Volume 463 Issue 7282, 11 February 2010

The nation's science enterprise still carries the scars of apartheid. But with reform — and increased funding — South Africa could become a catalyst for scientific progress throughout Africa.

NASA is taking a risk on commercial space services. But the pay-offs could be high.

The time is ripe for Europe's scientists to lobby for community-wide infrastructure funding.

The week in science

The advent of commercial trips could open up research opportunities.

An expensive recovery plan to save the ivory-billed woodpecker from extinction may come decades too late.

Industry turns to cell lines for drug screens.

Interim director appointed to Europe's part of programme.

With a new research commissioner arriving in Brussels, and big policy changes on the cards, Nature explains how scientists could be affected.

Eske Willerslev combines Arctic escapades with meticulous lab work in his quest to pull ancient DNA from the ice. Rex Dalton talks to the adventurer about extracting the first ancient human genome.

The release of Nelson Mandela sent optimism coursing through South Africa's research community. Twenty years on, Michael Cherry finds that it is still struggling to get on its feet.

As calls for reform intensify following recent furores about e-mails, conflicts of interest, glaciers and extreme weather, five climatologists propose ways forward for the Intergovernmental Panel on Climate Change. Their suggestions range from reaffirming the panel' governing principles to increasing the number and speed of its publications to replacing the volunteer organization with a permanently staffed structure.

HIV research in South Africa is world class. To halt the country's epidemic, scientists need to shift focus from global problems to priorities at home, say Salim Abdool Karim and Quarraisha Abdool Karim.

Roger Bilham enjoys a history of a potentially useful field in which spectacular failures can win accolades.

Acclaimed essayist Carl Zimmer has eight popular-science books to his name, on topics from parasites and Escherichia coli to evolution. In the second in a series of five interviews with authors who each write science books for a different audience, Zimmer describes how passion breeds popular success.

DNA is particularly well preserved in hair — enabling the genome of a human to be sequenced, and his ancestry and appearance to be determined, from 4,000-year-old remains.

To discover superheavy elements and study their properties, we need to know the masses of the isotopes of elements heavier than uranium. Weighing these isotopes in an electromagnetic trap has now become possible.

Experiments with simple chordate animals show how decay may make the resulting fossils seem less evolved. The consequence is to distort evidence of the evolution of the earliest vertebrates and their precursors.

Chronic drug use can lead to addiction, which is initiated by specific brain circuits. The mystery of how one class of drugs, the benzodiazepines, affects activity in this circuitry has finally been solved.

Defects in mitochondria are implicated in Parkinson's disease. Study of a quality-control pathway involving the proteins PINK1 and Parkin provides further clues about the mechanism involved.

The cool molecular gas from which stars form has been detected in relatively ordinary faraway galaxies. The results point to a continuous fuelling of gas into the star-forming guts of assembling galaxies.

The first genome sequence of an ancient human is reported. It comes from an approximately 4,000-year-old permafrost-preserved hair from a male from the first known culture to settle in Greenland. Functional single-nucleotide polymorphism (SNP) assessment is used to assign possible phenotypic characteristics and high-confidence SNPs are compared to those of contemporary populations to find those most closely related to the individual.

The genome of the wild grass Brachypodium distachyon (Brachypodium), a member of the Pooideae subfamily, is sequenced. The Pooideae are one of three subfamilies of grasses that provide the bulk of human nutrition and may become major sources of renewable energy. Availability of the genome sequence should help establish Brachypodium as a model for developing new energy and food crops.

Benzodiazepines, such as valium, are used both in clinics and for recreational purposes, but lead to addiction in some individuals. Addictive drugs increase the levels of dopamine and trigger synaptic adaptations in the mesolimbic reward system, but the neural basis for the addictive nature of benzodiazepines remains elusive. Here, they are shown to increase firing of dopamine neurons in the ventral tegmental area through GABA_A receptor activation in nearby interneurons.

Pancreatic β-cells release insulin, which controls energy homeostasis in vertebrates, and its lack causes diabetes mellitus. The transcription factor neurogenin 3 (Neurog3) initiates differentiation of β-cells and other islet cell types from pancreatic endoderm; here, the transcription factor Rfx6 is shown to direct islet cell differentiation downstream of Neurog3 in mice and humans. This may be useful in efforts to generate β-cells for patients with diabetes.

Stars form from cold molecular interstellar gas, which is relatively rare in the local Universe, such that galaxies like the Milky Way form only a few new stars per year. However, typical massive galaxies in the distant Universe formed stars much more rapidly, suggesting that young galaxies were more rich in molecular gas. The results of a survey of molecular gas in samples of typical massive star-forming galaxies when the Universe was 40% and 24% of its current age now reveal that distant star-forming galaxies were indeed gas rich.

