Science news digest – 13th November 2013
In the science news this week, a new ligament is discovered in the knee, fossil discovery suggests an Asian origin for big cats, and finally… the GOCE satellite burns up in the Earth’s atmosphere.
Belgian surgeons discover new ligament in the knee
It seems unlikely, but two surgeons in Belgium claim they have identified a new ligament in the human knee, which could play a part in one of the most common sports injuries, reported the BBC.
Although the fibrous band has been previously glimpsed, the anatomy of the knee is fairly complex, and this is the first time the structure and purpose of this particular ligament have been so clearly established.
However, some experts believe that more research needs to be done to prove its relevance to knee surgery.
There are four main ligaments that surround the knee joint, connecting the upper and lower leg bones and provide stability in the joint.
However, Dr Claes and Professor Johan Bellemans of the University Hospitals of Leuven, Belgium now claim to have mapped a ligament band that runs from the outer side of the thigh bone to the shin bone.
The pair used macroscopic dissection techniques to examine 41 donated knee joints, and they found their proposed anterolateral ligament (ALL) in all but one of the joints.
Mr Joel Melton, a consultant knee surgeon at Addenbrooke’s Hospital in Cambridge, UK, who was not involved in the research, told the BBC: "If you look back through history there has been a veiled understanding that something is going on on that side of the knee but this work finally gives us a better understanding.
"I think this is very exciting - there is no doubt they have hit upon a very important anatomical structure."
The Belgian surgeons believe this discovery could explain why some people who suffer injuries to the anterior cruciate ligament (ACL) don’t fully recover – because they have also damaged the ALL at the same time.
However, Gordon Bannister, professor of orthopaedics at Bristol University, has some reservations about the research: "There is no doubt this is a very interesting paper from the anatomical point of view but at the moment this is not a major clinical breakthrough.
"Its role in knee injuries is a perfectly reasonable hypothesis to test but the most important step is to see whether any intervention to the ligament actually makes a significant difference to patients."
Fossils point to Asian origin for big cats
The origin of big cats has until now been a bit of a mystery, but recent findings suggest that the answer may be found in the Himalayas, reported New Scientist.
A partial skull, jawbone and a few teeth have been discovered in the Zanda basin in the south-west Tibetan plateau by the palaeontologist Zhijie Jack Tseng at the American Museum of Natural History in New York and his colleagues. The fossils date back to 5.95 to 4.10 million years ago.
Prior to this discovery, the oldest fossils dated back to 3.8 million years ago and came from Africa, but molecular analysis of living species suggested that big cats originated in Asia about 10.8 million years ago.
This latest find could be the missing evidence needed to prove the Asian origin for big cats. The species has been named Panthera blytheae and is a close relative of the snow leopard.
"The study is very important because fossils of big cats are extremely rare," says Lars Werdelin at the Swedish Museum of Natural History in Stockholm. "The new findings lend strong support for the Asian origin of big cats."
Tseng says that this fossil also changes the family tree of big cats as it puts the origin of the Panthera genus, which includes lions and tigers, at 16.4 million years ago, rather than at 6.4 million years ago, which was the previous estimate.
However, Tseng believes that although this latest find is the oldest big cat fossil, it is not the most primitive. The researchers suspect the first species evolved in forested regions in Asia.
GOCE satellite burns up as it re-enters Earth’s atmosphere
A large satellite has burnt up in the Earth’s atmosphere over the weekend roughly three weeks after the spacecraft ran out of fuel and began to lose altitude, reported the Guardian.
The last contact with the European Space Agency’s (ESA) Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite, was at 10.42pm GMT as it flew over Antarctica.
About 25% of the car-sized satellite was expected to survive re-entry into the atmosphere, but most of the debris was expected to fall into the ocean rather than on land.
"By the time you read this, the spacecraft's amazing flight will, most likely, have come to an end," space agency spokesman Daniel Scuka wrote in an update posted at about 11.45pm on the ESA website.