Volume 525 Issue 7568, 10 September 2015

It is not how much people have, it is how much we know they have that stokes inequality.

There can be more to a question than appears at first sight.

A bill to make data for environmental regulation more transparent reveals the fuzzy boundary between science and ideology, argues Daniel Sarewitz.

New journal aims to publish from ‘all stages of the research cycle’.

Pentagon freezes pathogen research; El Niño set to be a record breaker; and Lasker awards announced.

Brain plaques may have been seeded by contaminated hormone extracts from cadavers.

Long-awaited revision proposed for regulations governing studies of human subjects.

Encryption fix begins in preparation for arrival of futuristic computers.

Report praises US$5-billion scheme for making leading universities more competitive — but some smaller institutions have done just as well.

Survey of surveys finds 422 trees for every person on Earth.

Move over X-ray crystallography. Cryo-electron microscopy is kicking up a storm by revealing the hidden machinery of the cell.

Archaeology is moving underwater and along riverbanks to find clues left by the people who colonized the New World.

Cities need to understand and manage their carbon footprint at the level of streets, buildings and communities, urge Kevin Robert Gurney and colleagues.

UK data hold lessons for how to close the gender gap in bioscience grant applications, success and size, argue Paul Boyle and colleagues.

Nathaniel Comfort takes issue with the second instalment of the evolutionary biologist's autobiography.

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

Cartoonist and former robotics researcher Jorge Cham wowed graduate students with The PhD Movie in 2011. With the follow-up The PhD Movie 2: Still in Grad School — an astute, funny look at more academic tribulations — set to screen at campuses worldwide from the end of September, Cham talks about crowdfunding, the grim scrabble for grants, the under-representation of women in science and coaxing a cameo from a Nobel laureate.

Neurologist who made house calls.

An analysis of energy markets with prices that vary according to demand finds that this market design unexpectedly serves to amplify, rather than dampen, fluctuations in power use.

Two studies find that a lipid-exchange cycle mediates the enrichment of the lipid phosphatidylserine in the cell membrane compared with the membrane of an organelle called the endoplasmic reticulum, where the lipid is produced.

People who died of the neurodegenerative condition Creutzfeldt-Jakob disease after treatment with cadaver-derived human growth hormone also developed some of the pathological traits of Alzheimer's disease. See Letter p.247

Ice clouds in marine regions at high latitudes might form in warmer and drier air than was previously believed because of freezing induced by airborne particles that contain organic materials from ocean surface waters. See Letter p.234

The first well-resolved images of local-galaxy stellar nurseries that are poor in elements heavier than helium give the best picture yet of the conditions in which stars may have formed in the early Universe. See Letter p.218

The development of an algorithm called RaceID enables the identification of rare cell types by single-cell RNA sequencing, even when they are part of a complex mixture of similar cells. See Letter p.251

An in silico, three-dimensional model of tumour evolution suggests that cell motility is a key factor in the initial growth of a tumour mass. The model also reveals the dynamics of mutation spread. See Letter p.261

The finding that genes encoding enzymes that modify histone proteins are among the targets of certain mutant forms of the p53 protein sheds light on how these mutations cause cancer beyond p53 inactivation. See Article p.206

Ground-sourced tree density data is assembled to provide a global map of tree density, which reveals that there are three trillion trees (tenfold more than previous estimates); tree numbers have declined by nearly half since the start of human civilization and over 15 billion trees are lost on an annual basis.

A ChIP-seq analysis of the DNA-binding properties of mutant gain-of-function p53 protein compared to wild-type p53 reveals the gain-of-function proteins bind to and activate a distinct set of genes including chromatin modifying enzymes such as the histone methyltransferase MLL; small molecular inhibitors of MLL function may represent a new target for cancers with mutant p53.

The atomic structure of human γ-secretase at 3.4 Å resolution, determined by single-particle cryo-electron microscopy.

