SciByte

One explanation may be that as a group, teenagers react more impulsively to threatening situations than do children or adults

likely because their brains have to work harder to rein in their behavior

teenagers have a reputation for courting danger that is often attributed to immaturity or poor decision-making

If immaturity or lack of judgment were the only problem, however, one would expect that children, whose brains are at an even earlier stage of development

younger children tend to be more cautious than teenagers, suggesting that there is something unique about adolescent brain development that lures them to danger

It's hard to generalize about teenage impulsivity

some adolescents clearly have more self-control than many adults

a growing body of evidence suggests that, in general, teens specifically struggle to keep their cool in social situations

many crimes committed during adolescence involve emotionally fraught social situations

to test whether teens perform badly on a common impulsivity task when faced with social cues of threat

recruited 83 people, ranging in age from 6 to 29, to perform a simple "Go/No-Go" task

they watched a series of faces making neutral or threatening facial expressions flicker past on a computer screen

Each time the participants saw a neutral face, they were instructed to hit a button

They were also told to hold back from pressing the button when they saw a threatening face

As the participants performed the task, the researchers monitored their brain activity with functional magnetic resonance imaging.

teenagers made about 15% more errors than adults and children when attempting to stop themselves from pressing the button when they saw the threatening facial expression

Males performed worse than females, suggesting a sex difference that fits with the disproportionate number of crimes that male teens commit,

adolescents who did manage to restrain themselves showed significantly higher activity in a brain region called the ventromedial prefrontal cortex (vmPFC), which is involved in top-down control of behavior

think of it as the break

the teenage brain might need to work a little harder to hold that response back

Flemish researchers has finally uncovered the problem: a previously unknown ligament in the knee

scientists were prompted to find the ligament after reading an article published in 1879

The French surgeon described a “pearly, fibrous band” and hypothesized it was an additional ligament located on the anterior part of the human knee

Over a century later knee surgeons and an anatomist

set out to determine whether the flexible connective tissue

exists

After investigating 41 unpaired knees from human cadavers the doctors found that all but one knee displayed the described ligament, now named the anterolateral ligament (ALL).

The discovery

has given basic anatomy a fresh jolt

hopes the study will encourage students to look to anatomy as an exciting science, where new features of the human body may be discovered

Other researchers, such as orthopedic surgeon

are currently trying to find a technique to repair that ligament

In the meantime they hope clinicians will take the ALL into consideration when making a diagnosis or planning reconstructive surgery.

evidence that passersby were chipping away at the exposed dinosaur bones in the rock, taking souvenirs.

Morrison sandstone surrounding the fragile fossils was so hard that Mossbrucker and his colleagues were afraid that trying to remove the rock would irreparably damage the bone.

in 2011, the museum acquired some state-of-the-art pneumatic tools that can remove hard rock without transmitting damaging vibrations to fossils embedded insid

cheeckbone nestles against the Apatosaurus maxilla and premaxillae, the bones of the snout, and tiny specks of fish bone surround the larger assemblage

snout is highlighting unknown anatomical features

including a large

hollow space in the skull, which would have influenced the tone of the Apatosaur's calls

Other long-necks had this space

but A. ajax's was particularly large

The discovery also reveals that Lakes' long-ago excavations were close to discovering yet another Apatosaur

Teeth found

were declared by Marsh in 1884 to belong to Diplodocus lacustris, another long-neck species

But those teeth, now held in Yale's collections, look just like Kevin's

, Diplodocus lacustris didn't exist — instead, Lakes found part of Kevin and missed the rest.

a slew of museum volunteers are still working to coax more of Kevin from its boulder

The specimen got its name simply because museum staff and guests found it amusing

The current plan is to cleave the block in half so that the pieces can be scanned with micro-CT (computed tomography

s technology would allow paleontologists to see inside the block and even to 3D-print a perfect copy of the bones inside without having to remove them physically

don't have to put the specimen at any more risk

and we still get the data we need

The process is slow going, however, in part because the team keeps finding bones in what they expected to be just rock

expects to publish his findings in about a year

the discovery is likely to help paleontologists understand how A. ajax is related to other Apatosaurus

volunteers have been painstakingly carving Kevin's bones out of sandstone for two years

Apatosaurus is perhaps most notorious for its complicated naming history

Another paleontologist, Elmer Riggs, killed the Brontosaurus genus in 1903 after noting that the skeletons didn't vary enough to justify two genuses

A. ajax was as long as three school busses and weighed as much as eight Asian elephants

Apatosaurus had lightweight vertebrae that would have allowed it to move its head rapidly: Imagine a neck the length of a school bus, flitting up and down and side to side like an ostrich neck

recent studies of musicians suggest lifelong musical training may offset these and other cognitive declines

previous studies show such age-related declines are not inevitable

the current study,

explored whether limited musical training early in life is associated with changes in the way the brain responds to sound decades later

t the more years study participants spent playing instruments as youth, the faster their brains responded to a speech sound.

