Volume 509 Issue 7500, 15 May 2014

Germany should follow the United Kingdom’s lead and spell out the benefits of animal research.

It has been no small feat for the Protein Data Bank to stay relevant for 100,000 structures.

Several groups are working to bring back long-dead species, but these efforts could undo some hard-learned lessons, argues Ben Minteer.

The week in science: Britain pledges to be more open about animal research; Stanford University axes coal-company investments; and Vermont passes GM-labelling law.

Accident at US repository highlights need for tougher safety monitoring, say experts.

Wave of investment suggests drugs from body-dwelling bacteria are heading for the clinic.

But more data are needed to indicate whether the slowing is a result of human-induced climate change.

Agency to narrow down list of landing sites for 2020 mission.

A wave of anti-gay laws and homophobia in Africa is hampering efforts to study and curb the spread of HIV.

The left-over radiation from the Big Bang has given up what may be its last great secret about the early Universe, but astronomers are determined to mine more from this primordial prize.

Expand ground monitoring of polar sources of this greenhouse gas to find out how climate change will influence its release, says Torben R. Christensen.

Janine A. Clayton and Francis S. Collins unveil policies to ensure that preclinical research funded by the US National Institutes of Health considers females and males.

Herbert Gintis salutes the follow-up to a study on sociality and hominin brain size.

Jamie Goode drinks in two views of that most venerable and destructive drug — alcohol.

Monya Baker is swept along by a documentary film tracing humanity's complex relationship with water.

An analysis of historical storm data reveals that the average latitude at which tropical cyclones attain their maximum intensity has undergone a pronounced shift towards the poles over the past three decades. See Letter p.349

The five bases found in nucleic acids define the 'alphabet' used to encode life on Earth. The construction of an organism that stably propagates an unnatural DNA base pair redefines this fundamental feature of life. See Letter p.385

A chemical synthesis has led to the reassignment of the molecular structure of the naturally occurring compound citrinalin B. This, in turn, helps to untangle the biochemical origins of an intriguing family of natural products. See Article p.318

The behaviour of adult mice towards pups varies depending on gender and sexual experience. The activity of a population of neurons in the hypothalamus of the brain has now been found to regulate these differing responses. See Article p.325

Weak radio waves in the medium-wave band are sufficient to disrupt geomagnetic orientation in migratory birds, according to a particularly well-controlled study. But the underlying biophysics remains a puzzle. See Letter p.353

Data from the Galapagos Islands exemplify how geology and climate can interact to cause episodes of isolation and fusion of the biota across a landscape. Different scales of such cycles dictate varying mechanisms of species generation.

Some of the most recent and significant developments in homogeneous nickel catalysis are reviewed, including nickel-mediated cross-coupling reactions and carbon–hydrogen bond activation reactions.

Extracellular ATP released from cells during inflammatory responses predominantly functions as a signalling molecule through the activation of purinergic P2 receptors and contributes to both beneficial and detrimental inflammatory responses; this review examines P2 receptor signalling via ATP and its effect on the outcome of inflammatory and infectious diseases.

Natural products citrinalin B and cyclopiamine B, which contain basic nitrogen atoms that are susceptible to oxidation during synthesis, can be synthesized by the selective introduction and removal of functional groups.

Sexual experience brings radical changes in how male mice behave with pups—virgin males attack them whereas mature fathers display parental care; here the authors identify a subset of hypothalamic neurons whose ablation leads to parental deficits in both males and females, and whose activation in virgin males suppresses aggression and induces pup grooming.

Motion detection by the retina is thought to rely largely on the biophysics of starburst amacrine cell dendrites; here machine learning is used with gamified crowdsourcing to draw the wiring diagram involving amacrine and bipolar cells to identify a plausible circuit mechanism for direction selectivity; the model suggests similarities between mammalian and insect vision.

Whether or not endogenous c-kit⁺cells residing within the heart contribute cardiomyocytes during physiological ageing or after injury remains unknown; here, using an inducible lineage tracing system, the c-kit⁺lineage is shown to generate cardiomyocytes at very low levels, and, by contrast, contributes substantially to cardiac endothelial cell generation.

Five classical Cepheids have been detected in the outer parts of our Galaxy beyond the Galactic bulge; they are probably associated with the gas in the flared disk and, if so, they are the first stars to be identified in the flare.

Femtosecond resolution X-ray fluorescence spectroscopy is shown to track the charge and spin dynamics triggered when an iron coordination complex is excited by light, and establishes the critical role of intermediate spin states in the de-excitation process.

Analysis of global historical data in the Northern and Southern hemispheres reveals a statistically significant, poleward migration of 1° per decade in the average latitude at which tropical cyclones have achieved their lifetime-maximum intensity over the past 30 years.

For the first time under reproducible and fully double-blinded conditions, it is shown that anthropogenic electromagnetic noise below the WHO limits affects a biological system: night-migrating birds lose the ability to use the Earth’s magnetic field for orientation when exposed to anthropogenic electromagnetic noise at strengths routinely produced by commonly used electronic devices.

The microbiome composition of 300 individuals sampled over 12–18 months was partitioned into microbial community types, which could be associated with the type found at other body sites, as well as with whether individuals were breastfed as an infant, their gender and their level of education.

Activation of mucosal-associated invariant T (MAIT) cells is shown to require key genes encoding an early intermediate in bacterial riboflavin synthesis, 5-amino-6-d-ribitylaminouracil; this reacts non-enzymatically with metabolites to form short-lived antigens that are captured and stabilized by MR1 for presentation to MAIT cells.

Interferon-inducible GTPases are required for the release of vacuolar Gram-negative bacteria into the cytoplasm and subsequent inflammasome-mediated caspase-11 activation.

Single-cell transcriptome analysis enables the direct measurement of cell types and lineage hierarchies of the developing distal lung epithelium and identifies a population of bipotential alveolar progenitor cells.

Disruption of lignin biosynthesis has been proposed as a way to improve forage and bioenergy crops, but it can result in stunted growth and developmental abnormalities; here, the undesirable features of one such manipulation are shown to depend on the transcriptional co-regulatory complex Mediator.

The crystal structure of the core domain of the hepatitis C virus surface glycoprotein E2 has been solved; the structure shows that, contrary to expectation, E2 is unlikely to be the viral fusion protein.

Triphosphates of hydrophobic nucleotides d5SICS and dNaM are imported into Escherichia coli by an exogenous algal nucleotide triphosphate transporter and then used by an endogenous polymerase to replicate, and faithfully maintain over many generations of growth, a plasmid containing the d5SICS–dNaM unnatural base pair.

The support available for childbirth and rearing varies wildly. New parents come up with creative ways to juggle demands.

Researcher battles learning disabilities to study HIV.

It's all in the mind.