January 2 COVER A foreshaft used for quick replacement of broken spear points. This example, made from the horn of a woolly rhinoceros (Coelodonta antiquitatis), was discovered in arctic Siberia and is about 27,400 radiocarbon years old. See page 52. [Photo: E. Yu. Girya]

January 16 COVER Tetragnatha kauaiensis, one of a large radiation of long-jawed spiders (Tetragnathidae) endemic to the Hawaiian Islands. One group of species, which includes T. kauaiensis, has abandoned the web-building behavior characteristic of the genus and has diversified into ecologically similar sets of species on different islands, as described on page 356. [Photo: © 2003 David Liittschwager and Susan Middleton]

January 23 COVER The structure of the BAR domain from the protein amphiphysin. At high concentrations, BAR domains can force membranes to adopt a highly curved tubular structure, as described on page 495. The background shows tubulated membranes in a mammalian cell overexpressing amphiphysin 1. [Image: J. Moglia and Y. Vallis]

February 27 COVER Around the world, “science” goes by many names [from left to right, in descending rows: Japanese, German, Bengali (Roman script), Bahasa Malaysia, Bengali (Bengali script), Tamil, Cherokee, Swahili, Asante Twi, Hindi, Finnish, Slovak, Albanian, Arabic, Italian, Spanish, Tibetan, Russian, Dutch, Malayalam, Chinese, Hebrew, Hawaiian, and Swedish]. This special section explores new research on the origins, history, and future of language. See page 1315.

March 5 COVER Scanning electron micrograph of Staphylococcus aureus bound to neutrophil extracellular traps (NETs). These novel structures formed by activated neutrophils can disarm and kill bacteria before they reach host cells, as described on page 1532. [Image: V. Brinkmann]

April 9 COVER Spiral trails deposited by the parasite Toxoplasma as it moves. Such gliding motility powers cell invasion by an important group of intracellular parasites known as apicomplexans. See the Review on page 248 in this special section. [Image: David Sibley]

May 7 COVER Crystal structure of Earth’s deep mantle. Coordination polyhedra of oxygen atoms (white) around silicon atoms are shown as octahedra; magnesium ions are in yellow. Experiments simulating the high pressure and temperature of the deep Earth yield a new view of the lowest 200 to 300 kilometers of mantle, as described on page 855. [Image: M. Murakami]

May 14 COVER Immune cells (red) are shown engulfing yeast within 5 minutes (green with yellow halo) or bacteria (green/yellow) and dying cells (blue with green halo) within 1 hour before their destruction. In these deconvoluted fluorescent micrographs, the immune cell cytoskeleton is stained red and nuclei are blue. See page 1014. [Image: J. M. Blander, M. Magarian Schmidt, and R. Medzhitov]

May 21 COVER Map of the Southern Hemisphere showing the wind resistance encountered in traveling from Bouvet Island (black square) for 1 to 10 May 2003 (increasing resistance from orange to blue; land and ice over oceans are black). Wind resistance predicts plant dispersal between landmasses, as described on page 1144. [Map: Á. M. Felicísimo]

July 2 COVER Chinese hamster ovary cells in the late stage of cell division, surrounded by isolated midbodies. Midbodies, first described in 1891 by Walther Flemming and dismissed by many biologists as “cellular garbage,” play a key role in cell division. Microtubules are green, the actin cytoskeleton is red, and DNA is labeled in blue. See page 61. [Image: A. R. Skop]

July 16 COVER The pteropod Clio pyramidata, a common planktonic mollusk with a calcium carbonate shell. The oceanic uptake of CO2 released to the atmosphere from human activities is changing seawater chemistry (see page 367). These changes make calcium carbonate shells dissolve at shallower depths and ultimately may impair the ability of pteropods, corals, and other marine organisms to calcify (see page 362). [Photo: R. W. Gilmer and G. R. Harbison]

September 24 COVER Economically important fishes of the southeastern United States include amberjack, red snapper, vermilion snapper, black seabass, red grouper, black grouper, goliath grouper, and gag. All of these species are considered overfished or experiencing overfishing in the Gulf of Mexico, the South Atlantic, or both. See page 1958. See page [Drawings: Diane Rome Peebles]

October 8 COVER The AAAS Annual Meeting is widely recognized as the world’s premier showcase of advances in science, technology, and engineering. The upcoming meeting in Washington, D.C., 17 to 21 February 2005, will attract more than 9000 participants, including 1000 press registrants from around the world. [Illustration: Jeffrey Pelo]

October 15 COVER A large number of brain areas are activated during higher cognitive functions. A special section in this issue of Science explores recent advances in research on cognition and behavior. See page 431 [Image: Tim Rue/True Photo, modified from a suggestion by K. R. Ridderinkhof et al.]

November 5 COVER Autophagy, in which cells degrade their own organelles and proteins to reuse the constituents, is important for normal human physiology. Cells form a double-membrane vesicle (blue) that sequesters cytosol and organelles (red oblong). The resulting autophagosome fuses with the lysosome (green sphere), allowing the cargo to be broken down and reused. See page 990. [Image: design by D. J. Klionsky and B. A. Rafferty, 3D modeling and rendering by B. A. Rafferty]

November 12 COVER Development of the light organ of the Hawaiian bobtail squid Euprymna scolopes is triggered by its luminescent bacterial partner Vibrio fischeri shortly after the symbiont colonizes epithelium-lined crypts deep within the organ. In this confocal micrograph, hemocytes can be seen infiltrating the host tissue that will undergo morphogenesis. See page 1186. [Image: T. Koropatnick]

December 10 COVER An optical reflectivity image of a semiconductor wire (lower layer) and a digitally filtered image of the spin polarization (upper layer) in three different perspectives. When an electrical current passes through a nonmagnetic semiconductor, the spin Hall effect gives rise to a spin current-a combination of currents of spin-up electrons (red hill) and spin-down electrons (blue valley) in opposite directions-without application of a magnetic field. See page 1910. [Image: Y. K. Kato and D. D. Awschalom]