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Volume 453 Issue 7193, 15 May 2008

The air bubbles trapped in the Antarctic Vostok and EPICA Dome C ice cores provide composite records of levels of atmospheric carbon dioxide and methane covering the past 650,000 years. Now the record of atmospheric carbon dioxide and methane concentrations has been extended by two more complete glacial cycles to 800,000 years ago. The new data are from the lowest 200 metres of the Dome C core. This ice core went down to just a few metres above bedrock at a depth of 3,270 metres. Two papers report analyses of this deep ice, including the lowest carbon dioxide concentration so far measured in an ice core. Atmospheric carbon dioxide is strongly correlated with Antarctic temperature throughout the eight glacial cycles, but with significantly lower concentrations between 650,000 and 750,000 years before present. The cover shows a strip of ice core from another ice core in Antarctica (Berkner Island) from a depth of 120 metres. Photo credit: Chris Gilbert, British Antarctic Survey.

Editorial

  • Editorial |

    Governments should work together to build the supercomputers needed for future predictions that can capture the detail required to inform policy.

  • Editorial |

    The Environmental Protection Agency must gather data on the toxicity of spreading sewage sludge.

  • Editorial |

    Retracted papers require a thorough explanation of what went wrong in the experiments.

Research Highlights

Journal Club

News

  • News |

    Air travel shows no sign of losing its allure but its environmental impact is not going to go away. Katharine Sanderson looks at some of the ways that scientists and engineers hope to reduce the carbon wing-print of aircraft.

    • Katharine Sanderson

News in Brief

  • News in Brief |

    Lightning rages over Chilean volcano.

    • Geoff Brumfiel

News

News in Brief

News Feature

  • News Feature |

    A high-profile scientist, a graduate student and two major retractions. Erika Check Hayden reports on a case that has rocked the chemistry community.

    • Erika Check Hayden

Correspondence

Books & Arts

Essay

  • Essay |

    In the second of a nine-part essay series, Josh McDermott explores the origins of the human urge to make and hear music.

    • Josh McDermott
  • Essay |

    Reflecting on how far we have come scientifically since isolating HIV in 1983, Anthony S. Fauci urges a renewed commitment to the far greater challenges ahead, especially that of vaccine development.

    • Anthony S. Fauci

News & Views

  • News & Views |

    Data laboriously extracted from an Antarctic ice core provide an unprecedented view of temperature, and levels of atmospheric carbon dioxide and methane, over the past 800,000 years of Earth's history.

    • Ed Brook
  • News & Views |

    Determination of the architecture of an invertebrate photoreceptor protein, squid rhodopsin, is a notable event. It illuminates the mechanism of invertebrate vision and a ubiquitous intracellular signalling system.

    • Gebhard F. X. Schertler
  • News & Views |

    There's a long wish list for a workable quantum computer: a viable system must be fast, compact and stable. The first integrated optical quantum logic circuits are a step in the right direction.

    • Paul G. Kwiat
  • News & Views |

    Many factors affect the severity of tuberculosis in infected individuals. Among these are the genetic make-up of the bacterial strain, that of the host, and the interplay between the two.

    • Stefan H. E. Kaufmann
  • News & Views |

    The climate is changing, and so are aspects of the world's physical and biological systems. It is no easy matter to link cause and effect — the latest attack on the problem brings the power of meta-analysis to bear.

    • Francis Zwiers
    • Gabriele Hegerl
  • News & Views |

    Polaritons are an odd cross-breed of a particle, half-matter, half-light. They could offer an abundant crop of new and improved optoelectronic devices — a promise already being fulfilled.

    • Benoît Deveaud-Plédran
  • News & Views |

    They can't move away from shade, so plants resort to a molecular solution to find a place in the sun. The action they take is quite radical, and involves a reprogramming of their development.

    • Jir̆í Friml
    • Michael Sauer

Insight

Review Article

Article

  • Article |

    Natural physical and biological systems change in regions of temperature increase. Such changes have occurred on all continents and in most oceans since at least 1970. This paper presents statistical evidence that these changes cannot be explained by natural climate variations alone, and concludes that anthropogenic climate change is affecting physical and biological systems globally and on some continents.

    • Cynthia Rosenzweig
    • David Karoly
    • Anton Imeson
  • Article |

    A map of nucleosome positions across the Drosophila genome reveals a chromatin organization that can be compared with that of budding yeast. The Drosophila nucleosome distribution pattern indicates that RNA polymerase II can access the transcription start site of active genes unimpeded by nucleosomes, but there is a nucleosome positioned at the site where the polymerase pauses.

