Analysis of DNA from the remains of ancient humans provides valuable insights into such important questions as the origin of genetic diseases, migration patterns of our forefathers and tribal and family patterns.

Unfortunately, severe problems connected with the retrieval and analysis of DNA from ancient organisms (like the scarcity of intact molecules) are further aggravated in the case of ancient humans. This is because of the great risk of contamination with abundant DNA from modern humans. Humans, then, are involved at all steps, from excavation to laboratory analyses. This means that many previous results have subsequently been disputed as attributed to the presence of contaminant DNA, and some researchers even claim that it is impossible to obtain reliable results with ancient human DNA.

Using freshly sampled material from ten Viking skeletons from around AD 1,000, from a non-Christian burial site on the Danish island of Funen, Dissing and colleagues showed that it is indeed possible to retrieve authentic DNA from ancient humans.

New research into gigantic flying reptiles has found that they weren’t all gull-like predators grabbing fish from the water but that some were strongly adapted for life on the ground.

Pterosaurs lived during the age of dinosaurs 230 to 65 million years ago. A new study by researchers at the University of Portsmouth on one particular type of pterosaur, the azhdarchids, claims they were more likely to stalk animals on foot than to fly.

Until now virtually all pterosaurs have been imagined by palaeontologists to have lived like modern seabirds: as gull- or pelican-like predators that flew over lakes and oceans, grabbing fish from the water. But a study of azhdarchid anatomy, footprints and the distribution of their fossils by Mark Witton and Dr Darren Naish shows that this stereotype does not apply to all flying reptiles and some were strongly adapted for terrestrial life.

As fossil fuel emissions continue to climb, reducing the amount of sunlight hitting the Earth would definitely have a cooling effect on surface temperatures.

The reduction in sunlight can be accomplished by geoengineering schemes. There are two classes: the so-called “sunshade” geoengineering scheme, which would mitigate climate change by intentionally manipulating the solar radiation on the earth's surface; the other category removes atmospheric CO2 and sequesters it into the terrestrial vegetation, oceans or deep geologic formations.

However, a new study from Lawrence Livermore National Laboratory, led by atmospheric scientist Govindasamy Bala, shows that this intentional manipulation of solar radiation also could lead to a less intense global water cycle. Decreasing surface temperatures through “geoengineering” also could mean less rainfall.

Eta Carinae has the shape of a 'little man' and surrounds a star doomed to explode within the next 100 000 years.

Being brighter than one million Suns, Eta Carinae is the most luminous star known in the Galaxy. It is the closest example of a luminous blue variable, the last phase in the life of a very massive star before it explodes in a fiery supernova.

Eta Carinae is surrounded by an expanding bipolar cloud of dust and gas known as the Homunculus ('little man' in Latin), which astronomers believe was expelled from the star during a great outburst seen in 1843 [1].

While estrogen is typically thought of as a "female" hormone, men produce it as well. Researchers say they have pinpointed estrogen as a key player in about half of all prostate cancers.

The findings are published in the May 27 online edition of the Journal of the National Cancer Institute. Dr. Mark A. Rubin, professor of pathology and laboratory medicine, and vice chair for experimental pathology at Weill Cornell Medical College, conducted the study while at the Brigham and Women's Hospital and in collaboration with Dr. Todd Golub and other members of the Broad Institute of MIT and Harvard, in Cambridge, Mass.

first discovered and described the common fusions between the TMPRSS2 and ETS family member genes subset of prostate cancer in the journal Science in 2005. "The discovery showed that these malignancies occur after an androgen (male hormone)-dependent gene fuses with an oncogene -- a type of gene that causes cancer," he explains.

Humor-

Comics are supposed to be fun, light reading. Something I read on MSNBC’s Comics & Games website has been on my mind for a few months. The column titled "News of the Weird" by Chuck Shepherd (March 30, 2008) had one paragraph that caught my attention.

"A team of researchers from the University of Calgary and the Tokyo Institute of Technology proudly announced in February that they had successfully stored "nothing" inside a puff of gas and then had managed to retrieve that same "nothing." That "nothing," is called a "squeezed vacuum," and the physicists tell us that a light wave can be manipulated so that its phases are of uncertain amplitude, then the light itself removed so that only the "uncertainty" property of the wave remains. ScienceNOW Daily News, 2-29-08"

Planting biofuel crops on converted forestlands or other ecologically valuable lands has already become a hotly debated practice. Now, a new report co-authored by Nature Conservancy scientists says that biofuel crops could also become invasive species -- and that the risk needs to be evaluated before these crops are planted. The Global Invasive Species Programme (GISP) and Conservancy scientists have identified all the crops currently being used or considered for biofuel production and ranked them according to the risk they pose of becoming invasive species.

The best places to get accurate data about the world's ice shelves are not exactly the safest. Using satellites is not an accurate solution.

Researchers at the Georgia Institute of Technology and Pennsylvania State University have created specially designed robots called SnoMotes to traverse these potentially dangerous ice environments. The SnoMotes work as a team, autonomously collaborating among themselves to cover all the necessary ground to gather assigned scientific measurements. Data gathered by the Snomotes could give scientists a better understanding of the important dynamics that influence the stability of ice sheets.

More than 34 percent of American adults — about 72 million people — are obese or overweight, according to the Centers for Disease Control and Prevention. Scientists once hoped leptin, a hormone that sends the body chemical signals to stop eating and use stored energy, would be a weight-loss weapon.

Studies in thin animals looked promising but overweight animals and people didn’t respond the same way, likely because their bodies already overproduce leptin, causing them to develop resistance to the hormone.

But now University of Florida researchers say pairing leptin with just a minor amount of exercise seems to revive the hormone’s ability to fight fat again.

Clouds have typically posed a problem to scientists using satellites to observe the lowest part of the atmosphere because they block the satellite's ability to capture a clear, unobstructed view of Earth's surface.

But these "obstructions" are worth a closer look, as clouds and their characteristics actually serve a valuable role in Earth's climate. That closer look is now available by satellites comprising the Afternoon Constellation, or A-Train.

The five satellites – NASA's Aqua, Aura, CloudSat and CALIPSO and the French Space Agency's PARASOL – of the A-Train orbit only eight minutes apart and can be thought of as an extended satellite observatory, providing unprecedented information about clouds, aerosols and atmospheric composition.