Articles in 2010

One reason for using photonic devices is their speed—much faster than electronic circuits—but there are many challenges in integrating the two technologies. Ferreraet al. construct a CMOS-compatible monolithic optical waveform integrator, a key building block for photonic circuits.

To ensure correct cell division Staphylococci must remember which plane they previously divided along, but the mechanism by which this is achieved is unclear. In this article, using atomic force microscopy, peptidoglycan ribs are reported to mark previous planes of division.

Peptidoglycans provide bacterial cell walls with mechanical strength. The spatial organization of peptidoglycan has previously been difficult to study. Here, atomic force microscopy, together with cells carrying mutations in cell-wall polysaccharides, has allowed an in-depth study of these molecules.

Optical cloaking has already been demonstrated in two dimensions, and also in three dimensions for a limited range of angles. Now, Ma and Cui present a metamaterial-based cloaking device that can shield an object lying on the ground plane from all viewing angles at microwave frequencies.

Adoption is an altruistic behaviour that incurs parental costs. Gorrellet al. examined more than 2,000 squirrel litters and showed that red squirrels adopt only their kin, resulting in an increase in their inclusive fitness. These data provide support for Hamilton's rule of altruism.

At room temperature, glasses are known to be brittle and fracture upon deformation. Zhenget al. show that, by exposing amorphous silica nanostructures to a low-intensity electron beam, it is possible to achieve dramatic shape changes, including a superplastic elongation of 200% for nanowires.

The faithful positioning and growth of cells during embryonic development is essential. In this study Seifertet al. demonstrate that inactivation of Sonic Hedgehogduring development of the genital tubercle results in a prolonged G1 phase and a slower rate of growth.

Notch inhibitors result in the differentiation of intestinal crypt progenitors into goblet cells, suggesting that they could be of use in treating intestinal neoplasia. Here van Eset al. show that Math1 is required for intestinal cell differentiation induced by Notch inhibition.

Spider silk adhesion is reliant on sticky droplets composed of glycoproteins surrounded by an aqueous coat. Sahni and co-workers show that these droplets behave as viscoelastic solids that enable large, rate-dependent adhesive forces capable of trapping fast- and slow-moving prey.

Semiconductor spintronics applications require materials that can exhibit large spin-splitting while preserving a large number of carriers. Yaji and co-workers show this is possible at room temperature using a germanium surface covered with a lead monolayer.

Microtubules act as molecular tracks for the transport of substances within cells, and have inspired the construction of artificial supramolecular fibres. Here, self-assembled glycol–lipid fibres are shown to be sufficiently fluid to allow directional movement of attached molecules, proteins and nanobeads.

Fish stocks in the ocean are known to be under threat. Here, using government data describing commercial fish landings, Thurstan and colleagues show that these stocks began to decline rapidly in the 1970s.

A phase transition between two liquid states is a counterintuitive phenomenon, but one that is known to happen in certain materials. Murata and Tanaka now show in tryphenyl phosphite that this can also produce a change in the wetting of a surface, from partial to complete, at the transition temperature.

The ubiquitin-like modifier FAT10 targets proteins for proteolytic degradation. Here the ubiquitin-conjugating enzyme USE1 is identified as a component of the FAT10 conjugation cascade.

Many animals adapt their behaviour according to their surroundings. Here, Bateset al.show that animals living in deep-sea hydrothermal vents choose habitats within their thermal limits.

Miniaturizing fuel cells for biological applications is challenging due to poor performance at these small scales. Now Gao and coworkers show that electrodes made with porous microfibers composed of oriented carbon nanotubes are capable of delivering fast mass transport of the reagents and greatly enhanced currents.

The synthesis of sequence-regulated copolymers continues to challenge polymer chemists. Here step-growth radical polymerisation of designed abc and abcc monomers leads to vinyl copolymers with repeating ABC and ABCC sequences.

Microwave generation from nanoscale devices is important for future wireless technology, but the power generated in such devices can be small. Dussaux and coworkers have developed a powerful microwave emitter using magnetic vortices induced by spin transfer in a MgO-based magnetic tunnel junction.

Different types of correlations in quantum mechanical systems are crucial for quantum information processing. Xu and colleagues determine the sizes of classical correlations, entanglement and other types of quantum correlations in an optical setup.

Many animals communicate through gestures, some caterpillars use scraping and drumming signals to ward off unwanted neighbours. Here, Scottet al. demonstrate that "leg-like" structures used by some caterpillar species to communicate evolved from legs that their ancestors used to walk.