It is not known what genes turn leaves yellow in the fall. However, scientists at Umeå Plant Science Center, Umeå University, and the Royal Institute of Technology in Stockholm (KTH) have managed to identify more than 2,400 genes that take part in the process.

One of the most magnificent pageants of nature every year is when trees take on their autumn colors. Scientists have long known that these colors appear when the green pigment chlorophyll is broken down at the same time as the yellow c

There is a better way to determine risk of heart disease than measuring cholesterol, according to a new study by cardiologists from the Research Institute of the McGill University Health Centre (MUHC). This study shows that measuring the amount of a protein called apoprotein B or apoB, is a more accurate and efficient test than measuring cholesterol. These findings will be published in the March issue of the international journal, The Lancet. ôThe tradition in clinical practice is to look at

Of the five basic senses, the sense of smell is the least understood. Now, scientists at the University of Illinois at Urbana-Champaign have sniffed out potential clues to how olfactory receptors in the nose detect odors. Those clues may also explain why dietary zinc deficiencies lead to a loss of smell.

Olfactory receptors are proteins that bridge through the cell membrane. Professor Kenneth S. Suslick and co-workers have found that the structure of the protein changes dramatically when a

A recently discovered enzyme called endothelial lipase regulates the structure, metabolism and blood concentration of high density lipoprotein (HDL), the so-called “good cholesterol,” said researchers from Baylor College of Medicine in a report in the online version of the Proceedings of the National Academy of Sciences.

In a series of studies in mice, Dr. Lawrence Chan, chief of the section of endocrinology and metabolism at Baylor, his co-workers and colleagues from the section of cardiol

Darwin in his time wondered about the existence of ants – how can natural selection as a process based on individual reproductive success give rise to sterile individuals such as ant workers? The solution comes from kin selection theory, which holds that an individual’s reproductive success can also be measured in the number of collateral kin produced. This is how the ants have solved the problem. In an ant colony with only one queen all the workers are her offspring and will in practice help to

In studies using rats, researchers from Duke University Medical Center (USA) and Imperial College London, have found evidence that the chemically inert gas xenon can protect the brain from the neurological damage often associated with the use of the heart-lung machine during coronary artery bypass surgery.

The researchers say that xenon appears to block receptors on nerve cells in the brain that can be “overstimulated” in response to the surgery. This overstimulation can lead to ner

They may cause excruciating pain, auditory or visual disturbances, dizziness and many other problems that compromise or eventually threaten life. They often grow for years, causing ever-worsening symptoms but evading detection and diagnosis. In fact, many tumors situated beneath the brain are considered benign because they don’t spread to other organs or increase rapidly in size, but they gradually interrupt blood flow, hormone production, and normal sensations as they grow and press against organs,

DM2 more common than previously thought

Researchers at the University of Minnesota Medical School’s Muscular Dystrophy Center have developed the first reliable diagnostic test for myotonic muscular dystrophy type 2 (DM2), leading to the accurate determination of the disease’s clinical and molecular features. Initial results indicate that DM2 is much more common than previously thought, and may be one of the more common forms of muscular dystrophy. The findings will be reported in the

May revolutionize medical research and transplantation

The particularly powerful – and very scarce – flexible forms of stem cells needed for medical research and treatment may now be both plentiful and simple to produce, with a new technology developed at the U.S. Department of Energy’s Argonne National Laboratory – and the source is as close as your own bloodstream.

These flexible stem cells, able to morph into a variety of cell types, are called “pluripotent,” and before th

A new liquid crystal lattice created by scientists at the University of Pennsylvania and University of Sheffield may be invisible to the naked eye, but it’s a giant in its own way.

Uniting hundreds of thousands of atoms, this supramolecular structure is one of the most complex ever made via self-assembly, where molecules organize themselves into larger structures. What’s more, it’s the first organic compound to assume an intricate structure previously seen only in metals such

In an unexpected discovery, a team led by Northwestern University scientists has become the first to show that progesterone, a hormone usually associated with female reproduction and maternal behavior, plays a key role in regulating male aggression toward infants in mice. Testosterone, not progesterone, had been thought to be responsible.

The researchers found that the absence of progesterone’s actions reduced aggression while promoting positive paternal behavior. The findings, to be p

Parents concerned about use of oral steroids to treat their asthmatic children will be reassured by a new study conducted by a team of clinicians at the Research Institute of the McGill University Health Centre (MUHC) and the Shriners Hospital (Montreal). This study, the first to evaluate the effects of short courses of oral steroids on bone density and hormone function, was published in the February issue of the international journal Pediatrics.

“Often parents will be hesitant to administer

Findings Support Hygiene Hypothesis

Researchers at National Jewish Medical and Research Center have gathered strong experimental support for the hygiene hypothesis, a proposed explanation for the worldwide rise in asthma and allergies. The research team, led by Richard Martin, M.D., found that early infection with the bacterium Mycoplasma pneumoniae reduced a mouse’s subsequent response to allergens. Alternatively, mice exposed to allergens prior to infection, developed a stronge

The drug ramipril significantly reduced the onset of debilitating and often-fatal heart failure in a large group of high-risk patients, researchers report in today’s rapid access issue of Circulation: Journal of the American Heart Association.

Ramipril, trade-named Altace, is one of a family of high blood pressure medications known as ACE inhibitors. The drugs reduce the risk of death from heart failure – the inability of a weakened or damaged heart to pump enough blood through the body

Discovery could explain current treatment failures and lead to more effective therapies for many cancers

Of all the neoplastic cells in human breast cancers, only a small minority – perhaps as few as one in 100 – appear to be capable of forming new malignant tumors, according to just-published research by scientists in the University of Michigan Comprehensive Cancer Center. The discovery could help researchers zero in on the most dangerous cancer cells to develop new, more effective t

Researchers devise new technique and measure the forces required to unzip DNA

Fifty years after James Watson and Francis Crick’s publication of the structure of DNA, research in the latest issue of the Journal of Biology shows how scientists can now measure the forces needed to tear the DNA double helix apart. The work was carried out using the first successful simultaneous combination of two important techniques for looking at single molecules – single molecule fluorescence and