This Week in Science

Science  01 Nov 2013:
Vol. 342, Issue 6158, pp. 531
  1. Designer Vaccine


    Respiratory syncytial virus (RSV) is one of the last remaining childhood diseases without an approved vaccine. Using a structure-based approach, McLellan et al. (p. 592) designed over 150 fusion glycoprotein variants, assessed their antibody reactivity, determined crystal structures of stabilized variants, and measured their ability to elicit protective responses. This approach yielded an immunogen that elicits higher protective responses than the postfusion form of the fusion glycoprotein, which is one of the current leading RSV vaccine candidates entering clinical trials. Importantly, highly protective responses were elicited in both mice and macaques.

  2. Magnetic Crab

    Since pulsars—highly magnetized rotating neutron stars—were discovered 45 years ago, the evolution of their magnetic field structure has been subject to much theoretical conjecture. However, observational evidence has been sparse. Now Lyne et al. (p. 598) report high-precision measurements, spanning more than two decades, that reveal the systematic evolution of the radiation pattern of the pulsar in the Crab Nebula, one of the youngest neutron stars known.

  3. Deep Heating

    Global warming is popularly viewed only as an atmospheric process, when, as shown by marine temperature records covering the last several decades, most heat uptake occurs in the ocean. How did subsurface ocean temperatures vary during past warm and cold intervals? Rosenthal et al. (p. 617) present a temperature record of western equatorial Pacific subsurface and intermediate water masses over the past 10,000 years that shows that heat content varied in step with both northern and southern high-latitude oceans. The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future.

  4. Quantum Heating


    Mesoscopic wires exhibit peculiar properties at low temperatures. Their electric conductance can show plateaus at evenly spaced values, which reflects the sequential opening of “quantum transport channels,” each of which can only carry a finite amount of charge or heat. Whereas the step size for the electric conductance depends on the type of the particle carrying the charge, for heat conduction this “quantum” is universal. Jezouin et al. (p. 601, published online 3 October; see the Perspective by Sothmann and Flindt) measured the quantum of heat conduction through a single electronic channel by comparing the amount of heat needed to heat a small metal plate to a constant temperature, while varying the number of electronic channels through which the heat was dissipated from the plate. Encouragingly, the measurement was in agreement with the theoretical prediction.

  5. Not All Neurons Are Alike

    As life proceeds, many cells acquire individualized mutations. In the immune system, genome rearrangements generate useful antibody diversity. McConnell et al. (p. 632; see the Perspective by Macosko and McCarroll) now show that human neurons also diversify. Neurons taken from postmortem human frontal cortex tissue and neurons derived from induced pluripotent stem cell differentiation in vitro showed surprising diversity in individual cell genomes. Up to 41% of the frontal cortex neurons had copy number variations—no two alike—with deletions more common than duplications.

  6. Better Contact Along the Edge

    Electrical contact to graphene is normally done with metal contacts on its flat face, where there are few strong bonding sites for the metal. Wang et al. (p. 614) encapsulated graphene with hexagonal boron nitride sheets and made metal contacts along its edge, where bonding orbitals are exposed. The resulting heterostructures had high electronic performance, with room-temperature carrier mobilities near the theoretical phonon-scattering limit.

  7. Prairie Redux

    Tallgrass prairie is extinct across much of its former range in the midwestern United States, but relicts preserved in cemeteries and nature reserves allow functional comparison of former grassland soils with modern agricultural soils. Fierer et al. (p. 621; see the Perspective by Scholes and Scholes) took matched soil samples from sites representing the gamut of climate conditions and modeled the combination of genomic analysis and environmental data to resurrect the historical prairie soil communities, identifying the nutrient-scavenging Verrucomicrobia as keystone bacteria in functioning prairie.

  8. First Defense

    In defense against bacterial infection, plants carry a cell-surface receptor, known as FLS2, that can bind to a fragment of bacterial flagellin and trigger defense responses. Y. Sun et al. (p. 624, published online 10 October) investigated the structural details that govern the binding between FLS2, its co-receptor BAK1, and the flagellin fragment flg22. The assembled complex initiates signals to activate the plant's innate immune response.

