January 14 COVER Tens of thousands of books appear in this photograph of the interior of the sculpture Idiom, by Matej Kré n. On page 176, Michel et al. describe an even larger collection: a 5.2-million-book corpus containing 4% of all books ever published. Statistical analysis of this corpus makes it possible to study cultural trends quantitatively. Original sculpture (Municipal Library of Prague): Matej Krén/Photograph: Zdeněk Urbánek

February 4 COVER False-colored scanning electron micrograph of aligned zinc oxide nanowire arrays. Nanowires, each 10 to 50 nanometers in diameter and 0.5 to 1 micrometers long, have a variety of potential applications from medical diagnostics to miniature electronics. The Gordon Research Conference on Cancer Nanotechnology will be held 17 to 22 July 2011 at Colby College in Waterville, Maine. See page 602 for the conference schedule and preliminary programs. Image: Z. L. Wang, School of Materials Science and Engineering, Georgia Institute of Technology

February 11 COVER A word cloud generated from all of the content from the Dealing with Data special section beginning on p. 692. The size of each word relates to the frequency with which it appears in the combined texts. References and figure legends were included; common words, authors, and affiliations were excluded. All words are lowercase. See an expanded version of this cloud and other features at www.sciencemag.org/special/data/. Credit: Yael Fitzpatrick, using www.wordle.net

March 18 COVER Reaction of a CN radical with cyclohexane (ball-and-stick structures in green-blue and green-black, respectively) in dichloromethane solvent (space-filling representation). Observations of this reaction on the time scale of picoseconds reveal a wealth of information about the chemical mechanism and shed light on how solvents widely used in chemical synthesis influence reactions on a molecular scale. See page 1423. Image: David R. Glowacki/School of Chemistry, University of Bristol

April 15 COVER Schematic representations of DNA nanostructures with complex curvatures including two-dimensional arrangements of concentric rings and three-dimensional shapes, including a nanoflask 70 nanometers tall and 40 nanometers wide (DNA molecule is not shown to scale). On page 342, Han et al. describe the creation of these structures using a DNA origami folding technique in which double-helical DNA is bent to follow the rounded contours of the target object. Image: Dongran Han and Hao Yan, The Biodesign Institute and Department of Chemistry and Biochemistry, Arizona State University

April 22 COVER False-colored two-photon microscopy image showing green fluorescent protein–labeled pollen on the stigma (the top of the pistil) of Arabidopsis thaliana. On page 434, Michard et al. describe a plant signaling mechanism that directs the growth of pollen tubes, which carry sperm cells to the ovule at the base of the pistil, and that is analogous to amino acid–mediated communication commonly observed in animal nervous systems. Image: L. Boavida and J. A. Feijó, Instituto Gulbenkian de Ciencia and Universidade de Lisboa, Portugal

April 29 COVER False-colored atomic force microscopy image of three carbon nanotubes on a silicon dioxide substrate (composite of scans on three devices). The middle nanotube is disconnected by a ~40-nanometer gap; the outer nanotubes have similar nanogaps bridged by a phase-change material (PCM) bit. Such small bits can be switched by voltage pulses with energy consumption that is one hundred times lower than that of modern PCM data storage. See page 568. Image: Alex Jerez, Feng Xiong, and Eric Pop, University of Illinois Urbana-Champaign

May 27 COVER A 1-year-old child will spend more time looking at a visual display of moving objects when what he sees is not what he expects. How young children incorporate prior probabilities with current dynamic cues to make predictions about future events can be explained by modeling the child as a Bayesian observer. See the Research Article by Téglás et al. on page 1054. Photo: Ryan McVay/Getty Images

June 3 COVER Three possible phases of the kagome Heisenberg antiferromagnet, a model of geometrically “frustrated ” magnetism: the diamond-pattern valence bond crystal (lower left), honeycomb valence bond crystal (lower right), and quantum spin liquid (upper empty wedge). Deviations of bond strengths from their average values are shown by bond widths and colors (red, stronger; blue, weaker). The simulations of Yan et al. (p. 1173) show that the true ground-state phase is the quantum spin liquid. Image: Steven R. White, University of California, Irvine

