Volume 541 Issue 7636

Editorials

p.133

It may sound vague, but the term represents real and vital concepts.

doi: 10.1038/541133b

p.133

A US congressional investigation has distorted the truth about research that uses human fetal tissue — and sets a troubling precedent.

doi: 10.1038/541133a

p.134

doi: 10.1038/541134a

News

p.141

iCarbonX believes its cutting-edge partners and generous funding give it the upper hand.

doi: 10.1038/541141a

p.142

Updated version of DeepMind's AlphaGo program behind mystery online competitor.

doi: 10.1038/nature.2017.21253

p.143

US National Science Foundation looks to slash funding for Puerto Rico’s Arecibo Observatory.

doi: 10.1038/541143a

p.144

Spice extract dupes assays and leads some drug hunters astray.

doi: 10.1038/541144a

p.145

Environmental scientists plan to push for policy changes but are nervous about losing current protections.

doi: 10.1038/541145a

p.146

The agency's next leader will have an opportunity to reshape its approach to regulation.

doi: 10.1038/nature.2017.21256

News Features

p.148

The country is gearing up to get rid of rats, possums, stoats and other invasive predators by 2050. Is it a pipe dream?

doi: 10.1038/541148a

News & Views

p.160

A protocol has been developed to grow structures that resemble the main part of the stomach in vitro from human embryonic stem cells — an advance that provides insights into stomach development. See Article p.182

doi: 10.1038/nature21110

p.161

Superhydrophobic surfaces reduce the frictional drag between water and solid materials, but this effect is often temporary. The realization of sustained drag reduction has applications for water vehicles and pipeline flows.

doi: 10.1038/541161a

p.162

A molecular analysis of human oesophageal cancers reveals abnormalities that might be targetable by existing drugs, and indicates that the current stratification of these tumours into subtypes is incomplete. See Article p.169

doi: 10.1038/nature21112

p.164

Light in a laser is confined in the form of standing waves. By engineering such waves, scientists have designed an optical system that enhances this confinement, producing a compact laser that emits a high-quality beam. See Letter p.196

doi: 10.1038/541164a

p.165

The Piezo2 protein senses changes in lung volume, acting in different neurons to convey this information to the brain. This finding adds to the list of roles for Piezo2 in mechanosensation. See Article p.176

doi: 10.1038/nature21111

p.166

The haematopoietic stem cells that rejuvenate blood depend on a dietary source of the amino acid valine — a finding that has been exploited to reduce the toxicity of bone-marrow transplantation in mice.

doi: 10.1038/nature21106

p.167

Isotope evidence suggests that, during dry periods associated with the most recent ice age, the Amazonian forest survived in a region that is sensitive to rainfall changes — settling a debate about Amazonian aridity. See Letter p.204

doi: 10.1038/541167a

Articles

p.169

The Cancer Genome Atlas Research Network report integrated genomic and molecular analyses of 164 squamous cell carcinomas and adenocarcinomas of the oesophagus; they find genomic and molecular features that differentiate squamous and adenocarcinomas of the oesophagus, and strong similarities between oesophageal adenocarcinomas and the chromosomally unstable variant of gastric adenocarcinoma, suggesting that gastroesophageal adenocarcinoma is a single disease entity.

doi: 10.1038/nature20805

p.176

The mechanoreceptor Piezo2 is required for both the Hering–Breuer inflation reflex in adult mice and the inflation of the lungs of newborn mice.

doi: 10.1038/nature20793

p.182

Wnt signalling is shown to be required for specification of the gastric fundus in mice, and was used to develop human gastric organoids with functional fundic cell types.

doi: 10.1038/nature21021

Letters

p.188

Simulations of Pluto suggest that the sharp ridges in the Tartarus Dorsa region of Pluto are penitentes that formed over the past tens of millions of years.

doi: 10.1038/nature20779

p.191

Squeezed light is used to sideband cool the motion of a macroscopic mechanical object below the limit imposed by quantum fluctuations.

