Volume 528 Number 7580

Editorials

Make the most of PhDs p.7

The number of people with science doctorates is rapidly increasing, but there are not enough academic jobs for them all. Graduate programmes should be reformed to meet students’ needs.

doi: 10.1038/528007a

Root causes p.7

Research has a part to play in identifying the factors that breed terrorism.

doi: 10.1038/528007b

Take more risks p.8

Scientific innovation is being smothered by a culture of conformity.

doi: 10.1038/528008a

News

News Features

How to build a better PhD p.22

There are too many PhD students for too few academic jobs — but with imagination, the problem could be solved.

doi: 10.1038/528022a

News & Views

Close encounters of the alpha kind p.42

Breakthrough calculations of collisions between two helium nuclei pave the way to a quantitative understanding of how the elements carbon and oxygen were made in stars — and to improved models of stellar evolution. See Letter p.111

doi: 10.1038/528042a

Ecosystem vulnerability to ocean warming p.43

Analysis of the temperature ranges occupied by marine species finds that the vulnerability of ecological communities to global warming may depend more on organismal physiology than on the magnitude of change. See Article p.88

doi: 10.1038/nature16314

Inflammation keeps old mice healthy p.44

Immune cells called regulatory T cells accumulate in fat during ageing. The anti-inflammatory activity of these cells worsens age-associated defects in metabolism, in contrast to its effect in obesity. See Letter p.137

doi: 10.1038/nature15648

A century of phage lessons p.46

One hundred years after the first description of viruses that infect bacterial cells, the contribution of these bacteriophages to fundamental biology, biotechnology and human health continues unabated and deserves celebration.

doi: 10.1038/528046a

Getting the measure of entanglement p.48

A property called entanglement entropy helps to describe the quantum states of interacting particles, and it has at last been measured. The findings open the door to a deeper understanding of quantum systems. See Article p.77

doi: 10.1038/528048a

Tumour cells on neighbourhood watch p.49

The discovery of microtube structures that link tumour cells in some invasive brain tumours reveals how these cancers spread, and how they resist treatment. See Article p.93

doi: 10.1038/nature15649

Perspectives

Managing nitrogen for sustainable development p.51

Careful management of nitrogen fertilizer usage is required to ensure world food security while limiting environmental degradation; an analysis of historical nitrogen use efficiency reveals socio-economic factors and technological innovations that have influenced a range of past national trends and that suggest ways to improve global food production and environmental stewardship by 2050.

doi: 10.1038/nature15743

The contentious nature of soil organic matter p.60

Instead of containing stable and chemically unique ‘humic substances’, as has been widely accepted, soil organic matter is a mixture of progressively decomposing organic compounds; this has broad implications for soil science and its applications.

doi: 10.1038/nature16069

Analysis

Pharmacogenomic agreement between two cancer cell line data sets p.84

n panels of cancer cell lines analysed for their response to drug libraries, some studies have proposed distinct pharmacological sensitivities for some cell lines while other studies have not seen the same trends; here the data in the Cancer Cell Line Encyclopedia and the Genomics of Drug Sensitivity in Cancer are reassessed, and the authors report a stronger degree of concordance between the two data sets than that in a previous study.

doi: 10.1038/nature15736

Articles

Thermal biases and vulnerability to warming in the world’s marine fauna p.88

How marine communities will respond to climate change depends on the thermal sensitivities of existing communities; existing reef communities do not show a perfect fit between current temperatures and the thermal niches of the species within them and this thermal bias is a major contributor to projected local species loss.

doi: 10.1038/nature16144

Brain tumour cells interconnect to a functional and resistant network p.93

Brain tumours are difficult to treat because of their propensity to infiltrate brain tissue; here long processes, or tumour microtubes, extended by astrocytomas are shown to promote brain infiltration and to create an interconnected network that enables multicellular communication and that protects the tumours from radiotherapy-induced cell death, suggesting that disruption of the network could be a new therapeutic approach.

doi: 10.1038/nature16071

Overflow metabolism in Escherichia coli results from efficient proteome allocation p.99

