Volume 525 Issue 7567, 3 September 2015

Drought highlights the state’s lack of an ecological strategy.

Governments maintaining their antipathy for transgenic crops are sensibly balancing public consent with scientific evidence, says Colin Macilwain.

Scientists with ‘super ties’ gain citation-rate reward.

Oliver Sacks dies; rare nautilus spotted after 30 years; and mystery of Knut’s death is solved.

Discrepancy arises between New Horizons and Earth-based measurements.

Experiment plugs loopholes in previous demonstrations of 'action at a distance', against Einstein's objections — and could make data encryption safer.

Swedish synchrotron promises to open up new avenues for researchers.

US Precision Medicine Initiative must decide how much data to release to participants.

Inspired by biology, chemists have created a cornucopia of molecular parts that act as switches, motors and ratchets. Now it is time to do something useful with them.

Electronic gadgets on — and in — our bodies are multiplying fast, but transmitting all their data safely will be a challenge.

Tie funding to verified good institutional practice, and robust science will shoot up the agenda, say C. Glenn Begley, Alastair M. Buchan and Ulrich Dirnagl.

Make wind and solar power even cheaper by opening up access to the electricity grid and ending fossil-fuel subsidies, urge Gernot Wagner and colleagues.

Richard Holmes re-examines the legacy of Ada Lovelace, mathematician and computer pioneer.

Barbara Kiser reviews five of the week's best science picks.

Expansion of a repetitive DNA sequence is associated with neurodegeneration. Three studies identify genes involved in nuclear import and export that can mediate the toxicity this expansion causes. See Article p.56 & Letter p.129

By increasing the sensitivity of an established technique, researchers have shown that swimming bacteria can make frictionless fluids — with potential applications in areas such as microfluidics.

Many naturalized non-native plants pose ecological and economic threats. A quantitative analysis of the global distribution of naturalized plants confirms some anticipated trends and exposes new patterns. See Letter p.100

Attitudes to high-temperature superconductivity have swung from disbelief to a conviction that it occurs only 'unconventionally'. But conventional superconductivity is now reported at record high temperatures. See Letter p.73

Monitored changes in the number of copies of a gene during DNA replication control the timing of sporulation in bacteria. This discovery links replication to the concept that a gene's location on a chromosome can influence cell traits.

Soil water that evaporates or is tapped by plants is largely separate from that which runs into streams and recharges groundwater. This finding has big implications for our understanding of water cycling. See Letter p.91

The DNA breakage-and-repair mechanism that generates antibodies of different classes has, in theory, a 50% chance of occurring correctly. But this recombination turns out to be heavily biased towards productive events. See Letter p.134

The cumulative progress of numerical weather prediction represents one of the most remarkable successes of modern science; here the many technological and scientific advances that have brought NWP to its present level are reviewed, as are the considerable challenges for the future.

A candidate-based genetic screen in Drosophila expressing 30 G₄C₂-repeat-containing RNAs finds that RanGAP, a key regulator of nucleocytoplasmic transport, is a potent suppressor of neurodegeneration; the defects caused by the G₄C₂ repeat expansions can be rescued with antisense oligonucleotides or small molecules targeting the G-quadruplexes.

The first crystal structures of complexes between synaptotagmin-1 and neuronal SNARE, bound to either Ca²⁺ or Mg²⁺, are described, and show that Ca²⁺-triggered neurotransmitter release relies on a large, Ca²⁺-independent interface.

The crystal structure of the 240-kilodalton C–P lyase core complex from the bacterium E. coli offers insights into the relatively unknown mechanisms of the enzymatic machinery that allows some microbes to extract phosphate from phosphonate compounds.

Conventional superconductivity is observed at 203 kelvin in the sulfur hydride system, well above the highest superconducting transition temperature obtained in the copper oxides, raising hopes that even higher transition temperatures will be discovered in other hydrogen-rich systems.

A negative refractive index, a property that does not exist in natural materials, can be produced in so-called metamaterials by combining two building blocks; here it is shown that it is possible to design and fabricate a metamaterial with a negative refractive index that consists of only one type of building block by taking advantage of its crystalline structure, and this approach is demonstrated through an acoustic superlens.

Probing the assembly process that occurs when single-stranded DNA is folded into desired shapes by ‘DNA origami’ shows that it can be guided by controlling the strengths of local and long-range interactions, enabling more reproducible synthesis.

The biochemical process of spin-centre shift is used to accomplish mild, non-traditional alkylation reactions using alcohols as radical precursors; this represents the first broadly applicable use of unactivated alcohols as latent alkylating reagents, achieved via the successful merger of photoredox and hydrogen atom transfer catalysis.

Soil water is usually assumed to be equally available for all purposes, supplying plant transpiration as well as groundwater and streamflow; however, a study of hydrogen and oxygen isotopes from 47 globally distributed sites shows that in fact the water used by plants tends to be isotopically distinct from the water that feeds streamflow.

A whole-mantle seismic imaging technique, combining accurate wavefield computations with information contained in whole seismic waveforms, is used to reveal the presence of broad conduits beneath many of Earth’s surface hotspots, supporting the idea that these conduits are the source of hotspot volcanoes.

A global database of alien plants, showing that over 13,000 species, nearly 4% of the global flora, have become naturalized in a new location.

Previous genetic studies have suggested that the Americas were peopled by a single founding population of Eurasian origin, but a genome-wide study of 30 Native American groups shows that Amazonian Native Americans also have a second source of ancestry that is deeply related to indigenous Australians, New Guineans and Andaman Islanders.

Two mutations in the gene DCHS1 are shown to cause non-syndromic mitral valve prolapse (MVP), a common cardiac valve disease; understanding the role of DCHS1 in mitral valve development and MVP pathogenesis holds therapeutic potential.

PIK3CA mutations are associated with distinct types of human breast cancers but the cellular origin and mechanisms responsible for this heterogeneity were unclear; here, using a genetic approach in mice, the PIK3CA^H1047R mutation is shown to induce multipotent stem-like cells and mammary tumours with different levels of malignancy depending on the cell of origin.

PIK3CA mutations are associated with distinct types of human breast cancers but the cellular origin and mechanisms responsible for this heterogeneity were unclear; here, using a genetic approach in mice, PIK3CA mutations are shown to activate a genetic program directing multiple cell fates in normally lineage-restricted cell types.

Mitochondria have essential functions within cells, and their dysfunction is linked to various disorders; here, the fatty acid stearic acid (C18:0), which is a dietary component, and the transferrin receptor (TFR1) are shown to regulate mitochondrial function.

An unbiased genetic screen in Drosophila expressing G₄C₂-repeat-containing transcripts (repeats that in human cause pathogenesis in C9orf72-related neurological disease) finds genes that encode components of the nuclear pore and nucleocytoplasmic transport machinery, and reveals that G₄C₂ expanded-repeat-induced alterations in nucleocytoplasmic transport contribute to C9orf72 pathology and neurodegeneration.

High-throughput genome-wide sequencing reveals why class switch recombination in the IgH locus, an essential step in the process of antibody generation, has a directional joining bias towards deletion rather than inversion.

Csp1, a novel copper-binding protein that is exported from the cytosol of the methanotroph Methylosinus trichosporium OB3b and stores copper ions for particulate methane monooxygenase, is identified and characterized.

Software tools that track how animals move are helping researchers to do everything from diagnosing neurological conditions to illuminating evolution.

An innovative US National Institutes of Health programme aims to expose junior scientists to different career paths.

How an ecosystem modeller adjusted to a tenure track through research, teaching and outreach.

The catch of a lifetime.