A few Republicans agreeing with basic climate research is not an environmental victory.
The discovery of part of a 55,000-year-old human skull in Israel will help to answer some questions about our species' evolution — but it shows that the tale is complicated.
Technicians are often under appreciated, but without them there could be no research.
US president defies hostile Congress and takes action on global warming.
Rosetta mission would have to sacrifice other science to search for comet lander.
Study on decision-making stokes controversy over power of distracted mind.
Major report calls for cuts to infrastructure, including fledgling Ocean Observatories Initiative, to increase spending on science.
Announcement by President Obama comes amidst growing interest in targeted therapies.
Cranium discovery shows that Homo sapiens was living in Middle East 55,000 years ago.
Research relies on unsung heroes working behind the scenes — and some of them have rather unusual jobs.
News & Views
Influenza virus severely damages the epithelial tissue that lines the lung. Findings suggest that, in mice, activation of a back-up population of stem cells mediates effective repair of the injured lung. See Letters p.616 & p.621
A link between rotation and age for Sun-like stars has long been known, but a stringent test of it for older stars has been lacking. The Kepler mission helps to fill this gap with observations of an old star cluster. See Letter p.589
The identification of the gene regulatory network that controls the formation of xylem — the major component of wood — opens up new avenues for manipulating plant biomass. See Article p.571
Splitting and recombining an electron wave packet has been used to test relativity at a record sensitivity. The result heralds an era of precision measurements of relativity using quantum-information methods. See Letter p.592
The repurposing of a bacterial defence system known as CRISPR into a potent activator of gene expression in human cells enables powerful studies of gene function, as exemplified in cancer cells. See Article p. 583
A combination of simulations and data shows that short-term climate trends are dominated by natural internal variations, providing a basis for climate forecasting, but not for assessing sensitivity to forced changes. See Article p.565
The discovery that the estimated number of stem-cell divisions in a tissue correlates with cancer incidence suggests that the varying probability of developing cancer in different tissues is mostly down to random mutations.
A study of the effect of radiative forcing, climate feedback and ocean heat uptake on global-mean surface temperature indicates that overestimation of the response of climate models to radiative forcing from increasing greenhouse gas concentrations is not responsible for the post-1998 discrepancy between model simulations and observations.
The full complement of transcriptional regulators that affect synthesis of the plant secondary cell wall remains largely undetermined; here, the network of protein–DNA interactions controlling secondary cell wall synthesis of Arabidopsis thaliana is determined, showing that gene expression is regulated by a series of feed-forward loops to ensure that the secondary cell wall is deposited at the right time and in the right place.
The Cancer Genome Atlas presents an integrative genome-wide analysis of genetic alterations in 279 head and neck squamous cell carcinomas (HNSCCs), which are classified by human papillomavirus (HPV) status; alterations in EGFR, FGFR, PIK3CA and cyclin-dependent kinases are shown to represent candidate targets for therapeutic intervention in most HNSCCs.
The CRISPR-Cas9 system, a powerful tool for genome editing, has been engineered to activate endogenous gene transcription specifically and potently on a genome-wide scale and applied to a large-scale gain-of-function screen for studying melanoma drug resistance.
The measurement of the rotational periods of 30 cool stars in the 2.5-billion-year-old cluster NGC 6819 allows the calibration of gyrochronology — the determination of a star’s age on the basis of its rotation period — over a much broader age range than hitherto, meaning that it might be possible to determine the ages of many cool stars in the Galactic field with a precision of roughly 10 per cent.
An electronic analogue of a Michelson–Morley experiment, in which an electron wave packet bound inside a calcium ion is split into two parts and subsequently recombined, demonstrates that the relative change in orientation of the two parts that results from the Earth’s rotation reveals no anisotropy in the electron dispersion; this verification of Lorentz symmetry improves on the precision of previous tests by a factor of 100.
