This Week in Science

Nanoparticles, Lightly Twisted

The helical structures that are widespread in natural macromolecules result from well-coordinated bonding interactions and affect their physical properties in striking ways. To obtain helical nanoparticles, Srivastava et al. (p. … [Read more]

Thalidomide Teratogenicity Target

In the late 1950s and early 1960s, thalidomide was prescribed to pregnant women as a cure for morning sickness, but it was then found to have developmental defects, most obviously, … [Read more]

Scattered and Coupled

Cavity electrodynamics explores the coupling of light with matter—ideally, that of a single photon with a single atom. Typically, this requires that the photon and the atom be confined to … [Read more]

Slightly Cracked

While there are detailed theories to explain the propagation of a crack in the bulk of a material, our understanding of cracking breaks down near the tip of the crack. … [Read more]

Speak to Me, Mama

Maternal effects are effects of the mother (for example, hormones) on her offspring that are independent of genetic inheritance, but related to the mother's phenotype and her environment. Despite their … [Read more]

Dinosaur Plumage

Coloration and appearance provide important behavioral and evolutionary information in animals. However, for the most part, we do not know the coloration of fossil terrestrial animals. Li et al. (p. … [Read more]

Titan Through to the Core

Gravity measurements acquired from orbiting spacecraft can provide useful information about the interior of planets and their moons. Iess et al. (p. 1367; see the Perspective by Sohl) used gravity … [Read more]

Moving Signals

Many types of human breast cancers overexpress a cell-surface receptor—EphA2—a tyrosine kinase activated by the ligand ephrin-A1 present on adjoining cells. Salaita et al. (p. 1380; see the Perspective by … [Read more]

Diheme Conversion

A dehydrogenase enzyme found in methylotrophic and autotrophic bacteria, which converts methylamine to ammonia and formaldehyde, must be posttranslationally modified to create a covalently bound cofactor. Synthesis of the cofactor … [Read more]

Hair Today, Skin Tomorrow

The epidermis of mammals contains hair follicles, sebaceous glands, and interfollicular epidermis, but it has not been clear how the development and repair of these structures is regulated. Snippert et … [Read more]

Steady As She Blows

A fundamental characteristic of many biological control networks is the capacity to maintain the concentration of a particular component at steady state within a narrow range, in spite of variations … [Read more]

Spite and Altruism

Many social animal species can exhibit altruism—the loss of their own individual fitness to help others. One of the most extreme examples is that of the social insects (bees and … [Read more]

Solar Meridional Flow

The surface of the Sun is composed of plasma that exhibits observable flow patterns. The weakest flow pattern occurs along meridional lines from the equator toward the poles. Hathaway and … [Read more]

An Electrochemical Landscape

Electrochemical detection is an analytical method that has been used for a wide range of purposes, including trace chemical analysis, glucose and neurotransmitter monitoring, DNA and protein detection, and electrocatalysis. … [Read more]

Theoretically Speedy Trees

Phylogenetic tree construction often uses distance matrix methods, which offer promising scalable methods for rapid building of very large phylogenies. It has generally been assumed that trees constructed from distance … [Read more]