This Week in Science

Water and Ice

The water at the base of glacial ice sheets lubricates the ice-earth interface, allowing the ice sheet to slide more quickly and easily over the ground below, but its role … [Read more]

A Not-So-Happy Anniversary

This year marks a quarter-century since the discovery of the human immunodeficiency virus (HIV) as the cause of AIDS. Over this time, enormous effort has been expended in developing a … [Read more]

The Making of the Sahara

Analysis of mid- and late Holocene environmental and climate change in northern Africa has been hampered by the extreme aridity of the Sahara during recent millennia, which has eradicated most … [Read more]

Nanoscale Thermal Motors

Powering very small devices--nanoelectromechanical systems--will require compact ways of converting electrical energy into directed motion. Barreiro et al. (p. 775, published online 10 April) describe a linear motor in which … [Read more]

Quantum Dot Optoelectronics

There is great interest in developing architectures that allow the quantum state of one part of a system to be controlled by the quantum state of another part. The ability … [Read more]

Pre-Clovis South...

Monte Verde, in Chile, provides some of the best evidence for the early inhabitation of the Americas prior to the widespread Paleo-Indian Clovis culture. Dillehay et al. (p. 784) now … [Read more]

...and Pre-Clovis North

Evidence for a human presence in North America significantly before the appearance of the widespread Clovis complex about 13,000 years ago has been enigmatic. Gilbert et al. (p. 786, published … [Read more]

Divide and Conquer

During division, the bacterial cell division machinery selects the center of the rod-shaped cell as the division site and uses a protein array to physically separate daughter cells (see the … [Read more]

Birds of a Feather Adapt Together

Recent studies of biological responses to climate change have mostly focused on changes in abundance and distribution of species and adaptive evolutionary change. Charmantier et al. (p. 800) use data … [Read more]

Home Is Where the Hearth Is

The nematode Caenorhabditis elegans can "remember" the temperature at which it was grown and will seek out that temperature if later exposed to a gradient of temperatures. In an effort … [Read more]

Identifying Receptor-Ligand Pairs

Secreted proteins that interact with receptors on the cell surface control all sorts of biological processes and provide targets for therapeutic intervention. Lin et al. (p. 807) used a systematic … [Read more]

Lights Out

Plants have evolved an exquisitely tunable mechanism for harmlessly dissipating excess light energy in bright conditions without otherwise sacrificing the efficiency of photosynthesis. Ahn et al. (p. 794) make progress … [Read more]

Viral Subversion Strategy

Viruses have numerous clever strategies for commandeering control of cellular functions. Hume et al. (p. 797) found that the human cytomegalovirus UL97 had effects on progression through the cell division … [Read more]

Wholesale Heat Shock

Exposure to increased temperature can damage cells, and individual cells respond to heat shock by synthesizing protective chaperone proteins that help maintain proper protein folding. Prahlad et al. (p. 811) … [Read more]