Reviews & Analysis

Simulations of the cosmos cast doubt on assumptions about the temperature of primordial hydrogen gas when it was ionized by the first stars and galaxies, complicating the interpretation of ongoing observations. See Letter p.197

Globally consistent surveys of five factors influencing the success of marine protected areas — age, size, isolation, protection and enforcement — reveal that only when all five are present does nature thrive. See Letter p.216

Three studies have characterized the full complement of RNA folding in cells. They find large numbers of secondary structures in RNA, some of which may have functional consequences for the cell. See Letters p.696, p.701 & p.706

Differentiated cells have been reprogrammed to an embryonic-like state using a physical stimulus. This treatment generates a new cell population that contributes to both the embryo and the placenta. See Article p.641 & Letter p.676

A broad in vivo screen of the effects of specific gene inhibition on the antitumour activity of immune cells in mice bearing melanomas has revealed potential targets for cancer therapy. See Article p.52

Ocean eddies tens of kilometres in radius can delineate local ecosystems and contribute to biogeochemical budgets. The characterization of three such eddies in a coastal upwelling region provides insight into these wonders of nature.

Brown dwarfs are celestial objects that lack the mass to become fully fledged stars. High-resolution maps of one such object add to the evidence that these exotic worlds have highly dynamic weather and climate. See Letter p.654

Members of a newly described candidate bacterial genus, Entotheonella, have been identified as the sources of the rich array of natural products found in the marine sponge Theonella swinhoei. Two scientists discuss this discovery from the perspectives of microbial ecology and drug discovery. See Article p.58

Magnetic monopoles — particles carrying a single magnetic charge — have never been seen. Analogues of these entities have now been produced in an ultracold cloud of rubidium atoms. See Letter p.657

Synchrotrons have long been the preferred X-ray sources for crystallography, but competition has arrived with the advent of X-ray free-electron lasers. A synchrotron expert and an advocate of free-electron lasers discuss the prospects of the respective source types for applications in structural biology.

Ecologists have long pondered how so many species of plant can coexist locally in tropical forests. It seems that fungal pathogens have a central role, by disadvantaging species where they are locally common. See Letter p.85

The asteroid Ceres has been thought to contain abundant water. Observations acquired with the Herschel Space Observatory now show that this Solar System object is spewing water vapour from its surface. See Letter p.525

Mating competition between males often has harmful consequences for females. But it seems that fruit flies alter their behaviour among kin, with brothers being less aggressive and females reproducing for longer as a result. See Letter p.672

A combination of observational data and modelling reveals the potential significance of the north and tropical Atlantic Ocean in driving change in Antarctic winds and sea ice on decadal timescales and longer. See Letter p.538

Haematopoietic stem cells, from which blood cells originate, are shown to respond to oestrogen and divide more frequently in female mice than in males, probably preparing females for the increased demand for blood in pregnancy. See Letter p.555

The discovery that most CD4⁺ T cells killed during HIV infection die through a process known as pyroptosis may provide long-sought explanations for HIV-associated T-cell depletion and inflammation. See Article p.509

Stars of spectral type 'Be' are often found with neutron stars or other evolved analogues, but a black-hole companion has never been spotted before. Optical emission from a black hole's surroundings has given it away. See Letter p.378