Human echolocation kicks off the Nature podcast’s new series on sound science
As two new fronts in the war on disease demonstrate, creativity remains a key weapon for scientists in the hunt for drugs.
Leading researchers hang on despite austerity, but their Herculean efforts may not be enough.
Geneticists debate whether focus should shift from sequencing genomes to analysing function.
Vessels used mainly for seabed surveys will expand in focus.
Companies and clinicians turn to ketamine to treat mental-health disorder as pipeline of new drugs dries up.
Twenty-four years after the conflict ended, scientists and veterans are still fighting for recognition of Gulf War illness.
Step aside, fitness trackers. The next wave of personal sensors is giving people the ability to monitor the air they breathe.
News & Views
The extent to which coastal-ocean regions act as a sink for carbon dioxide has been enigmatic. An estimate based on more than 3 million observations suggests a smaller sink than was thought, concentrated at high latitudes.
Molecular diffusion of some enzymes is enhanced when they catalyse reactions, but the reason for this was obscure. Dissipation of heat generated by catalysis through the protein is now thought to propel the molecules. See Letter p.227
How much more of Earth's fossil fuels can we extract and burn in the short- to medium-term future and still avoid severe global warming? A model provides the answer, and shows where these 'unburnable' reserves are. See Letter p.187
Bladder-cancer cells have been found to release prostaglandin E2 when they are killed by chemotherapy. Paradoxically, this molecule stimulates the proliferation of surviving cancer stem cells, leading to tumour repopulation. See Letter p.209
Spin systems have now been found that have lifetimes of up to six hours. They could be used to build quantum-communication networks and, if optical transmission fails, could even be shipped as a 'quantum memory stick'. See Letter p.177
There is conflicting evidence about which cell type is responsible for liver regeneration following damage. It emerges that duct-like progenitor cells arise from hepatocytes after liver damage, a finding that reconciles previous data.
The discovery that the neural navigation system of the mammalian brain acts in three dimensions sheds light on how mammals orient themselves in complex environments. See Article p.159
A study of freely moving bats provides new insights into how the brain encodes a three-dimensional neural compass; neurons were identified encoding the three Euler rotation angles of the head (azimuth, pitch, and roll) and recordings from these head-direction cells revealed a toroidal model of spatial orientation mapped out by cells tuned to two circular variables (azimuth × pitch).
Mannan, a component of yeast cell walls, is shown to be a viable food source for Bacteroides thetaiotamicron, a dominant member of the gut microbiota, which catabolizes the mannan ‘selfishly’—countering the general assumption that multiple members of the gut microbiota take a role in, and benefit from, polysaccharide catabolism.
This study shows that glutathione, a ubiquitous antioxidant, is also a critical signalling molecule that allosterically activates the master virulence regulator in the intracellular pathogen Listeria monocytogenes.
Spectrographically obtained zirconium, niobium and technetium abundances in a sample of low-mass stars of type S are used to determine that, in these stars, heavy elements are synthesized by the slow-neutron-capture process at a temperature of less than about 250 million kelvin, and that the process began one million to three million years ago.
An essential ingredient of future worldwide quantum communication is the generation of long-lived entangled quantum states; a coherence time of six hours is now reported for optically addressable nuclear spins in europium-doped yttrium orthosilicate.
A ruthenium–disulfide catalyst is presented that is effective in generating compounds of medical and industrial utility (alcohols that contain a phenol, an aldehyde, or a carboxylic acid) by room-temperature, inexpensive, high-yielding cross-metathesis.
Policy makers have generally agreed that the average global temperature rise caused by greenhouse gas emissions should not exceed 2 °C above the average global temperature of pre-industrial times. It has been estimated that to have at least a 50 per cent chance of keeping warming below 2 °C throughout the twenty-first century, the cumulative carbon emissions between 2011 and 2050 need to be limited to around 1,100 gigatonnes of carbon dioxide (Gt CO2). However, the greenhouse gas emissions contained in present estimates of global fossil fuel reserves are around three times higher than this, and so the unabated use of all current fossil fuel reserves is incompatible with a warming limit of 2 °C. Here we use a single integrated assessment model that contains estimates of the quantities, locations and nature of the world’s oil, gas and coal reserves and resources, and which is shown to be consistent with a wide variety of modelling approaches with different assumptions, to explore the implications of this emissions limit for fossil fuel production in different regions. Our results suggest that, globally, a third of oil reserves, half of gas reserves and over 80 per cent of current coal reserves should remain unused from 2010 to 2050 in order to meet the target of 2 °C. We show that development of resources in the Arctic and any increase in unconventional oil production are incommensurate with efforts to limit average global warming to 2 °C. Our results show that policy makers’ instincts to exploit rapidly and completely their territorial fossil fuels are, in aggregate, inconsistent with their commitments to this temperature limit. Implementation of this policy commitment would also render unnecessary continued substantial expenditure on fossil fuel exploration, because any new discoveries could not lead to increased aggregate production.
Seismicity and ground deformation measurements show how a recent segmented dyke intrusion in the Bárðarbunga volcanic system in Iceland grew laterally for 45 kilometres over 14 days; dyke opening and seismicity were focused at the most distal segment, where lateral dyke growth with segment barrier breaking by pressure build-up occurred.
The discovery of claspers in fossils of antiarch placoderms, an ancient group of armoured fish, suggests that internal fertilization was the ancestral type of reproduction for all jawed vertebrates: this contrasts with the current understanding that external fertilization must be the ancestral state.
In vivo evidence for the existence of regenerative dendritic events in place cell dendrites of awake, behaving mice suggests an active role for dendritic spikes in building the representation of space in the hippocampus.
A fraction of the intestinal microbiota as precise as a single bacterial species confers infection resistance by synthesizing Clostridium difficult-inhibiting metabolites from host-derived bile salts.
Using human bladder cancer xenograft models, a new mechanism involving an active proliferative response of cancer stem cells to chemotherapy-induced damage is shown, driven by prostaglandin E2 (PGE2) release in a manner similar to PGE2-induced wound repair; pharmacological inhibition of the PGE2/COX2 axis by celecoxib attenuates chemoresistance, suggesting a possible adjunctive therapy for bladder carcinomas.
Interactions between T and B cells in the germinal centre are brief but involve extensive cell-surface contact in an entangled mode; ICOSL promotes T–B entanglement and B-cell acquisition of CD40L, which drives B cells to upregulate ICOSL, thus forming an intercellular feed-forward loop that is required for efficient positive selection and development of the bone marrow plasma cell compartment.
Unlike the limited post-injury neuronal regeneration in humans, severed axons in C. elegant can regenerate through a cellular fusion mechanism; this study identifies the molecular basis for this process which includes phosphatidylserine recognition and a role for specific molecules that also act in apoptosis.
Structural and biochemical approaches are used to show how RNF146 activity is allosterically regulated by the binding of poly(ADP-ribose) ligand, and how substrate specificity is achieved with protein poly(ADP-ribosyl)ation and ubiquitination occurring in the same protein complex.
It has been traditionally assumed that the heat released during a single enzymatic catalytic event does not perturb the enzyme in any way; however, here single-molecule fluorescence correlation spectroscopy is used to show that, for enzymes that catalyse chemical reactions with large reaction enthalpies, the heat released at the protein's active site during catalysis transiently displaces the protein's centre-of-mass, essentially giving rise to a recoil effect that propels the enzyme.