Editors' Choice

Science  11 Dec 2015:
Vol. 350, Issue 6266, pp. 1328
  1. Restoration Ecology

    Planting to enhance positive interactions

    1. Andrew M. Sugden

    Planting marsh grasses in a clumped, rather than dispersed, pattern can improve outcomes when restoring wetlands

    PHOTO: © NICO VAN KAPPEL/BUITEN-BEELD/MINDEN PICTURES/CORBIS

    Rising sea levels and human development threaten coastal ecosystems worldwide. Efforts to protect and restore these environments include a range of physical and biological measures, including reestablishing vegetation to stabilize the habitat and restore ecosystem function. Silliman et al. report the results of experiments in coastal wetlands in Florida and the Netherlands, showing that the simple pattern of planting (clumped versus dispersed) marsh grasses influences the success of restoration. Compared to a dispersed pattern of planting, planting marsh grasses in a clumped pattern enhanced their survival, biomass, and density. Clumped plants interacted positively; for instance, they reduced their anoxia stress, and neighboring roots shared oxygen more readily, effectively producing a more oxygen-rich microenvironment than isolated individual plants can achieve.

    Proc. Natl. Acad. Sci. U.S.A. 112, 14297 (2015).

  2. Geophysics

    Setting the table for an old plate

    1. Brent Grocholski

    New pictures of Earth's interior reveal an ancient tectonic plate sinking toward the bottom of the mantle. Simmons et al. find the structure in seismic tomography images under the data-limited region of the Indian Ocean. Complete subduction of the plate occurred more than 100 million years ago. This observation suggests that old plates can hang around in the mantle longer than previously thought. It also provides a new piece of information for reconstructing plate motions and landmass locations in the distant past.

    Geophys. Rev. Lett. 10.1002/2015GL066237 (2015).

  3. Behavior

    Empathy is for the birds

    1. Sacha Vignieri

    Monogamous zebra finches empathize through song

    PHOTO: KICHIGIN/ISTOCK PHOTO

    Many species empathize with one other by state matching, a process whereby an individual shifts its physiological state to match another's. Increasing evidence suggests that empathy occurs across mammals, but whether other vertebrates empathize is unclear. Birds are prime candidates for state matching, given their extensive parental care, pair bonding, and sociality. Perez et al. now show that in highly monogamous zebra finches, females match their state of stress (as measured by glucocorticoids) to that of their male mate, as perceived only through changes in his call. No match appeared when females listened to the calls of unknown males, which suggests that the close bond facilitates empathy.

    Horm. Behav. 10.1016/j.yhbeh.2015.09.002 (2015).

  4. Aging

    A circadian secret to a long life

    1. L. Bryan Ray

    Dietary restriction (reduced nutrient intake without malnutrition) increases life span in multiple species, including fruit flies, but how this occurs is largely unknown. Katewa et al. now find that in flies, changes in the expression of genes that regulate the circadian clock underlie the life-extending effect of dietary restriction. Dietary restriction increased the amplitude of daily cycles of clock gene expression in tissues such as the fly head and body. In flies with mutated clock genes, dietary restriction failed to increase longevity. Moreover, genetically increasing the periodicity of circadian gene expression also extended the life span of flies. Further analysis indicated that circadian gene expression contributes to changes in metabolism that mediate the effects of dietary restriction on life span.

    Cell Metab. 10.1016/j.cmet.2015.10.014 (2015)

  5. Catalysis

    Upgrading ethanol without adding hydrogen

    1. Phil Szuromi

    Catalytic conversion to hydrocarbons allows more ethanol to be used in automobile fuel

    PHOTO: ©WEGNER, JORG & PETRA/ANIMALS ANIMALS

    An issue with ethanol–usage mandates for gasoline is the “blend wall”: Many vehicles can only use up to 10 to 15% ethanol. In order to use more ethanol as a fuel, it must be converted to hydrocarbons that blend into gasoline, but existing processes have suffered from the need to add hydrogen or produce a high fraction of undesirable small hydrocarbons. Narula et al. report the conversion of ethanol to larger hydrocarbons suitable for use in gasoline, as well as diesel and jet fuels, with a ZSM-5 zeolite containing indium and vanadium. A hydrocarbon pool mechanism appears to operate without dehydration steps.

    Sci. Rep. 10.1038/srep16039 (2015).

  6. Nephrology

    A circulating harbinger of kidney disease

    1. Paula A. Kiberstis

    Chronic kidney disease affects 600 million people worldwide. Initially asymptomatic, the disease often follows a progressive course that can lead to heart disease and kidney failure. An easily measured biomarker that identifies people at high risk of developing kidney disease would allow doctors to intervene earlier so that patients' disease progresses at a slower rate. Toward that end, Hayek et al. examined the predictive capacity of suPAR, a protein previously linked to a certain type of kidney disease. They serially monitored plasma levels of suPAR in a large group of patients, many with normal kidney function at the study's start, and found that elevated levels of the protein correlated with a decline in kidney function and with new-onset chronic kidney disease.

    N. Engl. J. Med. 373, 1916 (2015).

  7. Physics

    Studying magnetism in an atomic chain

    1. Jelena Stajic

    When we think of magnets, solid materials generally come to mind, but researchers can also study magnetism by placing individual atoms in an egg-crate–like potential created by lasers: an optical lattice. This approach, however, requires extraordinarily low temperatures. To circumvent that requirement, Murmann et al. studied a string of three or four fermionic 6Li atoms in an elongated optical trap. In this one-dimensional system, no lattice was needed because the atoms, tuned to interact strongly, spontaneously formed an ordered chain. The researchers first placed three atoms in a particular spin configuration and then tilted the trap to let the outermost atom tunnel out. The spin state of the tunneling atom revealed that the atoms were initially in an antiferromagnetic state.

    Phys. Rev. Lett. 115, 215301 (2015).