The release of radioactive material at a US nuclear-waste repository reveals an all-too-common picture of complacency over safety and a gradual downgrading of regulations.
Germany should follow the United Kingdom’s lead and spell out the benefits of animal research.
It has been no small feat for the Protein Data Bank to stay relevant for 100,000 structures.
Accident at US repository highlights need for tougher safety monitoring, say experts.
Wave of investment suggests drugs from body-dwelling bacteria are heading for the clinic.
But more data are needed to indicate whether the slowing is a result of human-induced climate change.
Agency to narrow down list of landing sites for 2020 mission.
A wave of anti-gay laws and homophobia in Africa is hampering efforts to study and curb the spread of HIV.
The left-over radiation from the Big Bang has given up what may be its last great secret about the early Universe, but astronomers are determined to mine more from this primordial prize.
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An analysis of historical storm data reveals that the average latitude at which tropical cyclones attain their maximum intensity has undergone a pronounced shift towards the poles over the past three decades. See Letter p.349
The five bases found in nucleic acids define the 'alphabet' used to encode life on Earth. The construction of an organism that stably propagates an unnatural DNA base pair redefines this fundamental feature of life. See Letter p.385
A chemical synthesis has led to the reassignment of the molecular structure of the naturally occurring compound citrinalin B. This, in turn, helps to untangle the biochemical origins of an intriguing family of natural products. See Article p.318
The behaviour of adult mice towards pups varies depending on gender and sexual experience. The activity of a population of neurons in the hypothalamus of the brain has now been found to regulate these differing responses. See Article p.325
Weak radio waves in the medium-wave band are sufficient to disrupt geomagnetic orientation in migratory birds, according to a particularly well-controlled study. But the underlying biophysics remains a puzzle. See Letter p.353
Data from the Galapagos Islands exemplify how geology and climate can interact to cause episodes of isolation and fusion of the biota across a landscape. Different scales of such cycles dictate varying mechanisms of species generation.
Some of the most recent and significant developments in homogeneous nickel catalysis are reviewed, including nickel-mediated cross-coupling reactions and carbon–hydrogen bond activation reactions.
Extracellular ATP released from cells during inflammatory responses predominantly functions as a signalling molecule through the activation of purinergic P2 receptors and contributes to both beneficial and detrimental inflammatory responses; this review examines P2 receptor signalling via ATP and its effect on the outcome of inflammatory and infectious diseases.
Natural products citrinalin B and cyclopiamine B, which contain basic nitrogen atoms that are susceptible to oxidation during synthesis, can be synthesized by the selective introduction and removal of functional groups.
Sexual experience brings radical changes in how male mice behave with pups—virgin males attack them whereas mature fathers display parental care; here the authors identify a subset of hypothalamic neurons whose ablation leads to parental deficits in both males and females, and whose activation in virgin males suppresses aggression and induces pup grooming.
Motion detection by the retina is thought to rely largely on the biophysics of starburst amacrine cell dendrites; here machine learning is used with gamified crowdsourcing to draw the wiring diagram involving amacrine and bipolar cells to identify a plausible circuit mechanism for direction selectivity; the model suggests similarities between mammalian and insect vision.
Whether or not endogenous c-kit+ cells residing within the heart contribute cardiomyocytes during physiological ageing or after injury remains unknown; here, using an inducible lineage tracing system, the c-kit+ lineage is shown to generate cardiomyocytes at very low levels, and, by contrast, contributes substantially to cardiac endothelial cell generation.
Five classical Cepheids have been detected in the outer parts of our Galaxy beyond the Galactic bulge; they are probably associated with the gas in the flared disk and, if so, they are the first stars to be identified in the flare.
Femtosecond resolution X-ray fluorescence spectroscopy is shown to track the charge and spin dynamics triggered when an iron coordination complex is excited by light, and establishes the critical role of intermediate spin states in the de-excitation process.
Analysis of global historical data in the Northern and Southern hemispheres reveals a statistically significant, poleward migration of 1° per decade in the average latitude at which tropical cyclones have achieved their lifetime-maximum intensity over the past 30 years.
For the first time under reproducible and fully double-blinded conditions, it is shown that anthropogenic electromagnetic noise below the WHO limits affects a biological system: night-migrating birds lose the ability to use the Earth’s magnetic field for orientation when exposed to anthropogenic electromagnetic noise at strengths routinely produced by commonly used electronic devices.
The microbiome composition of 300 individuals sampled over 12–18 months was partitioned into microbial community types, which could be associated with the type found at other body sites, as well as with whether individuals were breastfed as an infant, their gender and their level of education.
T cells discriminate between foreign and host molecules by recognizing distinct microbial molecules, predominantly peptides and lipids. Riboflavin precursors found in many bacteria and yeast also selectively activate mucosal-associated invariant T (MAIT) cells, an abundant population of innate-like T cells in humans. However, the genesis of these small organic molecules and their mode of presentation to MAIT cells by the major histocompatibility complex (MHC)-related protein MR1 (ref. 8) are not well understood. Here we show that MAIT-cell activation requires key genes encoding enzymes that form 5-amino-6-d-ribitylaminouracil (5-A-RU), an early intermediate in bacterial riboflavin synthesis. Although 5-A-RU does not bind MR1 or activate MAIT cells directly, it does form potent MAIT-activating antigens via non-enzymatic reactions with small molecules, such as glyoxal and methylglyoxal, which are derived from other metabolic pathways. The MAIT antigens formed by the reactions between 5-A-RU and glyoxal/methylglyoxal were simple adducts, 5-(2-oxoethylideneamino)-6-d-ribitylaminouracil (5-OE-RU) and 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU), respectively, which bound to MR1 as shown by crystal structures of MAIT TCR ternary complexes. Although 5-OP-RU and 5-OE-RU are unstable intermediates, they became trapped by MR1 as reversible covalent Schiff base complexes. Mass spectra supported the capture by MR1 of 5-OP-RU and 5-OE-RU from bacterial cultures that activate MAIT cells, but not from non-activating bacteria, indicating that these MAIT antigens are present in a range of microbes. Thus, MR1 is able to capture, stabilize and present chemically unstable pyrimidine intermediates, which otherwise convert to lumazines, as potent antigens to MAIT cells. These pyrimidine adducts are microbial signatures for MAIT-cell immunosurveillance.
Interferon-inducible GTPases are required for the release of vacuolar Gram-negative bacteria into the cytoplasm and subsequent inflammasome-mediated caspase-11 activation.
Single-cell transcriptome analysis enables the direct measurement of cell types and lineage hierarchies of the developing distal lung epithelium and identifies a population of bipotential alveolar progenitor cells.
Disruption of lignin biosynthesis has been proposed as a way to improve forage and bioenergy crops, but it can result in stunted growth and developmental abnormalities; here, the undesirable features of one such manipulation are shown to depend on the transcriptional co-regulatory complex Mediator.
The crystal structure of the core domain of the hepatitis C virus surface glycoprotein E2 has been solved; the structure shows that, contrary to expectation, E2 is unlikely to be the viral fusion protein.
Triphosphates of hydrophobic nucleotides d5SICS and dNaM are imported into Escherichia coli by an exogenous algal nucleotide triphosphate transporter and then used by an endogenous polymerase to replicate, and faithfully maintain over many generations of growth, a plasmid containing the d5SICS–dNaM unnatural base pair.