Using experimental proteomics and modelling in E. coli, the amount of protein needed to run respiration (per ATP produced) is shown to be twice as much as that needed to run fermentation; results demonstrate that overflow metabolism (known as the Warburg effect in cancer cells) is a necessary outcome of optimal bacterial growth, governed by a global resource allocation program, and that the methodology is directly applicable to synthetic biology and cancer research.

doi: 10.1038/nature15765

Letters

Warm–hot baryons comprise 5–10 per cent of filaments in the cosmic web p.105

In the local Universe, the census of all observed baryons falls short of the estimated number by a factor of two, and simulations have indicated that the missing baryons reside throughout the filaments of the cosmic web; X-ray observations of filamentary structures associated with the galaxy cluster Abell 2744 now find that 5 to 10 per cent of the filament mass is in the form of baryonic gas.

doi: 10.1038/nature16058

Relativistic baryonic jets from an ultraluminous supersoft X-ray source p.108

Persistent low-velocity baryonic jets have been detected from a supersoft X-ray source; the low velocity suggests that these jets have not been launched from a white dwarf, and the persistence speaks against the origin being a canonical black hole or neutron star, indicating that a different type of source must be implicated.

doi: 10.1038/nature15751

Ab initio alpha–alpha scattering p.111

An ab initio calculation of alpha–alpha scattering is described for which the number of computational operations scales approximately quadratically with particle number and which uses lattice Monte Carlo simulations and lattice effective field theory, combined with the adiabatic projection method to reduce the eight-body system to a two-cluster system.

doi: 10.1038/nature16067

Potential sea-level rise from Antarctic ice-sheet instability constrained by observations p.115

Recent work has suggested that sections of the West Antarctic ice sheet are already rapidly retreating, raising concerns about increased sea-level rise; now, an ice-sheet model is used to simulate the mass loss from the entire Antarctic ice sheet to 2200, suggesting that it could contribute up to 30 cm of sea-level rise by 2100 and 72 cm by 2200, but is unlikely to contribute more.

doi: 10.1038/nature16147

Death from drought in tropical forests is triggered by hydraulics not carbon starvation p.119

It has been suggested that carbon starvation, owing to reduced availability of non-structural carbohydrates (NSCs), is an important contributor to tree mortality during drought in tropical rainforests; however, data from the world’s longest-running experimental drought study presented here show no evidence of carbon starvation, and instead the researchers conclude that impaired water hydraulic processes (involving the transport of water from soil to leaf) have a more important role in triggering tree death from long-term drought.

doi: 10.1038/nature15539

Reversal of phenotypes in MECP2 duplication mice using genetic rescue or antisense oligonucleotides p.123

Genetic correction of MeCP2 levels largely reversed the behavioural, molecular and physiological deficits associated with MECP2 duplication syndrome in a transgenic mouse model; similarly, reduction of MeCP2 levels using an antisense oligonucleotide strategy resulted in phenotypic rescue in adult transgenic mice, and dose-dependently corrected MeCP2 levels in cells from patients with MECP2 duplication.

doi: 10.1038/nature16159

Therapeutic antibodies reveal Notch control of transdifferentiation in the adult lung p.127

Inhibitory antibodies to two specific human and mouse Notch ligands, Jagged1 and Jagged2, are generated and shown to have beneficial effects in a goblet cell metaplasia asthma model; systemic Jagged1 inhibition transdifferentiates secretory cells into ciliated cells in the mouse, demonstrating that Jagged1 from ciliated cells normally holds back secretory cells to adopt the ciliated fate.

doi: 10.1038/nature15715

Depletion of fat-resident Treg cells prevents age-associated insulin resistance p.137

Fat-resident regulatory T cells (fTreg cells) accumulate in adipose tissue of mice as a function of age, but not obesity; mice without fTreg cells are protected against age-associated insulin resistance, but remain susceptible to obesity-associated insulin resistance and metabolic disease, indicating different aetiologies of age-associated versus obesity-associated insulin resistance.

doi: 10.1038/nature16151