Volume 459 Issue 7247, 4 June 2009

Microscopes are changing the face of biology. Researchers should innovate and collaborate if they want to be part of the new vision.

The draft NIH guidelines on stem-cell research are a good first step, but some revision is needed.

The US president's delay in naming an NIH director is symptomatic of a widespread problem.

Academic institutes lock horns in legal action over mutant mice.

Researchers look to quantify pollution levels.

This week's Europe-wide elections will affect researchers more than they realize, reports Alison Abbott.

Redefinition rescues once-threatened terminology from extinction.

US intelligence agency axes funding for work on quantum computing.

European spallation facility looks set to land near Lund.

Deciding how to evaluate a cap-and-trade programme raises some thorny questions, says David Goldston.

New microscopes are revealing sights that have never been seen before. Nature profiles five machines that are changing how biologists view the world.

The earliest microscopes shed light on a once-invisible world. But, Patricia Fara explains, microscopists were uncertain about how well the images reflected reality — just as they are today.

A journalistic account of the case of data manipulation by physicist Jan Hendrik Schön is rich in detail but draws the wrong conclusions about the self-correcting processes of science, argues Martin Blume.

Actor and playwright Anna Deavere Smith has pioneered documentary theatre through her one-woman plays constructed from interviews. As she prepares to portray biologists Edward O. Wilson and James Watson at the World Science Festival in New York next week, Smith talks about life, death and the influence of science on her work.

Semiconducting nanocrystals emit light in many different colours, but they blink on and off at random. The latest nanocrystals emit photons steadily, thanks to the blending of their cores into their outer shells.

Study of an under-appreciated subclass of stars that brighten and dim periodically brings to light their potential use as cosmic yardsticks — out to distances of a few hundred million light years.

Pore-forming proteins are deadly biological weapons that punch holes in target-cell membranes. The structure of the pore formed by a bacterial toxin suggests that diverse pore formers have similar assembly pathways.

The study of Earth's core is an exacting task that involves interpreting indirect evidence. An innovative approach to understanding decadal changes in the magnetic field provides a new probe of core dynamics.

A neat experiment shows that the mechanical vibration of two ion pairs separated by a few hundred micrometres is entangled — their motions are intrinsically and inseparably connected in a quantum way.

What factors direct the formation of heart muscle in the developing embryo? Unexpectedly, a chromatin-remodelling protein complex turns out to be a crucial determinant of cardiac-cell fate.

Candida species are the most common cause of opportunistic fungal infection worldwide. Here, the genomes of six Candida species are sequenced and compared with each other and with related pathogens and non-pathogens; providing insight into the genetic features that underlie the diversity of Candida biology, including pathogenesis and the architecture of mating and meiotic processes.

Cortical gamma oscillations (20–80 Hz) predict increases in focused attention, and failure in gamma regulation is a hallmark of neurological and psychiatric disease; however, what induces this activity band is unclear. Here, by using a cell-type targeted optogenetic approach, it is revealed that gamma oscillations can be driven by specific activation of fast-spiking interneurons in vivo, and that sensory input relative to these oscillations can determine the extent of evoked cortical activity.

Amino acid mutations that alter a protein's function can affect the stability of the protein, but these mutations are believed to be 'buffered' by chaperones, or heat-shock proteins-potentially facilitating the acquisition of genetic diversity and the rate of adaptation. Here, the overexpression of bacterial GroEL/GroES chaperonins is found to double the number of accumulating mutations in four different enzymes in vitro.

Theory suggests that stars with initial masses greater than 25–30 solar masses end up as Wolf-Rayet stars, which are deficient in hydrogen in their outer layers; subsequent supernova explosions should produce ejecta of low kinetic energy, a faint optical luminosity and a small mass fraction of radioactive nickel, but no weak, hydrogen-deficient, core-collapse supernovae have hitherto been see. Now, SN 2008ha is reported to be a faint hydrogen-poor supernova.

Clouds on Titan result from the condensation of methane and ethane and, at present, cloud activity mainly occurs in the southern hemisphere; general circulation models predict that this distribution should change with the seasons on a 15-year timescale. Now, global spatial cloud coverage on Titan is reported to be in general agreement with the models.

