The high diversity of phytoplankton has puzzled biological oceanographers for a long time. Diversity of life abounds on Earth, and there's no need to look any farther than the ocean's surface for proof. There are over 200,000 species of phytoplankton alone, and all of those species of microscopic marine plants that form the base of the marine food web need the same basic resources to grow--light and nutrients.

Placebos have helped to ease symptoms of illness for centuries and have been a fundamental component of clinical research to test new drug therapies for more than 70 years. But why some people respond to placebos and others do not remains under debate.

It may come as a bit of a surprise to learn that bacteria have an immune system - in their case to fight off invasive viruses called phages. And like any immune system - from single-celled to human - the first challenge of the bacterial immune system is to detect the difference between "foreign" and "self." This is far from simple, as viruses, bacteria and all other living things are made of DNA and proteins. A group of researchers at the Weizmann Institute of Science and Tel Aviv University has now revealed exactly how bacteria do this. Their results were published online today in Nature.

This is a Polyrhachis sp ant with prey. Ants like this keep invertebrate numbers down. Invertebrates perform essential functions for the smooth running of the ecosystems in tropical forests. For example, creatures such as termites and millipedes help dead leaves decompose and release their nutrients back into the soil, and carnivorous ants and spiders act as predators of herbivorous invertebrates that would otherwise munch through all the foliage.

Researchers from Brown University and the University of Rhode Island have demonstrated a promising new way to increase the effectiveness of radiation in killing cancer cells.