August 5 COVER A pair of chemical compounds (light blue and purple) target wild-type and mutant forms of the Plasmodium falciparum chloroquine resistance transporter, which mediates the parasite’s (yellow) resistance to the widely used antimalarial drug. Using high-throughput chemical and genetic analyses, Yuan et al. identify potential new antimalarial drugs that could be used in combination to suppress the development of drug resistance. 724 [Image: Ethan Tyler and Alan Hoofring, Division of Medical Arts, National Institutes of Health]

August 12 COVER Low-energy (<10 millielectron volts) electronic spectra of bilayer graphene undergoing nematic phase transition from an isotropic, unperturbed form (top left) to an asymmetric form (bottom right). Electron-electron interactions in suspended graphene layers drive this transition, causing a change in the material’s band structure and, thus, its electronic properties. See page 860. [Image: Kostya S. Novoselov/University of Manchester and Yael Fitzpatrick/Science]

August 19 COVER Prior to beginning formal schooling, young children can learn a great deal, forming affiliations with favorite topics and experiences. What are these children best able to learn? What value does this early learning hold for later-life experiences? The special section beginning on p. 951 focuses on science that can guide decisions about when, how, and what to teach in these early years. Image: Fotosearch/iStockphoto.com

October 7 COVER Scanning electron microscope image of a strand of hair (about 80 micrometers wide) from the Aboriginal Australian whose genome was sequenced. The genomic sequence provides evidence for multiple dispersals into Asia of modern humans. See P. 94. Image: Courtesy of Timothy P. Topper, Natural History Museum of Denmark.

October 14 COVER Whiskers at the snout are instrumental for the rat to explore the external world. During development, sensory information provided by the whiskers is critical for the formation of their representation in the brain. Minlebaev et al. show how this process is controlled by gamma oscillations in developing neuronal networks. See P. 226. Image: Henrik Sorensen/Getty Images

October 21 COVER Illustration of a generalized form of Snell’s Law that fully accounts for light interaction with subwavelength structured materials, which can produce phase jumps at the interface between media. To illustrate this effect, origami ribbons are folded into tapered cylinders (phase jumps at interfaces), and the lines (light rays) form angles that depend on the degree of taper. Initially diverging rays converge after passing through two interfaces. See page 333. Image: Nanfang Yu/Harvard University; Yi Tan and Jinhua Tan.

November 4 COVER Conceptual illustration of information, in the form of electrical impulses, flowing through neuronal processes within the brain. Fundamental aspects of neuroscience are based in the study of neurons and how they interact. An Editorial (p. 567) and several Reviews (pp. 618 and 623), Reports (pp. 690, 693, and 697), and Perspectives (pp. 606 and 608) highlight current and future approaches in neuroscience research. Image: ktsimage/iStockphoto.com.

November 18 COVER Nighttime view of present-day Chicago, USA. Since the 1893 Chicago World’s Fair introduced alternating current to the public, demand for electrical power has soared. Increased use of power from renewable resources will require new materials to store energy or generate power to ensure proper load balancing, as discussed in the special section beginning on p. 921. Image: Jim Richardson/National Geographic/Getty Images.

December 2 COVER As streams of data continue to grow in size and complexity, the need to ensure that scientific results are reliable has become even greater. The special section beginning on page 1225 and associated Editorial, News, Careers, and Readers’ Poll features explore the opportunities and the challenges of replicating or reproducing data in a variety of fields. Image: iStockphoto.com.

December 9 COVER Scanning electron micrograph of a female Anopheles stephensi mosquito, a transmitter of malaria (proboscis length: ~0.6 millimeters). To drive malaria eradication, new medicines that target all stages of the malaria life cycle are needed. In their study, Meister et al. used thousands of A. stephensi mosquitos to identify chemical classes with activity against the silent malaria liver stage. See page 1372. Image: David Scharf/Getty Images

December 16 COVER Crystal structure of the 80S ribosome from the yeast Saccharomyces cerevisiae. Ribosomes are responsible for protein synthesis in all cells. The eukaryotic ribosome, which consists of four RNA chains (gray) and 79 different proteins (colored ribbons), is more intricate and 40% larger than its bacterial counterpart. With an atomic mass of 3.3 megadaltons, this is the largest asymmetrical structure resolved by x-ray crystallography to date. See page 1524. Image: Sergey Melnikov, Nicolas Garreau de Loubresse, Adam Ben-Shem, Lasse Jenner, Gulnara Yusupova, Marat Yusupov/Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg