Reviews & Analysis

The size of a cell's nucleus is usually proportional to the size of the cell itself. How are the two linked? The answer lies, at least in part, in the import of one or more cytoplasmic cargoes into the nucleus.

The use of catch data to determine indicators of biodiversity such as 'mean trophic level' does not adequately measure ecosystem changes induced by fishing. Improved ways to assess those changes are required. See Letter p.431

In roundworms, age-related decline in egg quality is regulated by specific humoral signalling pathways. If similar mechanisms operate in mammals, these findings may suggest ways to delay reproductive ageing in women.

Many naturally occurring substances have a 'handedness' that enables them to interact highly specifically with matter or light. The helical features responsible for this can now be replicated in solid, porous films. See Letter p.422

An extension of synthetic biology to a medicinal plant involves the transfer of chlorination equipment from bacteria. This exercise adds implements to the enzymatic toolbox for generating natural products. See Letter p.461

Nuclear magnetic resonance is a versatile analytical technique, but acquiring well-resolved NMR spectra of chemical surfaces has been hard. The coming of age of a spectral enhancement method should change all that.

Mobile DNA sequences called L1 contribute to the brain's genetic heterogeneity and may affect neuron function. The protein MeCP2, which is mutated in Rett syndrome, seems to regulate the activity of these genomic elements. See Letter p.443

Quantum physics is known for its counter-intuitive principles. One such principle — that a single photon can be in as many as four places at the same time — has now been demonstrated. See Letter p.412

We know that dark matter constitutes 85 per cent of all the matter in the Universe, but we do not know of what it is made. Among the many dark matter candidates proposed, WIMPs (weakly interacting massive particles) occupy a special place. The moment of truth has now come for WIMPs: either we will discover them in the next five to ten years, or we will witness their inevitable decline.

In both fruitflies and vertebrates, signals from photoreceptor cells are immediately split into two opposing channels in the downstream neurons. This might facilitate the computation of visual motion. See Letter p.300

One might think that aneuploidy — having an abnormal number of chromosomes — would be harmful, and would reduce an organism's fitness. Not necessarily: it all depends on the type of aneuploidy and the associated conditions. See Letter p.321

The discovery of predicted collective electronic behaviour in copper-oxide superconductors in the non-superconducting state provides clues to unlocking the 24-year-old mystery of high-temperature superconductivity. See Letter p.283

Measuring Newton's constant of gravitation is a difficult task, because gravity is the weakest of all the fundamental forces. An experiment involving two simple pendulums provides a seemingly accurate but surprising value.

Once a blood vessel supplying the brain has been blocked, the opportunity to prevent brain damage is fleeting. An alternative strategy might be to guide the damaged area onto the path to recovery. See Letter p.305

An approach that entails printing compound-semiconductor ribbons on a silicon substrate offers the means to build nanoscale transistors that can be switched on and off much more effectively than their bulk analogues. See Letter page 286