To understand the birth of stars, observations of the clouds in which they form are key; here, interferometric observations are reported of carbon monoxide clouds in the galaxy WLM, which has a metallicity that is 13 per cent of the value of our Sun.

Measurements of a steady emission of single photons from a quantum dot demonstrate that the fluctuations of the electric field can periodically be 3% below the fundamental quantum limit and confirm the long-standing prediction that the quantum state of single photons can be squeezed.

Subtle anomalies in how the structure of metallic osmium evolves with pressure are detected using powder X-ray diffraction measurements at ultra-high static pressures; the anomaly at 440 gigapascals is attributed to an electronic transition caused by pressure-induced interactions between core electrons.

Computational protein design is used to create a protein–DNA co-assembling nanomaterial; by varying the arrangement of protein-binding sites on the double-stranded DNA, a ‘nanowire’ with single-molecule width can be spontaneously formed by mixing the protein and double-stranded DNA building blocks.

The presence of ice in clouds can influence cloud lifetime, precipitation and radiative properties; here, organic material at the sea–air interface, possibly associated with phytoplankton cell exudates, is shown to nucleate ice under conditions relevant for ice cloud formation in the atmospheric environment.

Computed tomography and phylogenetic analysis of the Eunotosaurus africanus skull suggests that not only is Eunotosaurus an early relative of the group that eventually evolved into turtles, but that it is also a diapsid caught in the act of evolving towards a secondarily anapsid state.

Dopamine neurons in the ventral tegmental area calculate reward prediction error by subtracting input from neighbouring GABA neurons.

Treatment of children with human cadaver-derived growth hormone (c-hGH) contaminated with prions resulted in transmission of Creutzfeldt–Jakob disease (CJD); unexpectedly, in an autopsy study of eight such iCJD patients, the authors found amyloid-β deposition in the grey matter typical of that seen in Alzheimer's disease and amyloid-β in the blood vessel walls characteristic of cerebral amyloid angiopathy, consistent with iatrogenic transmission of amyloid-β pathology in addition to CJD and suggests that healthy c-hGH-exposed individuals may also be at risk of Alzheimer's disease and cerebral amyloid angiopathy.

An algorithm that allows rare cell type identification in a complex population of single cells, based on single-cell mRNA-sequencing, is applied to mouse intestinal cells, revealing novel subtypes of enteroendocrine cells and showing that the Lgr5-expressing population consists of a homogenous stem cell population with a few rare secretory cells, including Paneth cells.

This study finds that the epithelial-to-mesenchymal (EMT) transition program, which is common to both mammary gland reconstituting stem cells and mammary tumour-initiating cells, is differentially regulated by two distinct EMT factors, Slug and Snail; the findings illustrate that although they appear similar, normal tissue stem cells and tumour-initiating cells are controlled by distinct regulatory processes.

A new model of tumour evolution is presented to explain how short-range migration and cell turnover within the tumour can provide the basic environment of rapid cell mixing, allowing even a small selective advantage to dominate the mass within relevant time frames.

Insights derived from the crystal structures of the extracellular domain of PSKR, the receptor for the plant hormone phytosulfokine (PSK) that affects plant growth and development, reveal that PSK interacts with PSKR and enhances PSKR interaction with its co-receptor SERK allosterically.

Structural view of a dynamic molecular switch mechanism that governs repression and activation of the jasmonate plant hormone pathway.

A single-molecule optical tweezer assay is developed to monitor transcription initiation in eukaryotic RNA polymerase II in real-time, making use of a highly purified preinitiation complex (PIC) from yeast; observations show that a large bubble is opened up in the DNA template during initiation, driven by the TFIIH helicase that forms part of the PIC, along with synthesis of an extended transcript before the transition from transcription initiation into elongation.

As institutions attempt to redefine the postdoctoral position, early-career researchers are joining together to wage a battle for proper benefits.

A funds manager explains how his physics PhD helped him to transition into the world of finance and investments.

Standard United Galactic Treaty Dictionary, 2nd edn, Caelum Univ. Press (11 June 2287).