In recent years, the incidence of breast cancer has been increasing worldwide, and breast cancer is becoming a serious object of public concern. The onset of breast cancer is closely related to the sex hormone estrogen, and estrogen antagonists such as tamoxifen have been used as anti-breast cancer drugs.

During pregnancy, the elevated blood estrogen level induces the proliferation of mammary epithelial cells, leading to the development of the mammary gland in preparation for lactation. The mammary epithelial cells eventually stop proliferation at late stages of pregnancy, impairment of which potentially results in breast tumorigenesis . However, the regulatory mechanisms of mammary epithelial cell proliferation during pregnancy have been unclear.

This is a news story that broke recently, on the idea that Elon Musk's plans would violate the Outer Space Treaty. The articles I've read so far focus on property rights and the  provisions in the OST that rule out ownership of territory. But that can be fixed with future legislation, especially since it's not really the land but the habitats that are of most value, and ownership of those is already covered in the OST . So far none of them have mentioned by far the toughest legal and practical obstacle, which is planetary protection of Mars from Earth microbes to preserve its science value for the future of mankind. That can't be fixed by passing new laws. Elon Musk says the mission would be dangerous, with colonists risking death, especially the first ones.

 Microsporidia are typically found in the intestinal tracts of animals and humans, which are made up of millions of cells, which is why studying their mode of reproduction has been so difficult. Yet it's important. Microsporidia cause diarrhea, an illness called microsporidiosis, and even death in immune-compromised individuals.

In spite of those known widespread medical problems, scientists were uncertain about how these single-celled fungi reproduced in human or animal cells. In a study that employed transparent roundworms, biologists at the University of California San Diego succeeded in directly observing how these microorganisms replicate and spread. And what they saw surprised them.

Some loss of memory is often considered an inevitable part of aging, but new research reveals how some people appear to escape that fate. A study older adults whose memory performance is equivalent to that of younger individuals and finds that certain key areas of their brains resemble those of young people. 

Research published today in Research in Veterinary Science reveals that vitamin D supplementation reduces the incidence and severity of tuberculosis (TB) in wild boar and red deer. The pilot study of 40 animals was conducted by a multidisciplinary team of scientists from the University of Surrey (UK), Universidad de Extremadura (Spain), and SME Ingulados (Spain).

Wild boar and red deer are key hosts of bovine tuberculosis – a chronic, infectious disease mainly caused by Mycobacterium bovis - in southern Europe, with the incidence of TB in these animals particularly high in certain areas of Spain. The research could therefore have a positive impact on animal health and – since these species are valuable in the hunting and meat products industries – local economies.

A new paper shows that recent rises in levels of methane in our atmosphere is being driven by biological sources, such as swamp gas, cow burps, or rice fields, rather than fossil fuel emissions.

Atmospheric methane is a major greenhouse gas that traps heat in our atmosphere, contributing to global warming. Its levels have been growing strongly since 2007, and in 2014 the growth rate of methane in the atmosphere was double that of previous years, largely driven by biological sources as opposed to fossil fuel emissions.

Conventional wisdom refuted

51 members of the U.S. House of Representatives have signed a letter to the U.S. Drug Enforcement Agency (DEA) urging the federal agency to halt an emergency push to ban the analgesic herb kratom by as early as tomorrow.