The decreased use of cocaine in the United States over the last 20 years mostly occurred among the highly educated, while cocaine use among non-high school graduates remained constant, according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health.

The study authors suspect that the inverse relationship between cocaine use and education is related to access to health warnings and resources. They also concluded that the emerging disparity highlights the need for improved interventions that target persistent cocaine users who are lower educated.

“Much like smoking, people with a better understanding of the impact cocaine has on health are more likely to modify their behavior,” said Valerie S.

Volcanoes sometimes get a bad rap for belching CO2 but today it turns out they're also responsible for the air we breathe.

National Science Foundation-funded research published this week in the journal Nature indicates that billions of years ago, when the Earth was home largely to undersea volcanoes, a previously unknown agent was removing the gas.

The researchers suggest that mixture of gases and lavas produced by submarine volcanoes scrubbed oxygen from the atmosphere and bound it into oxygen-containing minerals.

An artist's cross-section of an underwater volcano and the processes that drive them. Submarine volcanoes can sometimes form islands. Credit: Zina Deretsky, National Science Foundation

In the debate about the climate effects of carbon dioxide emissions from transportation it is assumed that fuel is the key source of pollution from vehicle traffic.

“What you seldom think about is the huge amounts of brake linings and tires that are worn out in traffic and the fact that these products contain considerable amounts of metals,” says David Hjortenkrans, one of the scientists at The University of Kalmar in Sweden who performed a new study of the issue.

Despite the fact that authorities have regulated the metal content of auto parts and the fact that the auto industry has made improvements, brake linings and tires are still among the major sources of metals in urban environments.

The organs that produce sperm also may make it easier for mutations to pass to offspring, USC biologists say. The testes in humans may act as mutation multipliers that raise the odds of passing improved DNA to offspring – but that can also backfire by increasing the frequency of certain diseases.

The new theory is part of a study, appearing in PLOS Biology, that tries to explain the puzzlingly high frequency of Apert syndrome, a genetic cranial deformity found in approximately one out of every 70,000 newborns.

The study’s authors suggest that natural selection may favor “germline” cells – the precursors to sperm – carrying a mutation that causes Apert syndrome.

In a report that is among the first to describe the prevalence of HIV and Hepatitis B and C viruses in Afghanistan, a researcher from the University of California, San Diego (UCSD) School of Medicine voiced concerns that increasing injection drug use and accompanying high-risk behavior could lead to an HIV epidemic in Afghanistan.

“Our findings suggest that interventions to reduce high-risk behaviors among injection drug users are urgently needed in Afghanistan,” said Catherine S. Todd, M.D., MPH, assistant professor in UCSD’s Division of International Health and Cross-cultural Medicine, who is currently working in Kabul, Afghanistan.

A new poisonous frog was recently discovered in a remote mountainous region in Colombia by a team of young scientists supported by the Conservation Leadership Programme (CLP). The new frog, which is almost two centimetres in length, was given the name the “golden frog of Supatá.”

Originally, the young scientists thought the frog was similar to several other common species in the area. However, after scientific analysis of the frog’s characteristics, and review of their findings by experts at Conservation International, it was determined that the golden frog of Supatá is unique and only found within a 20 hectare area in Colombia’s Cundinamarca region.

Turbulence plays an important role in Earth’s weather system, and can be more than an inconvenience - hundreds of injuries have occurred on commercial flights due to turbulence. It is studied both in Earth's atmosphere and in that of Saturn's moon, Titan, aided by data from ESA’s Huygens probe. The study of one is helping the other.

Giles Harrison, atmospheric physicist at the University of Reading in the UK, devised an inexpensive way to measure the effects of turbulence using weather balloons. The instrument package contains a magnetic field sensor which measures fluctuations in Earth’s magnetic field due to turbulence.

Dating younger women is not just about trophy wives, say the researchers behind the PLoS paper, "Why Men Matter: Mating Patterns Drive Evolution of Human Lifespan." It's also about understaning evolution.

Male reproduction begins and ends later than women’s, and declines much more gradually. In many population a fraction of men continue to father children into their 60s and 70s with younger women.

It is summertime in Greece, and with it come the traditional wildfires. These are not natural forest fires; at least, it is thought that most of them are the result of deliberate arson. This is the product of a conflict between Greek law and society that has been going on for years. Most forested land in Greece is protected from development.

Colorectal cancer is one of the most prevalent cancers in the Western world. The tumor starts off as a polyp but then turns into an invasive and violent cancer, which often spreads to the liver. Prof. Avri Ben-Ze’ev and Dr. Nancy Gavert of the Weizmann Institute’s Molecular Cell Biology Department reveal mechanisms that help this cancer metastasize.

In a majority of cases, colorectal cancer is initiated by changes in a key protein – beta-catenin. One of the roles of this protein is to enter the cell nucleus and activate gene expression. But in colorectal and other cancers, beta-catenin over-accumulates in the cell and inappropriately activates genes, leading to cancer.