Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
The world faces great risks from nuclear weapons that need to be urgently addressed by political leaders and scientists worldwide. There is now a window of opportunity to do so.
In the first of a series of articles covering nuclear issues, Declan Butler looks at the nuclear non-proliferation treaty and finds that there has never been a better climate for negotiation.
A winning combination of isolation, local involvement and a broad ecological remit are making the management of the seas around Colombia's San Andrés islands a model for other conservationists, reports Mark Schrope.
Long dismissed as featureless, disorganized sacks, bacteria are now revealing a multitude of elegant internal structures. Ewen Callaway investigates a new field in cell biology.
Studies of an old genetic puzzle in a little-known protozoan reveal a new frontier in the expanding world of RNAs: an RNA template guides genome-wide DNA rearrangements during sexual reproduction.
Using silicon as a 'thermoelectric' material to convert heat into electricity would be a technological leap forward. But silicon conducts heat so well that nobody thought that could work — until now.
It requires a quirk of fossilization for the soft parts of an animal to be preserved. Study of such a specimen of the mysterious machaeridians provides these organisms with a well defined evolutionary home.
Cats kill birds, and therefore eradicating cats from an island would seem to be a good strategy for protecting the native population of seabirds. But that thinking does not take account of ecological complications.
Manipulating cells from adult human tissue, scientists have generated cells with the same developmental potential as embryonic stem cells. The research opportunities these exciting observations offer are limitless.
Strange forces and effects dominate the world at the microscopic level. One such force, rooted in the random fluctuations of matter, has only now been accurately measured — 30 years after it was first predicted.
How do you watch the evolution of something that doesn't evolve? In the classical world, even posing this question would provoke raised eyebrows. But where quantum physics is involved, no question is too silly.
This paper reports the ability to isolate human donor biopsies and use transcription factors to derive induced Pluripotent Stem (iPS) cells from fetal, neonatal, and adult human primary cells, including dermal fibroblasts isolated from a skin biopsy of a healthy adult volunteer. The human iPS cells resembled embryonic stem cells in their morphology and gene expression. These data establish a method to isolate iPS cells from patients, suggesting that it may be possible to use this procedure to isolate patient-specific cells in culture.
The microRNAs miR-126 and miR-335 have an important role in breast cancer tumourigenesis and metastasis. Loss of miR-335 expression promotes breast cancer cell invasion by targeting SOX4 and tenascin C. In breast cancer patients, loss of miR-126 and miR-335 expression is indicative of a poor prognosis.
The ciliate Oxytricha trifallax cuts up and removes most of its nuclear DNA during one developmental stage, stitching 5% of its chromosomes back together at specific points. This paper demonstrates that maternal RNA remaining in the new cell could serve as a template for the chromosomal rearrangements, as shown by the disruption of proper assembly when several RNAs are removed from the cell.
Gamma-ray line radiation at 511 keV is the signature of electron–positron annihilation, which comes from the general direction of the Galactic centre, but the origin of the positrons was a mystery. This paper reports a distinct asymmetry in the 511 keV line emission coming from the inner Galactic disk, which resembles an asymmetry in the distribution of low mass X-ray binaries with strong emission at photon energies >20 keV, indicating that they may be the dominant origin of the positrons.
The wafer-scale electrochemical synthesis of arrays of rough silicon nanowires is reported, as is their substantially reduced thermal conductivity, which improves their potential for thermoelectric applications.
Laboratory experiments in microcosms monitoring the hydrocarbon composition of degraded oils are used with carbon isotopic compositions of gas and oil samples taken at wellheads and a Rayleigh isotope fractionation box model to elucidate the mechanisms of hydrocarbon degradation in reservoirs. The data imply a common methanogenic biodegradation mechanism in subsurface degraded oil reservoirs resulting in consistent patterns of hydrocarbon alteration.
The location of microearthquakes beneath a hydrothermal vent field on the East Pacific Rise has been mapped to shed light on hydrothermal pathways at this location. The earthquake locations indicate that a hydrothermal down-flow zone is located on the ridge axis and that hydrothermal flow is oriented along the ridge axis, arguing that models that suggest hydrothermal cells are orientated across-axis, with off-axis recharge zones, may not apply to the East Pacific Rise.
A new machaeridian from the Early Ordovician of Morocco with preserved soft parts is reported, showing that machaeridians are the calcareous plates carried on the back of a hitherto unknown form of segmented worm, resolving a 150-year-old mystery.
It is shown that if individuals vary in their degree of cooperativeness, and if they can decide whether or not to continue interacting with each other on the basis of their respective levels of cooperativeness, then cooperation can gradually evolve from an uncooperative state. These results highlight the importance of individual behavioural differences in fostering the evolution of cooperation.
The availability of genomic data for many species is shedding light on the origin of sex and mating types over evolutionary time. This paper describes the sex-determination region of a zygomycete, the fungus Phycomyces blakesleeanus.
Widespread sense-antisense transcripts have been identified in mammalian cells. Many tumour suppressor genes have nearby antisense RNAs, and an antisense RNA to the cyclin-dependent kinase inhibitor p15 can silence the p15 gene by inducing heterochromatin formation.
Calcium signalling is important for apicomplexan parasite virulence. A newly discovered calcium signalling pathway based on the plant hormone abscisic acid is now reported in Toxoplasma gondii. As this pathway is absent in most animals, it may present a new target for drug intervention.
Chronic granulomatous disease is associated with lack of NADPH activity in phagocytes and characterized by recurrent bacterial and fungal infections as well as exagerated inflammation. This paper shows that the excessive inflammation can be attributed to the lack of NAPPH-derived reactive oxygen which is required for the conversion of tryptophan to kynurenine.