  9. The Good Scar

    We tend to think of scars as bad and, in the central nervous system, as counterproductive to recovery. Studying mice, Sabelström et al. (p. 637) prevented resident stem cells from proliferating after spinal cord injury. Without the astrocytes generated by the neural stem cells, recovery from spinal cord lesions was poorer than normal. Thus, somewhat counterintuitively, glial scarring appears to limit spinal cord damage and support the remaining cells.

  10. Wiring the Retina

    Starburst amacrine cells in the retina detect motion by responding to light going on or off. L. O. Sun et al. (1241974) analyzed how the cellular circuits develop in the mouse retina to form the basis of motion detection. Expression patterns of semaphorin 6A and its receptor plexin A2 defined the shape and reactivity of the starburst amacrine cells. Semaphorin 6A expression was restricted to particular cells, generating two classes of starburst amacrine cells with distinct morphologies and opposing functions.

  11. Dinner Time!

    Biological clocks allow organisms to anticipate cycles of feeding, activity, and rest so that metabolic enzymes in mitochondria are ready when needed. Peek et al. (1243417, published online 19 September; see the Perspective by Rey and Reddy) describe a mechanism by which the biochemical elements of the circadian clock are linked to such control of mitochondrial metabolism. The clock controls rhythmic transcription of the gene encoding the rate-limiting enzyme required for synthesis of nicotinamide adenine dinucleotide (NAD+). The concentration of NAD+ in mitochondria determines the activity of the deacetylase SIRT3, which then controls acetylation and activity of key metabolic enzymes. NAD+ also influences clock function, and thus appears to be a versatile point at which regulation of oxidative metabolism is coordinated with the daily cycles of energy consumption.

  12. Information Physics

    Multiparameter models, which can emerge in biology and other disciplines, are often sensitive to only a small number of parameters and robust to changes in the rest; approaches from information theory can be used to distinguish between the two parameter groups. In physics, on the other hand, one does not need to know the details at smaller length and time scales in order to understand the behavior on large scales. This hierarchy has been recognized for a long time and formalized within the renormalization group (RG) approach. Machta et al. (p. 604) explored the connection between two scales by using an information-theoretical approach based on the Fisher Information Matrix to analyze two commonly used physics models—diffusion in one dimension and the Ising model of magnetism—as the time and length scales, respectively, were progressively coarsened. The expected “stiff” parameters emerged, in agreement with RG intuition.

  13. Imaging Hydrogen Bonds


    The decoration of atomic force microscope tips with terminal CO molecules has afforded much higher resolution of the bonding of adsorbed molecules. Zhang et al. (p. 611, published online 26 September) show that this method, in combination with density function theory calculations, can image and characterize hydrogen-bonding contacts formed between 8-hydroxyquinoline molecules adsorbed on the (111) surface of copper under cryogenic conditions. At room temperature, a different bonding configuration was revealed that was the result of the molecules dehydrogenating on the copper surface and coordinating with surface copper atoms.

  14. Chilly Repression Stalls Flowering

    In a cool spring, flowering might be delayed compared to a warm spring, even though the change in day length marches on regardless of temperature. Lee et al. (p. 628, published online 12 September; see the Perspective by Nilsson) now show that this delay in flowering is a regulated process, not simply a consequence of sluggish metabolism. In the model plant Arabidopsis, transcription of the gene encoding the regulator SHORT VEGETATIVE PHASE (SVP) is unaffected by temperature, but the stability of the SVP protein is decreased at higher temperatures. Its regulatory partner, FLOWERING LOCUS M (FLM)-β, is the product of alternative splicing of transcripts from the gene encoding FLM that favors the β form at lower temperatures. SVP and FLM-β form a complex that represses flowering. At lower temperatures, more of the repressive complex is present and flowering is delayed. At higher temperatures, SVP tends to degrade and FLM-β tends not to be produced, yielding reduced levels of the repressive complex, which allows flowering to proceed.

  15. Coherently Controlling Large Cats

    The control and manipulation of quantum information based on superconducting circuits is an attractive route because of the possibility of scale-up. Vlastakis et al. (p. 607, published online 26 September; see the Perspective by Leek) were able to generate and control quantum entanglement between a superconducting qubit and hundreds of photons stored in a cavity resonator by using deterministic methods for on-demand generation of large Schrödinger cat states in a microwave cavity with arbitrary size and phase. The ability to map the state of a qubit to large Schrödinger cat states should provide a robust quantum resource in future quantum-based technologies.

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