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Media attention will be focused on Brazil and its South American neighbours for sporting reasons over the next few weeks. But with science in mind Natures special issue kicks off with a graphic tour of South and Central America that details the inputs and outputs of research and development there. We profile key institutions and research groups, and report on a programme that sends some of the regions finest researchers to gain experience in North American labs, and on efforts to repatriate scientists who have already made their names abroad. Finally, we canvass opinions on how science can help towards achieving the goal of sustainable economic growth in the region. (Cover: Jasiek Krzysztofiak/Nature)
The week in science: Germany quits mega-telescope project; a $4.5-billion proposal for the US BRAIN initiative; and NASA is told to plot a course for Mars.
Growing resources for research and development are creating opportunities across the continent, but many countries still struggle to build their programmes.
Overseas scholarships that encourage scientists to return to their home countries are helping to rebuild science in Latin America, says Torsten Wiesel.
Investigative food journalist Jo Robinson has spent more than a decade scouring the literature on plant nutrition. Her demonstration garden in Washington state opens this month as her book Eating on the Wild Side (Little, Brown, 2013) emerges in paperback. She talks about eating tomatoes to protect from sunburn, why bitter is better — and how purple is the new green.
Composite materials that incorporate diamond are among the hardest in the world, but fail under extreme conditions. A nanostructured form of diamond, made from onion-like carbon precursors, might overcome this problem. See Letter p.250
Tomato plants that have been damaged by herbivorous insects emit airborne chemicals that warn neighbours of an impending attack. It emerges that the receiving plants transform these signals into defensive weapons.
The finding that absence of the enzyme CTPS1 underlies a form of human immunodeficiency highlights the role of metabolism in immune responses and suggests avenues for treating diseases such as leukaemia. See Letter p.288
Finding that neutrinos are their own antiparticles would revolutionize particle physics. A high-sensitivity technique accelerates the search for the nuclear-decay process that would enable such a discovery. See Article p.229
An enzyme previously implicated in gene regulation has now been found to have a role in cancer progression, potentiating an intracellular signalling pathway that is driven by a mutated K-Ras protein. See Letter p.283
One approach to treating inherited diseases is repairing the defective genes, but this has proved challenging in stem cells. An optimized protocol has now been developed that allows gene repair in blood-cell precursors. See Article p.235
Neutrinos are known to have mass, in contradiction to the predictions of the standard model, and one explanation of this mass is that they are Majorana fermions; this conjecture could be proved by observation of the neutrinoless double-β decay process, but new experiments with 136Xe find no statistically significant evidence for this process.
The feasibility of targeted genome editing in human haematopoietic stem cells is demonstrated; the study overcomes previously existing barriers by tailoring delivery platforms and culture conditions.
DNA double-stranded breaks (DSBs) are shown to form in greater numbers in yeast cells lacking ZMM proteins, which are traditionally regarded as acting strictly downstream of DSB formation; these findings shed light on how cells balance the beneficial and deleterious outcomes of DSB formation.
Emission spectra from the host galaxies of two γ-ray bursts reveal that the regions where the bursts occur are rich in dust but not in molecular gas, which is unexpected because γ-ray bursts are associated with the explosions of massive stars that require molecular gas as fuel.
Nanotwinned diamond synthesized with onion carbon nanoparticles as precursors has much higher hardness and thermal stability than natural diamond; its enhanced hardness is due to the reduced size of its twin structures.
Extreme positive-Indian-Ocean-dipole events cause devastating floods in eastern tropical Africa and severe droughts in Asia; increasing greenhouse gas emissions will make these dipole events about three times more frequent in the twenty-first century.
A grassland warming and CO2 enrichment experiment shows that temperature increase brings forward the growing season of early leafing species, but does not affect or delays senescence in late species, the latter enhanced by elevated CO2.
Inhibitory neuron activity is found to be relatively stable during motor learning whereas excitatory neuron activity is much more dynamic — the results indicate that a large number of neurons exhibit activity changes early on during motor learning, but this population is refined with subsequent practice.
Molecular, pharmacological and functional data show that haematopoietic stem cells (HSCs) are predisposed to ER-stress-mediated apoptosis compared to closely related progenitors; a framework for understanding how stress signalling is coordinated within the hematopoietic hierarchy and integrated with stemness is provided, and may have implications for the improvement of clinical transplantation of HSCs.
Regeneration of the heart muscle after myocardial infarction with cardiomyocytes derived from human embryonic stem cells is demonstrated in non-human primates, with the grafts showing evidence of electromechanical coupling, although they were also associated with non-fatal arrhythmias.
Small-molecule compounds that target the BET domain in proteins such as BRD4 have recently been identified as potential anticancer agents; here, the efficacy of the BRD4-targeting compound JQ1 is demonstrated in castration-resistant prostate cancer driven by deregulated androgen receptor action.
SMYD3 is a methyltransferase overexpressed in several human tumours; here methylation of the MAP3K2 kinase by SMYD3 is shown to be critical for Ras-induced tumour development in mouse models and human tumour cells, showing an unexpected role for methylation in a kinase signalling pathway and revealing a candidate therapeutic target.
Loss-of-function mutations in the human CTP synthase 1 gene cause an immunodeficiency disease with impaired T cell proliferation after antigen stimulation, revealing a potential new target for immunosuppressive drugs.
This study shows how the yeast Ctf4 protein couples the DNA helicase, Cdc45–MCM–GINS, to DNA polymerase α — the GINS subunit of the helicase and the polymerase use a similar interaction to bind Ctf4, suggesting that, as Ctf4 is a trimer, two polymerases could be simultaneously coupled to a single helicase during lagging-strand synthesis.
A metabolomics quantification of NADPH production and consumption fluxes in proliferating mammalian cells reveals that, in addition to canonical pathways such as the oxidative pentose phosphate pathway, NADPH can also be produced by a folate metabolism pathway, a discovery providing new insights into the metabolism of cell growth.