Micrometre-sized particles covered with stiff, nanoscale spikes are shown to exhibit long-term colloidal stability in both hydrophilic and hydrophobic media, without the need for chemical coating, owing to the effect of the spikes on the contact area and, consequently, the force between the particles.
Most currently used catalysts for the amination of C–H bonds are ill suited to the functionalization of complex molecules; here it is shown that a mild, selective, iron-catalysed azidation of tertiary C–H bonds is suitable for the amination of complex molecules containing a range of functional groups.
Based on first-principles resistivity calculations, it was recently concluded that the thermal conductivity of iron in Earth’s core was too high to sustain thermal convection, thus invalidating such geodynamo models; new calculations including electron correlations find that electron–electron scattering is comparable to the electron–phonon scattering at high temperatures in iron, doubling the expected resistivity, and reviving conventional geodynamo models.
Single-molecule, real-time DNA sequencing is used to analyse a haploid human genome (CHM1), thus closing or extending more than half of the remaining 164 euchromatic gaps in the human genome; the complete sequences of euchromatic structural variants (including inversions, complex insertions and tandem repeats) are resolved at the base-pair level, suggesting that a greater complexity of the human genome can now be accessed.
Using a model of tuberculosis in zebrafish, granuloma formation is shown to coincide with hypoxia and angiogenesis; furthermore, the pharmacological inhibition of the pro-angiogenic VEGF pathway reduces infection burden, suggesting a possible treatment strategy in patients with the disease.
Lung diseases such as chronic obstructive pulmonary disease and pulmonary fibrosis involve the progressive and inexorable destruction of oxygen exchange surfaces and airways, and have emerged as a leading cause of death worldwide. Mitigating therapies, aside from impractical organ transplantation, remain limited and the possibility of regenerative medicine has lacked empirical support. However, it is clinically known that patients who survive sudden, massive loss of lung tissue from necrotizing pneumonia or acute respiratory distress syndrome often recover full pulmonary function within six months. Correspondingly, we recently demonstrated lung regeneration in mice following H1N1 influenza virus infection, and linked distal airway stem cells expressing Trp63 (p63) and keratin 5, called DASCp63/Krt5, to this process. Here we show that pre-existing, intrinsically committed DASCp63/Krt5 undergo a proliferative expansion in response to influenza-induced lung damage, and assemble into nascent alveoli at sites of interstitial lung inflammation. We also show that the selective ablation of DASCp63/Krt5 in vivo prevents this regeneration, leading to pre-fibrotic lesions and deficient oxygen exchange. Finally, we demonstrate that single DASCp63/Krt5-derived pedigrees differentiate to type I and type II pneumocytes as well as bronchiolar secretory cells following transplantation to infected lung and also minimize the structural consequences of endogenous stem cell loss on this process. The ability to propagate these cells in culture while maintaining their intrinsic lineage commitment suggests their potential in stem cell-based therapies for acute and chronic lung diseases.
Lineage-tracing experiments identify a rare, undifferentiated population of quiescent cells in the mouse distal lung that are activated through a Notch signalling pathway to repair the epithelium after bleomycin- or influenza-mediated injury; inappropriate Notch signalling may be a major contributor to failed regeneration within the lungs of patients with chronic lung disease.
p53 is often mutated or lost in cancer; here inactivation of ΔNp63 and ΔNp73 in the absence of p53 is shown to result in metabolic reprogramming and tumour regression via activation of IAPP (islet amyloid polypeptide or amylin), and IAPP-based anti-diabetes therapeutic strategies show potential for the treatment of p53-deficient and mutant tumours.
By binding and inhibiting a second CDC20 molecule, the mitotic checkpoint complex can convert a local ‘wait’ signal from unattached kinetochores to inhibit the anaphase promoting complex/cyclosome throughout the cell and avoid premature cell division.
Time--β bound to substrate DNA as it inserts 8-oxo-dGTP opposite either cytosine or adenine.
A working model for histone H3-induced dynamic regulation of the de novo DNA methyltransferase.