The dose makes the poison, it is often said, and it is true. Lots of medicines and chemicals are harmless or beneficial in reasonable quantities but dangerous in high quantities. What about CO2 in plants? Plants need it for food but they also recognize too much is a bad thing.
Biologists have been studying a long-standing mystery concerning the way plants reduce the numbers of their breathing pores in response to rising carbon dioxide levels in the atmosphere.
The authors report the discovery of a new genetic pathway in plants, made up of four genes from three different gene families that control the density of breathing pores—or "stomata"—in plant leaves in response to elevated CO2 levels.
There are numerous ways to address carbon emissions but are we choosing the right approaches? America and Europe have invested heavily in subsidizing solar and wind generation and solar panels - but critics contend that the same money spent modernizing older buildings would have done far more than funding Chinese corporations or wealthy homeowners has.
Low-carbon energy won't cost more than what is currently spent on today's fossil-dominated energy system, according to new research from the International Institute for Applied Systems Analysis (IIASA) and partners.
Evolutionary adaptations have allowed Tibetans to have no trouble living at 13,000 feet, but how they became able to conquer the harsh environment of hypoxia has long been a mystery.
Medicine is advancing rapidly and it always has risks, but in early going the risks are going to be greater. A paper found that the risk of patient harm increased two-fold in 2006, the year when teaching hospitals nationwide embraced the pursuit of minimally invasive robotic surgery for prostate cancer.
What is the impact of volcanic sulfate emissions on climate? Researchers have completed the most accurate and precise reconstruction to date of historic volcanic sulfate emissions in the Southern Hemisphere, derived from a large number of individual ice cores collected at various locations across Antarctica and is the first annually resolved record extending through the Common Era - the last 2,000 years of human history.
Reconstructions of the past are critical to creating accurate model simulations used to assess natural versus anthropogenic climate forcing. Such model simulations underpin environmental policy decisions including those aimed at regulating greenhouse gas and aerosol emissions to mitigate projected global warming.
The small intestine is not easy to examine. X-rays, MRIs and ultrasound images provide snapshots but each suffers limitations.
The average human small intestine is roughly 23 feet long and 1 inch thick. Sandwiched between the stomach and large intestine, it is where much of the digestion and absorption of food takes place. It is also where symptoms of irritable bowel syndrome, celiac disease, Crohn's disease and other gastrointestinal illnesses occur. To assess the organ, doctors typically require patients to drink a thick, chalky liquid called barium. Doctors then use X-rays, magnetic resonance imaging and ultrasounds to assess the organ, but these techniques are limited with respect to safety, accessibility and lack of adequate contrast, respectively.
Lasers are ubiquitous but there are still wavelengths for which only large and expensive ones exist, or none at all. Remote sensing and medical applications call for compact laser systems, for example with wavelengths from the near infrared to the Terahertz region and now researchers at the Technische Universitaet Muenchen and the University of Texas Austin have developed a 400 nanometer thick nonlinear mirror that reflects frequency-doubled output using input light intensity as small as that of a laser pointer.
A breakthrough discovery into how living cells process and respond to chemical information could help advance the development of treatments for a large number of cancers and resistant to therapy.
Researchers have unlocked the secret behind the activation of the Ras family of proteins, one of the most important components of cellular signaling networks in biology and major drivers of cancers that are among the most difficult to treat.
A small tree or shrub found in mountainous Central and South American rainforests has a most unusual relationship with the birds that pollinate its flowers, according to a new study - the plant known as Axinaea offers up its male reproductive organs as a tempting and nutritious food source for the birds.
As the birds seize those bulbous stamens with their beaks, they are blasted with pollen by the flowers' complex "bellows" organs. The birds then deliver that pollen to receptive female floral organs as they forage on.
Food bodies situated on male reproductive organs are otherwise only known from beetle-pollinated flowers. There is no other known example among plants of such a precise and anatomically distinct bellows organ.
A newly discovered planet now named OGLE-2013-BLG-0341LBb
in a binary star system located 3,000 light-years from Earth is expanding astronomers' notions of where Earth-like—and even potentially habitable—planets can form. And how to find them.
At twice the mass of Earth, the planet orbits one of the stars in the binary system at almost exactly the same distance from which Earth orbits the sun. However, because the planet's host star is much dimmer than the sun, the planet is much colder than the Earth—a little colder, in fact, than Jupiter's icy moon Europa.
Astronomers search for exoplanets by measuring shifts in the pattern of a star's spectrum - the different wavelengths of radiation that it emits as light.
These "Doppler shifts" result from subtle changes in the star's velocity caused by the gravitational tugs of orbiting planets, but Doppler shifts of a star's absorption lines can also result from magnetic events like sunspots originating within the star itself -- giving false clues of a planet that does not actually exist.
Researchers at the Royal Veterinary College have identified a highly specialized ligament structure that is thought to prevent giraffes' legs from collapsing under the immense weight of these animals.
"Giraffes are heavy animals (around 1000 kg), but have unusually skinny limb bones for an animal of this size" explained lead investigator Christ Basu, a PhD student in the Structure&Motion Lab. "This means their leg bones are under high levels of mechanical stress."
Sequences of DNA called enhancers, which control a gene's output, find their targets long before they are activated during embryonic development, according to scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, who write in Nature that the degree of complexity of enhancers' interactions in the 'simple' fruit fly Drosophila is comparable to what is seen in vertebrates.