Reproductive efficiency has suffered a dramatic decrease since the mid-1980s despite rapid worldwide progress in genetics and management of high producing dairy herds.

Researchers from the University of Barcelona propose that summer heat stress is likely to be a major factor related to low fertility in high producing dairy herds, especially in countries with warm weather.

The environmental temperature, radiant energy, relative humidity, and wind speed all contribute to the degree of heat stress. Heat stress may be defined as any combination of environmental variables that give rise to conditions that are higher than those of the temperature range of the animal’s thermal neutral zone.

Rice University biomedical engineers have developed a new technique for growing cartilage from human embryonic stem cells, a method that could be used to grow replacement cartilage for the surgical repair of knee, jaw, hip, and other joints.

"Because native cartilage is unable to heal itself, researchers have long looked for ways to grow replacement cartilage in the lab that could be used to surgically repair injuries," said lead researcher Kyriacos A. Athanasiou, the Karl F. Hasselmann Professor of Bioengineering.

Scientists know that inside each cell, a little engine called RNA polymerase II does one essential job: It copies instructions from genes in the nucleus that get carried to production units in the rest of the cell to support our daily needs.

Now researchers at the University of Michigan Medical School have shown that RNA polymerase II also constantly scans the cell’s DNA for damage. When certain types of damage in DNA halt the action of RNA polymerase II, a stress signal is generated that alerts a key tumor-suppressor protein called p53.

The activities of p53, a master protein that responds to DNA damage by marshaling hundreds of genes to repair or eliminate damaged cells, have been the subject of thousands of studies.

New insights into the role of estrogen receptor in mammary gland development may help scientists better understand the molecular origin of breast cancer, according to new research from the University of Cincinnati.

About a decade ago, U.S. scientists at the National Institutes of Health (NIH) developed a standard estrogen receptor (ER) gene knock-out mouse model to study the estrogen receptor’s role in human diseases.

“Unfortunately, because these mice lacked mammary glands as a consequence of genetic manipulation, using this model to study the relationship between the estrogen receptor and breast cancer proved ineffective,” explains Sohaib Khan, PhD, professor of cell and cancer biology.

A study by researchers at the University of Southampton has shown evidence of increased levels of hyperactivity in young children consuming mixtures of some artificial food colors and the preservative sodium benzoate.

The possibility of food colors and preservatives affecting children's behavior has long been an unresolved question for parents. This significant new research by a team from the University of Southampton's Schools of Psychology and Medicine provides a clear demonstration that changes in behavior can be detected in three-year-old and eight-year-old children.

A common hospital superbug called Clostridium has a protective coat of armor that can self assemble when put into a test tube on its own, which may have important commercial uses in nanotechnology, according to scientists.

Like many other micro-organisms, Clostridium difficile produces a lattice coat made of proteins to surround its cell wall and protect it like a suit of armour. The complete protein coat is then attached to the underlying cell wall with chemical bonds.

“We have discovered that these protein coats have a remarkable ability to self-assemble when they are taken off the bacteria and put into a test tube.