Editors' Choice

Science  03 Oct 2014:
Vol. 346, Issue 6205, pp. 51
  1. Atmospheric Physics

    A light-induced lightning rod

    1. Ian S. Osborne
    PHOTO: © JEFF SMITH/ALAMY

    Lightning storms are fantastic examples of the power of nature, but also extremely damaging. They can destroy buildings, create power surges, are a major cause of forest fires, and make golfers abandon their games to seek shelter. Using light pulses fired from a powerful laser, Scheller et al. demonstrate the possibility of taming this wild force of nature. In a lab-based experiment, intense pulses of light vaporized a column of air and created a conducting filament of electrons that then acted as a lightning rod to channel the electrical discharge to ground. Scaling up this approach could enable the control of lightning strikes.

    Optica 10.1364/OPTICA.1.000125 (2014).

  2. RNA Structure

    Unlocking the secrets of RNA in 3D

    1. Guy Riddihough

    RNA can both store information in its linear sequence and take on critical structural and catalytic roles in the cell, such as during the translation of messenger RNA into proteins. These latter functions depend on the complex higher-order structures RNA is able to form. Homan et al. now report a method to probe these intricate conformational states. They chemically modified exposed segments of three complex RNA structures. They then sequenced the RNA to map the locations of the multiple modifications in each individual linear RNA molecule. This allowed the researchers to deduce interactions in three-dimensional space, and to uncover new and previously hidden conformations, providing valuable information on the folding and function of RNAs.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1407306111 (2014).

  3. Plant Genomics

    Shelling out the genetics of peanut allergies

    1. Laura M. Zahn
    CREDIT: DERKIEN/ISTOCK PHOTO

    Peanut allergies are on the rise, but how did the genes that encode these allergens evolve? To find out, Ratnaparkhe et al. examined the genomes of the cultivated and wild peanut and compared them to other plants to determine how the major peanut allergens Arah1, Arah2, Arah3, and the closely related Arah6 evolved. Relative to other plant species, some of these genes changed their position within the genome, duplicated, expanded (added new nucleotides to the sequence), and/or mutated. Despite this, the researchers observed genetic similarities in the specific regions of these peanut genes that cause the immune system to react.

    Genome Biol. Evol. 10.1093/gbe/evu189 (2014).

  4. Biomedicine

    Illuminating brain stimulation therapy

    1. Michael D. Crabtree

    Stroke, the disruption in blood supply to the brain, affects approximately 15 million people worldwide each year. With few treatment options, strokes leave one third of their sufferers permanently disabled. Magnetic stimulation of the brain is one promising therapy,but it is relatively non-specific. To determine which cell types may promote recovery; Cheng et al. engineered mice to express light-activated protein receptors in their neurons. They then used light to activate specific neurons and found that while stimulating neurons in the ipsilesional primary motor cortex had no effect on healthy mice, it did help mice recover after stroke. Stimulating neurons in a targeted manner may be a promising therapy for stroke patients and cause fewer side effects.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1404109111 (2014).

  5. Chemistry

    A drop in a drop in a drop in the bucket

    1. Marc S. Lavine

    Emulsions consist of droplets of one liquid that are held inside a second liquid, where the two liquids do not normally mix. Haase and Brujic show a simple method to make emulsions in which multiple layers of droplets can be trapped inside each other. By varying the concentrations of oil, a polar solvent, and water, they can get up to five layers of inner droplets as the ternary mixture is dripped into a water solution containing surfactant. It is also possible to fuse droplets to give larger, stabilized droplets with ordered internal structure.

    Angew. Chemie. Int. Ed. 10.1002/anie.201406040 (2014).

  6. Structural Biology

    Molecular insights into Alzheimer's

    1. Valda Vinson
    Ribbon diagram of nicastrin. CREDIT: T. XIE ET AL. PNAS 111, 37 (16 SEPTEMBER 2014) © 2014 NATIONAL ACADEMY OF SCIENCES

    An intramembrane protein called γ-secretase cleaves amyloid precursor protein (APP) to generate amyloid-β peptides. These peptides clump together to form the plaques found in the brains of people with Alzheimer's disease. Modulating the activity of the γ-secretase might be a useful strategy in treating Alzheimer's disease. Lu et al. recently reported the atomic resolution structure of an intact human γ-secretase complex. Now Xie et al. report an atomic resolution structure of eukaryotic nicastrin, the largest component of γ-secretase. Analysis of the structure suggests a model for how nicastrin recruits APP for cleavage by a second component of the complex. These structures may provide important insights for the design of much needed-new drug candidates.

    Nature 512, 166 (2014); Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1414837111 (2014).

  7. Earth History

    Ancient soils record early oxygen

    1. Nicholas S. Wigginton

    The Great Oxidation Event marks the permanent appearance of appreciable concentrations of oxygen in Earth's atmosphere 2.4 billion years ago, a consequence of biological activity. Determining the history of oxygen levels leading up to this time, however, is hindered by spotty and incomplete records. Mukhopadhyay et al. describe an ancient soil deposit in eastern India that formed 3 billion years ago, or ∼600 million years before the Great Oxidation Event. Geochemical clues in the soil and overlying sediments point to a fleeting presence of free oxygen at the time the soil formed. It is likely that several small, short-lived oxygenation events occurred before Earth's atmosphere reached high oxygen levels permanently.

    Geology 10.1130/G36091.1 (2014).

  8. Biogeography

    Economic isolation limits biodiversity

    1. Lizzie Wade

    It's an ecological truism that the more isolated an island, the fewer species it will have; isolation (along with island size) is thought to influence colonization, extinction, and speciation. But Helmus et al., mapping the distribution of anole lizard species across the Caribbean, suggest that economic, not geographic, isolation is determining species diversity. Anole lizards hitch rides on cargo ships, making it easier to reach farflung islands, so the more trade an island participates in, the more species diversity it tends to have. Conversely, economic isolation might protect native lizards from imported competitors: Cuba would rapidly gain 1.65 lizard species if the United States lifted its trade embargo, the authors say.

    Nature 10.1038/nature13739 (2014).