For the study, 44 healthy adults, ages 55-76, listened to a synthesized speech syllable ("da") while researchers measured electrical activity in the auditory brainstem

This region of the brain processes sound and is a hub for cognitive, sensory, and reward information

researchers discovered that, despite none of the study participants having played an instrument in nearly 40 years

participants who completed 4-14 years of music training early in life had the fastest response to the speech sound (on the order of a millisecond faster than those without music training).

a millisecond faster may not seem like much, but the brain is very sensitive to timing and a millisecond compounded over millions of neurons can make a real difference

occurred about four-and-half hours after new flight software had been temporarily loaded into the rover's memory

At the time the event occurred, Curiosity was in the middle of a scheduled, week-long flight software update and checkout activity

A warm reset is executed by flight software when it identifies a problem with one of its operations

The reset restarts the flight software into its initial state. Since the reset, the rover has been performing operations and communications as expected

This is the first time that Curiosity has executed a fault-related warm reset during its 16-plus months of Mars surface operations.

provided enough data to complete its mission objective: to determine how many of the 100 billion stars in our galaxy have potentially habitable planets

Based on a statistical analysis

astronomers now estimate that one in five stars like the sun have planets about the size of Earth and a surface temperature conducive to life.

nearly 20 years since the discovery of the first extrasolar planet around a normal star

Since then we have learned that most stars have planets of some size and that Earth-size planets are relatively common in close-in orbits that are too hot for life

Earth-size planets in Earth-size orbits are not necessarily hospitable to life, even if they orbit in the habitable zone of a star where the temperature is not too hot and not too cold

thick atmospheres, making it so hot at the surface that DNA-like molecules would not survive

rocky surfaces that could harbor liquid water suitable for living organisms

Last week,

provided hope that many such planets actually are rocky

NASA launched the Kepler space telescope in 2009 to look for planets that cross in front of, or transit, their stars, which causes a slight diminution – about one hundredth of one percent – in the star's brightness

150,000 stars photographed every 30 minutes for four years

reported more than 3,000 planet candidates

the Keck Telescopes in Hawaii

help them determine each star's true brightness and calculate the diameter of each transiting planet, with an emphasis on Earth-diameter planets.

The team's definition of habitable is that a planet receives between four times and one-quarter the amount of light that Earth receives from the sun

Independently

focused on the 42,000 stars that are like the sun or slightly cooler and smaller, and found 603 candidate planets orbiting them

Only 10 of these were Earth-size, that is, one to two times the diameter of Earth and orbiting their star at a distance where they are heated to lukewarm temperatures suitable for life

Accounting for missed planets, as well as the fact that only a small fraction of planets are oriented so that they cross in front of their host star as seen from Earth, allowed them to estimate that 22 percent of all sun-like stars in the galaxy have Earth-size planets in their habitable zones.

All of the potentially habitable planets found in their survey are around K stars, which are cooler and slightly smaller than the sun

analysis shows that the result for K stars can be extrapolated to G stars like the sun

the team has been testing their blood substitute in both mice and in cultured cells

initial results suggest that many of the adverse effects normally associated with either perfluorocarbon (PFC) or hemoglobin-based oxygen carrier (HBOC) substitutes can be eliminated, or at least minimized

Human blood only has a shelf life of a few weeks

It also needs to be matched to the recipient's blood type,

the risks of disease transmission can be minimized by testing, dangers still present if the donor has been recently infected

What makes hemoglobin such a success, is a phenomenon known as cooperative binding

as more oxygen binds to hemoglobin in the lungs, it becomes even easier for additional oxygen to bind

The problem

is that one way or another, the hemoglobin they contain ends up escaping and causing serious damage to organs like the kidneys

While their small size allows them to penetrate and oxygenate the nooks and crannies of the body much better than RBCs, that same feature also leads to undesireable extravasation into tissue

The goal is not to develop a permanent replacement solution, but rather something that could be used to bridge a critical situation for the few hours or days

Researchers have found when these modified hemoglobins do get into tissues, they bind nitric oxide, which appears to have the result that the patient's blood pressure rises precipitously

South Carolina is a well-known pupping ground for several species of sharks, which means that researchers were collecting samples there for study

The scalloped hammerheads that they were collecting had two different genetic signatures in both the mitochondrial and nuclear genomes

the scientists found that the anomalous scalloped hammerhead had been described in 1967 and had 10 fewer vertebrae than the normal scalloped hammerhead. Intrigued

In the end, the scientists found that there was genetic evidence to show that this hammerhead was, in fact, a new species.

scientists aren't sure exactly how many individuals still exist in the wild

Hemiscyllium halmahera, named after the eastern Indonesian island of Halmahera where it was found

Of all known

walking sharks, six of nine species hail from Indonesia

The animals lay eggs under coral ledges, after which the young sharks lead relatively sedentary lives until adulthood

These sharks do not cross areas of deep water and are found in isolated reefs

The real reason for the spacewalk is to do some routine Russian maintenance outside the station

Then,

three crew members will return

and they will bring the torch back home

The torch then will be given back to Olympic officials and it will be used in the opening ceremonies of the February games

There have not been nine crew members on the ISS since 2009.