quasiparticles" ricocheting around in the fluid are to blame, Finnish researchers report in an upcoming issue of Physical Review Letters.
It takes a special kind of fluid to pull off this quantum trick. Physicists Timo Virtanen and Erkki Thuneberg of the University of Oulu have been studying helium-3 atoms, which at very low temperatures form a substance known as a Fermi liquid. In such a liquid, the atoms stop interacting with each other as they ordinarily do and instead start behaving in strange quantum ways.
Researchers have studied Fermi liquids for decades to better understand phenomena that kick in at cold temperatures, such as superconductivity. "It's a very profound theory — one of the most basic things to understand," says Thuneberg.
So he was intrigued when, in the early 2000s, researchers in Helsinki reported experiments in which a pendulum sped up when dunked in a Fermi liquid mixture. He decided to see if he could figure out why. In a series of calculations, Thuneberg and his student Virtanen worked out the mathematics of how the pendulum interacts with the fluid.
When chilled down into a Fermi liquid, particles no longer interact strongly with one another as they do at higher temperatures. Instead there appear quasiparticles, which are the combination of a particle itself along with how it affects the environment around it. Like the original particle, each quasiparticle carries spin, charge and momentum.
The researchers calculated that the quasiparticles ricochet around in the liquid like bullets, increasing the force on the pendulum. They do not, as ordinary particles would, interact with each other strongly enough to create resistance to the pendulum moving through them. "That's why the behavior is different," says Thuneberg.
The scientists dub the newfound effect the "Landau force" and plan to calculate how it might work in other systems, such as oscillating walls.
George Pickett, a physicist at Lancaster University in England and a member of the team originally reporting the effect, says the new study is an interesting and direct demonstration of the importance of Fermi liquids.
Posted: 31 Jan 2011 06:37 AM PST
Slimy mats of bacteria called biofilms may be the most liquid-repellent materials in nature, researchers have discovered.
"There are a few man-made materials that can perform better, and they have to be made in clean rooms. They're incredibly expensive and brittle," said materials scientist Alexander Epstein of Harvard University, co-author of the new study. "Making biofilm is as easy as growing bacteria."
The goo secreted by Bacillus subtilis bacteria not only deflects water like a lotus leaf, but also repels concentrated alcohol, acetone and even vaporized liquid, according to a study published Jan. 18 in Proceedings of the National Academy of Sciences.
Biofilms are communities of bacteria that stick together using a mixture of sugars and proteins called the extracellular matrix, which takes on a wrinkled form under powerful microscopes (see image below). Since the discovery of bacteria in the late 1600s, most research has covered individual cells. It's only since the 1990s that scientists have begun to understand the pervasiveness and importance of biofilms.
"We're realizing more and more that almost all bacteria in nature are found as biofilms," Epstein said. "It offers a lot of advantages for them, including better protection and increased chances they'll stick to sources of food. It's crazy stuff."
While trying to map the internal structure of B. subtilis biofilm using a vaporized radioactive tracer that would show up in x-ray photos, the researchers found it couldn't get inside. They were frustrated at first, but Epstein said his team soon realized the significance of the stubborn biofilm.
"We started to put different liquids on it. Concentrated alcohols just [beaded up]," Epstein said. For comparison, the researchers also tried a non-stick Teflon surface. "We found the biofilms substantially superior to Teflon," he said.
To analyze resistance to wetting, Epstein and his team measured the angle between droplets of liquid and the materials' surfaces (right). At 10 percent alcohol, similar to wine's concentration, Teflon started getting wet. Biofilms, however, balled up all concentrations of alcohol up to 80 percent (similar to Everclear). Liquids wetted biofilms only after sitting on them for minutes or hours.
Epstein isn't suggesting we grow biofilms for frying pans or rain jackets, but thinks the research will inspire practical new applications. His team ultimately hopes to resolve biofilm's molecular structure to develop new materials.
"We don't fully understand it, but it's broadly true that you need both protein and sugars for this repelling property," Epstein wrote in an e-mail to Wired.com. "Sugars absolutely have to be there, but we don't know why. We're doing some followup research on that now," he said.
Images: Courtesy of PNAS/Alexander Epstein et al. 1) A bead of 50 percent ethanol rests on a biolfilm of B. subtilis bacteria sliced from a Petri dish. 2) Wetness of a surface is determined by the contact angle of liquid droplets, and increases sharply when a droplet's inner contact angle is less than 90 degrees. 3) A scanning electron micrograph of a mutant B. subtilis strain's extracellular matrix, or ECM.
Via: It Takes 30
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