WASHINGTON, Feb. 2—Sliced light is how we communicate now. Millions of phone calls and cable television shows per second are dispatched through fibers in the form of digital zeros and ones formed by chopping laser pulses into bits. This slicing and dicing is generally done with an electro-optic modulator, a device for allowing an electric signal to switch a laser beam on and off at high speeds (the equivalent of putting your hand in front of a flashlight). Reading that fast data stream with a compact and reliable receiver is another matter.
As the on-board GPS has become one of the key POD approaches for LEO satellites and will be widely placed on the future LEO mission to support their orbit accuracy requirements, Shanghai Astronomical Observatory has developed the SHOEDEE-III procedure which may support zero-difference dynamic orbit determination as well as single-difference dynamic orbit determination using on-board GPS data by fixing GPS ephemeris and clock bias.
St. Louis, MO, USA, February 1, 2009 – A special Supplement to the February 2009 issue of the Journal of the American Dietetic Association presents findings from the recently released Third School Nutrition Dietary Assessment Study (SNDA-III), conducted by Mathematica Policy Research, Inc., as well as research from other studies using SNDA-III data.
In Arctic Canada, a team of geologists from the University of Rochester has discovered a surprise fossil: a tropical, freshwater, Asian turtle.
The find strongly suggests that animals migrated from Asia to North America not around Alaska, as once thought, but directly across a freshwater sea floating atop the warm, salty Arctic Ocean.
Published today in the journal Geology, the finding also suggests that a rapid influx of carbon dioxide some 90 million years ago was the likely cause of a super-greenhouse effect that created extraordinary polar heat.
BUFFALO, N.Y. -- A family sociologist at the University at Buffalo says this month's murder-suicides involving a family of four in Ohio and a family of five in California may be "just the tip of the iceberg."
Sampson Blair, Ph.D., associate professor of sociology at UB, says, "Family murder-suicide is still relatively uncommon, but I expect an increase in such incidents over the next few years because economic strain on families provokes depression and desperation."
An extensive new review summarizes the many studies refuting the claim of a link between vaccines and autism. The review, in the February 15, 2009 issue of Clinical Infectious Diseases and now available online, looks at the three main hypotheses and shows how epidemiological and biological studies refute these claims.
New Rochelle, NY, January 29, 2009—Two common strains of methicillin-resistant Staphylococcus aureus, commonly known as MRSA, were virtually eradicated in the laboratory by exposing them to a wavelength of blue light, in a process called photo-irradiation that is described in a paper published online ahead of print in Photomedicine and Laser Surgery. The article will appear in the April 2009 issue (Volume 27, Number 2) of the peer-reviewed journal published by Mary Ann Liebert, Inc.
If you've ever wondered why some allergic reactions progress quickly and may even become fatal, a new research report published in the February 2009 issue of the Journal of Leukocyte Biology (http://www.jleukbio.org) provides an important part of the answer.
Reed warblers use mobbing as a front line of nest defense against parasitic cuckoos, according to a new report published online on January 29th in Current Biology, a Cell Press publication. Cuckoos act as parasites by laying their eggs in the nests of other birds, reed warblers in particular, burdening their hosts with the trouble of raising young that don't belong to them.
MADISON — Times are tough for wildlife living at the frontier between Uganda and the Democratic Republic of the Congo. Armies are reportedly encamped in a national park and wildlife preserve on the Congolese side, while displaced herders and their cattle have settled in an adjoining Ugandan park.
And yet, the profusion of prey in the region could potentially support more than 900 individuals of the emblematic African lion, according to new research – but only if immediate conservation steps are taken.