The difference between the mass of an atom and the sum of its building blocks (the binding energy) is a manifestation of Einstein's famous relation E = mc². Superheavy elements have been observed, but our present knowledge of the binding energy of these nuclides is based only on the detection of their decay products, although they represent the gateway to the predicted 'island of stability'. Here, direct mass measurements of trans-uranium nuclides are reported, providing reliable anchor points en route to the island of stability.

Ferroelectrics are electro-active materials that can store and switch their polarity, sense temperature changes, interchange electric and mechanical functions, and manipulate light. Subtle changes in the topology of certain chemical bonds have long been identified as a possible route for achieving ferroelectricity in organic molecular crystals. Ferroelectricity above room temperature is now demonstrated by applying an electric field to coherently align the molecular polarities in crystalline croconic acid.

Zonal jets are common in nature and are spontaneously generated in turbulent systems. Because the Earth's outer core is believed to be in a turbulent state, it is possible that there is zonal flow in the liquid iron of the outer core. By investigating numerical simulations of the geodynamo with lower viscosities than most previous simulations have been able to use, a convection regime of the outer core is now found that has a dual structure comprising inner, sheet-like radial plumes and an outer, westward cylindrical zonal flow.

Our only direct information on the origin of vertebrates comes from preserved soft-bodied Cambrian chordates; however, reading this fossil record is fraught with difficulties owing to a lack of data on when and how important characters change as they decompose. Here, from experimental decay of amphioxus and ammocoetes, it is shown that loss of chordate characters during decay is non-random, with the features that are most phylogenetically informative tending to decay first.

Sperm can increase their swimming velocity and gain a competitive advantage over sperm from another male by forming cooperative groups, such that selection should favour cooperation of the most closely related sperm. Sperm of deer mice are now shown to aggregate more often with conspecific than heterospecific sperm, in accordance with this theory, whereas in a monogamous species lacking sperm competition, sperm indiscriminately group with unrelated conspecific sperm.

Animals use the Earth's magnetic field for orientation but the biophysical basis of this is unclear. The light-dependent magnetic sense of Drosophila melanogaster was recently shown to be mediated by the cryptochrome (Cry) photoreceptor; here, using a transgenic approach, the type 1 and 2 Cry of the monarch butterfly are shown to both function in the magnetoreception system of Drosophila, and probably use an unconventional photochemical mechanism.

Immune homeostasis relies on tight control over the size of a population of regulatory T cells (T_reg) that can suppress over-exuberant immune responses. Cells commit to the T_reg lineage by upregulating the transcription factor Foxp3. Conserved non-coding DNA sequence elements at the Foxp3 locus are now shown to control the composition, size and maintenance of the T_reg cell population.

The small coding capacity of the influenza A virus demands that the virus use the host cellular machinery for many aspects of its life cycle. An integrated systems approach, based on genome-wide RNA interference screening, is now used to identify 295 cellular cofactors required for early-stage influenza virus replication. Knowledge of these host cell requirements provides further targets that could be pursued for antiviral drug development.

High mutation rates in the influenza A virus facilitate the generation of viral escape mutants, rendering vaccines and drugs potentially ineffective, but targeting host cell determinants could prevent viral escape. Here, 287 human host cell genes influencing influenza A virus replication are found using a genome-wide RNA interference screen. An independent assay is then used to investigate overlap between genes necessary for different viral strains.

Semaphorins and their receptors, plexins, relay guidance information to neurons during development and regulate actin dynamics through an unknown mechanism. Recently, proteins of the Mical family of enzymes have been found to associate with plexins; here, Mical is reported to directly link semaphorins and their plexin receptors to the precise control of actin filament dynamics.

The amino acid antiporter AdiC is important for the survival of enteric bacteria such as Escherichia coli in extremely acid environments. Although the structure of substrate-free AdiC is known, how the substrate (arginine or agmatine) is recognized and transported by AdiC remains unclear. The crystal structure of an E. coli AdiC variant bound to arginine is now reported and analysed.

Former astronaut John Grunsfeld is the latest deputy director of the Space Telescope Science Institute in Baltimore, Maryland, and will oversee the launch of the James Webb Space Telescope.

Thousands of PhDs will be needed to fill faculty science posts by 2014.

Russia is one of only two countries whose science-paper publishing rate has fallen.

United States proves to be a major draw.

More start-ups may be sticking around in New York City, as the city looks to a new science park, prizes and tax breaks to help kick-start a life-sciences cluster. Anne Harding reports.

It's all sewn up.