    • Travis N. Mavrich
    • Cizhong Jiang
    • B. Franklin Pugh
  • Article |

    Invertebrate rhodopsins are light-activated G-protein-coupled receptors, whose activity is coupled to Gq-type G-proteins. This paper reports the crystal structure of squid rhodopsin, at 2.5 Å, in which a putative G-protein-binding site is resolved.

    • Midori Murakami
    • Tsutomu Kouyama

Letter

  • Letter |

    The application of pressure can raise the superconducting transition temperature of oxypnictide (a pnicogen being a group V element) substantially, to a maximum value of about 43 K. This is the highest transition temperature yet reported for a non-copper-based material, but this record is unlikely to last for long: the material system offers considerable flexibility for chemical modification, and we can reasonably anticipate that this record will soon be superseded.

    • Hiroki Takahashi
    • Kazumi Igawa
    • Hideo Hosono
  • Letter |

    A detailed atmospheric methane record from the EPICA Dome C ice core that extends the history of atmospheric methane to 800,000 years before present is detailed. Spectral analyses indicate that the long-term variability in atmospheric methane levels is dominated by 100,000 year glacial–interglacial cycles up to 400,000 years ago with an increasing contribution of the precessional component during the four more recent climatic cycles.

    • Laetitia Loulergue
    • Adrian Schilt
    • Jérôme Chappellaz
  • Letter |

    Animals of many kinds can orient themselves with respect to the Earth's magnetic field. Magnetic orientation seems to be through the eye, possibly by the magnetic modulation of a photochemical reaction. The problem is that nobody knows whether such modulation is even possible, for any chemical system, as that the Earth's magnetic field is relatively weak. This paper presents evidence that weak magnetic fields can modulate photochemical reactions in the expected manner. The model system is entirely artificial, and the temperature rather low, but the point has been made.

    • Kiminori Maeda
    • Kevin B. Henbest
    • P. J. Hore
  • Letter |

    Strains of the model plant Arabidopsis vary in their ability to thrive in heavy-metal environments, presumably due to adaptations throughout evolution. This paper demonstrates that the strain A. halleri has accumulated multiple copies of the gene HMA4 and changes to the regulatory elements for these genes to survive in extreme conditions. Their results should be useful in bioremediation for metal-contaminated soils.

    • Marc Hanikenne
    • Ina N. Talke
    • Ute Krämer
  • Letter |

    Genetic techniques have been used to delete different combinations of fibroblast growth factors (FGFs) from the mouse limb, to study the contribution that each FGF makes to the total apical ectodermal ridge (AER)–FGF signal. Out of the four AER–FGFs, it is shown that only one of them, Fgf8 is sufficient for normal limb development. This dispels a longstanding notion that there is a positive feedback loop between the three other FGF genes expressed in the posterior AER, and the sonic hedgehog gene.

    • Francesca V. Mariani
    • Christina P. Ahn
    • Gail R. Martin
  • Letter |

    In primates, planning movements to selected targets involves a number of areas in anatomically connected frontal and parietal cortex, but how these areas interact is poorly understood. This paper simultaneously records spikes and local field potentials in dorsal pre-motor and parietal reach region and find that correlations between the two areas increase when monkeys choose which movement among several alternatives to make, rather than when they are following instructions.

    • Bijan Pesaran
    • Matthew J. Nelson
    • Richard A. Andersen
  • Letter |

    RGS5, a signalling protein that regulates the activity of G proteins, is shown to be an important regulator of the tumour vasculature. Deletion of RGS5 leads to normalization of blood vessels of tumours, making them less leady and improving their coverage with pericytes. As a consequence, more immune cells that can target the tumour cells reach the tumour, which enhances the survival of tumour-bearing mice.

    • Juliana Hamzah
    • Manfred Jugold
    • Ruth Ganss

Prospects

Postdocs and Students

  • Postdocs and Students |

    Graduate students can be key links in interdisciplinary science, but training them for this role is a challenge, says Brian Vastag.

    • Brian Vastag

Movers

Networks and Support

  • Networks and Support |

    Consider asking these questions during your next postdoc interview.

    • Kryste Ferguson
    • Ivonne Vidal Pizarro

Career View

Futures

  • Futures |

    All life is here.

    • Heather Bradshaw

Authors

Insight

  • Insight |

    Regenerative medicine

    The capacity of most tissues to regenerate derives from stem cells, but there are many barriers to the use of stem-cell-based therapies in the clinic. Such therapies, however, have the potential to improve human health enormously, and knowledge gained from studying cells in culture and in model organisms is now laying the groundwork for a new era of regenerative medicine.

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