doi: 10.1038/nature20604

p.196

Lasing action from an optically pumped bound state in the continuum cavity is demonstrated, of both fundamental interest and with applications from optical trapping to biological sensing and quantum information.

doi: 10.1038/nature20799

p.200

By investigating ring currents, a six-porphyrin nanoring molecule is shown to be antiaromatic in its 4+ oxidation state and aromatic in its 6+ oxidation state.

doi: 10.1038/nature20798

p.204

Oxygen isotope records derived from stalagmites in the eastern Amazon reveal that rainfall was about half of today’s during the Last Glacial Maximum but half again as much during the mid-Holocene, broadly coinciding with global changes in temperature and carbon dioxide.

doi: 10.1038/nature20787

p.208

The chimaeroids are one of the four principal divisions of the living jawed vertebrates and their evolutionary origins have been hard to discern; here, the study of a skull of the extinct shark Dwykaselachus shows that the chimaeroids nest among the once fairly common and widespread symmoriiforms.

doi: 10.1038/nature20806

p.212

The genome sequence and genetic diversity of European ash (Fraxinus excelsior) trees reveals the species’ varying susceptibility to ash dieback.

doi: 10.1038/nature20786

p.217

Aggregation of amyloid-β peptides into fibrils or other self-assembled states is central to the pathogenesis of Alzheimer’s disease. Fibrils formed in vitro by 40- and 42-residue amyloid-β peptides (Aβ40 and Aβ42) are polymorphic, with variations in molecular structure that depend on fibril growth conditions. Recent experiments suggest that variations in amyloid-β fibril structure in vivo may correlate with variations in Alzheimer’s disease phenotype, in analogy to distinct prion strains that are associated with different clinical and pathological phenotypes. Here we investigate correlations between structural variation and Alzheimer’s disease phenotype using solid-state nuclear magnetic resonance (ssNMR) measurements on Aβ40 and Aβ42 fibrils prepared by seeded growth from extracts of Alzheimer’s disease brain cortex. We compared two atypical Alzheimer’s disease clinical subtypes—the rapidly progressive form (r-AD) and the posterior cortical atrophy variant (PCA-AD)—with a typical prolonged-duration form (t-AD). On the basis of ssNMR data from 37 cortical tissue samples from 18 individuals, we find that a single Aβ40 fibril structure is most abundant in samples from patients with t-AD and PCA-AD, whereas Aβ40 fibrils from r-AD samples exhibit a significantly greater proportion of additional structures. Data for Aβ42 fibrils indicate structural heterogeneity in most samples from all patient categories, with at least two prevalent structures. These results demonstrate the existence of a specific predominant Aβ40 fibril structure in t-AD and PCA-AD, suggest that r-AD may relate to additional fibril structures and indicate that there is a qualitative difference between Aβ40 and Aβ42 aggregates in the brain tissue of patients with Alzheimer’s disease.

doi: 10.1038/nature20814

p.222

A pathway triggered by chronic severe hypoxia boosts regeneration of injured hearts in adult mice.

doi: 10.1038/nature20173

p.228

The polypeptide SPAR is encoded by a long non-coding RNA, localizes to the late endosome and lysosome, and regulates muscle regeneration by inhibiting mTORC1.

doi: 10.1038/nature21034

p.233

Screening mutant mouse lines using a genome-wide in vivo assay identifies microenvironmental regulators of metastatic colonization and defines SPNS2 as an important mediator of lung colonization.

doi: 10.1038/nature20792

p.237

The first genome-wide map of human chromatin conformation at the 1–3 nucleosome (50–500 base pair) scale, obtained using ionizing radiation-induced spatially correlated cleavage of DNA with sequencing (RICC-seq), which identifies spatially proximal DNA–DNA contacts.

doi: 10.1038/nature20781

p.242

Femtosecond XFEL crystallography is used to identify dynamic changes in the adenine riboswitch aptamer domain, with at least four states identified in real time, two in the apo form before binding and two with the ligand bound.

doi: 10.1038/nature20599