The concentration of atmospheric CO2 rose by ∼80 parts per million (ppm), from ∼190 to 270 ppm, during the last deglaciation. It is widely believed that the primary source of … [Read more]
During meiosis, or in yeast sporulation, haploid cells are generated from diploid cells. Brar et al. (p. 552, published online 22 December) performed a detailed analysis of messenger RNA (mRNA) … [Read more]
A gas of fermions, the class of particle that protons, neutrons, and electrons belong to, can be found in contexts as different as neutron stars and a block of metal. … [Read more]
Pulsars are strongly magnetized, rapidly rotating neutron stars. Those with periods of the order of milliseconds obtain their fast spin by accreting mass from a companion star in a binary … [Read more]
Dansgaard/Oeschger (D/O) events—the sudden, millennial-scale periods of warmth that punctuate the cold climate of the Last Glacial period, and Heinrich events—cold intervals characterized by tremendous discharges of icebergs into the … [Read more]
Carbon-silicon bonds are integral to the structure of the silicone materials widely used in adhesives, cosmetics, and numerous other industrial and consumer products. Generally, platinum-based catalysts have performed best in … [Read more]
The potential of affirmative action policies to reduce overall outcomes because of lower individual performance has been discussed widely and at length. But do quotas or preferential treatment of applicants … [Read more]
Metagenomics has given us glimpses into the huge diversity of microorganisms that are the engines of Earth's elemental cycling. These kinds of surveys can supply a good idea of the … [Read more]
The question of how tropical coral reefs will respond to increasing atmospheric greenhouse gas concentrations and concomitant climate change is widely debated. Model predictions and laboratory experiments suggest that decreasing … [Read more]
A classic paradigm in immunology holds that the immune response occurs in two waves: Rapidly responding cells of the innate immune system help to contain the invading pathogen and alert … [Read more]
There are significant structural changes in striatal and prefrontal brain regions of stimulant drugdependent individuals. However, it is not clear if these brain abnormalities predate drug-taking, rendering individuals vulnerable for … [Read more]
Avermectins are the most widely used class of anthelmintic drugs, both as pesticides and as treatments for nematode-borne diseases, with the evolution of resistance presenting a major global health and … [Read more]
Segregation of endoderm and mesoderm lineages is a fundamental event in early embryogenesis. Using sea urchin embryos, Sethi et al. (p. 590) found that Notch and canonical Wnt pathways crosstalk … [Read more]