Almost nine hundred years ago, in the mid-12th century, the southwestern U.S. was in the middle of a multi-decade megadrought. It was the most recent extended period of severe drought known for this region. But it was not the first.
The second century A.D. saw an extended dry period of more than 100 years characterized by a multi-decade drought lasting nearly 50 years, says a new study from scientists at the University of Arizona.
Is the Fine Structure Constant truly constant?
J. K. Webb, J. A. King, M. T. Murphy, V. V. Flambaum, R. F. Carswell, and M. B. Bainbridge
Phys. Rev. Lett. 107, 191101 (2011)
Whether a species can evolve to survive climate change may depend on the biodiversity of its ecological community, according to a new mathematical model that simulates the effect of climate change on plants and pollinators.
The findings, published in the early online edition of Evolutionary Applications, are important because some species that have survived large climatic change in the past might not be able to survive current and ongoing climate change.
Over the past 50 years, 60 percent of all ecosystem services have declined as a direct result of the conversion of land to the production of foods, fuels and fibers.
This should come as no surprise, say seven of the world's leading environmental scientists, who met to collectively study the pitfalls of utilizing markets to induce people to take account of the environmental costs of their behavior and solutions. We are getting what we pay for.
Xi-Jun Ren and Yang Xiang from Henan Universities in China, in collaboration with Heng Fan at the Institute of Physics of the Chinese Academy of Sciences, have produced a theory for a quantum cloning machine able to produce several copies of the state of a particle at atomic or sub-atomic scale, or quantum state, in an article about to be published in EPJ D. This could have implications for quantum information processing methods used, for example, in message encryption systems.
Insects can run up walls, hang from ceilings, and perform other amazing feats that have for centuries fascinated human observers. Now scientists from the Zoological Institute at the University of Kiel, in Germany, who have been studying these able acrobats, have borrowed some of the insects' tricks to make a dry tape that can be repeatedly peeled off without losing its adhesive properties. The researchers presented their work at the AVS Symposium, held Oct. 30 – Nov. 4, in Nashville, Tenn.
Physicists from the Georgia Institute of Technology have developed a theory that describes, in a unified manner, the coexistence of liquid and pinned solid phases of electrons in two dimensions under the influence of a magnetic field. The theory also describes the transition between these phases as the field is varied.
Scientists braved ticks and a tiger - what people in Panama call 'home' - to discover how human activities have perturbed the nitrogen cycle in tropical forests. By perturbed, pollution has helped, according to studies at two remote Smithsonian Institution Global Earth Observatory sites in Panama and Thailand.
A new study published in European Obstetrics & Gynaecology (European Obstetrics & Gynaecology, 2011;6(2):92-4) shows that the DuoFertility monitor and service used for six months gives the same chance of pregnancy as a cycle of in-vitro fertilisation (IVF) for many infertile couples. This study demonstrates that there is a viable non-invasive, drug-free alternative to IVF for thousands of couples, with the potential to save them (and the NHS) millions of pounds each year.
Alexandria, VA – Haboobs, giant dust storms, walloped Arizona last summer — some close to 2 kilometers high and 160 kilometers wide — knocking out electricity, creating traffic jams and grounding airplanes. Even old-timers say they can't remember anything quite like this year's aerial assaults. Meanwhile Texas is experiencing one of the most extreme droughts in recent history, with almost 90 percent of the state in the most extreme level of drought. Arizona, California, Colorado, New Mexico, Oklahoma, Utah and other states are also experiencing drought conditions.
The debate may largely be drawn along political lines, but the human role in climate change remains one of the most controversial questions in 21st century science. Writing in WIREs Climate Change Dr Kevin Trenberth, from the National Center for Atmospheric Research, argues that the evidence for anthropogenic climate change is now so clear that the burden of proof should lie with research which seeks to disprove the human role.
PUNTA ARENAS, CHILE – After discovering an emerging crack that cuts across the floating ice shelf of Pine Island Glacier in Antarctica, NASA's Operation IceBridge has flown a follow-up mission and made the first-ever detailed airborne measurements of a major iceberg calving in progress.
NASA's Operation Ice Bridge, the largest airborne survey of Earth's polar ice ever flown, is in the midst of its third field campaign from Punta Arenas, Chile. The six-year mission will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice.
LOUISVILLE, Ky. – Paleontologist Guillermo Rougier, Ph.D., professor of anatomical sciences and neurobiology at the University of Louisville, and his team have reported their discovery of two skulls from the first known mammal of the early Late Cretaceous period of South America. The fossils break a roughly 60 million-year gap in the currently known mammalian record of the continent and provide new clues on the early evolution of mammals.
CHESTNUT HILL, MA (11/2/11) – Research carried out at Boston College, in collaboration with scientists at MIT and the University of Oxford, has led to the development of an efficient and highly selective catalyst for ring-closing olefin metathesis, one of the most widely used reactions in chemical synthesis, the team reports in this week's issue of the journal Nature.
A recent increase in the intensity of tropical cyclones in the Arabian Sea may be a side effect of increasing air pollution over the Indian sub-continent, a new multi-institutional study has found.