Superposition and entanglement are hallmarks of quantum mechanics. One system ubiquitous to nature where entanglement has not previously been shown is distinct mechanical oscillators, such as springs or pendula. Here, deterministic entanglement of separated mechanical oscillators—consisting of the vibrational states of two pairs of atomic ions held in different locations—is demonstrated.

The usefulness of semiconductor nanocrystals is severely limited by the fact that they 'blink': they turn on and off intermittently under continuous excitation. Here, ternary core/shell CdZnSe/ZnSe nanocrystals are realized, in which the transition between CdZnSe and ZnSe seems to be radially graded rather than abrupt, and which show completely non-blinking behaviour and strong photoluminescence.

The nature of initial glaciation on Antarctica about 34 million years ago is a mystery. Results from an intensive radar survey now show that the Gamburtsev mountains at Dome A, at the centre of the present ice sheet, were initially incised by rivers and then subsequently overdeepened by ice movement; this is suggestive of topographical development before 34 million years ago, when mean summer temperatures were about 3 °C.

The production of arc magmas at convergent plate margins is thought to involve the mantle wedge overlying subducting slabs, as well as fluids or melts from the subducting slab itself. However, the role of kinematic variables, such as slab dip and convergence rate, remains an open question. Here, a model is proposed to address how kinematic parameters of plate subduction relate to the location of mantle wedge melting and the position of arc volcanoes.

Interneurons defined by the fast-spiking phenotype and expression of the calcium-binding protein parvalbumin are thought to be involved in gamma oscillations. Here, optogenetic technology is used in mice to selectively modulate parvalbumin interneurons in vivo, revealing that inhibition of these interneurons suppresses gamma oscillations, whereas driving them is sufficient to generate emergent gamma-frequency rhythmicity.

N-methyl-D-aspartate (NMDA) receptors have different opening probabilities and pharmacological profiles according to the type of NR2 subunit they possess (NR2A to NR2D). The region formed by the NR2 amino-terminal domain, and the short linker connecting this to the agonist-binding domain, are now shown to be responsible for controlling the subunit-specific gating of NMDA receptors.

The heart has little regenerative capacity after damage, so understanding the factors required to produce new cardiac myocytes is of great interest. The minimal requirements for transdifferentiation of mouse mesoderm to cardiac myocytes are now defined, with implications for the reprogramming of cardiomyocytes for regenerative purposes in the future.

A20 is a negative regulator of the NF-κB pathway and has a pivotal role in regulation of the immune response. Using a genome-wide analysis of genetic lesions in B-cell lymphomas, A20 is shown to be a common genetic target in B-lineage lymphomas, with uncontrolled NF-κB signalling caused by loss of A20 function implicated in the pathogenesis of subsets of these lymphomas.

Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma in adulthood. Here, mutations in multiple genes that regulate the NK-κB pathway are shown to be present in DLBCL, with the most commonly affected being the A20 gene, which encodes a ubiquitin-modifying enzyme involved in termination of NK-κB responses.

Upon DNA damage, eukaryotic cells initiate the DNA damage response, a complex signalling pathway which coordinates cell cycle arrest with DNA repair. Using a genome-wide RNA interference screen, the human F-box protein FBXO31 is shown to regulate the G1/S cell cycle transition in response to DNA damage by mediating degradation of cyclin D1, an important regulator of progression from G1 to S phase.

Pore-forming toxins are a class of potent virulence factors that convert from a soluble form to a membrane-integrated pore. The bacterial toxin cytolysin A is one such pore-forming toxin, and it is responsible for the haemolytic phenotype of several Escherichia coli and Salmonella enterica strains. Here, the crystal structure of the assembled pore is reported, and a sequential mechanism for its assembly proposed.

Co-evolution of enzymes for metabolic diversification is not well understood, especially at the biochemical level. Here, the biosynthetic pathways responsible for the synthesis of two natural products, curacin and jamaicamide, are examined; several domains are characterized to help determine how, although the two pathways have a high sequence identity, they are responsible for the production of two such dramatically different chemical motifs.

For good reading, look more deeply, says Paul Smaglik.

Staying at home is making me jealous.

Attendance down for this year's BIO meeting.

Life-science sectors in the lead.

US agencies gear up for spending stimulus funds.

The solar-energy industry is poised for a strong comeback from the rough patch it has hit, thanks to solid governmental and private investment. Kurt Kleiner investigates.

There's something out there.