Bound to need essential minerals: Isotope fractionation in mineral uptake by plants

All life on Earth requires certain essential minerals, such are iron and zinc, to function properly. Animals obtain these minerals from their diet, but plants have to take them up directly from the environment and that can create problems. This is because although these minerals are generally abundant in the soil and water, they are mainly present in the form of ionic species that are not very soluble and so can’t easily be absorbed by plant roots.

One solution to this problem adopted by many plants, as well as by bacteria and fungi that obtain minerals directly from the soil, is to release compounds known as siderophores that can bind these ionic species. Because the resultant complexes are much more soluble, they can easily be taken up by plants, providing them with the necessary minerals. An interesting adjunct to this binding process is that it tends to work more effectively with certain isotopes than others, producing a natural isotopic fractionation of the metal ions in soil and water. Read more.

Radioisotopes have potential for medical diagnosis and treatment

Isotopes - atoms of an element that are chemically identical but vary in neutron number and mass - are essential to nuclear medicine. In an effort to return to a stable mass, isotopes known as radioisotopes emit radiation that can damage diseased tissue and can be traced in certain environments, making them useful for medical imaging and cancer therapy, as well as tracking environmental change in oceans and soil, studying the fundamental science of nuclei and safeguarding national security. Read more.

Clam analysis reveals how the oceans affected climate over the past 1,000 years

Alan Wanamaker, working as a postdoctoral researcher from 2007 to 2009, was charged with beginning to compile a 1,000-year record of the marine climate for a spot in the North Atlantic just off the fjords and fishing villages of North Iceland. He was at Bangor University in Wales, working with James Scourse and Chris Richardson, professors in the School of Ocean Sciences. Before Wanamaker were thousands of clams, each specimen of Arctica islandica taken from 80 meters of seawater on the North Icelandic Shelf.

Those clams - dead and alive, some able to live up to 500 years in the icy water - were the research group’s sensors under the sea. Just like tree rings say a lot about growing seasons over time, annual growth increments in the shells can tell researchers a lot about ocean conditions over time. Read more.

Earth’s carbon-climate feedbacks varied in past warming episodes

Records from drill holes in the eastern equatorial Pacific indicate that Earth’s orbital eccentricity played an important role in controlling climate as the planet warmed.

Embedded within the Earth’s long-term cooling trend over the past 65 million years are several climate spikes—swift transitions to “hothouse” conditions—that had profound consequences for life. These spikes could serve as analogues for the future of our warming planet.

The cause of these spikes may in part be due to changes in the atmospheric concentration of carbon dioxide, an important greenhouse gas. But the complex feedbacks between the Earth’s climate and the carbon cycle have been hotly debated, and there is little scientific consensus on this issue. Read more.

Mammoth and mastodon behavior was less roam, more stay-at-home

According to research conducted by the University of Cincinnati, the fuzzy relatives of modern-day elephants liked living in greater Cincinnati long before it became the trendy hot spot it is today - at the end of the last Ice Age. A study led by Brooke Crowley, an assistant professor of geology and anthropology, shows the ancient proboscideans enjoyed the area to such an extent that they probably resided there year round and were not the nomadic migrants as previously thought. Read more.